uu.seUppsala universitets publikasjoner
Endre søk
Begrens søket
45678910 301 - 350 of 539
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 301.
    Madec, Camille
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Ehrlén, Johan
    Stockholm University, Department of Ecology, Environment and Plant Sciences.
    Ågren, Jon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Genetic differentiation in flowering time of a short-lived perennial herb driven by divergent selectionManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Because flowering time influences the time available for fruit maturation, the optimal flowering time should vary among environments that differ in the length of the growing season. With field surveys and a common-garden experiment, we documented variation in flowering time among 20 populations of the perennial herb Primula farinosa growing on soils of different water availability within an 8 x 5 km area on the island Öland, SE Sweden. We tested the hypotheses that (a) among-population variation in flowering time in the field reflects genetic differentiation, (b) among-population differentiation in flowering time is larger than that at putatively neutral marker loci, and (c) genetic differentiation in flowering time is related to water availability at the sites of origin. Among-population variation in a common-garden experiment was positively correlated with variation observed among populations at their sites of origin, and among-population differentiation for start of flowering was significantly higher than at putatively neutral marker loci. In the field, flowering start tended to be positively related to soil moisture. However, among-population differentiation observed in the common-garden experiment was not related to variation in measures of water availability at the sites of origin, suggesting that factors other than soil characteristics influence the evolution of flowering time in this system of populations. The results indicate that variation in flowering time observed among natural populations of P. farinosa is the result of both genetic differentiation and phenotypic plasticity, and are consistent with divergent selection on flowering time. 

  • 302.
    Madec, Camille
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Hagenblad, Jenny
    Linköping University, Department of Physics, Chemistry and Biology.
    Ehrlén, Johan
    Stockholm University, Department of Ecology, Environment and Plant Sciences.
    Ågren, Jon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Genetic diversity and structure of the declining herb Primula farinosa across different spatial scalesManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Habitat fragmentation and reduced population sizes are important threats to biodiversity. These changes increase the influence of genetic drift and are therefore expected to lead to reduced genetic diversity and increased population differentiation. We analysed patterns of genetic variation in the declining herb Primula farinosa in Sweden. On the mainland, P. farinosa has scattered, isolated occurrences due to habitat fragmentation, whereas on the island of Öland, southeast Sweden, the species remains common. On Öland, populations were sampled on both shallow soils, where fluctuations in population size are substantial, and on deep soils, where populations are more stable. Genetic diversity was investigated at 12 putatively neutral microsatellite loci and at a floral display locus influencing plant fitness. Genetic diversity was found to be lower and more strongly structured on the mainland than on Öland, which is consistent with lower gene flow and increased influence of genetic drift in mainland than in Öland populations. On Öland, genetic diversity was not related to soil depth, suggesting that differences in the magnitude of fluctuations in population size are less important for the structuring of genetic variation in P. farinosa. Moreover, population differentiation was stronger at the floral display locus compared to microsatellite loci, consistent with divergent selection acting on floral display on Öland. Taken together, our findings indicate that to maintain genetic diversity in P. farinosa, management should promote gene flow among populations and variation in the direction of selection on floral display.

  • 303. Madrinan, Santiago
    et al.
    Cortés, Andres
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Richardson, James E.
    Páramo is the world’s fastest evolving and coolest biodiversity hotspot2013Inngår i: Frontiers in Genetics, ISSN 1664-8021, E-ISSN 1664-8021, Vol. 4, s. 192-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Understanding the processes that cause speciation is a key aim of evolutionary biology. Lineages or biomes that exhibit recent and rapid diversification are ideal model systems for determining these processes. Species rich biomes reported to be of relatively recent origin, i.e., since the beginning of the Miocene, include Mediterranean ecosystems such as the California Floristic Province, oceanic islands such as the Hawaiian archipelago and the Neotropical high elevation ecosystem of the Páramos. Páramos constitute grasslands above the forest tree-line (at elevations of c. 2800–4700 m) with high species endemism. Organisms that occupy this ecosystem are a likely product of unique adaptations to an extreme environment that evolved during the last three to five million years when the Andes reached an altitude that was capable of sustaining this type of vegetation. We compared net diversification rates of lineages in fast evolving biomes using 73 dated molecular phylogenies. Based on our sample, we demonstrate that average net diversification rates of Páramo plant lineages are faster than those of other reportedly fast evolving hotspots and that the faster evolving lineages are more likely to be found in Páramos than the other hotspots. Páramos therefore represent the ideal model system for studying diversification processes. Most of the speciation events that we observed in the Páramos (144 out of 177) occurred during the Pleistocene possibly due to the effects of species range contraction and expansion that may have resulted from the well-documented climatic changes during that period. Understanding these effects will assist with efforts to determine how future climatic changes will impact plant populations.

  • 304. Magyari, Eniko K.
    et al.
    Major, Agnes
    Balint, Miklos
    Nedli, Judit
    Braun, Mihaly
    Racz, Istvan
    Parducci, Laura
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Population dynamics and genetic changes of Picea abies in the South Carpathians revealed by pollen and ancient DNA analyses2011Inngår i: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 11, s. 66-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Studies on allele length polymorphism designate several glacial refugia for Norway spruce (Picea abies) in the South Carpathian Mountains, but infer only limited expansion from these refugia after the last glaciation. To better understand the genetic dynamics of a South Carpathian spruce lineage, we compared ancient DNA from 10,700 and 11,000-year-old spruce pollen and macrofossils retrieved from Holocene lake sediment in the Retezat Mountains with DNA extracted from extant material from the same site. We used eight primer pairs that amplified short and variable regions of the spruce cpDNA. In addition, from the same lake sediment we obtained a 15,000-years-long pollen accumulation rate (PAR) record for spruce that helped us to infer changes in population size at this site. Results: We obtained successful amplifications for Norway spruce from 17 out of 462 pollen grains tested, while the macrofossil material provided 22 DNA sequences. Two fossil sequences were found to be unique to the ancient material. Population genetic statistics showed higher genetic diversity in the ancient individuals compared to the extant ones. Similarly, statistically significant Ks and Kst values showed a considerable level of differentiation between extant and ancient populations at the same loci. Lateglacial and Holocene PAR values suggested that population size of the ancient population was small, in the range of 1/10 or 1/5 of the extant population. PAR analysis also detected two periods of rapid population growths (from ca. 11,100 and 3900 calibrated years before present (cal yr BP)) and three bottlenecks (around 9180, 7200 and 2200 cal yr BP), likely triggered by climatic change and human impact. Conclusion: Our results suggest that the paternal lineages observed today in the Retezat Mountains persisted at this site at least since the early Holocene. Combination of the results from the genetic and the PAR analyses furthermore suggests that the higher level of genetic variation found in the ancient populations and the loss of ancient allele types detected in the extant individuals were likely due to the repeated bottlenecks during the Holocene; however our limited sample size did not allow us to exclude sampling effect. This study demonstrates how past population size changes inferred from PAR records can be efficiently used in combination with ancient DNA studies. The joint application of palaeoecological and population genetics analyses proved to be a powerful tool to understand the influence of past population demographic changes on the haplotype diversity and genetic composition of forest tree species.

  • 305. Mahmoudi Shamsabad, M
    et al.
    Assadi, M
    Parducci, Laura
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Impact of climate change implies the northward shift in distribution of the Irano-Turanian subalpine species complex Acanthophyllum squarrosum2018Inngår i: Journal of Asia-Pacific Biodiversity, ISSN 2287-884X, Vol. 11, nr 4, s. 566-572Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this study, we used maximum entropy modeling to predict the climate changeeffects on the distribution range of a subalpine steppe flora species complex, Acanthophyllum squarrosum (Caryophyllaceae). We used data from four different models, with two representative concentration pathways of climate scenarios in modern time, 2030, 2070 and 2080. Our results showed that A. squarrosum has a suitable habitat in ca. 1 million km² (33% of our study area) and will likely experience a northward shift, gaining new habitat in Azerbaijan, Armenia and North of Afghanistan in the near decades. Maxent model predicts A. squarrosum complex populations from southern Iran to be under treat of extinction, especially at lower altitudes regions and this prediction may concern other subalpine species found in the same region. Among the climatic variables investigated, annual mean temperature, and precipitation of warmest and coldest quarter were those that mostly affected A. squarrosum complex distribution.

  • 306.
    Mazziotta, Adriano
    et al.
    Stockholm Univ, Stockholm Resilience Ctr, Stockholm, Sweden;Swedish Univ Agr Sci, Swedish Species Informat Ctr, Box 7007, SE-75007 Uppsala, Sweden.
    Granath, Gustaf
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Rydin, Håkan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Bengtsson, Fia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Norberg, Jon
    Stockholm Univ, Stockholm Resilience Ctr, Stockholm, Sweden.
    Scaling functional traits to ecosystem processes: Towards a mechanistic understanding in peat mosses2019Inngår i: Journal of Ecology, ISSN 0022-0477, E-ISSN 1365-2745, Vol. 107, nr 2, s. 843-859Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The role of trait trade-offs and environmental filtering in explaining the variability in functional traits and ecosystem processes has received considerable attention for vascular plants but less so for bryophytes. Thus, we do not know whether the same forces also shape the phenotypic variability of bryophytes. Here, we assess how environmental gradients and trade-offs shape functional traits and subsequently ecosystem processes for peat mosses (Sphagnum), a globally important plant genus for carbon accumulation. We used piecewise Structural Equation Modeling (SEM) to understand how environmental gradients influence vital processes across levels of biological organization. We gathered data on functional traits for 15 globally important Sphagnum species covering a wide range of ecological preferences. Phenotypes lie along well-established axes of the plant economic spectrum characterizing trade-offs between vital physiological functions. Using SEM, we clarified the mechanisms of trait covariation and scaling to ecosystem processes. We tested whether peat mosses, like vascular plants, constrain trait variability between a fast turnover strategy based on resource acquisition via fast traits and processes, and a strategy of resource conservation, via slow traits and processes. We parameterized a process-based model estimating ecosystem processes linking environmental drivers with architectural and functional traits. In our SEM approach the amount of variance explained varied substantially (0.29 <= R-2 <= 0.82) among traits and processes in Sphagnum, and the model could predict some of them with high to intermediate accuracy for an independent dataset. R-2 variability was mainly explained by traits and species identity, and poorly by environmental filtering. Some Sphagnum species avoid the stress caused by periodic desiccation in hollows via resource acquisition based on fast photosynthesis and growth, while other species are adapted to grow high above the water-table on hummocks by slow physiological traits and processes to conserve resources. Synthesis.We contribute to a unified theory generating individual fitness, canopy dynamics and ecosystem processes from trait variation. As for vascular plants, the functional traits in the Sphagnum economic spectrum are linked into an integrated phenotypic network partly filtered by the environment and shaped by trade-offs in resource acquisition and conservation.

  • 307.
    Mendoza, Sandra Petrone
    et al.
    Uppsala universitet, Science for Life Laboratory, SciLifeLab. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Lascoux, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Glemin, Sylvain
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab. Univ Montpellier, Inst Sci Evolu, CNRS, ISEM,EPHE,IRD,UMR 5554, Montpellier, France.
    Competitive ability of Capsella species with different mating systems and ploidy levels2018Inngår i: Annals of Botany, ISSN 0305-7364, E-ISSN 1095-8290, Vol. 121, nr 6, s. 1257-1264Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background and Aims

    Capsella is a model genus for studying the transition from outcrossing to selfing, with or without change in ploidy levels. The genomic consequences and changes in reproductive traits (selfing syndrome) associated with these shifts have been studied in depth. However, potential ecological divergence among species of the genus has not been determined. Among ecological traits, competitive ability could be relevant for selfing evolution, as selfing has been shown to be statistically associated with reduced competitiveness in a recent meta-analysis.

    Methods

    We assessed the effect of competition on three Capsella species differing in their mating system and ploidy level. We used an experimental design where fitness related traits were measured in focal individuals with and without competitors.

    Key Results

    The diploid selfer (C. rubella) was most sensitive to competition, whereas the tetraploid selfer (C. bursa-pastoris) performed the best, with the diploid outcrosser (C. grandiflora) being intermediate.

    Conclusions

    These results add to the detailed characterization of Capsella species and highlight the possible roles of ecological context and ploidy in the evolutionary trajectories of selfing species.

  • 308.
    Menzel, Mandy
    et al.
    Lund Univ, Lund, Sweden.
    Sletvold, Nina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Ågren, Jon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Hansson, Bengt
    Lund Univ, Lund, Sweden.
    Inbreeding Affects Gene Expression Differently in Two Self-Incompatible Arabidopsis lyrata Populations with Similar Levels of Inbreeding Depression2015Inngår i: Molecular biology and evolution, ISSN 0737-4038, E-ISSN 1537-1719, Vol. 32, nr 8, s. 2036-2047Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Knowledge of which genes and pathways are affected by inbreeding may help understanding the genetic basis of inbreeding depression, the potential for purging (selection against deleterious recessive alleles), and the transition from outcrossing to selfing. Arabidopsis lyrata is a predominantly self-incompatible perennial plant, closely related to the selfing model species A. thaliana. To examine how inbreeding affects gene expression, we compared the transcriptome of experimentally selfed and outcrossed A. lyrata originating from two Scandinavian populations that express similar inbreeding depression for fitness ((partial derivative approximate to 0.80). The number of genes significantly differentially expressed between selfed and outcrossed individuals were 2.5 times higher in the Norwegian population (approximate to 500 genes) than in the Swedish population (approximate to 200 genes). In both populations, a majority of genes were upregulated on selfing (approximate to 80%). Functional annotation analysis of the differentially expressed genes showed that selfed offspring were characterized by 1) upregulation of stress-related genes in both populations and 2) upregulation of photosynthesis-related genes in Sweden but downregulation in Norway. Moreover, we found that reproduction-and pollination-related genes were affected by inbreeding only in Norway. We conclude that inbreeding causes both general and population-specific effects. The observed common effects suggest that inbreeding generally upregulates rather than downregulates gene expression and affects genes associated with stress response and general metabolic activity. Population differences in the number of affected genes and in effects on the expression of photosynthesis-related genes show that the genetic basis of inbreeding depression can differ between populations with very similar levels of inbreeding depression.

  • 309.
    Milesi, Pascal
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Berlin, Mats
    The Forestry Research Institute of Sweden (Skogforsk), Uppsala, Sweden.
    Chen, Jun
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Orsucci, Marion
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Li, Lili
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Jansson, Gunnar
    The Forestry Research Institute of Sweden (Skogforsk), Uppsala, Sweden.
    Karlsson, Bo
    The Forestry Research Institute of Sweden (Skogforsk), Ekebo, Sweden.
    Lascoux, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Assessing the potential for assisted gene flow using past introduction of Norway spruce in southern Sweden: Local adaptation and genetic basis of quantitative traits in trees2019Inngår i: Evolutionary Applications, ISSN 1752-4571, E-ISSN 1752-4571, Vol. 12, nr 10, s. 1946-1959Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Norway spruce (Picea abies) is a dominant conifer species of major economic importance in northern Europe. Extensive breeding programs were established to improve phenotypic traits of economic interest. In southern Sweden, seeds used to create progeny tests were collected on about 3,000 trees of outstanding phenotype (‘plus’ trees) across the region. In a companion paper, we showed that some were of local origin but many were recent introductions from the rest of the natural range. The mixed origin of the trees together with partial sequencing of the exome of >1,500 of these trees and phenotypic data retrieved from the Swedish breeding program offered a unique opportunity to dissect the genetic basis of local adaptation of three quantitative traits (height, diameter and bud-burst) and assess the potential of assisted gene flow. Through a combination of multivariate analyses and genome-wide association studies, we showed that there was a very strong effect of geographical origin on growth (height and diameter) and phenology (bud-burst) with trees from southern origins outperforming local provenances. Association studies revealed that growth traits were highly polygenic and bud-burst somewhat less. Hence, our results suggest that assisted gene flow and genomic selection approaches could help to alleviate the effect of climate change on P. abies breeding programs in Sweden.

  • 310. Millett, J.
    et al.
    Foot, G. W.
    Svensson, Brita M.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Nitrogen deposition and prey nitrogen uptake control the nutrition of the carnivorous plant Drosera rotundifolia2015Inngår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 512, s. 631-636Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Nitrogen (N) deposition has important negative impacts on natural and semi-natural ecosystems, impacting on biotic interactions across trophic levels. Low-nutrient systems are particularly sensitive to changes in N inputs and are therefore more vulnerable to N deposition. Carnivorous plants are often part of these ecosystems partly because of the additional nutrients obtained from prey. We studied the impact of N deposition on the nutrition of the carnivorous plant Drosera rotundifolia growing on 16 ombrotrophic bogs across Europe. We measured tissue N, phosphorus (P) and potassium (K) concentrations and prey and root N uptake using a natural abundance stable isotope approach. Our aim was to test the impact of N deposition on D. rotundifolia prey and root N uptake, and nutrient stoichiometry. D. rotundifolia root N uptake was strongly affected by N deposition, possibly resulting in reduced N limitation. The contribution of prey N to the N contained in D. rotundifolia ranged from 20 to 60%. N deposition reduced the maximum amount of N derived from prey, but this varied below this maximum. D. rotundifolia tissue N concentrations were a product of both root N availability and prey N uptake. Increased prey N uptake was correlated with increased tissue P concentrations indicating uptake of P from prey. N deposition therefore reduced the strength of a carnivorous plant prey interaction, resulting in a reduction in nutrient transfer between trophic levels. We suggest that N deposition has a negative impact on D. rotundifolia and that responses to N deposition might be strongly site specific.

  • 311. Millett, J.
    et al.
    Svensson, Brita M.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Newton, J.
    Rydin, Håkan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Reliance on prey-derived nitrogen by the carnivorous plant Drosera rotundifolia decreases with increasing nitrogen deposition2012Inngår i: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 195, nr 1, s. 182-188Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Carnivory in plants is presumed to be an adaptation to a low-nutrient environment. Nitrogen (N) from carnivory is expected to become a less important component of the N budget as root N availability increases. Here, we investigated the uptake of N via roots versus prey of the carnivorous plant Drosera rotundifolia growing in ombrotrophic bogs along a latitudinal N deposition gradient through Sweden, using a natural abundance stable isotope mass balance technique. Drosera rotundifolia plants receiving the lowest level of N deposition obtained a greater proportion of N from prey (57%) than did plants on bogs with higher N deposition (22% at intermediate and 33% at the highest deposition). When adjusted for differences in plant mass, this pattern was also present when considering total prey N uptake (66, 26 and 26 mu g prey N per plant at the low, intermediate and high N deposition sites, respectively). The pattern of mass-adjusted root N uptake was opposite to this (47, 75 and 86 mu g N per plant). Drosera rotundifolia plants in this study switched from reliance on prey N to reliance on root-derived N as a result of increasing N availability from atmospheric N deposition.

  • 312.
    Millett, Jonathan
    et al.
    Loughborough Univ Technol, Ctr Hydrol & Ecosyst Sci, Dept Geog, Loughborough, Leics, England..
    Foot, George W.
    Loughborough Univ Technol, Ctr Hydrol & Ecosyst Sci, Dept Geog, Loughborough, Leics, England.;Univ Cambridge, Dept Plant Sci, Cambridge, England..
    Thompson, Julia C.
    Loughborough Univ Technol, Ctr Hydrol & Ecosyst Sci, Dept Geog, Loughborough, Leics, England..
    Svensson, Brita
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Geographic variation in Sundew (Drosera) leaf colour: plant-plant interactions counteract expected effects of abiotic factors2018Inngår i: Journal of Biogeography, ISSN 0305-0270, E-ISSN 1365-2699, Vol. 45, nr 3, s. 582-592Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: To identify geographic patterns in leaf colour of roundleaved sundew (Drosera rotundifolia) growing on ombrotrophic (rain fed) bogs across Europe and establish the controls over these patterns. Location: North-west Europe. Taxon: Angiosperms, Drosera rotundifolia. Methods: We measured leaf colour of D. rotundifolia plants growing on 24 ombrotrophic bogs across north-west Europe covering 26.4 degrees of longitude and 21.1 degrees of latitude. We measured the height and cover of co-occurring vascular plant vegetation and the amount of incident light intercepted by the vegetation canopy. We determined the role of abiotic variables in controlling the patterns found. In a separate experimental study, we manipulated plant-plant interactions with D. rotundifolia by removing aboveground vascular plant vegetation and monitoring leaf colour over a single summer. Results: Drosera rotundifolia leaf colour varied between bogs. Leaves were redder in northern latitudes and eastern longitudes, and in sites/plots with lower canopy influence, lower nutrient deposition, and a more continental climate. Canopy influence was greater on sites in southern latitudes, eastern longitudes, and with higher nutrient deposition, longer growing seasons and a more maritime climate. Nutrient deposition was higher at more southerly latitudes, eastern sites had a more continental climate, and southern and western sites had warmer and longer growing seasons. In the insitu experiment, leaves became more red when canopy light transmission was increased by removing vegetation, but not when shade net was subsequently added to reduce light transmission. Main Conclusion: Geographic variation in Drosera rotundifolia leaf colour is strongly affected by its light environment, mediated by plant-plant interactions, but leaf colour is also affected by other abiotic factors. The relative importance of biotic and abiotic factors in determining geographic patterns in traits, and also species responses to environmental change, might depend on the growth form and competitive ability of a species.

  • 313. Mimura, Makiko
    et al.
    Mishima, Misako
    Lascoux, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Yahara, Tetsukazu
    Range shift and introgression of the rear and leading populations in two ecologically distinct Rubus species2014Inngår i: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 14, s. 209-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: The margins of a species' range might be located at the margins of a species' niche, and in such cases, can be highly vulnerable to climate changes. They, however, may also undergo significant evolutionary changes due to drastic population dynamics in response to climate changes, which may increase the chances of isolation and contact among species. Such species interactions induced by climate changes could then regulate or facilitate further responses to climatic changes. We hypothesized that climate changes lead to species contacts and subsequent genetic exchanges due to differences in population dynamics at the species boundaries. We sampled two closely related Rubus species, one temperate (Rubus palmatus) and the other subtropical (R. grayanus) near their joint species boundaries in southern Japan. Coalescent analysis, based on molecular data and ecological niche modelling during the Last Glacial Maximum (LGM), were used to infer past population dynamics. At the contact zones on Yakushima (Yaku Island), where the two species are parapatrically distributed, we tested hybridization along altitudinal gradients. Results: Coalescent analysis suggested that the southernmost populations of R. palmatus predated the LGM (similar to 20,000 ya). Conversely, populations at the current northern limit of R. grayanus diverged relatively recently and likely represent young outposts of a northbound range shift. These population dynamics were partly supported by the ensemble forecasting of six different species distribution models. Both past and ongoing hybridizations were detected near and on Yakushima. Backcrosses and advanced-generation hybrids likely generated the clinal hybrid zones along altitudinal gradients on the island where the two species are currently parapatrically distributed. Conclusions: Climate oscillations during the Quaternary Period and the response of a species in range shifts likely led to repeated contacts with the gene pools of ecologically distinct relatives. Such species interactions, induced by climate changes, may bring new genetic material to the marginal populations where species tend to experience more extreme climatic conditions at the margins of the species distribution.

  • 314. Mitchell, E.
    et al.
    Gilbert, D.
    Buttler, A.
    Grosvernier, P.
    Albinsson, C.
    Rydin, Håkan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Hoosbeek, M.R.
    Heijmans, M.
    Greenup, A.
    Foot, J.
    Saarinen, T.
    Vasander, H.
    Gobat, J.-M.
    Can testate amoebae (Protozoa) and other microorganisms help to overcome biogeographic bias in large scale global change research?2001Inngår i: Advances in Global Change Research, Vol. 9, Springer , 2001Kapittel i bok, del av antologi (Fagfellevurdert)
  • 315. Moe, S. R.
    et al.
    Rutina, L.
    Hytteborn, Håkan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Du Toit, J. T.
    Impala as Controllers of Elephant-Driven Change within a Savanna Ecosystem2014Inngår i: Elephants and Savanna Woodland Ecosystems: A Study from Chobe National Park, Botswana / [ed] Christina Skarpe, Johan T. du Toit and Stein R. Moe, Wiley-Blackwell, 2014, s. 154-171Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    To understand ecosystem structure and dynamics we need more knowledge of how common species affect ecosystem dynamics. In this context, impala are especially interesting in the Chobe ecosystem, where they are now common but were much less so just a few decades ago. The chapter uses the Chobe ecosystem as a case-study to explore the possibility that the recovery of the elephant population has created habitat that favours impala. The authors hypothesise that, following changes in plant structure and species composition along the Chobe river caused by increasing numbers of elephant, the impala population grew substantially and is currently preventing the shrubland from reverting to its previous woodland state. The conceptual framework used in the chapter is that of Pickett et al., in which elephants function as agents responsible for the change in state. Species other than impala can also play a role in seedling predation in African Savannas.

  • 316.
    Moor, Helen
    et al.
    Stockholm Univ, Stockholm Resilience Ctr, Kraftriket 2B, SE-10691 Stockholm, Sweden.
    Rydin, Håkan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Hylander, Kristoffer
    Department of Ecology, Environment and Plant Sciences, Stockholm University, , Stockholm, Sweden.
    Nilsson, Mats B
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, , Umeå, Sweden.
    Lindborg, Regina
    Department of Physical Geography, Stockholm University, , Stockholm, Sweden.
    Norberg, Jon
    Stockholm Resilience Centre, Stockholm University, , Stockholm, Sweden.
    Towards a trait-based ecology of wetland vegetation2017Inngår i: Journal of Ecology, ISSN 0022-0477, E-ISSN 1365-2745, Vol. 105, nr 6, s. 1623-1635Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    1. Functional traits mechanistically capture plant responses to environmental gradients as well asplant effects on ecosystem functioning. Yet most trait-based theory stems from terrestrial systemsand extension to other habitats can provide new insights.

    2. Wetlands differ from terrestrial systems in conditions (e.g. soil water saturation, anoxia, pHextremes), plant adaptations (e.g. aerenchyma, clonality, ubiquity of bryophytes) and important pro-cesses (e.g. denitrificati on, peat accumulation, methane emission). Wetland plant adaptations andtrait (co-)variation can be situated along major plant trait trade-off axes (e.g. the resource economicsspectrum), but soil saturation represents a complex stress gradient beyond a simple extension ofcommonly studied water availability gradi ents.

    3. Traits that affect ecosystem functioning overlap with patterns in terrestrial systems . But wetland-specific traits that mediate plant effects on soil redox conditions, microbial communities and onwater flow, as well as trait spectra of mosses, vary among wetland types.

    4. Synthesis. With increasing availability of quantitative plant traits a trait-based ecology of wetlandsis emerging, with the potential to advance process-based understanding and prediction. We providean inte ractive cause-and-effect framework that may guide research efforts to disentangle the multipleinteracti ng processes involved in scaling from environmental conditions to ecosystem functioni ngvia plant communities.

  • 317.
    Moore, Paul A.
    et al.
    McMaster Univ, Sch Geog & Earth Sci, 1280 Main St West, Hamilton, ON L8S 4K1, Canada.
    Lukenbach, Maxwell C.
    McMaster Univ, Sch Geog & Earth Sci, 1280 Main St West, Hamilton, ON L8S 4K1, Canada;Univ Alberta, Dept Earth & Atmospher Sci, Edmonton, AB T6G 2E3, Canada.
    Thompson, Dan K.
    Nat Resources Canada, Northern Forestry Ctr, Canadian Forest Serv, Edmonton, AB T6H 3S5, Canada.
    Kettridge, Nick
    Univ Birmingham, Sch Geog Earth & Environm Sci, Birmingham B15 2TT, W Midlands, England.
    Granath, Gustaf
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Waddington, James M.
    McMaster Univ, Sch Geog & Earth Sci, 1280 Main St West, Hamilton, ON L8S 4K1, Canada.
    Assessing the peatland hummock-hollow classification framework using high-resolution elevation models: implications for appropriate complexity ecosystem modeling2019Inngår i: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 16, nr 18, s. 3491-3506Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The hummock-hollow classification framework used to categorize peatland ecosystem microtopography is pervasive throughout peatland experimental designs and current peatland ecosystem modeling approaches. However, identifying what constitutes a representative hummock-hollow pair within a site and characterizing hummock-hollow variability within or between peatlands remains largely unassessed. Using structure from motion (SfM), high-resolution digital elevation models (DEMs) of hummock-hollow microtopography were used to (1) examine how much area needs to be sampled to characterize site-level microtopographic variation; and (2) examine the potential role of microtopographic shape/structure on biogeochemical fluxes using plot-level data from nine northern peatlands. To capture 95% of site-level microtopographic variability, on average, an aggregate sampling area of 32 m(2) composed of 10 randomly located plots was required. Both site(i.e. transect data) and plot-level (i.e. SfM-derived DEM) results show that microtopographic variability can be described as a fractal at the submeter scale, where contributions to total variance are very small below a 0.5 m length scale. Microtopography at the plot level was often found to be non-bimodal, as assessed using a Gaussian mixture model (GMM). Our findings suggest that the non-bimodal distribution of microtopography at the plot level may result in an undersampling of intermediate topographic positions. Extended to the modeling domain, an underrepresentation of intermediate microtopographic positions is shown to lead to potentially large flux biases over a wide range of water table positions for ecosystem processes which are non-linearly related to water and energy availability at the moss surface. Moreover, our simple modeling results suggest that much of the bias can be eliminated by representing microtopography with several classes rather than the traditional two (i.e. hummock/hollow). A range of tools examined herein can be used to easily parameterize peatland models, from GMMs used as simple transfer functions to spatially explicit fractal landscapes based on simple power-law relations between microtopographic variability and scale.

  • 318.
    Moritz, Kim K.
    et al.
    Swedish Univ Agr Sci, Dept Ecol, POB 7044, SE-75007 Uppsala, Sweden..
    Bjorkman, Christer
    Swedish Univ Agr Sci, Dept Ecol, POB 7044, SE-75007 Uppsala, Sweden..
    Parachnowitsch, Amy L.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Stenberg, Johan A.
    Swedish Univ Agr Sci, Dept Plant Protect Biol, Alnarp, Sweden..
    Plant sex effects on insect herbivores and biological control in a Short Rotation Coppice willow2017Inngår i: Biological control (Print), ISSN 1049-9644, E-ISSN 1090-2112, Vol. 115, s. 30-36Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the wild, plant sex can affect plant-herbivore interactions and higher trophic levels, including natural enemies of the herbivores. However, the possibility of manipulating plant sex to improve biological control and reduce herbivory in domesticated dioecious crops remains unexplored. The dioecious bioenergy crop, Salix viminalis, is often planted in monoclonal, and thus monosexual, fields. We investigated whether using plant clones of either sex, or mixing plants of both sexes, reduced the performance and abundance of the herbivorous pest insect Phratora vulgatissima and its main natural enemy, Anthocoris nemorum, and whether predation was affected. The herbivore laid more eggs, and the predator survived longer, on female plants in the lab. However, these effects did not translate into differences in predation rates in laboratory experiments or differential insect abundances on plants of either sex or plantation sex composition in the field. Plant genotype did have a significant effect on insect abundances, but this was due to plant traits other than sex. The results indicate that manipulating plant sex will not lead to improved biological control or reduced insect herbivory in S. viminalis energy forestry, but suggest that a focus on plant genotypic differences offers promise for improving management practices.

  • 319.
    Moritz, Kim K.
    et al.
    Swedish Univ Agr Sci, Dept Ecol, POB 7044, SE-75007 Uppsala, Sweden..
    Björkman, Christer
    Swedish Univ Agr Sci, Dept Ecol, POB 7044, SE-75007 Uppsala, Sweden..
    Parachnowitsch, Amy L.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Stenberg, Johan A.
    Swedish Univ Agr Sci, Dept Plant Protect Biol, POB 102, SE-23053 Alnarp, Sweden..
    Female Salix viminalis are more severely infected by Melampsora spp. but neither sex experiences associational effects2016Inngår i: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, nr 4, s. 1154-1162Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Associational effects of plant genotype or species on plant biotic interactions are common, not least for disease spread, but associational effects of plant sex on interactions have largely been ignored. Sex in dioecious plants can affect biotic interactions with herbivores and pollinators; however, its effects on plant-pathogen interactions are understudied and associational effects are unknown. In a replicated field experiment, we assessed Melampsora spp. leaf rust infection in monosexual and mixed sex plots of dioecious Salix viminalis L. to determine whether plant sex has either direct or associational effects on infection severity. We found no differences in Melampsora spp. infection severity among sexual monocultures and mixtures in our field experiment. However, female plants were overall more severely infected. In addition, we surveyed previous studies of infection in S.viminalis clones and reevaluated the studies after we assigned sex to the clones. We found that females were generally more severely infected, as in our field study. Similarly, in a survey of studies on sex-biased infection in dioecious plants, we found more female-biased infections in plant-pathogen pairs. We conclude that there was no evidence for associational plant sex effects of neighboring conspecifics for either females or males on infection severity. Instead, plant sex effects on infection act at an individual plant level. Our findings also suggest that female plants may in general be more severely affected by fungal pathogens than males.

  • 320.
    Moritz, Kim K.
    et al.
    Swedish Univ Agr Sci, Dept Ecol, POB 7044, SE-75007 Uppsala, Sweden..
    Parachnowitsch, Amy L.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Julkunen-Tiitto, Riitta
    Univ Eastern Finland, Dept Biol, POB 111, FIN-80101 Joensuu, Finland..
    Björkman, Christer
    Swedish Univ Agr Sci, Dept Ecol, POB 7044, SE-75007 Uppsala, Sweden..
    Ayres, Matthew P.
    Dartmouth Coll, Dept Biol Sci, Hanover, NH 03755 USA..
    Stenberg, Johan A.
    Swedish Univ Agr Sci, Dept Plant Protect Biol, POB 102, SE-23053 Alnarp, Sweden..
    Roe deer prefer mixed-sex willow stands over monosexual stands but do not discriminate between male and female plants2018Inngår i: Environmental and Experimental Botany, ISSN 0098-8472, E-ISSN 1873-7307, Vol. 146, s. 62-67Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Male and female plants of dioecious species often experience differential herbivory, possibly due to differences in defences such as secondary metabolite composition or nutritional quality. These plant sex effects on herbivory have been extensively studied for plant individuals, but not for stands/populations. For mobile herbivores, such as deer, stands may be a more relevant scale to study than individual plants. We predicted that male Salts viminalis plants should be subject to more extensive roe deer (Capreolus capreolus) browsing than female plants due to weaker defence in male plants. Furthermore, we expected that mixed-sex stands should experience more damage than monosexual stands due to positive effects of diet mixing on browsing by generalists. We tested for differences in roe deer browsing in plots that were either monosexual male or female, or a mix of male and female plants in a replicated field experiment. Roe deer browsing was estimated after one growth season with heavy herbivory. We also measured plant secondary metabolite concentrations and nitrogen content in leaves from all experimental clones to test the assumption that the sexes differed in defence or nutrients. Mixed-sex plots were more extensively browsed than monosexual plots. However, there was no difference in browsing between male and female plant individuals within mixed-sex plots or between monosexual plots. Plant secondary metabolite profiles differed between male and female plants, while nitrogen content did not. Our findings suggest that the diversified plant secondary metabolite contents of mixed-sex plots may have led to more extensive herbivory. Higher browsing of plant sex mixes may impact both natural and commercial S. viminalis stands with different sex ratios.

  • 321.
    Muola, Anne
    et al.
    Abo Akad Univ, Environm & Marine Biol, Turku, Finland.;Swedish Univ Agr Sci, Dept Ecol, Uppsala, Sweden..
    Weber, Daniela
    Swedish Univ Agr Sci, Dept Plant Protect Biol, Alnarp, Sweden..
    Malm, Lisa E.
    Swedish Univ Agr Sci, Dept Ecol, Uppsala, Sweden..
    Egan, Paul A.
    Swedish Univ Agr Sci, Dept Plant Protect Biol, Alnarp, Sweden..
    Glinwood, Robert
    Swedish Univ Agr Sci, Dept Crop Prod Ecol, Uppsala, Sweden..
    Parachnowitsch, Amy L.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Stenberg, Johan A.
    Swedish Univ Agr Sci, Dept Plant Protect Biol, Alnarp, Sweden..
    Direct and Pollinator-Mediated Effects of Herbivory on Strawberry and the Potential for Improved Resistance2017Inngår i: Frontiers in Plant Science, ISSN 1664-462X, E-ISSN 1664-462X, Vol. 8, artikkel-id 823Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The global decline in pollinators has partly been blamed on pesticides, leading some to propose pesticide-free farming as an option to improve pollination. However, herbivores are likely to be more prevalent in pesticide-free environments, requiring knowledge of their effects on pollinators, and alternative crop protection strategies to mitigate any potential pollination reduction. Strawberry leaf beetles (SLB) Galerucella spp. are important strawberry pests in Northern Europe and Russia. Given that SLB attack both leaf and flower tissue, we hypothesized pollinators would discriminate against SLB-damaged strawberry plants (Fragaria vesca, cultivar 'Rügen'), leading to lower pollination success and yield. In addition we screened the most common commercial cultivar 'Rugen' and wild Swedish F. vesca genotypes for SLB resistance to assess the potential for inverse breeding to restore high SLB resistance in cultivated strawberry. Behavioral observations in a controlled experiment revealed that the local pollinator fauna avoided strawberry flowers with SLB-damaged petals. Low pollination, in turn, resulted in smaller more deformed fruits. Furthermore, SLB-damaged flowers produced smaller fruits even when they were hand pollinated, showing herbivore damage also had direct effects on yield, independent of indirect effects on pollination. We found variable resistance in wild woodland strawberry to SLB and more resistant plant genotypes than the cultivar 'Rugen' were identified. Efficient integrated pest management strategies should be employed to mitigate both direct and indirect effects of herbivory for cultivated strawberry, including high intrinsic plant resistance.

  • 322.
    Mälson, Kalle
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Plant responses after drainage and restoration in rich fens2008Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Rich fens are an important, but threatened, habitat type in the boreal landscape. In this thesis I have examined responses of rich fen vascular plants and bryophytes after drainage and restoration.

    The effects of drainage on the rich fen flora were observed in a long time study and the responses were rapid and drastic. During an initial stage a rapid loss of brown mosses was observed, followed by increases of sedges and early successional bryophytes, and later by an expansion of dominants. Initial effects of hydrological restoration showed that rewetting can promote re-establishment of an ecologically functional rich fen flora, but has to be combined with other treatments, such as mowing or surface disturbance.

    After restoration, re-establishment of locally extinct species may be hampered by dispersal limitations. To test if reintroductions could help to overcome dispersal limitations I performed transplantation studies with four common rich fens bryophytes to a rewetted site. The results showed that the species were able to establish, and that survival and growth were promoted by desiccation protection and liming.

    I further examined competition among three of the most common bryophytes in natural boreal rich fens that usually occur mixed in a mosaic pattern but show small but important microtopographical niche separation. The results indicate similar competitive abilities among the species, and no case of competitative exclusion occurred. The results help to explain the coexistence of these species under natural conditions with microtopographic variation and repeated small scale natural disturbances.

    Restoring a functional flora in drained rich fens is a complex task, which requires understanding of underlying causes of substrate degradation in combination with suitable restoration measures. The thesis suggests how the results can be used in practical restoration work, and also stresses the need for monitoring of restoration experiments over longer time.

    Delarbeid
    1. Long-term effects of drainage and initial effects of hydrological restoration on rich fen vegetation
    Åpne denne publikasjonen i ny fane eller vindu >>Long-term effects of drainage and initial effects of hydrological restoration on rich fen vegetation
    2008 (engelsk)Inngår i: Applied Vegetation Science, ISSN 1402-2001, E-ISSN 1654-109X, Vol. 11, nr 1, s. 99-106Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Questions: What vegetational changes does a boreal rich fen (alkaline fen) undergo during a time period of 24 years after drainage? How is plant species richness affected, and what are the changes in composition of ecological groups of species? Is it possible to recover parts of the original flora by rewetting the rich fen? Which are the initial vegetation changes in the flora after rewetting? What are the major challenges for restoration of rich fen flora after rewetting? Location: Eastern central Sweden, southern boreal vegetational zone. Previously rich fen site, drained for forestry purposes during 1978-1979. The site was hydrologically restored (rewetted) in 2002. Method: Annual vegetation survey in permanent plots during a period of 28 years. Results: There were three successional stages in the vegetational changes. In the first stage there was a rapid (< 5 years) loss of rich fen bryophytes. The second step was an increase of sedges and early successional bryophytes, which was followed by an increase of a few emerging dominants, such as Molinia caerulea, Betula pubescens and Sphagnum spp. After rewetting, there are indications of vegetation recovery, albeit at slow rates. Depending on, for instance, initial species composition different routes of vegetation change were observed in the flora after drainage, although after 24 years, species composition became more homogenous and dominated by a few species with high cover. Conclusion: Major changes have occurred after changes in the hydrology (drainage and rewetting) with a severe impact on the biodiversity among vascular plants and bryophytes. Several rich fen bryophytes respond quickly to the changes in water level (in contrast to vascular plants). The recovery after rewetting towards the original rich fen vegetation is slow, as delayed by substrate degradation, dispersal limitation and presence of dominant species.

    Emneord
    bryophyte, long-term study, mire, rewetting, succession, wetland restoration
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-97293 (URN)10.3170/2007-7-18329 (DOI)000252958300011 ()
    Tilgjengelig fra: 2008-05-16 Laget: 2008-05-16 Sist oppdatert: 2019-02-01
    2. Interspecific competition among rich fen bryophytes
    Åpne denne publikasjonen i ny fane eller vindu >>Interspecific competition among rich fen bryophytes
    (engelsk)Manuskript (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-97294 (URN)
    Tilgjengelig fra: 2008-05-16 Laget: 2008-05-16 Sist oppdatert: 2013-12-13
    3. Ditch blocking, soil disturbance and mowing as tools in rich fen restoration
    Åpne denne publikasjonen i ny fane eller vindu >>Ditch blocking, soil disturbance and mowing as tools in rich fen restoration
    (engelsk)Manuskript (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-97295 (URN)
    Tilgjengelig fra: 2008-05-16 Laget: 2008-05-16 Sist oppdatert: 2013-12-13
    4. The regeneration capabilities of bryophytes in rich fen restoration
    Åpne denne publikasjonen i ny fane eller vindu >>The regeneration capabilities of bryophytes in rich fen restoration
    2007 (engelsk)Inngår i: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 135, nr 3, s. 435-442Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Biodiversity in wetland habitats is strongly affected by drainage. In Sweden, rich fens (alkaline fens) have been particularly affected by drainage campaigns for forestry and conversion to agricultural land. Fragmentation of the landscape, invasion of tall vascular plants as well as Polytrichum and Sphagnum mosses and substrate degradation all lead to reduced plant diversity.

    We evaluated the recolonization potential of four characteristic rich fen bryophyte species that use to decrease rapidly after drainage (Scorpidium scorpioides, Scorpidium cossonii, Pseudocalliergon trifarium and Campylium stellatum) by performing transplantation studies with gametophyte fragments in recently hydrologically restored rich fens. In greenhouse and field experiments 1 cm fragments of all four species had a high survival rate and established well, especially after surface liming of the peat. A protective cover increased the colonization success and the growth potential of the added fragments. Even small alterations of the water level (5 cm) resulted in differences in biomass growth of the fragments of S. cossonii and C. stellatum. Our results show that it is possible to reintroduce bryophyte species lost after drainage using gametophyte fragments as propagules, and that these techniques seem feasible for a number of characteristic rich fen bryophytes. These findings will be of importance when methods for practical restoration of rich fens are developed.

    Emneord
    Brown mosses, Colonization, Dispersal limitation, Drainage, Liming, Peatland
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-97296 (URN)10.1016/j.biocon.2006.10.017 (DOI)000245695600015 ()
    Tilgjengelig fra: 2008-05-16 Laget: 2008-05-16 Sist oppdatert: 2019-02-01bibliografisk kontrollert
  • 323.
    Méndez, Marcos
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Karlsson, P. Staffan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Equivalence of three allocation currencies as estimates of reproductive allocation and somatic cost of reproduction in Pinguicula vulgaris2007Inngår i: Plant Biology, ISSN 1435-8603, E-ISSN 1438-8677, Vol. 9, nr 4, s. 462-468Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Which is the most appropriate currency (biomass, energy, water, or some mineral nutrient) for expressing resource allocation in plants has been repeatedly discussed. Researchers need to assess to which extent interindividual, interpopulational, or interspecific comparisons of resource allocation could be affected by the allocation currency chosen. The "currency issue" is relevant to at least three related aspects of resource allocation to reproduction: (a) reproductive allocation (RA), (b) size-dependence of reproductive allocation, and (c) somatic cost of reproduction (SCR). Empirical tests have mostly dealt with the first aspect only. We examined the equivalence of estimates for the three aspects above across three different allocation currencies (dry mass, N, P) in 11 populations of Pinguicula vulgaris. For RA we studied the equivalence of allocation currencies at three scales: among individuals of the same population, between populations of the same species, and among species. Equivalence of currencies in the ranking of RA for individuals within populations was high (R-s >= 0.43) and did not strongly decrease when comparing populations or species. Excepting for size-dependence of RA, ranking of RA, or SCR between populations was equivalent for biomass and N, but not for P. Our study gives two positive guidelines for empirical plant reproductive ecologists facing the "currency issue": (1) become increasingly concerned about the "currency issue" as you increase the scale of your comparison from individuals to populations to species, and (2) avoid estimating allocation in redundant currencies (biomass and N in our case) and choose preferentially "complementary" currencies that provide a broader view of allocation patterns (biomass and P in our case).

  • 324.
    Nemesio-Gorriz, Miguel
    et al.
    Swedish Univ Agr Sci, Dept Forest Mycol & Plant Pathol, S-75007 Uppsala, Sweden..
    Hammerbacher, Almuth
    Univ Pretoria, Forestry & Agr Biotechnol Inst, Dept Microbiol & Plant Pathol, ZA-0002 Pretoria, South Africa..
    Ihrmark, Katarina
    Swedish Univ Agr Sci, Dept Forest Mycol & Plant Pathol, S-75007 Uppsala, Sweden..
    Källman, Thomas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. BILS, Sci Life Lab, S-75237 Uppsala, Sweden..
    Olson, Åke
    Swedish Univ Agr Sci, Dept Forest Mycol & Plant Pathol, S-75007 Uppsala, Sweden..
    Lascoux, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Stenlid, Jan
    Swedish Univ Agr Sci, Dept Forest Mycol & Plant Pathol, S-75007 Uppsala, Sweden..
    Gershenzon, Jonathan
    Max Planck Inst Chem Ecol, Dept Biochem, D-07745 Jena, Germany..
    Elfstrand, Malin
    Swedish Univ Agr Sci, Dept Forest Mycol & Plant Pathol, S-75007 Uppsala, Sweden..
    Different Alleles of a Gene Encoding Leucoanthocyanidin Reductase (PaLAR3) Influence Resistance against the Fungus Heterobasidion parviporum in Picea abies2016Inngår i: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 171, nr 4, s. 2671-2681Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Despite the fact that fungal diseases are a growing menace for conifers in modern silviculture, only a very limited number of molecular markers for pathogen resistance have been validated in conifer species. A previous genetic study indicated that the resistance of Norway spruce (Picea abies) to Heterobasidion annosum s.l., a pathogenic basidiomycete species complex, is linked to a quantitative trait loci that associates with differences in fungal growth in sapwood (FGS) that includes a gene, PaLAR3, which encodes a leucoanthocyanidin reductase. In this study, gene sequences showed the presence of two PaLAR3 allelic lineages in P. abies. Higher resistance was associated with the novel allele, which was found in low frequency in the four P. abies populations that we studied. Norway spruce plants carrying at least one copy of the novel allele showed a significant reduction in FGS after inoculation with Heterobasidion parviporum compared to their half-siblings carrying no copies, indicating dominance of this allele. The amount of (+) catechin, the enzymatic product of PaLAR3, was significantly higher in bark of trees homozygous for the novel allele. Although we observed that the in vitro activities of the enzymes encoded by the two alleles were similar, we could show that allele-specific transcript levels were significantly higher for the novel allele, indicating that regulation of gene expression is responsible for the observed effects in resistance, possibly caused by differences in cis-acting elements that we observe in the promoter region of the two alleles.

  • 325. Nie, Xiang-Ping
    et al.
    Zie, Jenny
    Häubner, Norbert
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Tallmark, Bo
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Snoeijs, Pauline
    Why Baltic herring and sprat are weak conduits for astaxanthin from zooplankton to piscivorous fish2011Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 56, nr 3, s. 1155-1167Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Atlantic salmon living in the brackish Baltic Sea have lower muscle pigmentation than populations elsewhere. The pigment in question is the antioxidant and vitamin A precursor astaxanthin, which is synthesized by crustaceans from algal carotenoids. Baltic salmon feed nearly exclusively on the clupeids sprat and herring. To evaluate astaxanthin availability to salmon we assessed astaxanthin levels and isomeric composition in their prey fish. We also analyzed astaxanthin dynamics in the dominant piscivorous fish in the Baltic Sea, the Atlantic cod. The geometrical E-(trans-) and Z-(cis-) isomers were distributed selectively in fish tissues, with highest E : Z ratios in salmon gonads (82 : 18) and lowest in herring gonads (24 : 76). Sprat and herring are not ideal prey with respect to their high whole-body concentrations of Z-isomers, which have low bioavailability for salmon and cod. These Z-isomers predominantly accumulate in the clupeid gonads. A crucial mechanism for the transport of astaxanthin from clupeids to piscivores is the direct transfer of crustacean astaxanthin (mainly all-E) from the clupeid stomachs. Low stomach astaxanthin content in clupeids decreases total astaxanthin transfer to higher trophic levels. In autumn, herring stomachs (including contents) had 12.5 times lower astaxanthin concentrations than sprat stomachs, and herring had 2.8 times less whole-body all-E-astaxanthin (by weight) than sprat. These results confirm recent reports of starvation in the Baltic herring, which may further decrease astaxanthin levels in the Baltic salmon. Cod did not have lower astaxanthin levels than their Atlantic counterpart, which may be attributed to their lower need for astaxanthin and higher food diversity.

  • 326.
    Nilsson, L Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    The type material of Swedish bees (Hymenoptera, Apoidea) IV. Bees from Thomson’s collection2010Inngår i: Entomologisk Tidskrift, ISSN 0013-886X, Vol. 131, nr 1, s. 73-94Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This report presents the fourth part of the results of a taxonomic revision and examination of the actual, reputed or potential type material of bees of Swedish origin. Focus is on the status, depository, type locality, condition and history of name-bearing specimens. Here, 35 bee taxa based on material in the collection of the leading Swedish entomologist Carl Gustaf Thomson (1824 – 1899) have been examined. After a biographical sketch of Thomson and a summary of his contribution on bees and his legacy, lectotypes are designated for the specific taxa (bold= valid epithet) Colletes picistigma Thomson, 1872, Hylaeus clathratus Thomson, 1870, H. genalis Thomson, 1872, H. marginatus Thomson, 1870, Andrena curvungula Thomson, 1870, A. integra Thomson, 1870, A. morawitzi Thomson, 1872, A. nasalis Thomson, 1870, A. nigrospina Thomson, 1872, A. violascens Thomson, 1870, Sphecodes crassus Thomson, 1870, Megachile curvicrus Thomson, 1872 (now subspecies of M. nigriventris Schenck), M. lapponica Thomson, 1872 and Epeolus glacialis Alfken, 1913 (here identified as a distinct subspecies, stat. nov., of E. alpinus Friese). Already labelled but unpublished lectotypes of Hylaeus submarginatus Thomson, 1872, Andrena albo-fasciata Thomson, 1870, Epeolus productus Thomson, 1870 and E. rufipes Thomson, 1870 are validated. Further taxa examined (including more syntypes designated whenever located) are Andrena intermedia Thomson, 1870, Sphecodes pilifrons Thomson, 1870, S. puncticeps Thomson, 1870, S. reticulatus Thomson, 1870, Coelioxys obtusispina Thomson, 1872, Osmia claviventris Thomson, 1872 (now Hoplitis c.), O. truncatula Thomson, 1872 (now subspecies of O. leaiana (Kirby)), Nomada bifida Thomson, 1872, N. glabella Thomson, 1870, N. laeta Thomson, 1870, N. punctiscuta Thomson, 1870, N. 5-spinosa Thomson, 1870, N. rufilabris Thomson, 1870, N. villosa Thomson, 1870, Apathus lissonurus Thomson, 1872, Bombus arenicola Thomson, 1872 and B. brevigena Thomson, 1870 (now subspecies of B. wurflenii Radoszkowski). The typifications and validations define authentic material, type localities and establish correct synonymies, e.g., Andrena violascens Thomson is a synonym of A. fulvida Schenck, 1853.

  • 327.
    Nilsson, Tobias
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för biologisk grundutbildning.
    Pollination failure in traditionally managed hay meadows of low quality: Comparing two different pollination strategies2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Today traditionally managed wooded hay meadows only exist in small fractions of their former distributions. Because of the fragmentation and degeneration of hay meadows and the fact that pollinating insect diversity and abundance also are declining, pollination services in these habitats requires attention. To examine the pollination services in traditionally managed hay meadows I collected Ranunculus acris (Buttercup) in 20 meadows of varying quality on Gotland and evaluated the mean seed set and mean number of produced seeds per plant. I also collected Filipendula vulgaris (Dropwort) in 18 meadows and evaluated the mean seed set to be able to compare the pollination success of the insect pollinated R. acris with the wind pollinated F. vulgaris. A range of habitat variables were collected in the meadows and in older surveys to examine their relative impact on seed set. I found significantly higher seed set for R. acris in the meadows with higher habitat quality, than in meadows with lower quality. In contrast seed set in F. vulgaris was not related to habitat quality. The population density also seemed to play an important role in fertilization rate for R. acris, through increased seed set in high density areas, while plant height was positively correlated with number of produced seeds. For F. vulgaris seed set was positively correlated with moss cover, and number of seeds per plant was positively correlated with population density. These results suggest that reproductive success among insect pollinated plants are more sensitive to habitat degeneration than among wind pollinated plants. The status of pollination services in traditionally managed wooded hay meadows should be evaluated further.

  • 328.
    Noel, Elsa
    et al.
    Univ Paul Valery Montpellier, Univ Montpellier, CEFE, UMR 5175,CNRS,EPHE, 1919 Route Mende, F-34293 Montpellier 5, France..
    Jarne, Philippe
    Univ Paul Valery Montpellier, Univ Montpellier, CEFE, UMR 5175,CNRS,EPHE, 1919 Route Mende, F-34293 Montpellier 5, France..
    Glemin, Sylvain
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. Univ Montpellier, Inst Sci Evolut ISEM, UMR 5554, CNRS,IRD,EPHE, CC64,Pl Eugene Bataillon, F-34095 Montpellier, France.
    MacKenzie, Alicia
    Univ Paul Valery Montpellier, Univ Montpellier, CEFE, UMR 5175,CNRS,EPHE, 1919 Route Mende, F-34293 Montpellier 5, France..
    Segard, Adeline
    Univ Paul Valery Montpellier, Univ Montpellier, CEFE, UMR 5175,CNRS,EPHE, 1919 Route Mende, F-34293 Montpellier 5, France..
    Sarda, Violette
    Univ Paul Valery Montpellier, Univ Montpellier, CEFE, UMR 5175,CNRS,EPHE, 1919 Route Mende, F-34293 Montpellier 5, France..
    David, Patrice
    Univ Paul Valery Montpellier, Univ Montpellier, CEFE, UMR 5175,CNRS,EPHE, 1919 Route Mende, F-34293 Montpellier 5, France..
    Experimental Evidence for the Negative Effects of Self-Fertilization on the Adaptive Potential of Populations2017Inngår i: Current Biology, ISSN 0960-9822, E-ISSN 1879-0445, Vol. 27, nr 2, s. 237-242Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Self-fertilization is widely believed to be an "evolutionary dead end" [1, 2], increasing the risk of extinction [3] and the accumulation of deleterious mutations in genomes [4]. Strikingly, while the failure to adapt has always been central to the dead-end hypothesis [1, 2], there are no quantitative genetic selection experiments comparing the response to positive selection in selfing versus outcrossing populations. Here we studied the response to selection on a morphological trait in laboratory populations of a hermaphroditic, self fertile snail under either selfing or outcrossing. We applied both treatments to two types of populations: some having undergone frequent selfing and purged a substantial fraction of their mutation load in their recent history [5], and others continuously maintained under outcrossing. Populations with a history of outcrossing respond faster to selection than those that have experienced selfing. In addition, when self-fertilization occurs during selection, the response is initially fast but then rapidly slows, while outcrossing populations maintain their response throughout the experiment. This occurs irrespective of past selfing history, suggesting that high levels of inbreeding depression, contrary to expectation [6], do not set strong limits to the response to selection under inbreeding, at least at the timescale of a few generations. More surprisingly, phenotypic variance is consistently higher under selfing, although it quickly becomes less responsive to selection. This implies an increase in non-heritable variance, hence a breakdown of developmental canalization [7] under selfing. Our findings provide the first empirical support of the short-term positive and long-term negative effects of selfing on adaptive potential.

  • 329. Oakley, C. G.
    et al.
    Ågren, Jon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Schemske, D. W.
    Heterosis and outbreeding depression in crosses between natural populations of Arabidopsis thaliana2015Inngår i: Heredity, ISSN 0018-067X, E-ISSN 1365-2540, Vol. 115, nr 1, s. 73-82Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Understanding the causes and architecture of genetic differentiation between natural populations is of central importance in evolutionary biology. Crosses between natural populations can result in heterosis if recessive or nearly recessive deleterious mutations have become fixed within populations because of genetic drift. Divergence between populations can also result in outbreeding depression because of genetic incompatibilities. The net fitness consequences of between-population crosses will be a balance between heterosis and outbreeding depression. We estimated the magnitude of heterosis and outbreeding depression in the highly selfing model plant Arabidopsis thaliana, by crossing replicate line pairs from two sets of natural populations (C <-> R, B <-> S) separated by similar geographic distances (Italy <-> Sweden). We examined the contribution of different modes of gene action to overall differences in estimates of lifetime fitness and fitness components using joint scaling tests with parental, reciprocal F-1 and F-2, and backcross lines. One of these population pairs (C <-> R) was previously demonstrated to be locally adapted, but locally maladaptive quantitative trait loci were also found, suggesting a role for genetic drift in shaping adaptive variation. We found markedly different genetic architectures for fitness and fitness components in the two sets of populations. In one (C <-> R), there were consistently positive effects of dominance, indicating the masking of recessive or nearly recessive deleterious mutations that had become fixed by genetic drift. The other set (B <-> S) exhibited outbreeding depression because of negative dominance effects. Additional studies are needed to explore the molecular genetic basis of heterosis and outbreeding depression, and how their magnitudes vary across environments.

  • 330.
    Oakley, Christopher G.
    et al.
    Michigan State Univ, Dept Plant Biol, E Lansing, MI 48824 USA;Purdue Univ, Dept Bot & Plant Pathol, Ctr Plant Biol, W Lafayette, IN 47907 USA.
    Lundemo, Sverre
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. WWF Norway, Oslo, Norway.
    Ågren, Jon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Schemske, Douglas W.
    Michigan State Univ, Dept Plant Biol, WK Kellogg Biol Stn, E Lansing, MI 48824 USA.
    Heterosis is common and inbreeding depression absent in natural populations of Arabidopsis thaliana2019Inngår i: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 32, nr 6, s. 592-603Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The importance of genetic drift in shaping patterns of adaptive genetic variation in nature is poorly known. Genetic drift should drive partially recessive deleterious mutations to high frequency, and inter-population crosses may therefore exhibit heterosis (increased fitness relative to intra-population crosses). Low genetic diversity and greater genetic distance between populations should increase the magnitude of heterosis. Moreover, drift and selection should remove strongly deleterious recessive alleles from individual populations, resulting in reduced inbreeding depression. To estimate heterosis, we crossed 90 independent line pairs of Arabidopsis thaliana from 15 pairs of natural populations sampled across Fennoscandia and crossed an additional 41 line pairs from a subset of four of these populations to estimate inbreeding depression. We measured lifetime fitness of crosses relative to parents in a large outdoor common garden (8,448 plants in total) in central Sweden. To examine the effects of genetic diversity and genetic distance on heterosis, we genotyped parental lines for 869 SNPs. Overall, genetic variation within populations was low (median expected heterozygosity = 0.02), and genetic differentiation was high (median F-ST = 0.82). Crosses between 10 of 15 population pairs exhibited significant heterosis, with magnitudes of heterosis as high as 117%. We found no significant inbreeding depression, suggesting that the observed heterosis is due to fixation of mildly deleterious alleles within populations. Widespread and substantial heterosis indicates an important role for drift in shaping genetic variation, but there was no significant relationship between fitness of crosses relative to parents and genetic diversity or genetic distance between populations.

  • 331. Oakley, Christopher G.
    et al.
    Ågren, Jon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Atchison, Rachel A.
    Schemske, Douglas W.
    QTL mapping of freezing tolerance: links to fitness and adaptive trade-offs2014Inngår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 23, nr 17, s. 4304-4315Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Local adaptation, defined as higher fitness of local vs. nonlocal genotypes, is commonly identified in reciprocal transplant experiments. Reciprocally adapted populations display fitness trade-offs across environments, but little is known about the traits and genes underlying fitness trade-offs in reciprocally adapted populations. We investigated the genetic basis and adaptive significance of freezing tolerance using locally adapted populations of Arabidopsis thaliana from Italy and Sweden. Previous reciprocal transplant studies of these populations indicated that subfreezing temperature is a major selective agent in Sweden. We used quantitative trait locus (QTL) mapping to identify the contribution of freezing tolerance to previously demonstrated local adaptation and genetic trade-offs. First, we compared the genomic locations of freezing tolerance QTL to those for previously published QTL for survival in Sweden, and overall fitness in the field. Then, we estimated the contributions to survival and fitness across both field sites of genotypes at locally adaptive freezing tolerance QTL. In growth chamber studies, we found seven QTL for freezing tolerance, and the Swedish genotype increased freezing tolerance for five of these QTL. Three of these colocalized with locally adaptive survival QTL in Sweden and with trade-off QTL for overall fitness. Two freezing tolerance QTL contribute to genetic trade-offs across environments for both survival and overall fitness. A major regulator of freezing tolerance, CBF2, is implicated as a candidate gene for one of the trade-off freezing tolerance QTL. Our study provides some of the first evidence of a trait and gene that mediate a fitness trade-off in nature.

  • 332. Ohsawa, Takafumi
    et al.
    Tsuda, Yoshiaki
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Saito, Yoko
    Ide, Yuji
    The genetic structure of Quercus crispula in northeastern Japan as revealed by nuclear simple sequence repeat loci2011Inngår i: Journal of plant research, ISSN 0918-9440, E-ISSN 1618-0860, Vol. 124, nr 6, s. 645-654Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Previous studies have reached different discussions about the genetic variation and genetic structure of Quercus crispula populations in northeastern Japan. This is a common oak species in Eastern Asia. Some studies have suggested that the populations in northeastern Japan were derived from those remaining in the southwest after the last glacial maximum (LGM), whilst other studies have found evidence that populations persisted in northeastern Japan during the LGM. Using seven highly polymorphic nuclear simple sequence repeat loci, we investigated the genetic structure of 16 Q. crispula populations along a latitudinal gradient in northeastern Japan (northern Honshu and Hokkaido), spanning about half of the species' biogeographic range in the country. Although the level of population differentiation was low (F (ST) = 0.021; G '(ST) = 0.090), two geographically differentiated clusters were detected by STRUCTURE analysis. The first cluster included most of the populations in Hokkaido, and may indicate continued survival throughout past glacial periods. We found a significant decrease in allelic richness with latitude, so the second cluster may represent an expansion of the lineage from Honshu during the post-glacial period. These results should enhance our understanding of historical north-south migrations of this species in northeastern Japan.

  • 333.
    Orsucci, Marion
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. INRA IRD CIRAD Montpellier SupAgro, CBGP UMR 1062, Montpellier, France; Univ Montpellier, DGIMI UMR 1333, INRA, Montpellier, France.
    Audiot, P.
    INRA IRD CIRAD Montpellier SupAgro, CBGP UMR 1062, Montpellier, France.
    Dorkeld, F.
    INRA IRD CIRAD Montpellier SupAgro, CBGP UMR 1062, Montpellier, France.
    Pommier, A.
    INRA IRD CIRAD Montpellier SupAgro, CBGP UMR 1062, Montpellier, France.
    Vabre, M.
    INRA, MELGUEIL DIASCOPE UE 0398, Mauguio, France.
    Gschloessl, B.
    INRA IRD CIRAD Montpellier SupAgro, CBGP UMR 1062, Montpellier, France.
    Rialle, S.
    Inst Genom Fonct, MGX Montpellier GenomiX, Montpellier, France.
    Severac, D.
    Inst Genom Fonct, MGX Montpellier GenomiX, Montpellier, France.
    Bourguet, D.
    INRA IRD CIRAD Montpellier SupAgro, CBGP UMR 1062, Montpellier, France.
    Streiff, R.
    INRA IRD CIRAD Montpellier SupAgro, CBGP UMR 1062, Montpellier, France; Univ Montpellier, DGIMI UMR 1333, INRA, Montpellier, France.
    Larval transcriptomic response to host plants in two related phytophagous lepidopteran species: implications for host specialization and species divergence2018Inngår i: BMC Genomics, ISSN 1471-2164, E-ISSN 1471-2164, Vol. 19, artikkel-id 265Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Most phytophagous insects have morphological, behavioral and physiological adaptations allowing them to specialize on one or a few plant species. Identifying the mechanisms involved in host plant specialization is crucial to understand the role of divergent selection between different environments in species diversification, and to identify sustainable targets for the management of insect pest species. In the present study, we measured larval phenotypic and transcriptomic responses to host plants in two related phytophagous lepidopteran species: the European corn borer (ECB), a worldwide pest of maize, and the adzuki bean borer (ABB), which feeds of various dicotyledons. Our aim was to identify the genes and functions underlying host specialization and/or divergence between ECB and ABB.

    Results: At the phenotypic level, we observed contrasted patterns of survival, weight gain and developmental time between ECB and ABB, and within ECB and ABB reared on two different host plants. At the transcriptomic level, around 8% of the genes were differentially expressed (DE) between species and/or host plant. 70% of these DE genes displayed a divergent pattern of expression between ECB and ABB, regardless of the host, while the remaining 30% were involved in the plastic response between hosts. We further categorized plastic DE genes according to their parallel or opposite pattern between ECB and ABB to specifically identify candidate genes involved in the species divergence by host specialization. These candidates highlighted a comprehensive response, involving functions related to plant recognition, digestion, detoxification, immunity and development. Last, we detected viral, bacterial, and yeast genes whose incidence contrasted ECB and ABB samples, and maize and mugwort conditions. We suggest that these microorganism communities might influence the survival, metabolism and defense patterns observed in ECB and ABB larvae.

    Conclusions: The comprehensive approach developed in the present study allowed to identify phenotypic specialization patterns and underlying candidate molecular mechanisms, and highlighted the putative role of microorganisms in the insect-host plant interaction. These findings offer the opportunity to pinpoint specific and sustainable molecular or physiological targets for the regulation of ECB pest populations.

  • 334.
    Orsucci, Marion
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. Univ Montpellier, Montpellier SupAgro, CBGP, INRA,CIRAD,IRD, Montpellier, France;Univ Montpellier, INRA, DGIMI, Montpellier, France.
    Audiot, P.
    Univ Montpellier, Montpellier SupAgro, CBGP, INRA,CIRAD,IRD, Montpellier, France.
    Nidelet, S.
    Univ Montpellier, Montpellier SupAgro, CBGP, INRA,CIRAD,IRD, Montpellier, France.
    Dorkeld, F.
    Univ Montpellier, Montpellier SupAgro, CBGP, INRA,CIRAD,IRD, Montpellier, France.
    Pommier, A.
    Univ Montpellier, Montpellier SupAgro, CBGP, INRA,CIRAD,IRD, Montpellier, France.
    Vabre, M.
    INRA, DIASCOPE, Mauguio, France.
    Severac, D.
    MGX Montpellier GenomiX, Inst Genom Fonct, F-34094 Montpellier 5, France.
    Rohmer, M.
    MGX Montpellier GenomiX, Inst Genom Fonct, F-34094 Montpellier 5, France.
    Gschloessl, B.
    Univ Montpellier, Montpellier SupAgro, CBGP, INRA,CIRAD,IRD, Montpellier, France.
    Streiff, R.
    Univ Montpellier, Montpellier SupAgro, CBGP, INRA,CIRAD,IRD, Montpellier, France;Univ Montpellier, INRA, DGIMI, Montpellier, France.
    Transcriptomic response of female adult moths to host and non-host plants in two closely related species2018Inngår i: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 18, artikkel-id 145Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Divergent selection has been shown to promote speciation in many taxa and especially in phytophagous insects. In the Ostrinia species complex, the European corn borer (ECB) and adzuki bean borer (ABB) are two sibling species specialized to different host plants. The first is a well-known maize pest, whereas the second is a polyphagous species associated with various dicotyledons. Their specialization to host plants is driven by morphological, behavioral and physiological adaptations. In particular, previous studies have shown that ECB and ABB display marked behavior with regard to plant choice during oviposition, involving specific preference and avoidance mechanisms. In this study, our goal was to identify the mechanisms underlying this host-plant specialization in adult females through an analysis of their gene expression. We assembled and annotated a de novo reference transcriptome and measured differences in gene expression between ECB and ABB females, and between environments. We related differentially expressed genes to host preference behavior, and highlighted the functional categories involved. We also conducted a specific analysis of chemosensory genes, which are considered to be good candidates for host recognition before oviposition. Results: We recorded more differentially expressed genes in ECB than in ABB samples, and noticed that the majority of genes potentially involved in the host preference were different between the two species. At the functional level, the response to plant environment in adult females involved many processes, including the metabolism of carbohydrates, lipids, proteins, and amino acids; detoxification mechanisms and immunity; and the chemosensory repertoire (as expected). Until now, most of the olfactory receptors described in Ostrinia spp. had been tested for their putative role in pheromone recognition by males. Here we observed that one specific olfactory receptor was clearly associated with ECB's discrimination between maize and mugwort conditions, highlighting a potential new candidate involved in plant odor discrimination in adult females. Conclusions: Our results are a first step toward the identification of candidate genes and functions involved in chemosensory processes, carbohydrate metabolism, and virus and retrovirus dynamics. These candidates provide new avenues for research into understanding the role of divergent selection between different environments in species diversification.

  • 335. Osorio-Zuniga, Felipe
    et al.
    Fonturbel, Francisco E.
    Rydin, Håkan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Evidence of mutualistic synzoochory between cryptogams and hummingbirds2014Inngår i: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 123, nr 5, s. 553-558Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Endozoochory is usually involved in seed dispersal mutualisms, whereas ectozoochory is non-rewarding, and therefore neutral (or even negative) for the animal vector. Synzoochory is an intermediate dispersal type between endo and ectozoochory in which propagules are deliberately transported (usually in the mouth) but with no ingestion or gut passage involved. We present empirical evidence of synzoochoric mutualism between the hummingbird Sephanoides sephaniodes and cryptogams (one fern and seven moss species). Two species (Lophosoria quadripinnata and Ancistrodes genuflexa) constituted the bulk of nest biomass, and another six moss species were present in lesser quantity. The hummingbird was selective when collecting nest material so that the nests contained a higher density of reproductive structures (that could be dispersed further) than natural patches of the cryptogam species. Even after one year, the nests maintained half of the original reproductive structures (sporangia, sporophytes) and biomass, constituting an important dispersal source. These results show a new type of mutualism in which mosses could be dispersed throughout longer distances (several km) by hummingbirds and to higher positions (particularly for ground-living species, promoting dispersal potential). The hummingbird benefits from collecting cryptogam material for nest building, and cryptogams benefit from the concentration and relocation of diaspore sources into more effective recruiting sites. Similar mutualistic relationships could be a general phenomenon, of importance in many ecosystems.

  • 336. Page, Paul
    et al.
    Favre, Adrien
    Schiestl, Florian P.
    Karrenberg, Sophie
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Do Flower Color and Floral Scent of Silene Species affect Host Preference of Hadena bicruris, a Seed-Eating Pollinator, under Field Conditions?2014Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, nr 6, s. e98755-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Specialization in plant-insect interactions is an important driver of evolutionary divergence; yet, plant traits mediating such interactions are poorly understood. In this study, we investigated how flower color and floral scent are related to seed predation by a seed-eating pollinator. We used field-transplanted recombinant F-2 hybrids between Silene latifolia and S. dioica that are the preferred and alternative hosts of the moth Hadena bicruris and crosses within these species for comparison. We scored seed predation and flower color and analyzed floral scent. Pinker S. dioica-like flowers and emission of a-pinene decreased the odds of seed predation while emission of benzyl acetate and 6-methyl-5-hepten-2-one increased the odds of seed predation. Emission of these compounds did not differ significantly between the two Silene species. Our results suggest that flower color plays an important role in the specific interaction of H. bicruris with its preferred host S. latifolia. The compounds alpha-pinene, benzyl acetate and 6-methyl-5-hepten-2-one could represent non-specific deterrents and attractants to ovipositing moths. Alternatively, emission of these compounds could be related to herbivory or pathogen attack and act as a signal for host quality. This would weaken the predictability of the plant's costs and benefits of the interaction and act to maintain an imperfect degree of specialization.

  • 337.
    Palmqvist, Björn
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för biologisk grundutbildning. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Differences in floral scent and color between diploid and tetraploid cytotypes of Chamerion angustifolium2017Independent thesis Advanced level (degree of Master (Two Years)), 30 poäng / 45 hpOppgave
    Abstract [en]

    Differences in floral color and scent can affect pollinator behavior, creating assortative mating

    between flowers. For plants where genome duplication leads to different cytotypes

    (polyploids), floral traits could promote coexistence and speciation. I used GCMS analysis

    and optical spectrometry to test for differences in floral scent and color of greenhouse grown

    North American diploid and tetraploid fireweed Chamerion angustifolium. 25 volatile

    compounds were identified in the scent analysis, of which 10 differed significantly between

    diploids and tetraploids. Floral color differed with ploidy as well, with tetraploids having a

    higher brightness than diploids. However, a Bombus terrestris visual sensory model indicated

    that this species could not discriminate between the cytotypes based on color differences.

    Based on these data, it seems likely that differences in floral scent traits could contribute to

    pollinator discrimination between the cytotypes, which could help explain the pollinator

    mediated assortative mating observed in previous studies.

  • 338.
    Parachnowitsch, Amy
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    New Synthesis: The Evolutionary Ecology of Floral Volatiles2014Inngår i: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 40, nr 8, s. 859-859Artikkel i tidsskrift (Annet vitenskapelig)
  • 339.
    Parachnowitsch, Amy
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Burdon, Rosalie