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  • 1. Aarrestad, P. A.
    et al.
    Hytteborn, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Masunga, G.
    Skarpe, C.
    Vegetation: Between Soils and Herbivores2014In: 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, p. 61-88Chapter in book (Refereed)
    Abstract [en]

    The vegetation of the study area in Chobe National Park is influenced by a range of factors, including inundation by the Chobe River, soil moisture and fertility, and the impacts of different-size grazers and browsers. This chapter focuses on how the structure and species composition of the present vegetation in northern Chobe National Park is related to recent herbivory by elephants, as agents shaping the vegetation, and by mesoherbivores acting as controllers or responders, along with abiotic controllers such as soil type and distance to the river. In the study, a two-way indicator species analysis classified the vegetation data into four more or less distinct plant community groups (i) Baikiaea plurijuga-Combretum apiculatum woodland, (ii) Combretum mossambicense-Friesodielsia obovata wooded shrubland, (iii) Capparis tomentosa-Flueggea virosa shrubland and (iv) Cynodon dactylon-Heliotropium ovalifolium floodplain, named after the TWINSPAN indicator or preferential species with high cover, and the relative amount of shrubs and trees.

  • 2.
    Abeysinghe, Kasun S.
    et al.
    Chinese Acad Sci, Xishuangbanna Trop Bot Garden, Key Lab Trop Forest Ecol, Mengla, Yunnan, Peoples R China.;Univ Chinese Acad Sci, Beijing, Peoples R China..
    Yang, Xiao-Dong
    Chinese Acad Sci, Xishuangbanna Trop Bot Garden, Key Lab Trop Forest Ecol, Mengla, Yunnan, Peoples R China..
    Goodale, Eben
    Guangxi Univ, Coll Forestry, Nanning, Guangxi, Peoples R China..
    Anderson, Christopher W. N.
    Massey Univ, Inst Agr & Environm, Soil & Earth Sci, Palmerston North, New Zealand..
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden..
    Cao, Axiang
    Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang, Peoples R China.;Guizhou Normal Univ, Sch Chem & Mat Sci, Guiyang, Peoples R China..
    Feng, Xinbin
    Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang, Peoples R China..
    Liu, Shengjie
    Chinese Acad Sci, Xishuangbanna Trop Bot Garden, Key Lab Trop Forest Ecol, Mengla, Yunnan, Peoples R China.;Univ Chinese Acad Sci, Beijing, Peoples R China..
    Mammides, Christos
    Chinese Acad Sci, Xishuangbanna Trop Bot Garden, Key Lab Trop Forest Ecol, Mengla, Yunnan, Peoples R China..
    Meng, Bo
    Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang, Peoples R China..
    Quan, Rui-Chang
    Chinese Acad Sci, Xishuangbanna Trop Bot Garden, Key Lab Trop Forest Ecol, Mengla, Yunnan, Peoples R China..
    Sun, Jing
    Nanjing Agr Univ, Coll Resources & Environm Sci, Nanjing, Jiangsu, Peoples R China..
    Qiu, Guangle
    Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang, Peoples R China..
    Total mercury and methylmercury concentrations over a gradient of contamination in earthworms living in rice paddy soil2017In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 36, no 5, p. 1202-1210Article in journal (Refereed)
    Abstract [en]

    Mercury (Hg) deposited from emissions or from local contamination, can have serious health effects on humans and wildlife. Traditionally, Hg has been seen as a threat to aquatic wildlife, because of its conversion in suboxic conditions into bioavailable methylmercury (MeHg), but it can also threaten contaminated terrestrial ecosystems. In Asia, rice paddies in particular may be sensitive ecosystems. Earthworms are soil-dwelling organisms that have been used as indicators of Hg bioavailability; however, the MeHg concentrations they accumulate in rice paddy environments are not well known. Earthworm and soil samples were collected from rice paddies at progressive distances from abandoned mercury mines in Guizhou, China, and at control sites without a history of Hg mining. Total Hg (THg) and MeHg concentrations declined in soil and earthworms as distance increased from the mines, but the percentage of THg that was MeHg, and the bioaccumulation factors in earthworms, increased over this gradient. This escalation in methylation and the incursion of MeHg into earthworms may be influenced by more acidic soil conditions and higher organic content further from the mines. In areas where the source of Hg is deposition, especially in water-logged and acidic rice paddy soil, earthworms may biomagnify MeHg more than was previously reported. It is emphasized that rice paddy environments affected by acidifying deposition may be widely dispersed throughout Asia.

  • 3.
    Agić, Heda
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    A new species of small acritarch with porous wall structure from the early Cambrian of Estonia, and implications for the fossil record of eukaryotic picoplankton2015In: Palynology, ISSN 0191-6122, E-ISSN 1558-9188, Vol. 40, no 3, p. 343-356Article in journal (Refereed)
    Abstract [en]

    The Proterozoic-Phanerozoic transition records a general trend of decrease in phytoplankton cell size, in contrast tothe earlier and much larger Ediacaran acritarchs. Particularly minute, unornamented but sculptured organic-walledmicrofossils have been recovered from the lower Cambrian Lükati Formation in northern Estonia. The lack of anysignificant thermal alteration in the formation allowed for excellent preservation of fine microstructures on thesemicrofossils. Among the rich palynomorph assemblage in Lükati, a new species of tiny, spheroidal eukaryoticmicrofossil is recorded: Reticella corrugata gen. et sp. nov. It is characterised by a corrugated and flexible vesicle wallthat is densely perforated by nano-scale pores. Despite its unique morphology, the new species shares diagnosticcharacters with fossil and extant prasinophyte algae. R. corrugata is among the smallest microfossils with typicaleukaryotic morphology (conspicuous wall sculpture) and contributes to the diversity of the size class of smallacritarchs. Size, abundance, inferred prasinophyte affinity and eukaryotic wall sculpture make this new taxon alikely member of the early eukaryotic picoplankton.

  • 4.
    Agnas, Axel Jönses Bernard
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Non-Independent Mate Choice in Female Humans (Homo sapiens): Progression to the Field 2016Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    There is much evidence that mate-choice decisions made by humans are affected by social/contextual information. Women seem to rate men portrayed in a relationship as more desirable than the same men when portrayed as single. Laboratory studies have found evidence suggesting that human mate choice, as in other species, is dependent on the mate choice decisions made by same-sex rivals. Even though non-independent mate choice is an established and well-studied area of mate choice, very few field studies have been performed. This project aims to test whether women’s evaluation of potential mates desirability is dependent/non-independent of same-sex rivals giving the potential mates sexual interest. This is the first field study performed in a modern human’s natural habitat aiming to test for non- independent mate choice in humans.

    No desirability enhancement effect was found. The possibilities that earlier studies have found an effect that is only present in laboratory environments or have measured effects other than non-independent mate choice are discussed. I find differences in experimental design to be the most likely reason why the present study failed to detect the effect found in previous studies. This field study, the first of its sort, has generated important knowledge for future experimenters, where the most important conclusion is that major limitations in humans ability to register and remember there surrounding should be taken in consideration when designing any field study investigating human mate choice. 

  • 5.
    Ah-King, Malin
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Flexible mate choice2010In: Encyclopedia of Animal Behavior / [ed] Janice Moore & Michael D. Breed, Elsevier , 2010Chapter in book (Other academic)
  • 6. Ah-King, Malin
    et al.
    Elofsson, Helena
    Kvarnemo, Charlotta
    Rosenqvist, Gunilla
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Why is there no sperm competition in a pipefish with externally brooding males? Insights from sperm activitation and morphology2006In: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 68, no 3, p. 958-962Article in journal (Refereed)
    Abstract [en]

    Nerophis ophidion sperm activation and morphology were investigated with the aim of explaining the apparent lack of sperm competition in this syngnathid with externally brooding males. Nerophis ophidion sperm were activated by a mixture of ovarian fluid and sea water, but not by sea water alone. This indicated that sperm were not shed into the water but needed to be released near the eggs, which probably restrained sperm competition.

  • 7.
    Ah-King, Malin
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research. Dept Ecol & Evolutionary Biol, 621 Charles E Young Dr S, Los Angeles, CA 90095 USA.;Stockholm Univ, Dept Ethnol Hist Relig & Gender Studies, Univ Vagen 10 E, SE-10691 Stockholm, Sweden..
    Gowaty, Patricia Adair
    Dept Ecol & Evolutionary Biol, 621 Charles E Young Dr S, Los Angeles, CA 90095 USA.;Smithsonian Trop Res Inst, DPO, Box 0948,AA 34002-9998, Washington, DC USA.;Univ Calif Los Angeles, Inst Environm & Sustainabil, Los Angeles, CA 90095 USA..
    A conceptual review of mate choice: stochastic demography, within-sex phenotypic plasticity, and individual flexibility2016In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, no 14, p. 4607-4642Article, review/survey (Refereed)
    Abstract [en]

    Mate choice hypotheses usually focus on trait variation of chosen individuals. Recently, mate choice studies have increasingly attended to the environmental circumstances affecting variation in choosers' behavior and choosers' traits. We reviewed the literature on phenotypic plasticity in mate choice with the goal of exploring whether phenotypic plasticity can be interpreted as individual flexibility in the context of the switch point theorem, SPT (Gowaty and Hubbell ). We found >3000 studies; 198 were empirical studies of within-sex phenotypic plasticity, and sixteen showed no evidence of mate choice plasticity. Most studies reported changes from choosy to indiscriminate behavior of subjects. Investigators attributed changes to one or more causes including operational sex ratio, adult sex ratio, potential reproductive rate, predation risk, disease risk, chooser's mating experience, chooser's age, chooser's condition, or chooser's resources. The studies together indicate that choosiness of potential mates is environmentally and socially labile, that is, induced - not fixed - in the choosy sex with results consistent with choosers' intrinsic characteristics or their ecological circumstances mattering more to mate choice than the traits of potential mates. We show that plasticity-associated variables factor into the simpler SPT variables. We propose that it is time to complete the move from questions about within-sex plasticity in the choosy sex to between- and within-individual flexibility in reproductive decision-making of both sexes simultaneously. Currently, unanswered empirical questions are about the force of alternative constraints and opportunities as inducers of individual flexibility in reproductive decision-making, and the ecological, social, and developmental sources of similarities and differences between individuals. To make progress, we need studies (1) of simultaneous and symmetric attention to individual mate preferences and subsequent behavior in both sexes, (2) controlled for within-individual variation in choice behavior as demography changes, and which (3) report effects on fitness from movement of individual's switch points.

  • 8.
    Ah-King, Malin
    et al.
    Zoologiska institutionen, Stockholms universitet.
    Kvarnemo, Charlotta
    Zoologiska institutionen, Stockholms universitet.
    Tullberg, Birgitta S.
    Zoologiska institutionen, Stockholms universitet.
    The influence of territoriality and mating system for the evolution of male care, a phylogenetic study on fish2005In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101Article in journal (Refereed)
    Abstract [en]

    Evolution of male care is still poorly understood. Using phylogeneticallymatched-pairs comparisons we tested for effects of territoriality and matingsystem on male care evolution in fish. All origins of male care were found inpair-spawning species (with or without additional males such as sneakers) andnone were found in group-spawning species. However, excluding groupspawners, male care originated equally often in pair-spawning species withadditional males as in strict pair-spawning species. Evolution of male care wasalso significantly related to territoriality. Yet, most pair-spawning taxa withmale care are also territorial, making their relative influence difficult toseparate. Furthermore, territoriality also occurs in group-spawning species.Hence, territoriality is not sufficient for male care to evolve. Rather, we arguethat it is the combination of territoriality and pair spawning with sequentialpolygyny that favours the evolution of male care, and we discuss our results inrelation to paternity assurance and sexual selection.

  • 9.
    Ah-King, Malin
    et al.
    Zoologiska institutionen, Stockholms universitet.
    Tullberg, Birgitta S.
    Zoologiska institutionen, Stockholms universitet.
    Phylogenetic analysis of twinning in Callitrichinae2000In: American Journal of Primatology, ISSN 0275-2565, E-ISSN 1098-2345, Vol. 51, no 2, p. 135-146Article in journal (Refereed)
    Abstract [en]

    The callitrichines are known for twinning and for a communal rearingsystem in which all or most group members help care for the offspring.The origin of twinning has been the subject of much speculation. In thisstudy predictions from earlier hypotheses are tested on the basis of twoalternative phylogenetic trees. From this analysis we infer that helpingbehavior and male care preceded the origin of twinning, and that thesetraits did not coevolve with, but might have been important prerequisitesfor twinning in callitrichines. Small body size does not necessarilyresult in twinning, although it might still have been a prerequisite forits evolution. Gum feeding was an ecological change which evolved alongwith twinning. If nutrition was a limiting factor in the number of offspringproduced, then the use of a new feeding resource could have beencrucial for the origin of twinning in callitrichines. According to one of thetwo alternative solutions inferred by the total evidence tree, and in accordancewith the morphological tree, semi-annual breeding appears inthe marmosets together with specialization in gum feeding. The fact thatgums are available for these monkeys all year may have facilitated semiannualbreeding. We suggest that the exploitation of gums as a feedingresource could have been the decisive factor in the increase of the reproductiverate by twinning and by semi-annual breeding.

  • 10.
    Ahlgren, Gunnel
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Hyenstrand, Per
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Nitrogen limitation effects of different nitrogen sources on nutritional quality of two freshwater organisms, Scenedesmus Quadricauda (Clorophyceae) and Synechococcus sp. (Cyanophyceae)2003In: J. Phycol., Vol. 39, p. 906-917Article in journal (Refereed)
  • 11.
    Ahlgren, Ingemar
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Evolutionary Biology. Department of Ecology and Evolution, Limnology. Limnologi.
    Eriksson, R
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Evolutionary Biology. Department of Ecology and Evolution, Limnology. Limnologi.
    Moreno, L
    Pacheco, L
    Montenegro-Guillén, S
    Vammen, K
    Pelagic food web interactions in Lake Cocibolca, Nicaragua2001In: Verh. Internat. Verein. Limnol., Vol. 27, no 4, p. 1740-1746Article in journal (Refereed)
  • 12.
    Ahlgren, Joakim
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Tranvik, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Gogoll, Adolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Waldebäck, Monica
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Markides, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Rydin, Emil
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Sediment Depth Attenuation of Biogenic Phosphorus Compounds Measured by 31P NMR2005In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 39, no 3, p. 867-872Article in journal (Refereed)
    Abstract [en]

    Being a major cause of eutrophication and subsequent loss of water quality, the turnover of phosphorus (P) in lake sediments is in need of deeper understanding. A major part of the flux of P to eutrophic lake sediments is organically bound or of biogenic origin. This P is incorporated in a poorly described mixture of autochthonous and allochthonous sediment and forms the primary storage of P available for recycling to the water column, thus regulating lake trophic status. To identify and quantify biogenic sediment P and assess its lability, we analyzed sediment cores from Lake Erken, Sweden, using traditional P fractionation, and in parallel, NaOH extracts were analyzed using 31P NMR. The surface sediments contain orthophosphates (ortho-P) and pyrophosphates (pyro-P), as well as phosphate mono- and diesters. The first group of compounds to disappear with increased sediment depth is pyrophosphate, followed by a steady decline of the different ester compounds. Estimated half-life times of these compound groups are about 10 yr for pyrophosphate and 2 decades for mono- and diesters. Probably, these compounds will be mineralized to ortho-P and is thus potentially available for recycling to the water column, supporting further growth of phytoplankton. In conclusion, 31P NMR is a useful tool to asses the bioavailability of certain P compound groups, and the combination with traditional fractionation techniques makes quantification possible.

  • 13.
    Ahnesjo, Ingrid
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology.
    Kvarnemo, C
    Merilaita, S
    Using potential reproductive rates to predict mating competition among individuals qualified to mate2001In: BEHAVIORAL ECOLOGY, ISSN 1045-2249, Vol. 12, no 4, p. 397-401Article in journal (Refereed)
    Abstract [en]

    The potential reproductive rate (PRR), which is the offspring production per unit time each sex would achieve if unconstrained by mate availability, often differs between the sexes. An increasing sexual difference in PRR predicts an intensified mating com

  • 14.
    Akiyama, Reiko
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Life History and Tolerance and Resistance against Herbivores in Natural Populations of Arabidopsis thaliana2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, I combined observational studies with field and greenhouse experiments to examine selection on life history traits and variation in tolerance and resistance against herbivores in natural populations of the annual herb Arabidopsis thaliana in its native range. I investigated (1) phenotypic selection on flowering time and plant size, (2) the effects of timing of germination on plant fitness, (3) the effect of leaf damage on seed production, and (4) correlations between resistance against a specialist and a generalist insect herbivore.

    In all three study populations, flowering time was negatively related to plant fitness, but in only one of the populations, significant selection on flowering time was detected when controlling for size prior to the flowering season. The results show that correlations between flowering time and plant fecundity may be confounded by variation in plant size prior to the reproductive season.

    A field experiment detected conflicting selection on germination time: Early germination was associated with low seedling survival, but also with large leaf rosette before winter and high survival and fecundity among established plants. The results suggest that low survival among early germinating seeds is the main force opposing the evolution of earlier germination, and that the optimal timing of germination should vary in space and time as a function of the relative strength of selection acting during different life-history stages.

    Experimental leaf damage demonstrated that tolerance to damage was lowest among vegetative plants early in the season, and highest among flowering plants later in the season. Given similar damage levels, leaf herbivores feeding on plants before flowering should thus exert stronger selection on defence traits than those feeding on plants during flowering.

    Resistance against larval feeding by the specialist Plutella xylostella was negatively correlated with resistance against larval feeding by the generalist Mamestra brassicae and with resistance against oviposition by P. xylostella when variation in resistance was examined within and among two Swedish and two Italian A. thaliana populations. The results suggest that negative correlations between resistance against different herbivores and different life-history stages of herbivores may contribute to the maintenance of genetic variation in resistance.

    List of papers
    1. Selection on flowering time in three natural populations of Arabidopsis thaliana
    Open this publication in new window or tab >>Selection on flowering time in three natural populations of Arabidopsis thaliana
    (English)Manuscript (preprint) (Other academic)
    National Category
    Ecology Evolutionary Biology Botany
    Research subject
    Biology with specialization in Ecological Botany
    Identifiers
    urn:nbn:se:uu:diva-159506 (URN)
    Funder
    Swedish Research Council
    Available from: 2011-10-06 Created: 2011-10-03 Last updated: 2011-11-10
    2. Conflicting selection on the timing of germination in a natural population of Arabidopsis thaliana
    Open this publication in new window or tab >>Conflicting selection on the timing of germination in a natural population of Arabidopsis thaliana
    2014 (English)In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 27, no 1, p. 193-199Article in journal (Refereed) Published
    Abstract [en]

    The timing of germination is a key life-history trait that may strongly influence plant fitness and that sets the stage for selection on traits expressed later in the life cycle. In seasonal environments, the period favourable for germination and the total length of the growing season are limited. The optimal timing of germination may therefore be governed by conflicting selection through survival and fecundity. We conducted a field experiment to examine the effects of timing of germination on survival, fecundity and overall fitness in a natural population of the annual herb Arabidopsis thaliana in north-central Sweden. Seedlings were transplanted at three different times in late summer and in autumn covering the period of seed germination in the study population. Early germination was associated with low seedling survival, but also with high survival and fecundity among established plants. The advantages of germinating early more than balanced the disadvantage and selection favoured early germination. The results suggest that low survival among early germinating seeds is the main force opposing the evolution of earlier germination and that the optimal timing of germination should vary in space and time as a function of the direction and strength of selection acting during different life-history stages.

    National Category
    Ecology Evolutionary Biology Botany
    Research subject
    Biology with specialization in Ecological Botany
    Identifiers
    urn:nbn:se:uu:diva-159664 (URN)10.1111/jeb.12293 (DOI)000329254500018 ()
    Funder
    Swedish Research Council
    Available from: 2011-10-06 Created: 2011-10-06 Last updated: 2017-12-08Bibliographically approved
    3. Magnitude and timing of leaf damage affect seed production in a natural population of Arabidopsis thaliana (Brassicaceae)
    Open this publication in new window or tab >>Magnitude and timing of leaf damage affect seed production in a natural population of Arabidopsis thaliana (Brassicaceae)
    2012 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 1, p. e30015-Article in journal (Refereed) Published
    Abstract [en]

    Background: The effect of herbivory on plant fitness varies widely. Understanding the causes of this variation is of considerable interest because of its implications for plant population dynamics and trait evolution. We experimentally defoliated the annual herb Arabidopsis thaliana in a natural population in Sweden to test the hypotheses that (a) plant fitness decreases with increasing damage, (b) tolerance to defoliation is lower before flowering than during flowering, and (c) defoliation before flowering reduces number of seeds more strongly than defoliation during flowering, but the opposite is true for effects on seed size.

    Methodology/Principal Findings: In a first experiment, between 0 and 75% of the leaf area was removed in May from plants that flowered or were about to start flowering. In a second experiment, 0, 25%, or 50% of the leaf area was removed from plants on one of two occasions, in mid April when plants were either in the vegetative rosette or bolting stage, or in mid May when plants were flowering. In the first experiment, seed production was negatively related to leaf area removed, and at the highest damage level, also mean seed size was reduced. In the second experiment, removal of 50% of the leaf area reduced seed production by 60% among plants defoliated early in the season at the vegetative rosettes, and by 22% among plants defoliated early in the season at the bolting stage, but did not reduce seed output of plants defoliated one month later. No seasonal shift in the effect of defoliation on seed size was detected.

    Conclusions/Significance: The results show that leaf damage may reduce the fitness of A. thaliana, and suggest that in this population leaf herbivores feeding on plants before flowering should exert stronger selection on defence traits than those feeding on plants during flowering, given similar damage levels.

    National Category
    Ecology Evolutionary Biology Botany
    Research subject
    Biology with specialization in Ecological Botany
    Identifiers
    urn:nbn:se:uu:diva-159665 (URN)10.1371/journal.pone.0030015 (DOI)000301457200028 ()
    Funder
    Swedish Research Council
    Available from: 2011-10-06 Created: 2011-10-06 Last updated: 2017-12-08Bibliographically approved
    4. Genetic variation in leaf morphology and resistance against specialist and generalist insect herbivores in natural populations of Arabidopsis thaliana
    Open this publication in new window or tab >>Genetic variation in leaf morphology and resistance against specialist and generalist insect herbivores in natural populations of Arabidopsis thaliana
    (English)Manuscript (preprint) (Other academic)
    National Category
    Ecology Evolutionary Biology Botany
    Research subject
    Biology with specialization in Ecological Botany
    Identifiers
    urn:nbn:se:uu:diva-159685 (URN)
    Funder
    Swedish Research Council
    Available from: 2011-10-06 Created: 2011-10-06 Last updated: 2011-11-10
  • 15.
    Akiyama, Reiko
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Noack, Sibylle
    Department of Zoology, Stockholm University.
    Ågren, Jon
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Genetic variation in leaf morphology and resistance against specialist and generalist insect herbivores in natural populations of Arabidopsis thalianaManuscript (preprint) (Other academic)
  • 16.
    Akiyama, Reiko
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Ågren, Jon
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Conflicting selection on the timing of germination in a natural population of Arabidopsis thaliana2014In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 27, no 1, p. 193-199Article in journal (Refereed)
    Abstract [en]

    The timing of germination is a key life-history trait that may strongly influence plant fitness and that sets the stage for selection on traits expressed later in the life cycle. In seasonal environments, the period favourable for germination and the total length of the growing season are limited. The optimal timing of germination may therefore be governed by conflicting selection through survival and fecundity. We conducted a field experiment to examine the effects of timing of germination on survival, fecundity and overall fitness in a natural population of the annual herb Arabidopsis thaliana in north-central Sweden. Seedlings were transplanted at three different times in late summer and in autumn covering the period of seed germination in the study population. Early germination was associated with low seedling survival, but also with high survival and fecundity among established plants. The advantages of germinating early more than balanced the disadvantage and selection favoured early germination. The results suggest that low survival among early germinating seeds is the main force opposing the evolution of earlier germination and that the optimal timing of germination should vary in space and time as a function of the direction and strength of selection acting during different life-history stages.

  • 17.
    Akiyama, Reiko
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Ågren, Jon
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Magnitude and timing of leaf damage affect seed production in a natural population of Arabidopsis thaliana (Brassicaceae)2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 1, p. e30015-Article in journal (Refereed)
    Abstract [en]

    Background: The effect of herbivory on plant fitness varies widely. Understanding the causes of this variation is of considerable interest because of its implications for plant population dynamics and trait evolution. We experimentally defoliated the annual herb Arabidopsis thaliana in a natural population in Sweden to test the hypotheses that (a) plant fitness decreases with increasing damage, (b) tolerance to defoliation is lower before flowering than during flowering, and (c) defoliation before flowering reduces number of seeds more strongly than defoliation during flowering, but the opposite is true for effects on seed size.

    Methodology/Principal Findings: In a first experiment, between 0 and 75% of the leaf area was removed in May from plants that flowered or were about to start flowering. In a second experiment, 0, 25%, or 50% of the leaf area was removed from plants on one of two occasions, in mid April when plants were either in the vegetative rosette or bolting stage, or in mid May when plants were flowering. In the first experiment, seed production was negatively related to leaf area removed, and at the highest damage level, also mean seed size was reduced. In the second experiment, removal of 50% of the leaf area reduced seed production by 60% among plants defoliated early in the season at the vegetative rosettes, and by 22% among plants defoliated early in the season at the bolting stage, but did not reduce seed output of plants defoliated one month later. No seasonal shift in the effect of defoliation on seed size was detected.

    Conclusions/Significance: The results show that leaf damage may reduce the fitness of A. thaliana, and suggest that in this population leaf herbivores feeding on plants before flowering should exert stronger selection on defence traits than those feeding on plants during flowering, given similar damage levels.

  • 18.
    Akiyama, Reiko
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Ågren, Jon
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Selection on flowering time in three natural populations of Arabidopsis thalianaManuscript (preprint) (Other academic)
  • 19.
    Alatalo, Juha M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Jaegerbrand, Annika K.
    Molau, Ulf
    Climate change and climatic events: community-, functional- and species-level responses of bryophytes and lichens to constant, stepwise, and pulse experimental warming in an alpine tundra2014In: Alpine Botany, ISSN 1664-2201, E-ISSN 1664-221X, Vol. 124, no 2, p. 81-91Article in journal (Refereed)
    Abstract [en]

    We experimentally imposed three different kinds of warming scenarios over 3 years on an alpine meadow community to identify the differential effects of climate warming and extreme climatic events on the abundance and biomass of bryophytes and lichens. Treatments consisted of (a) a constant level of warming with open top chambers (an average temperature increase of 1.87 A degrees C), (b) a yearly stepwise increase of warming (average temperature increases of 1.0; 1.87 and 3.54 A degrees C, consecutively), and (c) a pulse warming, i.e., a single first year pulse event of warming (average temperature increase of 3.54 A degrees C only during the first year). To our knowledge, this is the first climate change study that attempts to distinguish between the effects of constant, stepwise and pulse warming on bryophyte and lichen communities. We hypothesised that pulse warming would have a significant short-term effect compared to the other warming treatments, and that stepwise warming would have a significant mid-term effect compared to the other warming treatments. Acrocarpous bryophytes as a group increased in abundance and biomass to the short-term effect of pulse warming. We found no significant effects of mid-term (third-year) stepwise warming. However, one pleurocarpous bryophyte species, Tomentypnum nitens, generally increased in abundance during the warm year 1997 but decreased in control plots and in response to the stepwise warming treatment. Three years of experimental warming (all treatments as a group) did have a significant impact at the community level, yet changes in abundance did not translate into significant changes in the dominance hierarchies at the functional level (for acrocarpous bryophytes, pleurocarpous bryophytes, Sphagnum or lichens), or in significant changes in other bryophyte or lichen species. The results suggest that bryophytes and lichens, both at the functional group and species level, to a large extent are resistant to the different climate change warming simulations that were applied.

  • 20.
    Alatalo, Juha M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Jagerbrand, Annika K.
    VTI, Swedish Natl Rd & Transport Res Inst, S-10215 Stockholm, Sweden..
    Molau, Ulf
    Univ Gothenburg, Dept Biol & Environm Sci, SE-40530 Gothenburg, Sweden..
    Testing reliability of short-term responses to predict longer-term responses of bryophytes and lichens to environmental change2015In: Ecological Indicators, ISSN 1470-160X, E-ISSN 1872-7034, Vol. 58, p. 77-85Article in journal (Refereed)
    Abstract [en]

    Environmental changes are predicted to have severe and rapid impacts on polar and alpine regions. At high latitudes/altitudes, cryptogams such as bryophytes and lichens are of great importance in terms of biomass, carbon/nutrient cycling, cover and ecosystem functioning. This seven-year factorial experiment examined the effects of fertilizing and experimental warming on bryophyte and lichen abundance in an alpine meadow and a heath community in subarctic Sweden. The aim was to determine whether shortterm responses (five years) are good predictors of longer-term responses (seven years). Fertilizing and warming had significant negative effects on total and relative abundance of bryophytes and lichens, with the largest and most rapid decline caused by fertilizing and combined fertilizing and warming. Bryophytes decreased most in the alpine meadow community, which was bryophyte-dominated, and lichens decreased most in the heath community, which was lichen-dominated. This was surprising, as the most diverse group in each community was expected to be most resistant to perturbation. Warming alone had a delayed negative impact. Of the 16 species included in statistical analyses, seven were significantly negatively affected. Overall, the impacts of simulated warming on bryophytes and lichens as a whole and on individual species differed in time and magnitude between treatments and plant communities (meadow and heath). This will likely cause changes in the dominance structures over time. These results underscore the importance of longer-term studies to improve the quality of data used in climate change models, as models based on short-term data are poor predictors of long-term responses of bryophytes and lichens.

  • 21.
    Alatalo, Juha M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Little, Chelsea J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Simulated global change: contrasting short and medium term growth and reproductive responses of a common alpine/Arctic cushion plant to experimental warming and nutrient enhancement2014In: SpringerPlus, E-ISSN 2193-1801, Vol. 3, article id 157Article in journal (Refereed)
    Abstract [en]

    Cushion plants are important components of alpine and Arctic plant communities around the world. They fulfill important roles as facilitators, nurse plants and foundation species across trophic levels for vascular plants, arthropods and soil microorganisms, the importance of these functions increasing with the relative severity of the environment. Here we report results from one of the few experimental studies simulating global change impacts on cushion plants; a factorial experiment with warming and nutrient enhancement that was applied to an alpine population of the common nurse plant, Silene acaulis, in sub-arctic Sweden. Experimental perturbations had significant short-term impacts on both stem elongation and leaf length. S. acaulis responded quickly by increasing stem elongation and (to a lesser extent) leaf length in the warming, nutrient, and the combined warming and nutrient enhancements. Cover and biomass also initially increased in response to the perturbations. However, after the initial positive short-term responses, S. acaulis cover declined in the manipulations, with the nutrient and combined warming and nutrient treatments having largest negative impact. No clear patterns were found for fruit production. Our results show that S. acaulis living in harsh environments has potential to react quickly when experiencing years with favorable conditions, and is more responsive to nutrient enhancement than to warming in terms of vegetative growth. While these conditions have an initial positive impact, populations experiencing longer-term increased nutrient levels will likely be negatively affected.

  • 22.
    Alatalo, Juha M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Little, Chelsea J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Jagerbrand, Annika K.
    Molau, Ulf
    Dominance hierarchies, diversity and species richness of vascular plants in an alpine meadow: contrasting short and medium term responses to simulated global change2014In: PeerJ, ISSN 2167-8359, E-ISSN 2167-8359, Vol. 2, p. e406-Article in journal (Refereed)
    Abstract [en]

    We studied the impact of simulated global change on a high alpine meadow plant community. Specifically, we examined whether short-term (5 years) responses are good predictors for medium-term (7 years) changes in the system by applying a factorial warming and nutrient manipulation to 20 plots in Latnjajaure, subarctic Sweden. Seven years of experimental warming and nutrient enhancement caused dramatic shifts in dominance hierarchies in response to the nutrient and the combined warming and nutrient enhancement treatments. Dominance hierarchies in the meadow moved from a community being dominated by cushion plants, deciduous, and evergreen shrubs to a community being dominated by grasses, sedges, and forbs. Short-termresponses were shown to be inconsistent in their ability to predict medium-term responses for most functional groups, however, grasses showed a consistent and very substantial increase in response to nutrient addition over the seven years. The non-linear responses over time point out the importance of longer-term studies with repeated measurements to be able to better predict future changes. Forecasted changes to temperature and nutrient availability have implications for trophic interactions, and may ultimately influence the access to and palatability of the forage for grazers. Depending on what anthropogenic change will be most pronounced in the future (increase in nutrient deposits, warming, or a combination of them both), different shifts in community dominance hierarchies may occur. Generally, this study supports the productivity-diversity relationship found across arctic habitats, with community diversity peaking in mid-productivity systems and degrading as nutrient availability increases further. This is likely due the increasing competition in plant-plant interactions and the shifting dominance structure with grasses taking over the experimental plots, suggesting that global change could have high costs to biodiversity in the Arctic.

  • 23.
    Alatalo, Juha M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Little, Chelsea J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Jagerbrand, Annika K.
    Molau, Ulf
    Vascular plant abundance and diversity in an alpine heath under observed and simulated global change2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, article id 10197Article in journal (Refereed)
    Abstract [en]

    Global change is predicted to cause shifts in species distributions and biodiversity in arctic tundra. We applied factorial warming and nutrient manipulation to a nutrient and species poor alpine/arctic heath community for seven years. Vascular plant abundance in control plots increased by 31%. There were also notable changes in cover in the nutrient and combined nutrient and warming treatments, with deciduous and evergreen shrubs declining, grasses overgrowing these plots. Sedge abundance initially increased significantly with nutrient amendment and then declined, going below initial values in the combined nutrient and warming treatment. Nutrient addition resulted in a change in dominance hierarchy from deciduous shrubs to grasses. We found significant declines in vascular plant diversity and evenness in the warming treatment and a decline in diversity in the combined warming and nutrient addition treatment, while nutrient addition caused a decline in species richness. The results give some experimental support that species poor plant communities with low diversity may be more vulnerable to loss of species diversity than communities with higher initial diversity. The projected increase in nutrient deposition and warming may therefore have negative impacts on ecosystem processes, functioning and services due to loss of species diversity in an already impoverished environment.

  • 24.
    Alatalo, Rauno V
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Lundberg, Arne
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Sundberg, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Can Female Preference Explain Sexual Dichromatism In The Pied Flycatcher, Ficedula-Hypoleuca1990In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 39, p. 244-252Article in journal (Refereed)
    Abstract [en]

    How important female choice is for the evolution of male secondary sexual characteristics is controversial. Two field and one laboratory experiment, using the pied flycatcher, were performed to test the female choice aspect of sexual selection. In addition, non-manipulative data from 5 years are presented. The observational data suggest a slight preference for dark males by females but in field experiments in which males had territories at random sites (i.e. they did not choose a territory) or the colour of concurrently arriving males was altered, there was no preference for darker ones. Similarly, oestradiol-treated females did not prefer black or brown males in the laboratory. Thus, there is little support for the idea that female choice has been an important mechanism in the evolution of sexual dichromatism in the pied flycatcher.

  • 25.
    Alcalde, Joaquín
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    The effects of endocrine disruptor cocktails on bleak (Alburnus alburnus) behavior, growth, and morphology2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 26.
    Alexander, Michelle
    et al.
    Univ York, York YO10 5DD, N Yorkshire, England.;Univ Aberdeen, Sch Geosci, Dept Archaeol, Aberdeen AB24 3UF, Scotland..
    Ho, Simon Y. W.
    Univ Sydney, Sch Biol Sci, Sydney, NSW 2006, Australia..
    Molak, Martyna
    Polish Acad Sci, Museum & Inst Zool, PL-00679 Warsaw, Poland..
    Barnett, Ross
    Palaeogen & Bioarchaeol Res Network, Res Lab Archaeol, Oxford OX1 3QY, England..
    Carlborg, Örjan
    Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Dorshorst, Ben
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Virginia Tech, Dept Anim & Poultry Sci, Blacksburg, VA 24061 USA..
    Honaker, Christa
    Virginia Tech, Dept Anim & Poultry Sci, Blacksburg, VA 24061 USA..
    Besnier, Francois
    Inst Marine Res, Sect Populat Genet, N-5024 Bergen, Norway..
    Wahlberg, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Molecular Medicine.
    Dobney, Keith
    Univ Aberdeen, Sch Geosci, Dept Archaeol, Aberdeen AB24 3UF, Scotland..
    Siegel, Paul
    Virginia Tech, Dept Anim & Poultry Sci, Blacksburg, VA 24061 USA..
    Andersson, Leif
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Swedish Univ Agr Sci, Dept Anim Breeding & Genet, S-75007 Uppsala, Sweden..
    Larson, Greger
    Palaeogen & Bioarchaeol Res Network, Res Lab Archaeol, Oxford OX1 3QY, England..
    Mitogenomic analysis of a 50-generation chicken pedigree reveals a rapid rate of mitochondrial evolution and evidence for paternal mtDNA inheritance2015In: Biology Letters, ISSN 1744-9561, E-ISSN 1744-957X, Vol. 11, no 10, article id 20150561Article in journal (Refereed)
    Abstract [en]

    Mitochondrial genomes represent a valuable source of data for evolutionary research, but studies of their short-term evolution have typically been limited to invertebrates, humans and laboratory organisms. Here we present a detailed study of 12 mitochondrial genomes that span a total of 385 transmissions in a well-documented 50-generation pedigree in which two lineages of chickens were selected for low and high juvenile body weight. These data allowed us to test the hypothesis of time-dependent evolutionary rates and the assumption of strict maternal mitochondrial transmission, and to investigate the role of mitochondrial mutations in determining phenotype. The identification of a non-synonymous mutation in ND4L and a synonymous mutation in CYTB, both novel mutations in Gallus, allowed us to estimate a molecular rate of 3.13 x 10(-7) mutations/site/year (95% confidence interval 3.75 x 10(-8)-1.12 x 10(-6)). This is substantially higher than avian rate estimates based upon fossil calibrations. Ascertaining which of the two novel mutations was present in an additional 49 individuals also revealed an instance of paternal inheritance of mtDNA. Lastly, an association analysis demonstrated that neither of the point mutations was strongly associated with the phenotypic differences between the two selection lines. Together, these observations reveal the highly dynamic nature of mitochondrial evolution over short time periods.

  • 27.
    Allander, Klas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Sundberg, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Temporal variation and reliability of blood parasite levels in captive Yellowhammer males Emberiza citrinella1997In: Journal of Avian Biology, ISSN 0908-8857, E-ISSN 1600-048X, Vol. 28, no 4, p. 325-330Article in journal (Refereed)
    Abstract [en]

    The temporal variation of blood parasites in captive Yellowhammer males was studied in order to investigate possible costs of parasites. Birds were caught in the wild in early April and kept in aviaries during the study period. Blood samples were taken, body mass measured, and moult was scored twelve times for the same individuals from April to October. Blood parasites were detectable in smears during the whole study period with an intensity peak coinciding with breeding in the wild. Young birds had more parasites and a consistently higher body mass than older birds. There was no relationship between parasite intensity and mass in older birds but possibly one in young birds. Parasites did not seem to affect moult in either age class. Repeatability of parasite counts of smears from the same individual was very high and smears are therefore a reliable method for estimating parasite intensity. We conclude that blood parasites are probably most severe during, but occur in their hosts long after, the breeding season. Possible costs of parasites outside the breeding season require further study.

  • 28.
    Amanda, Folkö
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    The relationship between body size and dry weight in hoverflies (Syrphidae), and their movements along an urban linear landscape element2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 29. Andersson, Jan-Olov
    et al.
    Hasselid, Sara
    Widen, Per
    Bax, Gerhard
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. ELD.
    Is the Snow Leopard (Unica unica) endangered?: A study of popular viability and distribution using vulnerability and GIS analysis methods2004In: Proceedings of the 7th International Symposium on High Mountain Remote Sensing Cartography, 2004, p. 224-Conference paper (Refereed)
  • 30.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Berga, Mercè
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Lindström, Eva S.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Langenheder, Silke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    The spatial structure of bacterial communities is influenced by historical environmental conditions2014In: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 95, no 5, p. 1134-1140Article in journal (Refereed)
    Abstract [en]

    The spatial structure of ecological communities, including that of bacteria, is often influenced by species sorting by contemporary environmental conditions. Moreover, historical processes, i.e., ecological and evolutionary events that have occurred at some point in the past, such as dispersal limitation, drift, priority effects, or selection by past environmental conditions, can be important, but are generally investigated much less. Here, we conducted a field study using 16 rock pools, where we specifically compared the importance of past vs. contemporary environmental conditions for bacterial community structure by correlating present differences in bacterial community composition among pools to environmental conditions measured on the same day, as well as to those measured 2, 4, 6, and 8 d earlier. The results prove that selection by past environmental conditions exists, since we were able to show that bacterial communities are, to a greater extent, an imprint of past compared to contemporary environmental conditions. We suggest that this is the result of a combination of different mechanisms, including priority effects that cause rapid adaptation to new environmental conditions of taxa that have been initially selected by past environmental conditions, and slower rates of turnover in community composition compared to environmental conditions.

  • 31.
    Andersson, Martin Gustav Ingemar
    Gotland University, School of Culture, Energy and Environment.
    Muddring i Ireån: indirekta effekter på bottenfaunan nedströms2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This research aims to investigate the effects that dredging may have on benthic fauna. The dredging took place in the stream Ireån on northern Gotland during the early summer 2010. My area of research was taking place in a scenic area downstream in Ireån close to the Baltic Sea. I chose this area due to the dredging that started just upstream of this area and continued further upstream. Thus it is not the direct impact of the dredging that is the focus for this paper but the side-effect the dredging may have on the area downstream. In this research I used the M42-method and BQI- index in order to evaluate the results. The effects on the dredging were weaker than expected, with only minor changes occurring within the benthic fauna (BQI-value before dredging: 3.35, BQI-value after dredging: 3.51).

  • 32.
    Andersson, Måns Sverker
    Uppsala University, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Faculty of Arts, Centre for Gender Research. Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Genusperspektiv på beteendens evolutionära genetik2006In: Dialoger mellan kön och genus, 2006Chapter in book (Other (popular scientific, debate etc.))
    Abstract [en]

    Psykologen Virginia Valian talar om traditionell kategorisering baserad på kön (gender schemas). Man har med experiment tydligt kunnat visa att sådana kategoriseringar påverkar vår perception radikalt. Studier visar till exempel att försöks¬personer som ställs inför uppgiften att uppskatta mäns och kvinnors längd regelmässigt underskattar kvinnors längd. Föga förvånande så bär vi med oss dessa könskategorier även när vi studerar djur och evolution.

    Den ornitologiskt kunnige som slår upp sparvhök i Bonniers Alla Europas fåglar i färg slås av att honan avbildas som likstor med hanen trots att honorna i verkligheten är mycket större. Tvärtemot vad fågelboken antyder så är det lättare att missta en sparvhökshona för hanen hos den större duvhöken, än för hanen av den egna arten. Det här är en typ av reproduktion av könsstereotyp och missvisande information som är vanlig i den ornitologiska litteraturen.

    Ornitologin i sin tur är intimt kopplad till och uppvisar strukturella likheter med den del av evolutionsbiologin som får allt större inflytande på vår förståelse av beteenden, beteendeekologin.

    Beteendeekologiska teorier och resultat kan innebära en revolution för tänkandet kring kön och könsbundna egenskaper. Att plocka isär och återuppbygga könsbegreppen har delvis varit nödvändigt, i synnerhet för de som studerar vad vi kallar ”sexuell selektion”. Därför har genusperspektiven stora möjligheter att kunna bidra med insikter viktiga för både teoribildningen och det praktiska vetenskapliga hantverket.

  • 33.
    Andersson, Måns Sverker
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology. zooekologi.
    Gustafsson, Lars
    Glycosylated haemoglobin: a new measure of condition in birds1995In: Proceedings of the Royal Society of London, no 260, p. 299-303Article in journal (Refereed)
    Abstract [en]

    Abstract: The influence of condition on time of breeding and reproductive success has been discussed since Darwin first suggested a relation in 1871. We used a novel method to investigate the influence of condition on the timing of breeding and reproductive success by measuring a relatively inert physiological parameter - the amount of glycosylated haemoglobin - in blood samples taken from the collared flycatcher Ficedula albicollis. The percentage of glycosylated haemoglobin (%HbG) was assumed to be proportional to the average blood glucose level, during the 3-5 weeks before the blood sampling. The %HbG was influenced neither by sex nor age. Date of arrival at the breeding ground was negatively correlated with %HbG so that early-arriving birds had significantly higher %HbG than those arriving later. Clutch size, corrected for the effect of laying date, correlated positively with %HbG in females, as did the number of fledged young, corrected for the effect of laying date, for both sexes. We found no correlation between body mass and the %HbG. We suggest that prebreeding condition influences the timing of breeding and subsequent reproductive performance and that %HbG can be used as an indicator of prebreeding-condition in migrating birds.

  • 34. Antoniazza, Sylvain
    et al.
    Kanitz, Ricardo
    Neuenschwander, Samuel
    Burri, Reto
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Gaigher, Arnaud
    Roulin, Alexandre
    Goudet, Jerome
    Natural selection in a postglacial range expansion: the case of the colour cline in the European barn owl2014In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 23, no 22, p. 5508-5523Article, review/survey (Refereed)
    Abstract [en]

    Gradients of variationor clineshave always intrigued biologists. Classically, they have been interpreted as the outcomes of antagonistic interactions between selection and gene flow. Alternatively, clines may also establish neutrally with isolation by distance (IBD) or secondary contact between previously isolated populations. The relative importance of natural selection and these two neutral processes in the establishment of clinal variation can be tested by comparing genetic differentiation at neutral genetic markers and at the studied trait. A third neutral process, surfing of a newly arisen mutation during the colonization of a new habitat, is more difficult to test. Here, we designed a spatially explicit approximate Bayesian computation (ABC) simulation framework to evaluate whether the strong cline in the genetically based reddish coloration observed in the European barn owl (Tyto alba) arose as a by-product of a range expansion or whether selection has to be invoked to explain this colour cline, for which we have previously ruled out the actions of IBD or secondary contact. Using ABC simulations and genetic data on 390 individuals from 20 locations genotyped at 22 microsatellites loci, we first determined how barn owls colonized Europe after the last glaciation. Using these results in new simulations on the evolution of the colour phenotype, and assuming various genetic architectures for the colour trait, we demonstrate that the observed colour cline cannot be due to the surfing of a neutral mutation. Taking advantage of spatially explicit ABC, which proved to be a powerful method to disentangle the respective roles of selection and drift in range expansions, we conclude that the formation of the colour cline observed in the barn owl must be due to natural selection.

  • 35. Aplin, Lucy M.
    et al.
    Farine, Damien R.
    Mann, Richard P.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics.
    Sheldon, Ben C.
    Individual-level personality influences social foraging and collective behaviour in wild birds2014In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 281, no 1789, p. 20141016-Article in journal (Refereed)
    Abstract [en]

    There is increasing evidence that animal groups can maintain coordinated behaviour and make collective decisions based on simple interaction rules. Effective collective action may be further facilitated by individual variation within groups, particularly through leader-follower polymorphisms. Recent studies have suggested that individual-level personality traits influence the degree to which individuals use social information, are attracted to conspecifics, or act as leaders/followers. However, evidence is equivocal and largely limited to laboratory studies. We use an automated data-collection system to conduct an experiment testing the relationship between personality and collective decision-making in the wild. First, we report that foraging flocks of great tits (Parus major) show strikingly synchronous behaviour. A predictive model of collective decision-making replicates patterns well, suggesting simple interaction rules are sufficient to explain the observed social behaviour. Second, within groups, individuals with more reactive personalities behave more collectively, moving to within-flock areas of higher density. By contrast, proactive individuals tend to move to and feed at spatial periphery of flocks. Finally, comparing alternative simulations of flocking with empirical data, we demonstrate that variation in personality promotes within-patch movement while maintaining group cohesion. Our results illustrate the importance of incorporating individual variability in models of social behaviour.

  • 36.
    Arbuthnott, Devin
    et al.
    Univ British Columbia, Dept Zool, 4200-6270 Univ Blvd, Vancouver, BC V6T 1Z4, Canada.;Univ British Columbia, Biodivers Res Ctr, 4200-6270 Univ Blvd, Vancouver, BC V6T 1Z4, Canada..
    Mautz, Brian S.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Rundle, Howard D.
    Univ Ottawa, Dept Biol, Ottawa, ON, Canada..
    Rugged fitness landscapes and by-product adaptation in experimental populations of Drosophila melanogaster2018In: Evolutionary Ecology Research, ISSN 1522-0613, E-ISSN 1937-3791, Vol. 19, no 1, p. 15-28Article in journal (Refereed)
    Abstract [en]

    Background: While the concept of the fitness landscape is central to evolutionary theory, empirical characterizations of fitness landscapes have remained difficult. Recently, a number of laboratory experiments using microbes have suggested that fitness landscapes are often rugged, though there is some variation across environments and species. However, there have been very few characterizations of fitness landscapes in sexual organisms, making it unclear whether the conclusions from studies of microbes are applicable to other groups. Questions: Are fitness landscapes smooth or rugged in simplified laboratory environments for sexual organisms? How does landscape topography influence patterns of adaptation? Methods: We conducted a series of experiments using replicate populations of Drosophila melanogaster adapted to either cadmium-or ethanol-enriched food to characterize the fitness and phenotypes of these populations in a simplified laboratory environment (ethanol-enriched media). Results: We found that replicate populations adapted to different laboratory environments have diverged phenotypically in physiology, mating behaviour, and offspring production in alternate environments. However, both ethanol-and cadmium-adapted populations show high fitness in the ethanol-enriched environment relative to their founding population, and cadmium-adapted males actually outcompete ethanol-adapted males for mates in an ethanol environment. Conclusions: Our data indicate that the simplified ethanol-enriched medium represents a rugged fitness landscape, and that alternately adapted populations occupy different fitness peaks on this landscape. Because cadmium-adapted populations were never exposed to ethanol previously, it appears that these populations adapted to ethanol as a by-product of adaptation to their cadmium-enriched environment. Therefore, even in simplified laboratory environments, we find evidence for rugged fitness landscapes, and the overlap of fitness peaks on the phenotypic landscape allowed for by-product adaptation.

  • 37. Archer, C. R.
    et al.
    Zajitschek, Felix
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Sakaluk, S. K.
    Royle, N. J.
    Hunt, J.
    Sexual selection affects the evolution of lifespan and ageing in the decorated cricket gryllodes sigillatus2012In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 66, no 10, p. 3088-3100Article in journal (Refereed)
    Abstract [en]

    Recent work suggests that sexual selection can influence the evolution of ageing and lifespan by shaping the optimal timing and relative costliness of reproductive effort in the sexes. We used inbred lines of the decorated cricket, Gryllodes sigillatus, to estimate the genetic (co)variance between age-dependent reproductive effort, lifespan, and ageing within and between the sexes. Sexual selection theory predicts that males should die sooner and age more rapidly than females. However, a reversal of this pattern may be favored if reproductive effort increases with age in males but not in females. We found that male calling effort increased with age, whereas female fecundity decreased, and that males lived longer and aged more slowly than females. These divergent life-history strategies were underpinned by a positive genetic correlation between early-life reproductive effort and ageing rate in both sexes, although this relationship was stronger in females. Despite these sex differences in life-history schedules, age-dependent reproductive effort, lifespan, and ageing exhibited strong positive intersexual genetic correlations. This should, in theory, constrain the independent evolution of these traits in the sexes and may promote intralocus sexual conflict. Our study highlights the importance of sexual selection to the evolution of sex differences in ageing and lifespan in G. sigillatus.

  • 38. Armbrecht, Linda
    et al.
    Thompson, Peter A.
    Wright, Simon W.
    Schaeffer, Amandine
    Roughan, Moninya
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Armand, Leanne K.
    Comparison of the cross-shelf phytoplankton distribution of two oceanographically distinct regions off Australia2015In: Journal of Marine Systems, ISSN 0924-7963, E-ISSN 1879-1573, Vol. 148, p. 26-38Article in journal (Refereed)
    Abstract [en]

    The coastline of Australia spans tropical to temperate latitudes and encompasses a highly diverse phytoplankton community. Yet little is known about environmental driving forces of compositional and distributional patterns in natural phytoplankton communities of Australia. We investigate the relationships of phytoplankton (pico-, nano-, microphytoplankton, determined by microscopy and CHEMTAX) with a variety of environmental variables along cross-shelf gradients. Case studies were conducted in two highly distinct oceanographic regions of Australia (2010/2012): the tropical-temperate Coffs Harbour region (similar to 30 degrees S, 153 degrees E), where the shelf is narrow (similar to 30 km), and the tropical Kimberley region (similar to 16 degrees S, 122 degrees E), where the shelf is-wide (similar to 200 km). We distinguished three water masses in both study regions: relatively cold, nutrient-rich inshore waters; oligotrophic, stratified offshore waters; and cold, nutrient-rich deep waters. Most phytoplankton taxa (cyanobacteria, cryptophytes, dinoflagellates, haptophytes and prasinophytes) showed group-specific relationships with similar environmental variables in both regions. Diatoms occurred in nutrient-rich inshore waters in the Kimberley, whereas they were widely spread across the narrow continental shelf at Coffs Harbour. Off Coffs Harbour, a senescent bloom of the diatom Leptocylindrus danicus probably caused shelf-scale surface nutrient depletion. While microphytoplankton clearly increased, pico- and nanophytoplankton decreased with distance from the coast over the wide shelf in the Kimberley region. In contrast, the abundance of individual phytoplankton size-classes remained relatively constant across the narrow Coffs Harbour shelf. We conclude that general similarities exist between the relationship of phytoplankton and cross-shelf environmental variables in the two sites and assign differences primarily to the varying spatial resolution of our case studies.

  • 39.
    Arnqvist, Göran
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Rowe, Locke
    The shape of preference functions and what shapes them: a comment on Edward2015In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 26, no 2, p. 325-325Article in journal (Other academic)
  • 40.
    Ashitani, T.
    et al.
    Yamagata Univ, Dept Bioenvirom, Fac Agr, Tsuruoka, Yamagata 9978555, Japan.;Royal Inst Technol, Sch Chem Sci & Engn, Ecol Chem Grp, Dept Chem, SE-10044 Stockholm, Sweden..
    Garboui, Samira Sadek
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Schubert, F.
    Royal Inst Technol, Sch Chem Sci & Engn, Ecol Chem Grp, Dept Chem, SE-10044 Stockholm, Sweden..
    Vongsombath, C.
    Royal Inst Technol, Sch Chem Sci & Engn, Ecol Chem Grp, Dept Chem, SE-10044 Stockholm, Sweden.;Natl Univ Laos NOUL, Viangchan, Laos..
    Liblikas, I.
    Inst Technol, Sect Organ Chem, EE-50411 Tartu, Estonia..
    Palsson, K.
    Royal Inst Technol, Sch Chem Sci & Engn, Ecol Chem Grp, Dept Chem, SE-10044 Stockholm, Sweden..
    Borg-Karlson, A. -K
    Activity studies of sesquiterpene oxides and sulfides from the plant Hyptis suaveolens (Lamiaceae) and its repellency on Ixodes ricinus (Acari:Ixodidae)2015In: Experimental & applied acarology, ISSN 0168-8162, E-ISSN 1572-9702, Vol. 67, no 4, p. 595-606Article in journal (Refereed)
    Abstract [en]

    Hyptis suaveolens (Lamiaceae), a plant traditionally used as a mosquito repellent, has been investigated for repellent properties against nymphs of the tick Ixodes ricinus. Essential oils and volatile compounds of fresh and dried leaves, from plants originating from Laos and Guinea-Bissau, were identified by GC-MS and tested in a tick repellency bioassay. All the essential oils were strongly repellent against the ticks, even though the main volatile constituents differed in their proportions of potentially tick repellent chemicals. (+)/(-)-sabinene were present in high amounts in all preparations, and dominated the emission from dry and fresh leaves together with 1,8-cineol and alpha-phellandrene. 1,8-Cineol and sabinene were major compounds in the essential oils from H. suaveolens from Laos. Main compounds in H. suaveolens from Guinea-Bissau were (-)-sabinene, limonene and terpinolene. Among the sesquiterpene hydrocarbons identified, alpha-humulene exhibited strong tick repellency (96.8 %). Structure activity studies of oxidation or sulfidation products of germacrene D, alpha-humulene and beta-caryophyllene, showed increased tick repellent activity: of mint sulfide (59.4 %), humulene-6,7-oxide (94.5 %) and caryophyllene-6,7-oxide (96.9 %). The substitution of oxygen with sulfur slightly lowered the repellency. The effects of the constituents in the oils can then be regarded as a trade off between the subsequently lower volatility of the sesquiterpene derivatives compared to the monoterpenes and may thus increase their potential usefulness as tick repellents.

  • 41.
    Attermeyer, Katrin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Leibniz Inst Freshwater Ecol & Inland Fisheries C, Muggelseedamm 310, D-12587 Berlin, Germany..
    Flury, S.
    Leibniz Inst Freshwater Ecol & Inland Fisheries C, Muggelseedamm 310, D-12587 Berlin, Germany.;Univ Geneva, Fac Sci, Blvd Carl Vogt 66, CH-1211 Geneva, Switzerland..
    Jayakumar, R.
    IITM, IGCS, Madras 600036, Tamil Nadu, India.;IITM, Environm & Water Resources Engn Div, Dept Civil Engn, Madras 600036, Tamil Nadu, India..
    Fiener, P.
    Univ Augsburg, Dept Geog, Alter Postweg 118, D-86159 Augsburg, Germany..
    Steger, K.
    IITM, IGCS, Madras 600036, Tamil Nadu, India..
    Arya, V.
    IITM, Environm & Water Resources Engn Div, Dept Civil Engn, Madras 600036, Tamil Nadu, India..
    Wilken, F.
    Univ Augsburg, Dept Geog, Alter Postweg 118, D-86159 Augsburg, Germany.;BTU, Chair Soil Protect & Recultivat, Konrad Wachsmann Allee 6, D-03013 Cottbus, Germany..
    van Geldern, R.
    Univ Erlangen Nurnberg, GeoZentrum Nordbayern, Schlossgarten 5, D-91054 Erlangen, Germany..
    Premke, K.
    Leibniz Inst Freshwater Ecol & Inland Fisheries C, Muggelseedamm 310, D-12587 Berlin, Germany.;Leibniz Ctr Agr Landscape Res ZALF, Inst Landscape Biogeochem, Eberswalder Str 84, D-15374 Muncheberg, Germany..
    Invasive floating macrophytes reduce greenhouse gas emissions from a small tropical lake2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 20424Article in journal (Refereed)
    Abstract [en]

    Floating macrophytes, including water hyacinth (Eichhornia crassipes), are dominant invasive organisms in tropical aquatic systems, and they may play an important role in modifying the gas exchange between water and the atmosphere. However, these systems are underrepresented in global datasets of greenhouse gas (GHG) emissions. This study investigated the carbon (C) turnover and GHG emissions from a small (0.6 km(2)) water-harvesting lake in South India and analysed the effect of floating macrophytes on these emissions. We measured carbon dioxide (CO2) and methane (CH4) emissions with gas chambers in the field as well as water C mineralization rates and physicochemical variables in both the open water and in water within stands of water hyacinths. The CO2 and CH4 emissions from areas covered by water hyacinths were reduced by 57% compared with that of open water. However, the C mineralization rates were not significantly different in the water between the two areas. We conclude that the increased invasion of water hyacinths and other floating macrophytes has the potential to change GHG emissions, a process that might be relevant in regional C budgets.

  • 42.
    Attermeyer, Katrin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Chemical Analytics and Biogeochemistry, Germany.
    Grossart, Hans-Peter
    Leibniz-Institute of Freshwater Ecology and InlandFisheries, Experimental Limnology, Germany; Institute for Biochemistry and Biology, Potsdam University, Germany.
    Flury, Sabine
    Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Chemical Analytics and Biogeochemistry, Germany; Faculty of Science, University of Geneva, Switzerland.
    Premke, Katrin
    Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Chemical Analytics and Biogeochemistry, Germany; Leibniz Centre for Agricultural Landscape Research (ZALF), Institute for Landscape Biogeochemistry, Germany.
    Bacterial processes and biogeochemical changes in the water body of kettle holes: mainly driven by autochthonous organic matter?2017In: Aquatic Sciences, ISSN 1015-1621, E-ISSN 1420-9055, Vol. 79, no 3, p. 675-687Article in journal (Refereed)
    Abstract [en]

    Kettle holes are small inland waters formed from glacially-created depressions often situated in agricultural landscapes. Due to their high perimeter-to-area ratio facilitating a high aquatic-terrestrial coupling, kettle holes can accumulate high concentrations of organic carbon and nutrients, fueling microbial activities and turnover rates. Thus, they represent hotspots of carbon turnover in the landscape, but their bacterial activities and controlling factors have not been well investigated. Therefore, we aimed to assess the relative importance of various environmental factors on bacterial and biogeochemical processes in the water column of kettle holes and to disentangle their variations. In the water body of ten kettle holes in north-eastern Germany, we measured several physico-chemical and biological parameters such as carbon quantity and quality, as well as bacterial protein production (BP) and community respiration (CR) in spring, early summer and autumn 2014. Particulate organic matter served as an indicator of autochthonous production and represented an important parameter to explain variations in BP and CR. This notion is supported by qualitative absorbance indices of dissolved molecules in water samples and C:N ratios of the sediments, which demonstrate high fractions of autochthonous organic matter (OM) in the studied kettle holes. In contrast, dissolved chemical parameters were less important for bacterial activities although they revealed strong differences throughout the growing season. Pelagic bacterial activities and dynamics might thus be regulated by autochthonous OM in kettle holes implying a control of important biogeochemical processes by internal primary production rather than facilitated exchange with the terrestrial surrounding due to a high perimeter-to-area ratio.

  • 43. Avia, Komlan
    et al.
    Karkkainen, Katri
    Lagercrantz, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Savolainen, Outi
    Association of FLOWERING LOCUS T/TERMINAL FLOWER 1-like gene FTL2 expression with growth rhythm in Scots pine (Pinus sylvestris)2014In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 204, no 1, p. 159-170Article in journal (Refereed)
    Abstract [en]

    Understanding the genetic basis of the timing of bud set, an important trait in conifers, is relevant for adaptation and forestry practice. In common garden experiments, both Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) show a latitudinal cline in the trait. We compared the regulation of their bud set biology by examining the expression of PsFTL2, a Pinus sylvestris homolog to PaFTL2, a FLOWERING LOCUS T/TERMINAL FLOWER 1 (FT/TFL1)-like gene, the expression levels of which have been found previously to be associated with the timing of bud set in Norway spruce. In a common garden study, we analyzed the relationship of bud phenology under natural and artificial photoperiods and the expression of PsFTL2 in a set of Scots pine populations from different latitudes. The expression of PsFTL2 increased in the needles preceding bud set and decreased during bud burst. In the northernmost population, even short night periods were efficient to trigger this expression, which also increased earlier under all photoperiodic regimes compared with the southern populations. Despite the different biology, with few limitations, the two conifers that diverged 140 million yr ago probably share an association of FTL2 with bud set, pointing to a common mechanism for the timing of growth cessation in conifers.

  • 44.
    Avril, Alexis
    et al.
    Linnaeus Univ, Ctr Ecol & Evolut Microbial Model Syst EEMiS, SE-39182 Kalmar, Sweden..
    Grosbois, Vladimir
    CIRAD, Campus Int Baillarguet, F-34398 Montpellier, France..
    Latorre-Margalef, Neus
    Linnaeus Univ, Ctr Ecol & Evolut Microbial Model Syst EEMiS, SE-39182 Kalmar, Sweden.;Univ Georgia, Southeeastern Cooperat Wildlife Dis Study, Coll Vet Med, Dept Populat Hlth, Athens, GA 30602 USA..
    Gaidet, Nicolas
    CIRAD, Campus Int Baillarguet, F-34398 Montpellier, France..
    Tolf, Conny
    Linnaeus Univ, Ctr Ecol & Evolut Microbial Model Syst EEMiS, SE-39182 Kalmar, Sweden..
    Olsen, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Waldenström, Jonas
    Linnaeus Univ, Ctr Ecol & Evolut Microbial Model Syst EEMiS, SE-39182 Kalmar, Sweden..
    Capturing individual-level parameters of influenza A virus dynamics in wild ducks using multistate models2016In: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 53, no 4, p. 1289-1297Article in journal (Refereed)
    Abstract [en]

    Disease prevalence in wildlife is governed by epidemiological parameters (infection and recovery rates) and response to infection, both of which vary within and among individual hosts. Studies quantifying these individual-scale parameters and documenting their source of variation in wild hosts are fundamental for predicting disease dynamics. Such studies do not exist for the influenza A virus (IAV), despite its strong impact on the global economy and public health. Using capture-recaptures of 3500 individual mallards Anas platyrhynchos during seven migration seasons at a stopover site in southern Sweden, we provide the first empirical description of the individual-based mechanisms of IAV dynamics in a wild reservoir host. For most years, prevalence and risk of IAV infection peaked at a single time during the autumn migration season, but the timing, shape and intensity of the infection curve showed strong annual heterogeneity. In contrast, the seasonal pattern of recovery rate only varied in intensity across years. Adults and juveniles displayed similar seasonal patterns of infection and recovery each year. However, compared to adults, juveniles experienced twice the risk of becoming infected, whereas recovery rates were similar across age categories. Finally, we did not find evidence that infection influenced the timing of emigration.Synthesis and applications. Our study provides robust empirical estimates of epidemiological parameters for predicting influenza A virus (IAV) dynamics. However, the strong annual variation in infection curves makes forecasting difficult. Prevalence data can provide reliable surveillance indicators as long as they catch the variation in infection risk. However, individual-based monitoring of infection is required to verify this assumption in areas where surveillance occurs. In this context, monitoring of captive sentinel birds kept in close contact with wild birds is useful. The fact that infection does not impact the timing of migration underpins the potential for mallards to spread viruses rapidly over large geographical scales. Hence, we strongly encourage IAV surveillance with a multistate capture-recapture approach along the entire migratory flyway of mallards.

  • 45.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    Comments on Conservation, reclamation and grazing in the northern Negev: contradictory or complementary concepts? (paper 38a) by Avi Perevolotsky1995In: Pastoral Development Network. Network Paper, Vol. 38b, p. 21-24Article in journal (Refereed)
  • 46.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    Distribution and vegetation dynamics of humid savannas in Africa and Asia1992In: Journal of Vegetation Science, ISSN 1100-9233, E-ISSN 1654-1103, Vol. 3, p. 345-356Article in journal (Refereed)
    Abstract [en]

    A review is presented on the literature about the distribution of savannas in humid climates in Africa and Asia and their vegetation dynamics. Sections are devoted to African lowland and montane savannas (the latter divided into southern, eastern, western and northern African), Madagascar, Indian subcontinent, SE Asia and New Guinea. It is concluded that the extension of savannas under humid climatic conditions and the relation to the distribution of forests is a function of cultivation, grazing by domestic and wild animals, present and previous climate, geomorphology and soil characteristics. Once established, savannas are often maintained by fires, both natural and man-made.

    Montane savannas are generally brought about by man's clearing, cultivation and burning. Fire is a stochastic variable; it creates an ecotone sensu stricto (an environmentally stochastic stress zone) at the forest/savanna border. On the other hand, if geomorphology and soil are the determinants, the transition between forest and savanna would have the character of an ecocline (a gradient zone) with fundamentally different conditions.

    In humid African lowland climates forests expand into savannas if the latter are not maintained by man. Whether forests also expand in less humid climates is disputed. In montane areas forest expansion may be delayed on degraded soils and when diaspores are lacking

  • 47.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Systematic Botany.
    Ecological studies of the vegetation on marshy shores1977In: Great Ruaha Power Project. Ecological studies of the Mtera Basin, Stockholm: Tanzania Electric Supply Co., Ltd. (SWECO) , 1977, p. 115-128Chapter in book (Other academic)
  • 48.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    Ecotone versus ecocline: vegetation zonation and dynamics around a small reservoir in Tanzania1993In: Journal of Biogeography, ISSN 0305-0270, E-ISSN 1365-2699, Vol. 20, p. 209-218Article in journal (Refereed)
    Abstract [en]

    Data from transects on the shores and drawdown area of a small reservoir in Tanzania with a strongly fluctuating water level were used to illuminate a spatial and shortterm temporalvariation in the vegetation of a borderzone. Vegetation data were related to the position of the sample plots in relation to a water level gauge and to time (seasonal changes and changes between two consecutive years).

    Few perennial species survived the rainy season in the zone exposed to the fluctuating water level. Most plants were annuals that colonized yearly. The vegetation under the full supply level (=FSL) was sparse and related to Eriochloetum nubicae and Ecliption albae. An observed great variation between sites and years of this kind of vegetation seems to be due to the unstable character of the sites with frequent recolonization of bare land.

    The need to distinguish formally between ecotones (in a strict sense) and ecoclines is stressed. The drawdown area has (a) a peak in β diversity just below FSL, (b) no β diversity in a zone below FSL that was not flooded the preceding rainy season and (c) a certain amount of β diversity further down.(a) and(b) are considered typical of an ecotone. (c) is interpreted as a 'shortterm ecocline' of colonizing annuals between two rainy seasons. The system belowFSL as a whole is an ecotone. The shore above FSL is an ecocline with high α and β diversity.

    A downward movement of plant species during the dry season is demonstrated using canonical correspondence analysis. Thus, this ecotone is driven by the environment and no internal (autonomous) control is likely to occur

  • 49.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecological Botany.
    Effekter av myrdikning på flora och vegetation: En problemstrukturerad sammanställning av litteratur1981Book (Other academic)
  • 50.
    Backéus, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Swedish Biodiversity Centre.
    Grönlands växtvärld2012In: Svensk Botanisk Tidskrift, ISSN 0039-646X, Vol. 106, no 1, p. 11-23Article in journal (Other (popular science, discussion, etc.))
    Abstract [en]

    Flora, vegetation and land-use history of Greenland are briefly described. The species-poor flora is Arctic. Thirteen endemic taxa may have survived the glacial period on Greenland.

    The latitudinal vegetation zones extend from High Arctic deserts to Low Arctic heaths with erect shrubs. A small area in the SW is Subarctic with elfin forests and meadows. A corresponding altitudinal zonation is also described.

    Greenland was colonised 1000 years ago by both Inuits and Norse settlers. The latter practised animal husbandry in the Subarctic SW. Hay-making was extensive on fertilized and irrigated fields. Extensive deforestation and land degradation took place, until the Norse population disappeared in the 15th century. It is argued that the decreasing population on Iceland during late medieval times made it possible for the Greenlandic Norse to move there. Modern sheep holdings have again caused land degradation. Notes on small-scale forest plantation and on ethnobotany are given.

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