TY - JOUR A1 - Schlägel, Ulrike E. A1 - Lewis, Mark A. T1 - Robustness of movement models: can models bridge the gap between temporal scales of data sets and behavioural processes? JF - Journal of mathematical biology KW - Animal movement KW - Sampling rate KW - Resource selection KW - GPS data KW - Parameter estimation KW - Markov model Y1 - 2016 U6 - https://doi.org/10.1007/s00285-016-1005-5 SN - 0303-6812 SN - 1432-1416 VL - 73 SP - 1691 EP - 1726 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Coutinho, Renato Mendes A1 - Klauschies, Toni A1 - Gaedke, Ursula T1 - Bimodal trait distributions with large variances question the reliability of trait-based aggregate models JF - Theoretical ecology N2 - Functionally diverse communities can adjust their species composition to altered environmental conditions, which may influence food web dynamics. Trait-based aggregate models cope with this complexity by ignoring details about species identities and focusing on their functional characteristics (traits). They describe the temporal changes of the aggregate properties of entire communities, including their total biomasses, mean trait values, and trait variances. The applicability of aggregate models depends on the validity of their underlying assumptions that trait distributions are normal and exhibit small variances. We investigated to what extent this can be expected to work by comparing an innovative model that accounts for the full trait distributions of predator and prey communities to a corresponding aggregate model. We used a food web structure with well-established trade-offs among traits promoting mutual adjustments between prey edibility and predator selectivity in response to selection. We altered the shape of the trade-offs to compare the outcome of the two models under different selection regimes, leading to trait distributions increasingly deviating from normality. Their biomass and trait dynamics agreed very well for stabilizing selection and reasonably well for directional selection, under which different trait values are favored at different times. However, for disruptive selection, the results of the aggregate model strongly deviated from the full trait distribution model that showed bimodal trait distributions with large variances. Hence, the outcome of aggregate models is reliable under ideal conditions but has to be questioned when confronted with more complex selection regimes and trait distributions, which are commonly observed in nature. KW - Fitness gradient KW - Communities as complex adaptive systems KW - Moment closure for trait-based aggregate model approaches KW - Multimodal trait distributions KW - Lumpiness in pattern formation and self-organization KW - Shape of trade-offs and stabilizing and disruptive selection Y1 - 2016 U6 - https://doi.org/10.1007/s12080-016-0297-9 SN - 1874-1738 SN - 1874-1746 VL - 9 SP - 389 EP - 408 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Reinecke, J. A1 - Wulf, M. A1 - Baeten, Lander A1 - Brunet, J. A1 - Decocq, G. A1 - De Frenne, G. A1 - Diekmann, M. A1 - Graae, B. J. A1 - Heinken, Thilo A1 - Hermy, M. A1 - Jamoneau, A. A1 - Lenoir, J. A1 - Plue, J. A1 - Orczewska, A. A1 - Van Calster, H. A1 - Verheyen, Kris A1 - Naaf, T. T1 - Acido- and neutrophilic temperate forest plants display distinct shifts in ecological pH niche across north-western Europe JF - Ecography : pattern and diversity in ecology ; research papers forum N2 - Ecological niches of organisms vary across geographical space, but niche shift patterns between regions and the underlying mechanisms remain largely unexplored. We studied shifts in the pH niche of 42 temperate forest plant species across a latitudinal gradient from northern France to boreo-nemoral Sweden. We asked 1) whether species restrict their niches with increasing latitude as they reach their northern range margin (environmental constraints); 2) whether species expand their niches with increasing latitude as regional plant species richness decreases (competitive release); and 3) whether species shift their niche position toward more acidic sites with increasing latitude as the relative proportion of acidic soils increases (local adaptation). Based on 1458 vegetation plots and corresponding soil pH values, we modelled species response curves using Huisman-Olff-Fresco models. Four niche measures (width, position, left and right border) were compared among regions by randomization tests. We found that with increasing latitude, neutrophilic species tended to retreat from acidic sites, indicating that these species retreat to more favorable sites when approaching their range margin. Alternatively, these species might benefit from enhanced nitrogen deposition on formerly nutrient-poor, acidic sites in southern regions or lag behind in post-glacial recolonization of potential habitats in northern regions. Most acidophilic species extended their niche toward more base-rich sites with increasing latitude, indicating competitive release from neutrophilic species. Alternatively, acidophilic species might benefit from optimal climatic conditions in the north where some have their core distribution area. Shifts in the niche position suggested that local adaptation is of minor importance. We conclude that shifts in the pH niche of temperate forest plants are the rule, but the directions of the niche shifts and possible explanations vary. Our study demonstrates that differentiating between acidophilic and neutrophilic species is crucial to identify general patterns and underlying mechanisms. Y1 - 2016 U6 - https://doi.org/10.1111/ecog.02051 SN - 0906-7590 SN - 1600-0587 VL - 39 SP - 1164 EP - 1175 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Lachmann, Sabrina C. A1 - Maberly, Stephen C. A1 - Spijkerman, Elly T1 - ECOPHYSIOLOGY MATTERS: LINKING INORGANIC CARBON ACQUISITION TO ECOLOGICAL PREFERENCE IN FOUR SPECIES OF MICROALGAE (CHLOROPHYCEAE) JF - Journal of phycology N2 - The effect of CO2 supply is likely to play an important role in algal ecology. Since inorganic carbon (C-i) acquisition strategies are very diverse among microalgae and C-i availability varies greatly within and among habitats, we hypothesized that C-i acquisition depends on the pH of their preferred natural environment (adaptation) and that the efficiency of C-i uptake is affected by CO2 availability (acclimation). To test this, four species of green algae originating from different habitats were studied. The pH-drift and C-i uptake kinetic experiments were used to characterize C-i acquisition strategies and their ability to acclimate to high and low CO2 conditions and high and low pH was evaluated. Results from pH drift experiments revealed that the acidophile and acidotolerant Chlamydomonas species were mainly restricted to CO2, whereas the two neutrophiles were efficient bicarbonate users. CO2 compensation points in low CO2-acclimated cultures ranged between 0.6 and 1.4 mu M CO2 and acclimation to different culture pH and CO2 conditions suggested that CO2 concentrating mechanisms were present in most species. High CO2 acclimated cultures adapted rapidly to low CO2 condition during pH-drifts. C-i uptake kinetics at different pH values showed that the affinity for C-i was largely influenced by external pH, being highest under conditions where CO2 dominated the C-i pool. In conclusion, C-i acquisition was highly variable among four species of green algae and linked to growth pH preference, suggesting that there is a connection between C-i acquisition and ecological distribution. KW - acidophile KW - carbon acquisition KW - CCM KW - Chlamydomonas KW - Chlorella KW - CO2 supply KW - extremophile KW - inorganic carbon uptake kinetics KW - pH-drift KW - Scenedesmus Y1 - 2016 U6 - https://doi.org/10.1111/jpy.12462 SN - 0022-3646 SN - 1529-8817 VL - 52 SP - 1051 EP - 1063 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Meyer, Sebastian T. A1 - Ebeling, Anne A1 - Eisenhauer, Nico A1 - Hertzog, Lionel A1 - Hillebrand, Helmut A1 - Milcu, Alexandru A1 - Pompe, Sven A1 - Abbas, Maike A1 - Bessler, Holger A1 - Buchmann, Nina A1 - De Luca, Enrica A1 - Engels, Christof A1 - Fischer, Markus A1 - Gleixner, Gerd A1 - Hudewenz, Anika A1 - Klein, Alexandra-Maria A1 - de Kroon, Hans A1 - Leimer, Sophia A1 - Loranger, Hannah A1 - Mommer, Liesje A1 - Oelmann, Yvonne A1 - Ravenek, Janneke M. A1 - Roscher, Christiane A1 - Rottstock, Tanja A1 - Scherber, Christoph A1 - Scherer-Lorenzen, Michael A1 - Scheu, Stefan A1 - Schmid, Bernhard A1 - Schulze, Ernst-Detlef A1 - Staudler, Andrea A1 - Strecker, Tanja A1 - Temperton, Vicky A1 - Tscharntke, Teja A1 - Vogel, Anja A1 - Voigt, Winfried A1 - Weigelt, Alexandra A1 - Wilcke, Wolfgang A1 - Weisser, Wolfgang W. T1 - Effects of biodiversity strengthen over time as ecosystem functioning declines at low and increases at high biodiversity JF - Ecosphere : the magazine of the International Ecology University KW - biodiversity ecosystem functioning (BEF) KW - ecosystem processes KW - grassland KW - mechanism KW - plant productivity KW - plant species richness KW - temporal effects KW - trophic interactions Y1 - 2016 U6 - https://doi.org/10.1002/ecs2.1619 SN - 2150-8925 VL - 7 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Mao, Hailiang A1 - Nakamura, Moritaka A1 - Viotti, Corrado A1 - Grebe, Markus T1 - A Framework for Lateral Membrane Trafficking and Polar Tethering of the PEN3 ATP-Binding Cassette Transporter JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - The outermost cell layer of plants, the epidermis, and its outer (lateral) membrane domain facing the environment are continuously challenged by biotic and abiotic stresses. Therefore, the epidermis and the outer membrane domain provide important selective and protective barriers. However, only a small number of specifically outer membrane-localized proteins are known. Similarly, molecular mechanisms underlying the trafficking and the polar placement of outer membrane domain proteins require further exploration. Here, we demonstrate that ACTIN7 (ACT7) mediates trafficking of the PENETRATION3 (PEN3) outer membrane protein from the trans-Golgi network (TGN) to the plasma membrane in the root epidermis of Arabidopsis (Arabidopsis thaliana) and that actin function contributes to PEN3 endocytic recycling. In contrast to such generic ACT7-dependent trafficking from the TGN, the EXOCYST84b (EXO84b) tethering factor mediates PEN3 outer-membrane polarity. Moreover, precise EXO84b placement at the outer membrane domain itself requires ACT7 function. Hence, our results uncover spatially and mechanistically distinct requirements for ACT7 function during outer lateral membrane cargo trafficking and polarity establishment. They further identify an exocyst tethering complex mediator of outer lateral membrane cargo polarity. Y1 - 2016 U6 - https://doi.org/10.1104/pp.16.01252 SN - 0032-0889 SN - 1532-2548 VL - 172 SP - 2245 EP - 2260 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Procter, Duncan S. A1 - Cottrell, Joan E. A1 - Watts, Kevin A1 - Hofreiter, Michael A1 - Robinson, Elva J. H. T1 - Does cooperation mean kinship between spatially discrete ant nests? JF - Ecology and evolution N2 - Eusociality is one of the most complex forms of social organization, characterized by cooperative and reproductive units termed colonies. Altruistic behavior of workers within colonies is explained by inclusive fitness, with indirect fitness benefits accrued by helping kin. Members of a social insect colony are expected to be more closely related to one another than they are to other conspecifics. In many social insects, the colony can extend to multiple socially connected but spatially separate nests (polydomy). Social connections, such as trails between nests, promote cooperation and resource exchange, and we predict that workers from socially connected nests will have higher internest relatedness than those from socially unconnected, and noncooperating, nests. We measure social connections, resource exchange, and internest genetic relatedness in the polydomous wood ant Formica lugubris to test whether (1) socially connected but spatially separate nests cooperate, and (2) high internest relatedness is the underlying driver of this cooperation. Our results show that socially connected nests exhibit movement of workers and resources, which suggests they do cooperate, whereas unconnected nests do not. However, we find no difference in internest genetic relatedness between socially connected and unconnected nest pairs, both show high kinship. Our results suggest that neighboring pairs of connected nests show a social and cooperative distinction, but no genetic distinction. We hypothesize that the loss of a social connection may initiate ecological divergence within colonies. Genetic divergence between neighboring nests may build up only later, as a consequence rather than a cause of colony separation. KW - colony organization KW - eusociality KW - Formica lugubris KW - kin selection KW - polydomy KW - social organization Y1 - 2016 U6 - https://doi.org/10.1002/ece3.2590 SN - 2045-7758 VL - 6 SP - 8846 EP - 8856 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Cepakova, Zuzana A1 - Hrouzek, Pavel A1 - Ziskova, Eva A1 - Nuyanzina-Boldareva, Ekaterina A1 - Sorf, Michal A1 - Kozlikova-Zapomelova, Eliska A1 - Salka, Ivette A1 - Grossart, Hans-Peter A1 - Koblizek, Michal T1 - High turnover rates of aerobic anoxygenic phototrophs in European freshwater lakes JF - Environmental microbiology N2 - Aerobic Anoxygenic Phototrophic (AAP) bacteria are bacteriochlorophyll (BChl) a -containing organisms which use light energy to supplement their predominantly heterotrophic metabolism. Here, we investigated mortality and growth rates of AAP bacteria in three different freshwater lakes in Central Europe: the mountain lake Plesne, the oligo-mesotrophic Lake Stechlin and the forest pond Huntov. The mortality of AAP bacteria was estimated from diel changes of BChl a fluorescence. Net and gross growth rates were calculated from the increases in AAP cell numbers. The gross growth rates of AAP bacteria ranged from 0.38 to 5.6 d(-1), with the highest values observed during summer months. Simultaneously, the rapidly growing AAP cells have to cope with an intense grazing pressure by both zooplankton and protists. The presented results document that during the day, gross growth usually surpased mortality. Our results indicate that AAP bacteria utilize light energy under natural conditions to maintain rapid growth rates, which are balanced by a generally intense grazing pressure. Y1 - 2016 U6 - https://doi.org/10.1111/1462-2920.13475 SN - 1462-2912 SN - 1462-2920 VL - 18 SP - 5063 EP - 5071 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Wutke, Saskia A1 - Benecke, Norbert A1 - Sandoval-Castellanos, Edson A1 - Döhle, Hans-Jürgen A1 - Friederich, Susanne A1 - Gonzalez Soto, Javier Esteban A1 - Hallsson, Jon Hallsteinn A1 - Hofreiter, Michael A1 - Lougas, Lembi A1 - Magnell, Ola A1 - Morales-Muniz, Arturo A1 - Orlando, Ludovic A1 - Palsdottir, Albina Hulda A1 - Reissmann, Monika A1 - Ruttkay, Matej A1 - Trinks, Alexandra A1 - Ludwig, Arne T1 - Spotted phenotypes in horses lost attractiveness in the Middle Ages JF - Scientific reports N2 - Horses have been valued for their diversity of coat colour since prehistoric times; this is especially the case since their domestication in the Caspian steppe in similar to 3,500 BC. Although we can assume that human preferences were not constant, we have only anecdotal information about how domestic horses were influenced by humans. Our results from genotype analyses show a significant increase in spotted coats in early domestic horses (Copper Age to Iron Age). In contrast, medieval horses carried significantly fewer alleles for these phenotypes, whereas solid phenotypes (i.e., chestnut) became dominant. This shift may have been supported because of (i) pleiotropic disadvantages, (ii) a reduced need to separate domestic horses from their wild counterparts, (iii) a lower religious prestige, or (iv) novel developments in weaponry. These scenarios may have acted alone or in combination. However, the dominance of chestnut is a remarkable feature of the medieval horse population. Y1 - 2016 U6 - https://doi.org/10.1038/srep38548 SN - 2045-2322 VL - 6 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Westbury, Michael V. A1 - Prost, Stefan A1 - Seelenfreund, Andrea A1 - Ramirez, Jose-Miguel A1 - Matisoo-Smith, Elizabeth A. A1 - Knapp, Michael T1 - First complete mitochondrial genome data from ancient South American camelids - The mystery of the chilihueques from Isla Mocha (Chile) JF - Scientific reports Y1 - 2016 U6 - https://doi.org/10.1038/srep38708 SN - 2045-2322 VL - 6 PB - Nature Publ. Group CY - London ER -