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  • 201.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Gunnar Björkman och hans expedition till Lule lappmark 1924: Gunnar Björkman’s expedition to Swedish Lapland in 19242013In: Svensk Botanisk Tidskrift, ISSN 0039-646X, Vol. 107, no 6, p. 354-358Article in journal (Other academic)
    Abstract [en]

    Drawings by Torsten Höjer from Gunnar Björkman's botanical expedition to Swedish Lapland in 1924 are presented with some biographical notes on Björkman. The paleontologist  Birger Bohlin also participated.

  • 202.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Mossflora över Sankta Helena2013In: Myrinia, ISSN 1102-4194, Vol. 23, p. 84-87Article in journal (Other academic)
    Abstract [en]

    A new bryophyte flora of St. Helena in the South Atlantic is presented. Of the known 110 species, 26 are (as presently known) endemic.

  • 203.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Swedish Biodiversity Centre.
    Om São Tomé, begonior och öar i havet2018In: Svensk Botanisk Tidskrift, ISSN 0039-646X, Vol. 112, no 1, p. 32-40Article in journal (Refereed)
    Abstract [en]

    A brief overview of the vegetation of São Tomë and Príncipe is presented. The several endemic and large species of Begonia on the islands are discussed in more detail.

  • 204.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Swedish Biodiversity Centre. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Sankta Helena: en hotad endemisk flora. 1. Den ursprungliga floran och vegetationen och den historiska utvecklingen2014In: Svensk Botanisk Tidskrift, ISSN 0039-646X, Vol. 108, no 3-4, p. 206-218Article in journal (Other academic)
    Abstract [en]

    An overview of the endemic flora and the original vegetation of Saint Helena is given.

  • 205.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Swedish Biodiversity Centre. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Sankta Helena: en hotad endemisk flora. 2. situationen i dag2014In: Svensk Botanisk Tidskrift, ISSN 0039-646X, Vol. 108, no 5, p. 232-244Article in journal (Refereed)
    Abstract [en]

    The present-day situation for the endemic flora of Saint Helena is described.

  • 206.
    Backéus, Ingvar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Swedish Biodiversity Centre. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Emanuelsson, Urban
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Swedish Biodiversity Centre.
    Karakin, Vladimir (Contributor)
    Russian Academy of Sciences, Far East Division, Vladivostok.
    von Bothmer, Roland (Contributor)
    Swedish University of Agriculture, Alnarp.
    The rural landscapes of Northeast Asia.2016Book (Other academic)
  • 207.
    Backéus, Ingvar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Hytteborn, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    "Det har vi vetat hela tiden" – akademikerna och lvängen för hundra år sedan.2019In: Svensk Botanisk Tidskrift, ISSN 0039-646X, Vol. 113, no 3–4, p. 219-231Article in journal (Refereed)
    Abstract [en]

    Mown meadows with scattered trees were a characteristic of the old Swedish landscape.  It has been an established truth that the botanists, particularly R. Sernander and H. Hesselman, did not understand that the meadows would turn into forests when abandoned, whereas the human geographer M. Sjöbeck in several publications from 1927 onwards made this clear. This view was supported by, i.a,. L.-G. Romell.

     We have scrutinized the literature and the minutes of the Plant Biology Seminar in Uppsala from 1892 to 1944, in order to understand Sernander’s views. Hesselman considered the matter uncertain. Sernander probably understood the dynamics also before 1927, but his standpoint was influenced by a wish to restore the postglacial broadleaved forests of which he saw the meadows as degraded relicts. This could be done by leaving meadows for free development. Gradually he saw the need also to maintain meadows and the cultural landscape as such. Several other botanists, e.g. G. Samuelsson and G. Einar Du Rietz, already early on understood the dependence of meadows on human management. 

  • 208.
    Backéus, Ingvar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Hytteborn, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Rydin, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Var Sellingaffären kulmen på en sekellång botanisk konflikt?2018In: Svensk Botanisk Tidskrift, ISSN 0039-646X, Vol. 112, no 6, p. 380-393Article in journal (Refereed)
    Abstract [en]

    The 1950s saw a series of miscarriages of justice against public persons in Sweden. In one of these, the Royal Swedish Academy of Sciences tried to force Olof Selling from his professorship in paleobotany at the Swedish Museum of Natural History, on the basis of mental illness, but this failed after a long and public calamity. In his book Naturen inför rätta [Nature facing trial], Keith Wijkander (2017) claims that Selling was the victimof a century-long conflict between botanists in Uppsala and Stockholm,and places Selling in the Uppsala camp. We try to give a more balanced picture of the relationships between plant ecology in Uppsala and Stockholm during the early 20th century. R. Sernander, L.-G. Romell and G. E. Du Rietz are among the main actors. The fierce debates between the two camps make this an interesting period in Swedish botany.

  • 209. Bagatini, Inessa Lacativa
    et al.
    Eiler, Alexander
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Klaveness, Dag
    Tessarolli, Leticia Piton
    Henriques Vieira, Armando Augusto
    Host-Specificity and Dynamics in Bacterial Communities Associated with Bloom-Forming Freshwater Phytoplankton2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 1, p. e85950-Article in journal (Refereed)
    Abstract [en]

    Many freshwater phytoplankton species have the potential to form transient nuisance blooms that affect water quality and other aquatic biota. Heterotrophic bacteria can influence such blooms via nutrient regeneration but also via antagonism and other biotic interactions. We studied the composition of bacterial communities associated with three bloom-forming freshwater phytoplankton species, the diatom Aulacoseira granulata and the cyanobacteria Microcystis aeruginosa and Cylindrospermopsis raciborskii. Experimental cultures incubated with and without lake bacteria were sampled in three different growth phases and bacterial community composition was assessed by 454-Pyrosequencing of 16S rRNA gene amplicons. Betaproteobacteria were dominant in all cultures inoculated with lake bacteria, but decreased during the experiment. In contrast, Alphaproteobacteria, which made up the second most abundant class of bacteria, increased overall during the course of the experiment. Other bacterial classes responded in contrasting ways to the experimental incubations causing significantly different bacterial communities to develop in response to host phytoplankton species, growth phase and between attached and free-living fractions. Differences in bacterial community composition between cyanobacteria and diatom cultures were greater than between the two cyanobacteria. Despite the significance, major differences between phytoplankton cultures were in the proportion of the OTUs rather than in the absence or presence of specific taxa. Different phytoplankton species favoring different bacterial communities may have important consequences for the fate of organic matter in systems where these bloom forming species occur. The dynamics and development of transient blooms may also be affected as bacterial communities seem to influence phytoplankton species growth in contrasting ways.

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  • 210.
    Baho, Didier
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Resistance and resilience of microbial communities - temporal and spatial insurance against perturbations2010Independent thesis Advanced level (degree of Master (One Year)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Bacterial communities are fundamental components of many processes occurring in aquatic ecosystems, since through microbial activities substantial amount of matter and energy is transferred from a pool of DOC to higher trophic levels. Previous studies highlighted the beneficial effects of diversity on ecosystem functioning, however studies on the resistance and resilience in microbial communities are scarce. Similarly, studies focusing on factors that might improve resistance or resilience of communities such as the influence of refuges are equally missing, although an understanding of the underlying mechanisms could be very useful in the field of conservation management. In this study, chemostat cultures were used to investigate the influence of a spatial and a temporal refuge on bacterioplankton communities’ resistance and resilience measured in terms of functioning and community composition after applying a salinity pulse disturbance. Respiration rate and substrate utilization were used to estimate bacterial functioning while community composition was determined by using T-RFLP. The perturbation was found to affect bacterial functioning and community composition. Moreover our findings indicate that the resistance and resilience measured in terms of bacterial functioning and community composition were significantly influenced by the provision of refuges.  

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  • 211.
    Baho, Didier
    et al.
    Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Peter, Hannes
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Tranvik, Lars J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Resistance and resilience of microbial communities: temporal and spatial insurance against perturbations2012In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 14, no 9, p. 2283-2292Article in journal (Refereed)
    Abstract [en]

    Bacteria play fundamental roles for many ecosystem processes; however, little empirical evidence is available on how environmental perturbations affect their composition and function. We investigated how spatial and temporal refuges affect the resistance and resilience of a freshwater bacterioplankton community upon a salinity pulse perturbation in continuous cultures. Attachment to a surface avoided the flushing out of cells and enabled re-colonization of the liquid phase after the perturbation, hence serving as a temporal refuge. A spatial refuge was established by introduction of bacteria from an undisturbed reservoir upstream of the continuous culture vessel, acting analogous to a regional species pool in a metacommunity. The salinity pulse affected bacterial community composition and the rates of respiration and the pattern of potential substrate utilization as well as the correlation between composition and function. Compared with the no-refuge treatment, the temporal refuge shortened return to pre-perturbation conditions, indicating enhanced community resilience. Composition and function were less disturbed in the treatment providing a spatial refuge, suggesting higher resistance. Our results highlight that spatial and temporal dynamics in general and refuges in particular need to be considered for conceptual progress in how microbial metacommunities are shaped by perturbations.

  • 212.
    Bai, Yang
    et al.
    Shanghai Acad Environm Sci, Inst Appl Ecol, Shanghai 200233, Peoples R China..
    Jiang, Bo
    Changjiang Water Resources Protect Inst, Wuhan 430051, Peoples R China..
    Wang, Min
    Shanghai Acad Environm Sci, Inst Appl Ecol, Shanghai 200233, Peoples R China..
    Li, Hui
    Yunnan Univ, Sch Urban Construct & Management, Kunming 650091, Peoples R China..
    Alatalo, Juha M.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution. Qatar Univ, Coll Arts & Sci, Dept Biol & Environm Sci, POB 2713, Doha, Qatar..
    Huang, Shenfa
    Shanghai Acad Environm Sci, Inst Appl Ecol, Shanghai 200233, Peoples R China..
    New ecological redline policy (ERP) to secure ecosystem services in China2016In: Land use policy, ISSN 0264-8377, E-ISSN 1873-5754, Vol. 55, p. 348-351Article in journal (Refereed)
    Abstract [en]

    China is facing huge environmental problems, with its current rapid rate of urbanization and industrialization causing biodiversity loss, ecosystem degradation, and land resources degradation on a major scale. To overcome management conflicts and secure ecosystem services, China has proposed a new 'ecological redline policy' (ERP) using ecosystem services as a way to meet its targets. By giving environmental policy redline status, China is demonstrating strong commitment in its efforts to tackle environmental degradation and secure ecosystem services for the future. This is already having impact, as the Chinese Ministry of Environmental Protection and the National Development and Reform Commission are prepared to work together to implement the new environmental policy.

  • 213.
    Bailey, Richard I.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Innocenti, Paolo
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Morrow, Edward H.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Friberg, Urban
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Qvarnström, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Female Drosophila melanogaster Gene Expression and Mate Choice: The X Chromosome Harbours Candidate Genes Underlying Sexual Isolation2011In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 2, p. e17358-Article in journal (Refereed)
    Abstract [en]

    Background: The evolution of female choice mechanisms favouring males of their own kind is considered a crucial step during the early stages of speciation. However, although the genomics of mate choice may influence both the likelihood and speed of speciation, the identity and location of genes underlying assortative mating remain largely unknown. Methods and Findings: We used mate choice experiments and gene expression analysis of female Drosophila melanogaster to examine three key components influencing speciation. We show that the 1,498 genes in Zimbabwean female D. melanogaster whose expression levels differ when mating with more (Zimbabwean) versus less (Cosmopolitan strain) preferred males include many with high expression in the central nervous system and ovaries, are disproportionately X-linked and form a number of clusters with low recombination distance. Significant involvement of the brain and ovaries is consistent with the action of a combination of pre- and postcopulatory female choice mechanisms, while sex linkage and clustering of genes lead to high potential evolutionary rate and sheltering against the homogenizing effects of gene exchange between populations. Conclusion: Taken together our results imply favourable genomic conditions for the evolution of reproductive isolation through mate choice in Zimbabwean D. melanogaster and suggest that mate choice may, in general, act as an even more important engine of speciation than previously realized.

  • 214. Bains, Ripudaman K.
    et al.
    Kovacevic, Mirna
    Plaster, Christopher A.
    Tarekegn, Ayele
    Bekele, Endashaw
    Bradman, Neil N.
    Thomas, Mark G.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Molecular diversity and population structure at the Cytochrome P450 3A5 gene in Africa2013In: BMC Genetics, ISSN 1471-2156, E-ISSN 1471-2156, Vol. 14, p. 34-Article in journal (Refereed)
    Abstract [en]

    Background: Cytochrome P450 3A5 (CYP3A5) is an enzyme involved in the metabolism of many therapeutic drugs. CYP3A5 expression levels vary between individuals and populations, and this contributes to adverse clinical outcomes. Variable expression is largely attributed to four alleles, CYP3A5*1 (expresser allele); CYP3A5*3 (rs776746), CYP3A5*6 (rs10264272) and CYP3A5*7 (rs41303343) (low/non-expresser alleles). Little is known about CYP3A5 variability in Africa, a region with considerable genetic diversity. Here we used a multi-disciplinary approach to characterize CYP3A5 variation in geographically and ethnically diverse populations from in and around Africa, and infer the evolutionary processes that have shaped patterns of diversity in this gene. We genotyped 2538 individuals from 36 diverse populations in and around Africa for common low/non-expresser CYP3A5 alleles, and re-sequenced the CYP3A5 gene in five Ethiopian ethnic groups. We estimated the ages of low/non-expresser CYP3A5 alleles using a linked microsatellite and assuming a step-wise mutation model of evolution. Finally, we examined a hypothesis that CYP3A5 is important in salt retention adaptation by performing correlations with ecological data relating to aridity for the present day, 10,000 and 50,000 years ago. Results: We estimate that similar to 43% of individuals within our African dataset express CYP3A5, which is lower than previous independent estimates for the region. We found significant intra-African variability in CYP3A5 expression phenotypes. Within Africa the highest frequencies of high-activity alleles were observed in equatorial and Niger-Congo speaking populations. Ethiopian allele frequencies were intermediate between those of other sub-Saharan African and non-African groups. Re-sequencing of CYP3A5 identified few additional variants likely to affect CYP3A5 expression. We estimate the ages of CYP3A5*3 as similar to 76,400 years and CYP3A5*6 as similar to 218,400 years. Finally we report that global CYP3A5 expression levels correlated significantly with aridity measures for 10,000 [Spearmann's Rho= -0.465, p=0.004] and 50,000 years ago [Spearmann's Rho= -0.379, p=0.02]. Conclusions: Significant intra-African diversity at the CYP3A5 gene is likely to contribute to multiple pharmacogenetic profiles across the continent. Significant correlations between CYP3A5 expression phenotypes and aridity data are consistent with a hypothesis that the enzyme is important in salt-retention adaptation.

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  • 215.
    Baison, John
    et al.
    Swedish Univ Agr Sci, Dept Forest Genet & Plant Physiol, Umea Plant Sci Ctr, Parallellvagen 21, S-90736 Umea, Sweden.
    Vidalis, Amaryllis
    Tech Univ Munich, Sect Populat Epigenet & Epigen, Ctr Life & Food Sci Weihenstephan, Lichtenbergstr 2a, D-85748 Munich, Germany.
    Zhou, Linghua
    Swedish Univ Agr Sci, Dept Forest Genet & Plant Physiol, Umea Plant Sci Ctr, Parallellvagen 21, S-90736 Umea, Sweden.
    Chen, Zhi-Qiang
    Swedish Univ Agr Sci, Dept Forest Genet & Plant Physiol, Umea Plant Sci Ctr, Parallellvagen 21, S-90736 Umea, Sweden.
    Li, Zitong
    Univ Helsinki, Dept Biosci, Ecol Genet Res Unit, POB 65, FI-00014 Helsinki, Finland.
    Sillanpää, Mikko J.
    Univ Oulu, Dept Math Sci, Bioctr Oulu, Pentti Kaiteran Katu 1, Oulu, Finland.
    Bernhardsson, Carolina
    Swedish Univ Agr Sci, Dept Forest Genet & Plant Physiol, Umea Plant Sci Ctr, Parallellvagen 21, S-90736 Umea, Sweden;Umea Univ, Dept Ecol & Environm Sci, Linnaeus Vag 4-6, S-90736 Umea, Sweden.
    Scofield, Douglas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Forsberg, Nils
    Swedish Univ Agr Sci, Dept Forest Genet & Plant Physiol, Umea Plant Sci Ctr, Parallellvagen 21, S-90736 Umea, Sweden.
    Grahn, Thomas
    RISE Bioecon, Drottning Kristinas Vag 61, SE-11486 Stockholm, Sweden.
    Olsson, Lars
    RISE Bioecon, Drottning Kristinas Vag 61, SE-11486 Stockholm, Sweden.
    Karlsson, Bo
    Skogforsk, Ekebo 2250, SE-26890 Svalov, Sweden.
    Wu, Harry
    Swedish Univ Agr Sci, Dept Forest Genet & Plant Physiol, Umea Plant Sci Ctr, Parallellvagen 21, S-90736 Umea, Sweden.
    Ingvarsson, Pär K:
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology. Umea Univ, Dept Ecol & Environm Sci, Linnaeus Vag 4-6, S-90736 Umea, Sweden.
    Lundqvist, Sven-Olof
    RISE Bioecon, Drottning Kristinas Vag 61, SE-11486 Stockholm, Sweden;IIC, Rosenlundsgatan 48B, SE-11863 Stockholm, Sweden.
    Niittylä, Totte
    Swedish Univ Agr Sci, Dept Forest Genet & Plant Physiol, Umea Plant Sci Ctr, Parallellvagen 21, S-90736 Umea, Sweden.
    Garcia-Gil, M. Rosario
    Swedish Univ Agr Sci, Dept Forest Genet & Plant Physiol, Umea Plant Sci Ctr, Parallellvagen 21, S-90736 Umea, Sweden.
    Genome-wide association study identified novel candidate loci affecting wood formation in Norway spruce2019In: The Plant Journal, ISSN 0960-7412, E-ISSN 1365-313X, Vol. 100, no 1, p. 83-100Article in journal (Refereed)
    Abstract [en]

    Norway spruce is a boreal forest tree species of significant ecological and economic importance. Hence there is a strong imperative to dissect the genetics underlying important wood quality traits in the species. We performed a functional genome-wide association study (GWAS) of 17 wood traits in Norway spruce using 178 101 single nucleotide polymorphisms (SNPs) generated from exome genotyping of 517 mother trees. The wood traits were defined using functional modelling of wood properties across annual growth rings. We applied a Least Absolute Shrinkage and Selection Operator (LASSO-based) association mapping method using a functional multilocus mapping approach that utilizes latent traits, with a stability selection probability method as the hypothesis testing approach to determine a significant quantitative trait locus. The analysis provided 52 significant SNPs from 39 candidate genes, including genes previously implicated in wood formation and tree growth in spruce and other species. Our study represents a multilocus GWAS for complex wood traits in Norway spruce. The results advance our understanding of the genetics influencing wood traits and identifies candidate genes for future functional studies.

  • 216. Bakker, Jan P.
    et al.
    Hoffmann, Frank
    Ozinga, Wim A.
    Rosén, Eje
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Shading results in depletion of the soil seed bank2014In: Nordic Journal of Botany, ISSN 0107-055X, E-ISSN 1756-1051, Vol. 32, no 5, p. 674-679Article in journal (Refereed)
    Abstract [en]

    To what extent is the decline of characteristic dry alvar species related to the decline in the soil seed bank during scrub encroachment? We recorded the number of flower stems in the vegetation in relation to light attenuation along an encroachment series progressing from open alvar through small gaps inside dense scrub of Juniperus communis (cover of 60%) to intact dense scrub (cover of 100%) on the island of oland, Sweden. This measurement of potential reproduction (number of flower stems) was then compared to the number of species in the soil seed bank at each site along the alvar encroachment series. Scrub encroachment results in light attenuation between and under the shrubs. The total number of flower stems averaged over all species was similar between gaps and open alvar, but that of alvar species was significantly lower in the gaps, indicating that light attenuation could reduce their seed set. Shading in gaps is related to depletion of the soil seed bank and loss of alvar species, particularly those that do not form a persistent soil seed bank.

  • 217. Bakker, Jan P.
    et al.
    Rosén, Eje
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Ozinga, Wim A.
    Bretfeld, Mario
    Feldt, Tobias
    Stahl, Julia
    Long-term effects of scrub clearance and litter removal on the re-establishment of dry alvar grassland species2012In: Annales Botanici Fennici, ISSN 0003-3847, E-ISSN 1797-2442, Vol. 49, no 1-2, p. 21-30Article in journal (Refereed)
    Abstract [en]

    Many characteristic dry alvar grassland species disappear after cessation of livestock grazing as a result of encroachment by Juniperus communis. We studied the re-establishment of these species after scrub clearance with and without the removal of the layer of litter and mosses in long-term (14 years) permanent plots. Most of the species belonging to the community species pool of dry alvar grassland species before clearance were found in permanent plots between 2 and 14 years after the clearance. A large part originated from vegetative spread of already occurring species in the established vegetation in the surroundings. Only a small part of the long-term persistent soil seed bank resulted in the re-establishment of alvar species. There was no significant difference in the traits soil seed bank, seed weight and long-distance dispersal by wind, dung or fur of animals of established and non-established species. Removal of litter and mosses positively affected the re-establishment of alvar species.

  • 218. Balding, David
    et al.
    Weale, Michael
    Richards, Michael
    Thomas, Mark
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Genetic and isotopic analysis and the UK border agency2010In: Significance, Vol. 7, no 2, p. 58-61Article in journal (Refereed)
  • 219.
    Balmonte, John Paul
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27599 USA.
    Buckley, Andrew
    Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27599 USA.
    Hoarfrost, Adrienne
    Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27599 USA.
    Ghobrial, Sherif
    Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA.
    Ziervogel, Kai
    Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27599 USA.
    Teske, Andreas
    Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27599 USA.
    Arnosti, Carol
    Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27599 USA.
    Community structural differences shape microbial responses to high molecular weight organic matter2019In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 21, no 2, p. 557-571Article in journal (Refereed)
    Abstract [en]

    The extent to which differences in microbial community structure result in variations in organic matter (OM) degradation is not well understood. Here, we tested the hypothesis that distinct marine microbial communities from North Atlantic surface and bottom waters would exhibit varying compositional succession and functional shifts in response to the same pool of complex high molecular weight (HMW-OM). We also hypothesized that microbial communities would produce a broader spectrum of enzymes upon exposure to HMW-OM, indicating a greater potential to degrade these compounds than reflected by initial enzymatic activities. Our results show that community succession in amended mesocosms was congruent with cell growth, increased bacterial production and most notably, with substantial shifts in enzymatic activities. In all amended mesocosms, closely related taxa that were initially rare became dominant at time frames during which a broader spectrum of active enzymes were detected compared to initial timepoints, indicating a similar response among different communities. However, succession on the whole-community level, and the rates, spectra and progression of enzymatic activities, reveal robust differences among distinct communities from discrete water masses. These results underscore the crucial role of rare bacterial taxa in ocean carbon cycling and the importance of bacterial community structure for HMW-OM degradation.

  • 220.
    Balmonte, John Paul
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27515 USA.
    Hasler-Sheetal, Harald
    Univ Southern Denmark, Dept Biol, Odense, Denmark.
    Glud, Ronnie N.
    Univ Southern Denmark, Dept Biol, Odense, Denmark;Tokyo Univ Marine Sci & Technol, Dept Ocean & Environm Sci, Tokyo, Japan.
    Andersen, Thorbjörn J.
    Univ Copenhagen, Dept Geosci & Nat Resources Management, Sect Geog, Copenhagen, Denmark.
    Sejr, Mikael K.
    Aarhus Univ, Arctic Res Ctr, Aarhus, Denmark;Aarhus Univ, Dept Biosci, Silkeborg, Denmark.
    Middelboe, Mathias
    Univ Copenhagen, Marine Biol Sect, Helsingor, Denmark.
    Teske, Andreas
    Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27515 USA.
    Arnosti, Carol
    Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27515 USA.
    Sharp contrasts between freshwater and marine microbial enzymatic capabilities, community composition, and DOM pools in a NE Greenland fjord2020In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 65, no 1, p. 77-95Article in journal (Refereed)
    Abstract [en]

    Increasing glacial discharge can lower salinity and alter organic matter (OM) supply in fjords, but assessing the biogeochemical effects of enhanced freshwater fluxes requires understanding of microbial interactions with OM across salinity gradients. Here, we examined microbial enzymatic capabilities-in bulk waters (nonsize-fractionated) and on particles (>= 1.6 mu m)-to hydrolyze common OM constituents (peptides, glucose, polysaccharides) along a freshwater-marine continuum within Tyrolerfjord-Young Sound. Bulk peptidase activities were up to 15-fold higher in the fjord than in glacial rivers, whereas bulk glucosidase activities in rivers were twofold greater, despite fourfold lower cell counts. Particle-associated glucosidase activities showed similar trends by salinity, but particle-associated peptidase activities were up to fivefold higher-or, for several peptidases, only detectable-in the fjord. Bulk polysaccharide hydrolase activities also exhibited freshwater-marine contrasts: xylan hydrolysis rates were fivefold higher in rivers, while chondroitin hydrolysis rates were 30-fold greater in the fjord. Contrasting enzymatic patterns paralleled variations in bacterial community structure, with most robust compositional shifts in river-to-fjord transitions, signifying a taxonomic and genetic basis for functional differences in freshwater and marine waters. However, distinct dissolved organic matter (DOM) pools across the salinity gradient, as well as a positive relationship between several enzymatic activities and DOM compounds, indicate that DOM supply exerts a more proximate control on microbial activities. Thus, differing microbial enzymatic capabilities, community structure, and DOM composition-interwoven with salinity and water mass origins-suggest that increased meltwater may alter OM retention and processing in fjords, changing the pool of OM supplied to coastal Arctic microbial communities.

  • 221.
    Balslev, Henrik
    et al.
    Aarhus Univ, Dept Biosci, Sect Ecoinformat & Biodivers, DK-8000 Aarhus, Denmark.
    Kristiansen, Soren M.
    Aarhus Univ, Dept Geosci, DK-8000 Aarhus, Denmark.
    Muscarella, Robert
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution. Aarhus Univ, Dept Biosci, Sect Ecoinformat & Biodivers, DK-8000 Aarhus, Denmark.
    Palm community transects and soil properties in western Amazonia2019In: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 100, no 12, article id e02841Article in journal (Refereed)
    Abstract [en]

    Western Amazonia is a global biodiversity hotspot that encompasses extensive variation in geologic, climatic, and biotic features. Palms (Arecaceae) are among the most diverse and iconic groups of plants in the region with more than 150 species that exhibit extraordinary variation of geographical distributions, regional abundance patterns, and life history strategies and growth forms, and provide myriad ecosystem services. Understanding the ecological and evolutionary drivers that underpin palm distribution and abundance patterns may shed light on the evolution and ecology of the tropical forest biomes more generally. Edaphic conditions, in particular, are increasingly recognized as critical drivers of tropical plant diversity and distributions but data deficiencies inhibit our understanding of plant-soil relationships at broad scales, especially in the tropics. We present data from 546, 0.25-ha (5 x 500 m) georeferenced transects located throughout western Amazonia where all individual palms were identified, counted, and assigned to a life-history stage. Several environmental covariates were recorded along each transect and surface soil samples were collected from multiple points in N = 464 of transects. Altogether, the transects include 532,602 individuals belonging to 135 species. Variation among transects in terms of palm species richness and abundance is associated with major habitat types and soil properties. The soil properties including pH, acidity, all macronutrients for all samples, and texture, carbon, nitrogen, and micronutrients for some transects vary substantially across the study area, providing insight to broad-scale variation of tropical surface soils. The data provided here will help advance our understanding of plant distributions and abundance patterns, and associations with soil conditions. No copyright restrictions are associated with this data set but please cite this paper if data are used for publication.

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    fulltext
  • 222.
    Barnaby, Jonathan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Cooperative Breeding in the Southern Anteater-Chat: Sexual Disparity, Survival and Dispersal2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Group-living sets the scene for complex social behaviours such as cooperative breeding, and exploring the factors that shape group-living is crucial in understanding these behaviours. This thesis explores the ecology of a population of the facultative cooperative breeding southern anteater-chat (Myrmecocichla formicivora), a group-living bird species endemic to southern Africa. It reveals a breeding system based around a breeding pair and up to three auxiliary males. Despite equal numbers of males and females produced as fledglings there was a surplus of adult males, which remained philopatric. Dispersal was strongly female biased. Females dispersed within their first year, they dispersed further than males, and they lost the benefits of the natal site. The sex skew in the population suggested that these factors drive differential mortality, with juvenile females having much lower annual survival than juvenile males. Adult survival was higher, with female survival only slightly lower than male survival. Dispersal distances suggested that males selected the breeding location, nearer to their natal site. There was no evidence of surplus non-breeding females. On the loss of a breeding female there was no replacement until new females entered the population, yet if a breeding male disappeared the female promptly re-paired with a male from another group. There was no indication of birds floating in the population, and if males were orphaned or widowed they joined other groups as unrelated helpers in preference to floating. There was no sign of inter-group or individual aggression among chats, and unrelated helpers were peacefully accepted into groups, suggesting mutual benefits. In fact all birds in a group helped raise offspring of the breeding pair, and groups with more helpers fledged more offspring, which implies that both direct and indirect fitness benefits can be gained through joining a group and helping. There was surprisingly little inheritance of breeding position by auxiliaries, and strikingly low levels of extra-pair paternity. This study suggests that the Southern anteater-chat group structure arises through male philopatry due to a shortage of breeding females, the benefits of remaining on the natal site and helping, and the potentially high costs of living alone.

    List of papers
    1. Group-living in the southern anteater-chat Myrmecocichla formicivora.
    Open this publication in new window or tab >>Group-living in the southern anteater-chat Myrmecocichla formicivora.
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Group-living sets the scene for complex social behaviours such as cooperative breeding, and exploring the factors that shape group-living is crucial in understanding these behaviours. Here we describe some aspects of the ecology of a population of the facultative cooperative breeding southern anteater-chat (Myrmecocichla formicivora), a group living bird species endemic to southern Africa. We used data from a four year study of individually marked birds, with pedigrees completed using microsatellite genotyping. Southern anteater-chats live in groups of 2-5 individuals - a breeding pair and up to three additional none-breeders. These auxiliary birds were either retained offspring or unrelated individuals, and all birds in a group assisted by feeding at the nest. Our population had a skewed sex ratio of approximately 58% males to 42% females, yet the sex ratio of fledglings was equal, suggesting sex-biased mortality. Helpers were predominantly retained male offspring; however 21% of helpers were unrelated to either of the breeding pair. Southern anteater-chats appear to be non-territorial, with an apparent lack of aggression both within and between groups. Our study confirms that the southern anteater-chat is a facultative cooperative breeder, with both pair breeders and groups with helpers capable of fledging youngsters. We provide evidence suggesting that the breeding system of the southern anteater-chat is based on prompt female dispersal, and male philopatry due to an apparent shortage of mates, potential benefits of the natal site and possible high costs of floating. It appears that ecological constraints promoting delayed dispersal are reinforced by benefits gained from remaining philopatric.

    Keywords
    Southern anteater-chat, cooperative breeding, social evolution, behavioural ecology, delayed dispersal, family living, Africa
    National Category
    Evolutionary Biology
    Research subject
    Biology with specialization in Population Biology
    Identifiers
    urn:nbn:se:uu:diva-179071 (URN)
    Available from: 2012-08-13 Created: 2012-08-07 Last updated: 2012-09-05
    2. Sex specific survival in the southern anteater-chat Mymecocichla formicivora.
    Open this publication in new window or tab >>Sex specific survival in the southern anteater-chat Mymecocichla formicivora.
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Survival is a key factor behind life-history variation both between and within species. It is also a major influence on sociality in species which delay dispersal and live in family groups. Knowledge of differential survival rates between males and females and juveniles and adults give insights into the costs and benefits of different behavioural and life-history strategies. Here we investigate patterns of survival in a population of the southern anteater-chat (Myrmecocichla formicivora), a facultative cooperatively breeding passerine of southern Africa. Using data from a 9-year mark-capture-recapture study, we examined juvenile and adult sex related variation in survival, and the role of environmental variables (rainfall, temperature) for survival patterns in the population. Annual adult survival probability (mean ± SE) was 0.71 ± 0.03 for males and 0.60 ± 0.04 for females. Juvenile survival was lower for each sex, with juvenile female survival (0.36 ± 0.04) being 35% lower than juvenile male survival (0.55 ± 0.04). Using these estimates we calculated the mean life span (MLS) in years for male southern anteater-chat to be 4.0 ± 0.7, considerably higher than for females at 2.0 ± 0.4. These figures closely matched the population-age structure of the study area, and could explain the high male biased sex skew of adult birds in this population. Higher annual mean temperature was associated with higher survival, whereas higher annual rainfall was associated with lower survival for both sex and age classes. Female survival, particularly female juvenile survival, may be reduced due to prompt dispersal and longer dispersal distances, and the additional costs of breeding early in life. Differential survival can promote male philopatry and this in turn could well encourage the cooperative breeding we see in the southern anteater-chat.

    Keywords
    Southern anteater-chat, cooperative breeding, social evolution, behavioural ecology, delayed dispersal, family living, Africa
    National Category
    Evolutionary Biology
    Research subject
    Biology with specialization in Population Biology
    Identifiers
    urn:nbn:se:uu:diva-179072 (URN)
    Available from: 2012-08-13 Created: 2012-08-07 Last updated: 2012-09-05
    3. The rarer sex - female natal dispersal and breeder replacement in the southern anteater-chat Myrmecocichla formicivora.
    Open this publication in new window or tab >>The rarer sex - female natal dispersal and breeder replacement in the southern anteater-chat Myrmecocichla formicivora.
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Sex biased dispersal is a crucial factor in understanding the mechanism of family dynamics in many cooperative breeders. Female biased dispersal occurs in many cooperatively breeding birds. It is often associated with females dispersing earlier and further, and a male biased sex skew in the population. Here we investigated female dispersal in the southern anteater-chat, a facultative cooperatively breeding passerine of southern Africa. Our study population had a male biased sex skew, and females had lower annual survival than males. Dispersal was strongly female biased, with females dispersing within their first year whereas many males remained philopatric beyond the next breeding season. Breeding females were on average younger than breeding males, and also dispersed further. Each breeding group contained only one female. No females were found floating in the population, and all females were associated with one or more males in a breeding group. It appears that all females disperse in their first year directly to a breeding position. If a female disappeared in the breeding season they were not replaced until new females matured and dispersed the following season, yet if a male breeder disappeared during the breeding season he was almost immediately replaced, indicating that there are no surplus females.

    Keywords
    Southern anteater-chat, cooperative breeding, social evolution, behavioural ecology, delayed dispersal, family living, Africa
    National Category
    Evolutionary Biology
    Research subject
    Biology with specialization in Population Biology
    Identifiers
    urn:nbn:se:uu:diva-179073 (URN)
    Available from: 2012-08-13 Created: 2012-08-07 Last updated: 2012-09-05
    4. From helping to breeding – male choice in the southern anteater-chats Myrmecocichla formicivora.
    Open this publication in new window or tab >>From helping to breeding – male choice in the southern anteater-chats Myrmecocichla formicivora.
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Dispersal choice is important in understanding population structure and dynamics. Here we examine male choice in the facultative cooperative breeding southern anteater-chat Myrmecocichla formicivora based on a four year study in South Africa. The sex ratio in our study population was male biased, with many males remaining philopatric. All groups consisted of one or more adult males associated with one adult female. We found a significant positive effect of auxiliary number on group productivity (both number of young fledged, and first year survival), while controlling for potentially confounding variables (territory and breeder identity). The majority of auxiliaries, 54%, were related to both birds in the breeding pair, with another 25% related to one member of the pair, and 21% related to neither of the breeders. There was no evidence of males floating within our study population, and it appears that if males lose their family due to mortality they join other groups as unrelated non-breeding auxiliaries rather than float. No aggression was observed between individual southern anteater-chats, and unrelated group members helped rear offspring in the group they had joined. Despite the presence of, and helping by unrelated group members there was very little evidence of breeding position inheritance (1/24 auxiliaries unrelated to the breeding female) or extra-pair paternity (2.4% of fledglings). This study suggests that the southern anteater-chat group structure arises through male philopatry due to a lack of breeding females and potentially high costs of living alone.

    Keywords
    Southern anteater-chat, cooperative breeding, social evolution, behavioural ecology, delayed dispersal, family living, Africa
    National Category
    Evolutionary Biology
    Research subject
    Biology with specialization in Population Biology
    Identifiers
    urn:nbn:se:uu:diva-179074 (URN)
    Available from: 2012-08-13 Created: 2012-08-07 Last updated: 2012-09-05
    5. Development of a suit of microsatellite markers for the southern anteater-chat Myrmecocichla formicivora.
    Open this publication in new window or tab >>Development of a suit of microsatellite markers for the southern anteater-chat Myrmecocichla formicivora.
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    We tested the cross amplification of 37 microsatellite markers for their suitability in genotyping the southern anteater-chat Myrmecocichla formicivora, an opportunistic cooperatively breeding passerine bird endemic to southern Africa. Fourteen microsatellite markers were identified as having suitable characteristics, with minor deviation from Hardy-Weinberg equilibrium and little evidence of null alleles. These 14 Primer pairs were combined in 4 multiplexes and run on 183 individual samples from our study population of southern anteater-chat on Benfontein Nature Reserve, near Kimberley in central South Africa. The loci ranged from 3-34 alleles per locus, and observed heterozygosity ranged from 0.45 -0.93. We then tested these 14 microsatellites for their use in examining paternity in a population of southern anteater-chat being studied on Benfontein Nature Reserve, near Kimberley in South Africa. Of the population of 183 individuals (the 2011 population) 93% of the offspring could be allocated a mother, 97% a father, and 87% a parent pair with 95% confidence. The remainder could be allocated at the 80% confidence level. Where mothers could be assigned from observations this was in 100% agreement with the microsatellite results, giving us good support for the accurate assignment of parentage in our population.

    Keywords
    Southern anteater-chat, cooperative breeding, social evolution, microsatellites, genotyping, cross-amplification, behavioural ecology, delayed dispersal, family living, Africa
    National Category
    Evolutionary Biology
    Research subject
    Biology with specialization in Population Biology
    Identifiers
    urn:nbn:se:uu:diva-179075 (URN)
    Available from: 2012-08-13 Created: 2012-08-07 Last updated: 2012-09-05
    Download full text (pdf)
    fulltext
  • 223.
    Barnaby, Jonathan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Ekman, Jan
    From helping to breeding – male choice in the southern anteater-chats Myrmecocichla formicivora.Manuscript (preprint) (Other academic)
    Abstract [en]

    Dispersal choice is important in understanding population structure and dynamics. Here we examine male choice in the facultative cooperative breeding southern anteater-chat Myrmecocichla formicivora based on a four year study in South Africa. The sex ratio in our study population was male biased, with many males remaining philopatric. All groups consisted of one or more adult males associated with one adult female. We found a significant positive effect of auxiliary number on group productivity (both number of young fledged, and first year survival), while controlling for potentially confounding variables (territory and breeder identity). The majority of auxiliaries, 54%, were related to both birds in the breeding pair, with another 25% related to one member of the pair, and 21% related to neither of the breeders. There was no evidence of males floating within our study population, and it appears that if males lose their family due to mortality they join other groups as unrelated non-breeding auxiliaries rather than float. No aggression was observed between individual southern anteater-chats, and unrelated group members helped rear offspring in the group they had joined. Despite the presence of, and helping by unrelated group members there was very little evidence of breeding position inheritance (1/24 auxiliaries unrelated to the breeding female) or extra-pair paternity (2.4% of fledglings). This study suggests that the southern anteater-chat group structure arises through male philopatry due to a lack of breeding females and potentially high costs of living alone.

  • 224.
    Barnaby, Jonathan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Ekman, Jan
    The rarer sex - female natal dispersal and breeder replacement in the southern anteater-chat Myrmecocichla formicivora.Manuscript (preprint) (Other academic)
    Abstract [en]

    Sex biased dispersal is a crucial factor in understanding the mechanism of family dynamics in many cooperative breeders. Female biased dispersal occurs in many cooperatively breeding birds. It is often associated with females dispersing earlier and further, and a male biased sex skew in the population. Here we investigated female dispersal in the southern anteater-chat, a facultative cooperatively breeding passerine of southern Africa. Our study population had a male biased sex skew, and females had lower annual survival than males. Dispersal was strongly female biased, with females dispersing within their first year whereas many males remained philopatric beyond the next breeding season. Breeding females were on average younger than breeding males, and also dispersed further. Each breeding group contained only one female. No females were found floating in the population, and all females were associated with one or more males in a breeding group. It appears that all females disperse in their first year directly to a breeding position. If a female disappeared in the breeding season they were not replaced until new females matured and dispersed the following season, yet if a male breeder disappeared during the breeding season he was almost immediately replaced, indicating that there are no surplus females.

  • 225.
    Barnaby, Jonathan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Fletcher, Kevin
    Ekman, Jan
    Development of a suit of microsatellite markers for the southern anteater-chat Myrmecocichla formicivora.Manuscript (preprint) (Other academic)
    Abstract [en]

    We tested the cross amplification of 37 microsatellite markers for their suitability in genotyping the southern anteater-chat Myrmecocichla formicivora, an opportunistic cooperatively breeding passerine bird endemic to southern Africa. Fourteen microsatellite markers were identified as having suitable characteristics, with minor deviation from Hardy-Weinberg equilibrium and little evidence of null alleles. These 14 Primer pairs were combined in 4 multiplexes and run on 183 individual samples from our study population of southern anteater-chat on Benfontein Nature Reserve, near Kimberley in central South Africa. The loci ranged from 3-34 alleles per locus, and observed heterozygosity ranged from 0.45 -0.93. We then tested these 14 microsatellites for their use in examining paternity in a population of southern anteater-chat being studied on Benfontein Nature Reserve, near Kimberley in South Africa. Of the population of 183 individuals (the 2011 population) 93% of the offspring could be allocated a mother, 97% a father, and 87% a parent pair with 95% confidence. The remainder could be allocated at the 80% confidence level. Where mothers could be assigned from observations this was in 100% agreement with the microsatellite results, giving us good support for the accurate assignment of parentage in our population.

  • 226.
    Barnaby, Jonathan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Fletcher, Kevin
    Ekman, Jan
    Group-living in the southern anteater-chat Myrmecocichla formicivora. Manuscript (preprint) (Other academic)
    Abstract [en]

    Group-living sets the scene for complex social behaviours such as cooperative breeding, and exploring the factors that shape group-living is crucial in understanding these behaviours. Here we describe some aspects of the ecology of a population of the facultative cooperative breeding southern anteater-chat (Myrmecocichla formicivora), a group living bird species endemic to southern Africa. We used data from a four year study of individually marked birds, with pedigrees completed using microsatellite genotyping. Southern anteater-chats live in groups of 2-5 individuals - a breeding pair and up to three additional none-breeders. These auxiliary birds were either retained offspring or unrelated individuals, and all birds in a group assisted by feeding at the nest. Our population had a skewed sex ratio of approximately 58% males to 42% females, yet the sex ratio of fledglings was equal, suggesting sex-biased mortality. Helpers were predominantly retained male offspring; however 21% of helpers were unrelated to either of the breeding pair. Southern anteater-chats appear to be non-territorial, with an apparent lack of aggression both within and between groups. Our study confirms that the southern anteater-chat is a facultative cooperative breeder, with both pair breeders and groups with helpers capable of fledging youngsters. We provide evidence suggesting that the breeding system of the southern anteater-chat is based on prompt female dispersal, and male philopatry due to an apparent shortage of mates, potential benefits of the natal site and possible high costs of floating. It appears that ecological constraints promoting delayed dispersal are reinforced by benefits gained from remaining philopatric.

  • 227.
    Barnaby, Jonathan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Griesser, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    The role of nepotism, cooperation, and competition in the avian families2010Book (Refereed)
    Abstract [en]

    A large number of bird species live in stable groups, and this sets the scene for complex social behaviours, such as cooperative breeding. The vast majority of groups consist of families which arise when young postpone dispersal and remain with their parents beyond independence. However, the factors selecting for the evolution of families and thus also cooperative breeding among birds, are still a challenging puzzle. The currently accepted key explanation for the evolution of families and cooperative breeding focuses on dispersal constraints. While constraints successfully explain within‐population dispersal decisions, they fail as an ultimate explanation because offspring in the majority of species face some sort of dispersal constraint, yet still disperse promptly. Recent alternative explanations focus on the role of philopatry and nepotism, and emphasise a key role of life‐history for the evolution of families. Phylogenetic analyses and field studies have indicated that living in family groups is far more widespread among long‐lived species than short‐lived ones. A long lifespan gives parents the opportunity to invest in their offspring for a prolonged period, while this option is less viable for short‐lived species. Thus, living with nepotistic parents provides offspring with direct fitness benefits that can select for the evolution of family living beyond independence. Nevertheless this generalisation is brought into question since many long‐lived bird species do not live in family groups. An alternative approach attempts to explain family living through the variation in territory quality. Here the incentive to remain with the parents is created by the availability of resources on the natal territory independent of parental nepotism. However, there is not only cooperation, conflicts are also common place in families. Living with independent, sexually mature offspring can lead to conflicts through a change in resource availability or the death of aparent. Therefore families can be expected to be dynamic societies where both parent and offspring decisions depend on each other, and family maintenance depends upon the current ecological conditions. Based on  this background, here we review recent studies that have investigated the processes that facilitate family formation, and which highlight both cooperation and conflict that arises from living in family groups. We examine the strengths of current models and explore ideas for a more coherent framework in which to understand prolonged family association in birds. We argue that two paths lead to family living, depending on the life-history. In medium-short lived species where the postponement of independent reproduction comes at a high cost, offspring can benefit from an association with their parents until the next breeding season. In longer-lived species, offspring actually benefit from postponing the onset of independent reproduction, making family living beyond the first year of life an adaptive strategy, and giving the option for cooperative breeding. These processes are illustrated by 5 species-specific case studies. We then finally suggest a number of key questions to developing a deeper understanding of the evolution of family living in birds.

  • 228.
    Barnaby, Jonathan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Herrmann, Eric
    Ekman, Jan
    Sex specific survival in the southern anteater-chat Mymecocichla formicivora. Manuscript (preprint) (Other academic)
    Abstract [en]

    Survival is a key factor behind life-history variation both between and within species. It is also a major influence on sociality in species which delay dispersal and live in family groups. Knowledge of differential survival rates between males and females and juveniles and adults give insights into the costs and benefits of different behavioural and life-history strategies. Here we investigate patterns of survival in a population of the southern anteater-chat (Myrmecocichla formicivora), a facultative cooperatively breeding passerine of southern Africa. Using data from a 9-year mark-capture-recapture study, we examined juvenile and adult sex related variation in survival, and the role of environmental variables (rainfall, temperature) for survival patterns in the population. Annual adult survival probability (mean ± SE) was 0.71 ± 0.03 for males and 0.60 ± 0.04 for females. Juvenile survival was lower for each sex, with juvenile female survival (0.36 ± 0.04) being 35% lower than juvenile male survival (0.55 ± 0.04). Using these estimates we calculated the mean life span (MLS) in years for male southern anteater-chat to be 4.0 ± 0.7, considerably higher than for females at 2.0 ± 0.4. These figures closely matched the population-age structure of the study area, and could explain the high male biased sex skew of adult birds in this population. Higher annual mean temperature was associated with higher survival, whereas higher annual rainfall was associated with lower survival for both sex and age classes. Female survival, particularly female juvenile survival, may be reduced due to prompt dispersal and longer dispersal distances, and the additional costs of breeding early in life. Differential survival can promote male philopatry and this in turn could well encourage the cooperative breeding we see in the southern anteater-chat.

  • 229. Barnes, Ian
    et al.
    Duda, Anna
    Pybus, Oliver G.
    Thomas, Mark G.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Ancient urbanization predicts genetic resistance to tuberculosis2011In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 65, no 3, p. 842-848Article in journal (Refereed)
    Abstract [en]

    A link between urban living and disease is seen in recent and historical records, but the presence of this association in prehistory has been difficult to assess. If the transition to urban living does result in an increase in disease-based mortality, we might expect to see evidence of increased disease resistance in longer-term urbanized populations, as the result of natural selection. To test this, we determined the frequency of an allele (SLC11A1 1729 + 55del4) associated with natural resistance to intracellular pathogens such as tuberculosis and leprosy. We found a highly significantly correlation with duration of urban settlement-populations with a long history of living in towns are better adapted to resisting these infections. This correlation remains strong when we correct for autocorrelation in allele frequencies due to shared population history. Our results therefore support the interpretation that infectious disease loads became an increasingly important cause of human mortality after the advent of urbanization, highlighting the importance of population density in determining human health and the genetic structure of human populations.

  • 230. Barros, Nathan
    et al.
    Cole, Jonathan J.
    Tranvik, Lars J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Prairie, Yves T.
    Bastviken, David
    Huszar, Vera L. M.
    del Giorgio, Paul
    Roland, Fabio
    Carbon emission from hydroelectric reservoirs linked to reservoir age and latitude2011In: Nature Geoscience, ISSN 1752-0894, E-ISSN 1752-0908, Vol. 4, no 9, p. 593-596Article in journal (Refereed)
    Abstract [en]

    Hydroelectric reservoirs cover an area of 3.4 x 10(5) km(2) and comprise about 20% of all reservoirs. In addition, they contain large stores of formerly terrestrial organic carbon. Significant amounts of greenhouse gases are emitted(2), especially in the early years following reservoir creation, but the global extent of these emissions is poorly known. Previous estimates of emissions from all types of reservoir indicate that these human-made systems emit 321 Tg of carbon per year (ref. 4). Here we assess the emissions of carbon dioxide and methane from hydroelectric reservoirs, on the basis of data from 85 globally distributed hydroelectric reservoirs that account for 20% of the global area of these systems. We relate the emissions to reservoir age, location biome, morphometric features and chemical status. We estimate that hydroelectric reservoirs emit about 48 Tg C as CO(2) and 3 Tg C as CH(4), corresponding to 4% of global carbon emissions from inland waters. Our estimates are smaller than previous estimates on the basis of more limited data. Carbon emissions are correlated to reservoir age and latitude, with the highest emission rates from the tropical Amazon region. We conclude that future emissions will be highly dependent on the geographic location of new hydroelectric reservoirs.

  • 231.
    Barsh, Gregory S.
    et al.
    Stanford University.
    Anderson, Tovi M.
    Stanford University.
    Vonholdt, Bridgett M.
    University of California.
    Candille, Sophie I.
    Stanford University.
    Musiani, Marco
    University of Calgary.
    Stahler, Daniel R.
    University of California.
    Leonard, Jennifer
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Padhukasahasram, Badri
    Cornell University.
    Randi, Ettore
    Instituto Nazionale per la Fauna Selvatica.
    Bustamante, Carlos D.
    Cornell University.
    Ostrander, Elaine A.
    National Human Genome Research Institute, Bethesda.
    Tang, Hua
    Stanford University.
    Wayne, Robert K.
    University of California.
    How the Gray Wolf Got Its Color - Response2009In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 325, no 5936, p. 34-34Article in journal (Refereed)
  • 232.
    Bartels, Pia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Ecology across Boundaries: Food web coupling among and within ecosystems2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Cross-boundary movements of energy and material are ubiquitous. Freshwater ecosystems receive nutrients, dissolved, and particulate organic matter from adjacent terrestrial ecosystems, whereas terrestrial ecosystems mainly receive prey organisms and detritus deposited by physical processes such as floods from freshwater ecosystems. Within lakes, fish are considered as integrators between habitats due to their high mobility, although they often occupy either near-shore littoral or open-water pelagic habitats and develop habitat-specific morphologies. Such intra-population divergence in morphological traits might limit the use of multiple habitats.

    In this thesis, I first focused on quantity and quality of reciprocal fluxes of particulate organic matter between freshwater and terrestrial ecosystems and responses of recipient consumers. Freshwater ecosystems generally received higher amounts of externally-produced resources than terrestrial ecosystems. Despite this discrepancy, aquatic and terrestrial consumer responses were similar, likely due to the differences in resource quality. Second, I investigated the potential of particulate organic carbon (POC) supporting benthic food webs in lakes; a pathway that has largely been neglected in previous studies. I found that POC can substantially subsidize the benthic food web and that the effects on the benthic food web were transferred to the pelagic habitat, thus emphasizing the importance of benthic pathways for pelagic production. Third, I examined how water transparency can affect intra-population divergence in perch (Perca fluviatilis). I observed that increased water transparency can considerably increase morphological divergence between littoral and pelagic populations likely due to its effects on foraging. Finally, I investigated the effects of such intra-population divergence on littoral-pelagic food web coupling. I found that low morphological divergence corresponded with high overlap in resource use, whereas strong morphological divergence resulted in low overlap in resource use. Here littoral populations mainly utilized littoral resources and pelagic populations primarily utilized pelagic resources, indicating that habitat coupling might be strongly limited when intra-population divergence is high.

    In conclusion, although different ecosystems seem separated by distinct physical boundaries, these boundaries are often crossed. However, the development of habitat-specific adaptive traits might limit movement between apparently contiguous habitats.

    List of papers
    1. Reciprocal subsidies between freshwater and terrestrial ecosystems structure consumer-resource dynamics
    Open this publication in new window or tab >>Reciprocal subsidies between freshwater and terrestrial ecosystems structure consumer-resource dynamics
    Show others...
    2012 (English)In: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 93, no 5, p. 1173-1182Article in journal (Refereed) Published
    Abstract [en]

    Cross-ecosystem movements of material and energy, particularly reciprocal resource fluxes across the freshwater-land interface, have received major attention. Freshwater ecosystems may receive higher amounts of subsidies (i.e., resources produced outside the focal ecosystem) than terrestrial ecosystems, potentially leading to increased secondary production in freshwaters. Here we used a meta-analytic approach to quantify the magnitude and direction of subsidy inputs across the freshwater-land interface and to determine subsequent responses in recipient animals. Terrestrial and freshwater ecosystems differed in the magnitude of subsidies they received, with aquatic ecosystems generally receiving higher subsidies than terrestrial ecosystems. Surprisingly, and despite the large discrepancy in magnitude, the contribution of these subsidies to animal carbon inferred from stable isotope composition did not differ between freshwater and terrestrial ecosystems, likely due to the differences in subsidy quality. The contribution of allochthonous subsidies was highest to primary consumers and predators, suggesting that bottom-up and top-down effects may be affected considerably by the input of allochthonous resources. Future work on subsidies will profit from a food web dynamic approach including indirect trophic interactions and propagating effects.

    National Category
    Ecology
    Identifiers
    urn:nbn:se:uu:diva-160772 (URN)10.1890/11-1210.1 (DOI)000304368100022 ()
    Available from: 2011-10-31 Created: 2011-10-31 Last updated: 2017-12-08Bibliographically approved
    2. Terrestrial subsidies to lake food webs: An experimental approach
    Open this publication in new window or tab >>Terrestrial subsidies to lake food webs: An experimental approach
    Show others...
    2012 (English)In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 168, no 3, p. 807-818Article in journal (Refereed) Published
    Abstract [en]

    Cross-ecosystem movements of material and energy are ubiquitous. Aquatic ecosystems typically receive material that also includes organic matter from the surrounding catchment. Terrestrial-derived (allochthonous) organic matter can enter aquatic ecosystems in dissolved or particulate form. Several studies have highlighted the importance of dissolved organic carbon to aquatic consumers, but less is known about allochthonous particulate organic carbon (POC). Similarly, most studies showing the effects of allochthonous organic carbon (OC) on aquatic consumers have investigated pelagic habitats; the effects of allochthonous OC on benthic communities are less well studied. Allochthonous inputs might further decrease primary production through light reduction, thereby potentially affecting autotrophic resource availability to consumers. Here, an enclosure experiment was carried out to test the importance of POC input and light availability on the resource use in a benthic food web of a clear-water lake. Corn starch (a C-4 plant) was used as a POC source due to its insoluble nature and its distinct carbon stable isotope value (delta C-13). The starch carbon was closely dispersed over the bottom of the enclosures to study the fate of a POC source exclusively available to sediment biota. The addition of starch carbon resulted in a clear shift in the isotopic signature of surface-dwelling herbivorous and predatory invertebrates. Although the starch carbon was added solely to the sediment surface, the carbon originating from the starch reached zooplankton. We suggest that allochthonous POC can subsidize benthic food webs directly and can be further transferred to pelagic systems, thereby highlighting the importance of benthic pathways for pelagic habitats.

    Keywords
    Allochthonous, Cross-ecosystem, Autochthonous, Aquatic-terrestrial linkage, Benthic
    National Category
    Ecology
    Identifiers
    urn:nbn:se:uu:diva-160774 (URN)10.1007/s00442-011-2141-7 (DOI)000301706800020 ()
    Available from: 2011-10-31 Created: 2011-10-31 Last updated: 2020-01-28Bibliographically approved
    3. Water transparency drives intra-population divergence in Eurasian perch (Perca fluviatilis)
    Open this publication in new window or tab >>Water transparency drives intra-population divergence in Eurasian perch (Perca fluviatilis)
    2012 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 8, p. e43641-Article in journal (Refereed) Published
    Abstract [en]

    Trait combinations that lead to a higher efficiency in resource utilization are important drivers of divergent natural selection and adaptive radiation. However, variation in environmental features might constrain foraging in complex ways and therefore impede the exploitation of critical resources. We tested the effect of water transparency on intra-population divergence in morphology of Eurasian perch (Perca fluviatilis) across seven lakes in central Sweden. Morphological divergence between near-shore littoral and open-water pelagic perch substantially increased with increasing water transparency. Reliance on littoral resources increased strongly with increasing water transparency in littoral populations, whereas littoral reliance was not affected by water transparency in pelagic populations. Despite the similar reliance on pelagic resources in pelagic populations along the water transparency gradient, the utilization of particular pelagic prey items differed with variation in water transparency in pelagic populations. Pelagic perch utilized cladocerans in lakes with high water transparency and copepods in lakes with low water transparency. We suggest that under impaired visual conditions low utilization of littoral resources by littoral perch and utilization of evasive copepods by pelagic perch may lead to changes in morphology. Our findings indicate that visual conditions can affect population divergence in predator populations through their effects on resource utilization.

    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-158689 (URN)10.1371/journal.pone.0043641 (DOI)000308063700123 ()
    Available from: 2011-09-13 Created: 2011-09-13 Last updated: 2017-12-08Bibliographically approved
    4. Intra-population niche separation mediated by water transparency limits habitat coupling
    Open this publication in new window or tab >>Intra-population niche separation mediated by water transparency limits habitat coupling
    (English)Manuscript (preprint) (Other academic)
    National Category
    Ecology
    Identifiers
    urn:nbn:se:uu:diva-160776 (URN)
    Available from: 2011-10-31 Created: 2011-10-31 Last updated: 2013-02-11
    Download full text (pdf)
    fulltext
  • 233.
    Bartels, Pia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Cucherousset, Julien
    Gudasz, Cristian
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Jansson, Mats
    Karlsson, Jan
    Persson, Lennart
    Premke, Katrin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Rubach, Anja
    Steger, Kristin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Tranvik, Lars J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Eklöv, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Terrestrial subsidies to lake food webs: An experimental approach2012In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 168, no 3, p. 807-818Article in journal (Refereed)
    Abstract [en]

    Cross-ecosystem movements of material and energy are ubiquitous. Aquatic ecosystems typically receive material that also includes organic matter from the surrounding catchment. Terrestrial-derived (allochthonous) organic matter can enter aquatic ecosystems in dissolved or particulate form. Several studies have highlighted the importance of dissolved organic carbon to aquatic consumers, but less is known about allochthonous particulate organic carbon (POC). Similarly, most studies showing the effects of allochthonous organic carbon (OC) on aquatic consumers have investigated pelagic habitats; the effects of allochthonous OC on benthic communities are less well studied. Allochthonous inputs might further decrease primary production through light reduction, thereby potentially affecting autotrophic resource availability to consumers. Here, an enclosure experiment was carried out to test the importance of POC input and light availability on the resource use in a benthic food web of a clear-water lake. Corn starch (a C-4 plant) was used as a POC source due to its insoluble nature and its distinct carbon stable isotope value (delta C-13). The starch carbon was closely dispersed over the bottom of the enclosures to study the fate of a POC source exclusively available to sediment biota. The addition of starch carbon resulted in a clear shift in the isotopic signature of surface-dwelling herbivorous and predatory invertebrates. Although the starch carbon was added solely to the sediment surface, the carbon originating from the starch reached zooplankton. We suggest that allochthonous POC can subsidize benthic food webs directly and can be further transferred to pelagic systems, thereby highlighting the importance of benthic pathways for pelagic habitats.

  • 234.
    Bartels, Pia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Cucherousset, Julien
    Steger, Kristin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Eklöv, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Tranvik, Lars J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Hillebrand, Helmut
    Reciprocal subsidies between freshwater and terrestrial ecosystems structure consumer-resource dynamics2012In: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 93, no 5, p. 1173-1182Article in journal (Refereed)
    Abstract [en]

    Cross-ecosystem movements of material and energy, particularly reciprocal resource fluxes across the freshwater-land interface, have received major attention. Freshwater ecosystems may receive higher amounts of subsidies (i.e., resources produced outside the focal ecosystem) than terrestrial ecosystems, potentially leading to increased secondary production in freshwaters. Here we used a meta-analytic approach to quantify the magnitude and direction of subsidy inputs across the freshwater-land interface and to determine subsequent responses in recipient animals. Terrestrial and freshwater ecosystems differed in the magnitude of subsidies they received, with aquatic ecosystems generally receiving higher subsidies than terrestrial ecosystems. Surprisingly, and despite the large discrepancy in magnitude, the contribution of these subsidies to animal carbon inferred from stable isotope composition did not differ between freshwater and terrestrial ecosystems, likely due to the differences in subsidy quality. The contribution of allochthonous subsidies was highest to primary consumers and predators, suggesting that bottom-up and top-down effects may be affected considerably by the input of allochthonous resources. Future work on subsidies will profit from a food web dynamic approach including indirect trophic interactions and propagating effects.

  • 235.
    Bartels, Pia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Hirsch, Philipp E.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Svanbäck, Richard
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Eklöv, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Intra-population niche separation mediated by water transparency limits habitat couplingManuscript (preprint) (Other academic)
  • 236.
    Bartels, Pia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Hirsch, Philipp E
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Svanbäck, Richard
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Eklöv, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Water transparency drives intra-population divergence in Eurasian perch (Perca fluviatilis)2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 8, p. e43641-Article in journal (Refereed)
    Abstract [en]

    Trait combinations that lead to a higher efficiency in resource utilization are important drivers of divergent natural selection and adaptive radiation. However, variation in environmental features might constrain foraging in complex ways and therefore impede the exploitation of critical resources. We tested the effect of water transparency on intra-population divergence in morphology of Eurasian perch (Perca fluviatilis) across seven lakes in central Sweden. Morphological divergence between near-shore littoral and open-water pelagic perch substantially increased with increasing water transparency. Reliance on littoral resources increased strongly with increasing water transparency in littoral populations, whereas littoral reliance was not affected by water transparency in pelagic populations. Despite the similar reliance on pelagic resources in pelagic populations along the water transparency gradient, the utilization of particular pelagic prey items differed with variation in water transparency in pelagic populations. Pelagic perch utilized cladocerans in lakes with high water transparency and copepods in lakes with low water transparency. We suggest that under impaired visual conditions low utilization of littoral resources by littoral perch and utilization of evasive copepods by pelagic perch may lead to changes in morphology. Our findings indicate that visual conditions can affect population divergence in predator populations through their effects on resource utilization.

  • 237.
    Bartels, Pia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Hirsch, Philipp Emanuel
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Svanbäck, Richard
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Eklöv, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Dissolved Organic Carbon Reduces Habitat Coupling by Top Predators in Lake Ecosystems2016In: Ecosystems (New York. Print), ISSN 1432-9840, E-ISSN 1435-0629, Vol. 19, p. 955-967Article in journal (Refereed)
    Abstract [en]

    Increasing input of terrestrial dissolved organic carbon (DOC) has been identified as a widespread environmental phenomenon in many aquatic ecosystems. Terrestrial DOC influences basal trophic levels: it can subsidize pelagic bacterial production and impede benthic primary production via light attenuation. However, little is known about the impacts of elevated DOC concentrations on higher trophic levels, especially on top consumers. Here, we used Eurasian perch (Perca fluviatilis) to investigate the effects of increasing DOC concentrations on top predator populations. We applied stable isotope analysis and geometric morphometrics to estimate long-term resource and habitat utilization of perch. Habitat coupling, the ability to exploit littoral and pelagic resources, strongly decreased with increasing DOC concentrations due to a shift toward feeding predominantly on pelagic resources. Simultaneously, resource use and body morphology became increasingly alike for littoral and pelagic perch populations with increasing DOC, suggesting more intense competition in lakes with high DOC. Eye size of perch increased with increasing DOC concentrations, likely as a result of deteriorating visual conditions, suggesting a sensory response to environmental change. Increasing input of DOC to aquatic ecosystems is a common result of environmental change and might affect top predator populations in multiple and complex ways.

  • 238.
    Bartoszek, Krzysztof
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics.
    Glemin, Sylvain
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution. CNRS Univ Montpellier IRD EPHE, UMR ISEM 5554, Montpellier, France..
    Kaj, Ingemar
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics.
    Lascoux, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Using the Ornstein-Uhlenbeck process to model the evolution of interacting populations2017In: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 429, p. 35-45Article in journal (Refereed)
    Abstract [en]

    The Ornstein-Uhlenbeck (OU) process plays a major role in the analysis of the evolution of phenotypic traits along phylogenies. The standard OU process includes random perturbations and stabilizing selection and assumes that species evolve independently. However, evolving species may interact through various ecological process and also exchange genes especially in plants. This is particularly true if we want to study phenotypic evolution among diverging populations within species. In this work we present a straightforward statistical approach with analytical solutions that allows for the inclusion of adaptation and migration in a common phylogenetic framework, which can also be useful for studying local adaptation among populations within the same species. We furthermore present a detailed simulation study that clearly indicates the adverse effects of ignoring migration. Similarity between species due to migration could be misinterpreted as very strong convergent evolution without proper correction for these additional dependencies. Finally, we show that our model can be interpreted in terms of ecological interactions between species, providing a general framework for the evolution of traits between "interacting" species or populations.

  • 239. Bastviken, David
    et al.
    Tranvik, Lars J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Downing, John A.
    Crill, Patrick M.
    Enrich-Prast, Alex
    Freshwater Methane Emissions Offset the Continental Carbon Sink2011In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 331, no 6013Article in journal (Refereed)
    Abstract [en]

    Inland waters (lakes, reservoirs, streams, and rivers) are often substantial methane (CH(4)) sources in the terrestrial landscape. They are, however, not yet well integrated in global greenhouse gas (GHG) budgets. Data from 474 freshwater ecosystems and the most recent global water area estimates indicate that freshwaters emit at least 103 teragrams of CH(4) year(-1), corresponding to 0.65 petagrams of C as carbon dioxide (CO(2)) equivalents year(-1), offsetting 25% of the estimated land carbon sink. Thus, the continental GHG sink may be considerably overestimated, and freshwaters need to be recognized as important in the global carbon cycle.

  • 240.
    Bauerfeind, Stephanie S.
    et al.
    Univ Zurich, Dept Evolutionary Biol & Environm Studies, Zurich, Switzerland.
    Schaefer, Martin A.
    Univ Zurich, Dept Evolutionary Biol & Environm Studies, Zurich, Switzerland.
    Berger, David
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology. Univ Zurich, Dept Evolutionary Biol & Environm Studies, Zurich, Switzerland.
    Blanckenhorn, Wolf U.
    Univ Zurich, Dept Evolutionary Biol & Environm Studies, Zurich, Switzerland.
    Fox, Charles W.
    Univ Kentucky, Dept Entomol, S225 Ag Sci Ctr North, Lexington, KY 40546 USA.
    Replicated latitudinal clines in reproductive traits of European and North American yellow dung flies2018In: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 127, no 11, p. 1619-1632Article in journal (Refereed)
    Abstract [en]

    Geographic variation in phenotypic traits is commonly correlated with spatial variation in the environment, e.g. seasonality and mean temperature, providing evidence that natural selection generates such patterns. In particular, both body size and egg size of ectothermic animals are commonly larger in northern climates, and temperature induces plastic responses in both traits. Size-independent egg quality can also vary with latitude, though this is rarely investigated. For the widespread yellow dung fly Scathophaga stercoraria (Diptera: Scathophagidae) we investigated whether there are latitudinal clines in reproductive traits (clutch size, egg size and egg composition), whether these clines are due to variation in body and/or egg size, and whether such clines replicate across independent experiments performed on different continents (North America and Europe). Egg size generally increased with latitude (especially in Europe), an effect largely explained by body size of the mother, while clutch size did not; overall reproductive effort thus increased with latitude. Both the absolute and relative (correcting for egg size) amount of egg protein increased with latitude, egg glycogen decreased with latitude, while latitudinal trends for egg lipids and total egg energy content were complex and non-linear. Altitude sometimes showed relationships analogous to those of latitude (egg proteins and glycogen) but occasionally opposite (egg size), possibly because latitude and altitude are negatively related among populations of this cold-adapted species. There was no evidence of a tradeoff between egg size and number across latitudinal populations; if anything, the relationship was positive. All traits, including body and egg size, varied with rearing temperature (12 degrees C, 18 degrees C, 24 degrees C), generally following the temperature-size rule. Clines based on common garden rearing, thus reflecting genetic differentiation, were qualitatively but not always quantitatively consistent between continents, and were similar across rearing temperatures, suggesting they evolved due to natural selection, although the concrete selective mechanisms involved require further study.

  • 241.
    Bauerfeind, Stephanie S.
    et al.
    Univ Zurich, Dept Evolutionary Biol & Environm Studies, Winterthurer Str 190, CH-8057 Zurich, Switzerland.
    Sorensen, Jesper G.
    Univ Aarhus, Sect Genet Ecol & Evolut, Dept Biosci, DK-8000 Aarhus C, Denmark.
    Loeschcke, Volker
    Univ Aarhus, Sect Genet Ecol & Evolut, Dept Biosci, DK-8000 Aarhus C, Denmark.
    Berger, David
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology. Univ Zurich, Dept Evolutionary Biol & Environm Studies, Winterthurer Str 190, CH-8057 Zurich, Switzerland.
    Broder, E. Dale
    Univ Zurich, Dept Evolutionary Biol & Environm Studies, Winterthurer Str 190, CH-8057 Zurich, Switzerland;Univ Denver, Interdisciplinary Res Incubator Study InEqual, Denver, CO 80208 USA.
    Geiger, Madeleine
    Univ Zurich, Dept Evolutionary Biol & Environm Studies, Winterthurer Str 190, CH-8057 Zurich, Switzerland.
    Ferrari, Manuela
    Univ Zurich, Dept Evolutionary Biol & Environm Studies, Winterthurer Str 190, CH-8057 Zurich, Switzerland.
    Blanckenhorn, Wolf U.
    Univ Zurich, Dept Evolutionary Biol & Environm Studies, Winterthurer Str 190, CH-8057 Zurich, Switzerland.
    Geographic variation in responses of European yellow dung flies to thermal stress2018In: Journal of Thermal Biology, ISSN 0306-4565, E-ISSN 1879-0992, Vol. 73, p. 41-49Article in journal (Refereed)
    Abstract [en]

    Climatic conditions can be very heterogeneous even over small geographic scales, and are believed to be major determinants of the abundance and distribution of species and populations. Organisms are expected to evolve in response to the frequency and magnitude of local thermal extremes, resulting in local adaptation. Using replicate yellow dung fly (Scathophaga stercoraria; Diptera: Scathophagidae) populations from cold (northern Europe) and warm climates (southern Europe), we compared 1) responses to short-term heat and cold shocks in both sexes, 2) heat shock protein (Hsp70) expression in adults and eggs, and 3) female reproductive traits when facing short-term heat stress during egg maturation. Contrary to expectations, thermal traits showed minor geographic differentiation, with weak evidence for greater heat resistance of southern flies but no differentiation in cold resistance. Hsp70 protein expression was little affected by heat stress, indicating systemic rather than induced regulation of the heat stress response, possibly related to this fly group's preference for cold climes. In contrast, sex differences were pronounced: males (which are larger) endured hot temperatures longer, while females featured higher Hsp70 expression. Heat stress negatively affected various female reproductive traits, reducing first clutch size, overall reproductive investment, egg lipid content, and subsequent larval hatching. These responses varied little across latitude but somewhat among populations in terms of egg size, protein content, and larval hatching success. Several reproductive parameters, but not Hsp70 expression, exhibited heritable variation among full-sib families. Rather than large-scale clinal geographic variation, our study suggests some local geographic population differentiation in the ability of yellow dung flies to buffer the impact of heat stress on reproductive performance.

  • 242.
    Baur, Julian
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology. Univ Zurich, Dept Evolutionary Biol & Environm Studies, Zurich, Switzerland.
    Roy, Jeannine
    Univ Zurich, Dept Evolutionary Biol & Environm Studies, Zurich, Switzerland.
    Schafer, Martin A.
    Univ Zurich, Dept Evolutionary Biol & Environm Studies, Zurich, Switzerland.
    Puniamoorthy, Nalini
    Natl Univ Singapore, Dept Biol Sci, Singapore, Singapore.
    Blanckenhorn, Wolf U. B.
    Univ Zurich, Dept Evolutionary Biol & Environm Studies, Zurich, Switzerland.
    Rohner, Patrick T.
    Univ Zurich, Dept Evolutionary Biol & Environm Studies, Zurich, Switzerland;Indiana Univ, Dept Biol, 915 East Third St,102 Myers Hall, Bloomington, IN 47405 USA.
    Intraspecific mating system evolution and its effect on complex male secondary sexual traits: Does male-male competition increase selection on size or shape?2020In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 33, no 3, p. 297-308Article in journal (Refereed)
    Abstract [en]

    Sexual selection is generally held responsible for the exceptional diversity in secondary sexual traits in animals. Mating system evolution is therefore expected to profoundly affect the covariation between secondary sexual traits and mating success. Whereas there is such evidence at the interspecific level, data within species remain scarce. We here investigate sexual selection acting on the exaggerated male fore femur and the male wing in the common and widespread dung flies Sepsis punctum and S. neocynipsea (Diptera: Sepsidae). Both species exhibit intraspecific differences in mating systems and variation in sexual size dimorphism (SSD) across continents that correlates with the extent of male-male competition. We predicted that populations subject to increased male-male competition will experience stronger directional selection on the sexually dimorphic male foreleg. Our results suggest that fore femur size, width and shape were indeed positively associated with mating success in populations with male-biased SSD in both species, which was not evident in conspecific populations with female-biased SSD. However, this was also the case for wing size and shape, a trait often assumed to be primarily under natural selection. After correcting for selection on overall body size by accounting for allometric scaling, we found little evidence for independent selection on any of these size or shape traits in legs or wings, irrespective of the mating system. Sexual dimorphism and (foreleg) trait exaggeration is therefore unlikely to be driven by direct precopulatory sexual selection, but more so by selection on overall size or possibly selection on allometric scaling.

  • 243.
    Bayram, Helen L.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics. Univ Liverpool, Inst Integrat Biol, Mammalian Behav & Evolut Grp, Leahurst Campus, Neston CH64 7TE, England..
    Claydon, Amy J.
    Univ Liverpool, Inst Integrat Biol, Ctr Proteome Res, Liverpool L69 7ZB, Merseyside, England..
    Brownridge, Philip J.
    Univ Liverpool, Inst Integrat Biol, Ctr Proteome Res, Liverpool L69 7ZB, Merseyside, England..
    Hurst, Jane L.
    Univ Liverpool, Inst Integrat Biol, Mammalian Behav & Evolut Grp, Leahurst Campus, Neston CH64 7TE, England..
    Mileham, Alan
    Genus Plc, 1525 River Rd, De Forest, WI 53532 USA..
    Stockley, Paula
    Univ Liverpool, Inst Integrat Biol, Mammalian Behav & Evolut Grp, Leahurst Campus, Neston CH64 7TE, England..
    Beynon, Robert J.
    Univ Liverpool, Inst Integrat Biol, Ctr Proteome Res, Liverpool L69 7ZB, Merseyside, England..
    Hammond, Dean E.
    Univ Liverpool, Inst Translat Med, Cellular & Mol Physiol, Liverpool L69 3BX, Merseyside, England..
    Cross-species proteomics in analysis of mammalian sperm proteins2016In: Journal of Proteomics, ISSN 1874-3919, E-ISSN 1876-7737, Vol. 135, p. 38-50Article in journal (Refereed)
    Abstract [en]

    Many proteomics studies are conducted in model organisms for which fully annotated, detailed, high quality proteomes are available. By contrast, many studies in ecology and evolution are conducted in species which lack high quality proteome data, limiting the perceived value of a proteomic approach for protein discovery and quantification. This is particularly true of rapidly evolving proteins in the reproductive system, such as those that have an immune function or are under sexual selection, and can compromise the potential for cross-species proteomics to yield confident identification. In this investigation we analysed the sperm proteome, from a range of ungulates and rodents, and explored the potential of routine proteomic workflows to yield characterisation and quantification in non-model organisms. We report that database searching is robust to cross-species matching for a mammalian core sperm proteome, comprising 623 proteins that were common to most of the 19 species studied here, suggesting that these proteins are likely to be present and identifiable across many mammalian sperm. Further, label-free quantification reveals a consistent pattern of expression level. Functional analysis of this core proteome suggests consistency with previous studies limited to model organisms and has value as a quantitative reference for analysis of species-specific protein characterisation.

    Significance: From analysis of the sperm proteome for diverse species (rodents and ungulates) using LC-MS/MS workflows and standard data processing, we show that it is feasible to obtain cross-species matches for a large number of proteins that can be filtered stringently to yield a highly expressed mammalian sperm core proteome, for which label-free quantitative data are also used to inform protein function and abundance.

  • 244.
    Bayram, Helen L.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Sayadi, Ahmed
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology. Uppsala Univ, Dept Ecol & Genet, Evolutionary Biol Ctr, Norbyvagen 18D, SE-75236 Uppsala, Sweden..
    Goenaga, Julieta
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology. Aarhus Univ, Aarhus Inst Adv Studies, Aarhus, Denmark..
    Immonen, Elina
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Novel seminal fluid proteins in the seed beetle Callosobruchus maculatus identified by a proteomic and transcriptomic approach2017In: Insect molecular biology (Print), ISSN 0962-1075, E-ISSN 1365-2583, Vol. 26, no 1, p. 58-73Article in journal (Refereed)
    Abstract [en]

    The seed beetle Callosobruchus maculatus is a significant agricultural pest and increasingly studied model of sexual conflict. Males possess genital spines that increase the transfer of seminal fluid proteins (SFPs) into the female body. As SFPs alter female behaviour and physiology, they are likely to modulate reproduction and sexual conflict in this species. Here, we identified SFPs using proteomics combined with a de novo transcriptome. A prior 2D-sodium dodecyl sulphate polyacrylamide gel electrophoresis analysis identified male accessory gland protein spots that were probably transferred to the female at mating. Proteomic analysis of these spots identified 98 proteins, a majority of which were also present within ejaculates collected from females. Standard annotation workflows revealed common functional groups for SFPs, including proteases and metabolic proteins. Transcriptomic analysis found 84 transcripts differentially expressed between the sexes. Notably, genes encoding 15 proteins were highly expressed in male abdomens and only negligibly expressed within females. Most of these sequences corresponded to 'unknown' proteins (nine of 15) and may represent rapidly evolving SFPs novel to seed beetles. Our combined analyses highlight 44 proteins for which there is strong evidence that they are SFPs. These results can inform further investigation, to better understand the molecular mechanisms of sexual conflict in seed beetles.

  • 245.
    Bayram, Helen L.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Sayadi, Ahmed
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Immonen, Elina
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Identification of novel ejaculate proteins in a seed beetle and division of labour across male accessory reproductive glands2019In: Insect biochemistry and molecular biology, ISSN 0965-1748, Vol. 104, p. 50-57Article in journal (Refereed)
    Abstract [en]

    The male ejaculate contains a multitude of seminal fluid proteins (SFPs), many of which are key reproductive molecules, as well as sperm. However, the identification of SFPs is notoriously difficult and a detailed understanding of this complex phenotype has only been achieved in a few model species. We employed a recently developed proteomic method involving whole-organism stable isotope labelling coupled with proteomic and transcriptomic analyses to characterize ejaculate proteins in the seed beetle Callosobruchus maculatus. We identified 317 proteins that were transferred to females at mating, and a great majority of these showed signals of secretion and were highly male-biased in expression in the abdomen. These male-derived proteins were enriched with proteins involved in general metabolic and catabolic processes but also with proteolytic enzymes and proteins involved in protection against oxidative stress. Thirty-seven proteins showed significant homology with SFPs previously identified in other insects. However, no less than 92 C. maculatus ejaculate proteins were entirely novel, receiving no significant blast hits and lacking homologs in extant data bases, consistent with a rapid and divergent evolution of SFPs. We used 3D micro-tomography in conjunction with proteomic methods to identify 5 distinct pairs of male accessory reproductive glands and to show that certain ejaculate proteins were only recovered in certain male glands. Finally, we provide a tentative list of 231 candidate female-derived reproductive proteins, some of which are likely important in ejaculate processing and/or sperm storage.

  • 246.
    Bebris, Kristaps
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Local adaptation of Grauer's gorilla gut microbiome2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The availability of high-throughput sequencing technologies has enabled metagenomicinvestigations into complex bacterial communities with unprecedented resolution andthroughput. The production of dedicated data sets for metagenomic analyses is, however, acostly process and, frequently, the first research questions focus on the study species itself. Ifthe source material is represented by fecal samples, target capture of host-specific sequencesis applied to enrich the complex DNA mixtures contained within a typical fecal DNA extract.Yet, even after this enrichment, the samples still contain a large amount of environmentalDNA that is usually left unanalysed. In my study I investigate the possibility of using shotgunsequencing data that has been subjected to target enrichment for mtDNA from the hostspecies, Grauer’s gorilla (Gorilla beringei graueri), for further analysis of the microbialcommunity present in these samples. The purpose of these analyses is to study the differencesin the bacterial communities present within a high-altitude Grauer’s gorilla, low-altitudeGrauer’s gorilla, and a sympatric chimpanzee population. Additionally, I explore the adaptivepotential of the gut microbiota within these great ape populations.I evaluated the impact that the enrichment process had on the microbial community by usingpre- and post-capture museum preserved samples. In addition to this, I also analysed the effectof two different extraction methods on the bacterial communities.My results show that the relative abundances of the bacterial taxa remain relatively unaffectedby the enrichment process and the extraction methods. The overall number of taxa is,however, reduced by each additional capture round and is not consistent between theextraction methods. This means that both the enrichment and extraction processes introducebiases that require the usage of abundance-based distance measures for biological inferences.Additionally, even if the data cannot be used to study the bacterial communities in anunbiased manner, it provides useful comparative insights for samples that were treated in thesame fashion.With this background, I used museum and fecal samples to perform cluster analysis to explorethe relationships between the gut microbiota of the three great ape populations. I found thatpopulations cluster by species first, and only then group according to habitat. I further foundthat a bacterial taxon that degrades plant matter is enriched in the gut microbiota of all threegreat ape species, where it could help with the digestion of vegetative foods. Another bacterialtaxon that consumes glucose is enriched in the gut microbiota of the low-altitude gorilla andchimpanzee populations, where it could help with the modulation of the host’s mucosalimmune system, and could point to the availability of fruit in the animals diet. In addition, Ifound a bacterial taxon that is linked with diarrhea in humans to be part of the gut microbiotaof the habituated high-altitude gorilla population, which could indicate that this pathogen hasbeen transmitted to the gorillas from their interaction with humans, or it could be indicative ofthe presence of a contaminated water source.

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  • 247.
    Beekman, Madeleine
    et al.
    Univ Sydney, Sch Life & Environm Sci, Sydney, NSW 2006, Australia..
    Nieuwenhuis, Bart
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Ortiz-Barrientos, Daniel
    Univ Queensland, Sch Biol Sci, St Lucia, Qld, Australia..
    Evans, Jonathan P.
    Univ Western Australia, Sch Anim Biol, Ctr Evolutionary Biol, Nedlands, WA 6009, Australia..
    Sexual selection in hermaphrodites, sperm and broadcast spawners, plants and fungi2016In: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 371, no 1706, article id 20150541Article, review/survey (Refereed)
    Abstract [en]

    Darwin was the first to recognize that sexual selection is a strong evolutionary force. Exaggerated traits allow same-sex individuals to compete over access to mates and provide a mechanism by which mates are selected. It is relatively easy to appreciate how inter-and intrasexual selection work in organisms with the sensory capabilities to perceive physical or behavioural traits that signal mate quality or mate compatibility, and to assess the relative quality of competitors. It is therefore not surprising that most studies of sexual selection have focused on animals with separate sexes and obvious adaptations that function in the context of reproductive competition. Yet, many sexual organisms are both male and female at the same time, often lack sexual dimorphism and never come into direct contact at mating. How does sexual selection act in such species, and what can we learn from them? Here, we address these questions by exploring the potential for sexual selection in simultaneous hermaphrodites, sperm-and broadcast spawners, plants and fungi. Our reviewreveals a range of mechanisms of sexual selection, operating primarily after gametes have been released, which are common in many of these groups and also quite possibly in more familiar (internally fertilizing and sexually dimorphic) organisms. This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'.

  • 248.
    Beier, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Bacterial Degradation and Use of Chitin in Aquatic Habitats2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Chitin belongs to the most abundant biopolymers on earth where it has an important role as a structural element in crustaceans, insects, fungi and some phytoplankton. Missing evidence for long-term accumulation of chitin in nature implies fast turnover and as chitin is composed of aminosugar subunits it holds central roles in both carbon and nitrogen cycles. The aim of this thesis was to contribute to a better understanding of organic matter cycling by learning more about the diversity, function and ecology of bacteria that degrade chitin. A metagenome-enabled study of the spatial distribution of chitinolytic bacteria in aquatic ecosystems identified salinity as the major environmental factor for shaping their community composition. To address the role of alternative environmental variables controlling chitinolytic communities, a temporally resolved study was completed in a dimictic freshwater lake. Pronounced seasonal change in the indigenous chitinolytic community was observed and parallel measured environmental parameters pointed to the availability and crystalline form of chitin as significant controlling factors.  The different ecological niches occupied by microbes that utilize chitin for growth were studied in an experimental study. Single-cell quantification of chitinolytic cells and cells incorporating chitin hydrolysis products suggested that commensal use of chitin hydrolysis products without simultaneous chitinase activity could be an important ecological strategy in freshwater bacterioplankton communities. Members of the ubiquitous and often quantitatively dominant group of freshwater Actinobacteria Ac1 were identified as particularly active in this “cheater” lifestyle. Further experiments based on artificially created gradients in bacterial diversity demonstrated the importance of specific bacterial populations and community composition rather than overall community richness in controlling more specific functions such as chitin and cellulose degradation. To conclude, results of this thesis provide insight into the biogeography, niche-separation and species interactions of the functional community of chitin degraders and the influence of general bacterial diversity to the respective system functioning.

     

     

     

     

    List of papers
    1. Mechanisms and ecology of bacterial chitin degradation
    Open this publication in new window or tab >>Mechanisms and ecology of bacterial chitin degradation
    (English)Manuscript (preprint) (Other academic)
    Identifiers
    urn:nbn:se:uu:diva-131084 (URN)
    Available from: 2010-09-22 Created: 2010-09-22 Last updated: 2011-03-21
    2.
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    3. Pronounced seasonal dynamics of freshwater chitinase genes and chitin processing
    Open this publication in new window or tab >>Pronounced seasonal dynamics of freshwater chitinase genes and chitin processing
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    2012 (English)In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 14, no 9, p. 2467-2479Article in journal (Refereed) Published
    Abstract [en]

    Seasonal variation in activity of enzymes involved in polymer degradation, including chitinases, has been observed previously in freshwater environments. However, it is not known whether the seasonal dynamics are due to shifts in the activity of bacteria already present, or shifts in community structure towards emergence or disappearance of chitinolytic organisms. We traced seasonal shifts in the chitinase gene assemblage in a temperate lake and linked these communities to variation in chitinase activity. Chitinase genes from 20 samples collected over a full yearly cycle were characterized by pyrosequencing. Pronounced temporal shifts in composition of the chitinase gene pool (beta diversity) occurred along with distinct shifts in richness (alpha diversity) as well as chitin processing. Changes in the chitinase gene pool correlated mainly with temperature, abundance of crustacean zooplankton and phytoplankton blooms. Also changes in the physical structure of the lake, e.g. stratification and mixing were associated with changes in the chitinolytic community, while differences were minor between surface and suboxic hypolimnetic water. The lake characteristics influencing the chitinolytic community are all linked to changes in organic particles and we suggest that seasonal changes in particle quality and availability foster microbial communities adapted to efficiently degrade them.

    Keywords
    chitinase genes, lake, temporal dynamics, seasonality, pyrosequencing
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-131091 (URN)10.1111/j.1462-2920.2012.02764.x (DOI)000308300600018 ()
    Available from: 2010-09-22 Created: 2010-09-22 Last updated: 2017-12-12Bibliographically approved
    4. Uncoupling of chitinase activity and uptake of hydrolyses products in freshwater bacterioplankton
    Open this publication in new window or tab >>Uncoupling of chitinase activity and uptake of hydrolyses products in freshwater bacterioplankton
    2011 (English)In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 56, no 4, p. 1179-1188Article in journal (Refereed) Published
    Abstract [en]

    We investigated to what extent chitinolytic bacteria subsidize bacterial populations that do not produce chitinolytic enzymes but still use the products of chitin hydrolysis. Applying single-cell techniques to untreated and chitin-enriched lake water, we show that the number of planktonic cells taking up chitin hydrolysis products by far exceeds the number of cells expressing chitinases. Flavobacteria, Actinobacteria, and specifically members of the abundant and ubiquitous freshwater Ac1 cluster of the Actinobacteria, increased in abundance and were enriched in response to the chitin amendment. Flavobacteria were frequently observed in dense clusters on chitin particles, suggesting that they are actively involved in the hydrolysis and solubilization of chitin. In contrast, Actinobacteria were exclusively planktonic. We propose that planktonic Actinobacteria contain commensals specialized in the uptake of small hydrolysis products without expressing or possibly even possessing the machinery for chitin hydrolysis. More research is needed to assess the importance of such "cheater'' substrate acquisition strategies in the turnover and degradation of polymeric organic matter in aquatic ecosystems.

    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-131094 (URN)10.4319/lo.2011.56.4.1179 (DOI)000294603400001 ()
    Available from: 2010-09-22 Created: 2010-09-22 Last updated: 2017-12-12Bibliographically approved
    5. Function-specific response to depletion of microbial diversity
    Open this publication in new window or tab >>Function-specific response to depletion of microbial diversity
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    2011 (English)In: The ISME Journal, ISSN 1751-7362, Vol. 5, no 2, p. 351-361Article in journal (Refereed) Published
    Abstract [en]

    Recent meta-analyses suggest that ecosystem functioning increases with biodiversity, but contradictory results have been presented for some microbial functions. Moreover, observations of only one function underestimate the functional role of diversity because of species-specific trade-offs in the ability to carry out different functions. We examined multiple functions in batch cultures of natural freshwater bacterial communities with different richness, achieved by a dilution-to-extinction approach. Community composition was assessed by molecular fingerprinting of 16S rRNA and chitinase genes, representing the total community and a trait characteristic for a functional group, respectively. Richness was positively related to abundance and biomass, negatively correlated to cell volumes and unrelated to maximum intrinsic growth rate. The response of chitin and cellulose degradation rates depended on the presence of a single phylotype. We suggest that species identity and community composition rather than richness matters for specific microbial processes.

    Keywords
    cellulose, chitin, functional diversity, species traits, T-RFLP
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-131083 (URN)10.1038/ismej.2010.119 (DOI)000290020000018 ()20686511 (PubMedID)
    Available from: 2010-09-22 Created: 2010-09-22 Last updated: 2017-11-30Bibliographically approved
    Download full text (pdf)
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  • 249.
    Beier, Sara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Bacterial chitin degradation: mechanisms and ecophysiological strategies2013In: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 4, p. 149-Article, review/survey (Refereed)
    Abstract [en]

    Chitin is one the most abundant polymers in nature and interacts with both carbon and nitrogen cycles. Processes controlling chitin degradation are summarized in reviews published some 20 years ago, but the recent use of culture-independent molecular methods has led to a revised understanding of the ecology and biochemistry of this process and the organisms involved. This review summarizes different mechanisms and the principal steps involved in chitin degradation at a molecular level while also discussing the coupling of community composition to measured chitin hydrolysis activities and substrate uptake. Ecological consequences are then highlighted and discussed with a focus on the cross feeding associated with the different habitats that arise because of the need for extracellular hydrolysis of the chitin polymer prior to metabolic use. Principal environmental drivers of chitin degradation are identified which are likely to influence both community composition of chitin degrading bacteria and measured chitin hydrolysis activities.

  • 250.
    Beier, Sara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Mechanisms and ecology of bacterial chitin degradationManuscript (preprint) (Other academic)
2345678 201 - 250 of 3133
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