TY - JOUR A1 - Wagner, Nicole D. A1 - Hillebrand, Helmut A1 - Wacker, Alexander A1 - Frost, Paul C. T1 - Nutritional indicators and their uses in ecology JF - Ecology letters N2 - The nutrition of animal consumers is an important regulator of ecological processes due to its effects on their physiology, life-history and behaviour. Understanding the ecological effects of poor nutrition depends on correctly diagnosing the nature and strength of nutritional limitation. Despite the need to assess nutritional limitation, current approaches to delineating nutritional constraints can be non-specific and imprecise. Here, we consider the need and potential to develop new complementary approaches to the study of nutritional constraints on animal consumers by studying and using a suite of established and emerging biochemical and molecular responses. These nutritional indicators include gene expression, transcript regulators, protein profiling and activity, and gross biochemical and elemental composition. The potential applications of nutritional indicators to ecological studies are highlighted to demonstrate the value that this approach would have to future studies in community and ecosystem ecology. KW - Ecological stoichiometry KW - lipid profiling KW - metabolism KW - nutrient-stress KW - nutrition KW - proteomics KW - transcriptomics Y1 - 2013 U6 - https://doi.org/10.1111/ele.12067 SN - 1461-023X VL - 16 IS - 4 SP - 535 EP - 544 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Filip, Joanna A1 - Bauer, Barbara A1 - Hillebrand, Helmut A1 - Beniermann, Anna A1 - Gaedke, Ursula A1 - Moorthi, Stefanie D. T1 - Multitrophic diversity effects depend on consumer specialization and species-specific growth and grazing rates JF - Oikos N2 - Ecosystem functioning is affected by horizontal (within trophic groups) and vertical (across trophic levels) biodiversity. Theory predicts that the effects of vertical biodiversity depend on consumer specialization. In a microcosm experiment, we investigated ciliate consumer diversity and specialization effects on algal prey biovolume, evenness and composition, and on ciliate biovolume production. The experimental data was complemented by a process-based model further analyzing the ecological mechanisms behind the observed diversity effects. Overall, increasing consumer diversity had no significant effect on prey biovolume or evenness. However, consumer specialization affected the prey community. Specialist consumers showed a stronger negative impact on prey biovolume and evenness than generalists. The model confirmed that this pattern was mainly driven by a single specialist with a high per capita grazing rate, consuming the two most productive prey species. When these were suppressed, the prey assemblage became dominated by a less productive species, consequently decreasing prey biovolume and evenness. Consumer diversity increased consumer biovolume, which was stronger for generalists than for specialists and highest in mixed combinations, indicating that consumer functional diversity, i.e. more diverse feeding strategies, increased resource use efficiency. Overall, our results indicate that consumer diversity effects on prey and consumers strongly depend on species-specific growth and grazing rates, which may be at least equally important as consumer specialization in driving consumer diversity effects across trophic levels. Y1 - 2014 U6 - https://doi.org/10.1111/oik.01219 SN - 0030-1299 SN - 1600-0706 VL - 123 IS - 8 SP - 912 EP - 922 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 - Meyer, Sebastian Tobias A1 - Ptacnik, Robert A1 - Hillebrand, Helmut A1 - Bessler, Holger A1 - Buchmann, Nina A1 - Ebeling, Anne A1 - Eisenhauer, Nico A1 - Engels, Christof A1 - Fischer, Markus A1 - Halle, Stefan A1 - Klein, Alexandra-Maria A1 - Oelmann, Yvonne A1 - Roscher, Christiane A1 - Rottstock, Tanja A1 - Scherber, Christoph A1 - Scheu, Stefan A1 - Schmid, Bernhard A1 - Schulze, Ernst-Detlef A1 - Temperton, Vicky M. A1 - Tscharntke, Teja A1 - Voigt, Winfried A1 - Weigelt, Alexandra A1 - Wilcke, Wolfgang A1 - Weisser, Wolfgang W. T1 - Biodiversity-multifunctionality relationships depend on identity and number of measured functions JF - Nature Ecology & Evolution N2 - Biodiversity ensures ecosystem functioning and provisioning of ecosystem services, but it remains unclear how biodiversity-ecosystem multifunctionality relationships depend on the identity and number of functions considered. Here, we demonstrate that ecosystem multifunctionality, based on 82 indicator variables of ecosystem functions in a grassland biodiversity experiment, increases strongly with increasing biodiversity. Analysing subsets of functions showed that the effects of biodiversity on multifunctionality were stronger when more functions were included and that the strength of the biodiversity effects depended on the identity of the functions included. Limits to multifunctionality arose from negative correlations among functions and functions that were not correlated with biodiversity. Our findings underline that the management of ecosystems for the protection of biodiversity cannot be replaced by managing for particular ecosystem functions or services and emphasize the need for specific management to protect biodiversity. More plant species from the experimental pool of 60 species contributed to functioning when more functions were considered. An individual contribution to multifunctionality could be demonstrated for only a fraction of the species. Y1 - 2017 U6 - https://doi.org/10.1038/s41559-017-0391-4 SN - 2397-334X VL - 2 IS - 1 SP - 44 EP - 49 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Gall, Andrea A1 - Uebel, Udo A1 - Ebensen, Uwe A1 - Hillebrand, Helmut A1 - Meier, Sandra A1 - Singer, Gabriel A1 - Wacker, Alexander A1 - Striebel, Maren T1 - Planktotrons BT - a novel indoor mesocosm facility for aquatic biodiversity and food web research JF - Limnology and oceanography-methods N2 - We established a new indoor mesocosm facility, 12 fully controlled Planktotrons, designed to conduct marine and freshwater experiments for biodiversity and food web approaches using natural or artificial, benthic or planktonic communities. The Planktotrons are a unique and custom-tailored facility allowing long-term experiments. Wall growth can be inhibited by a rotating gate paddle with silicone lips. Additionally, temperature and light intensity are individually controllable for each Planktotron and the large volume (600 L) enables high-frequency or volume-intense measurements. In a pilot freshwater experiment various trophic levels of a pelagic food web were maintained for up to 90 d. First, an artificially assembled phytoplankton community of 11 species was inoculated in all Planktotrons. After 22 d, two ciliates were added to all, and three Daphnia species were added to six Planktotrons. After 72 d, dissolved organic matter (DOM, an alkaline soil extract) was added as an external disturbance to six of the 12 Planktotrons, involving three Planktotrons stocked with Daphnia and three without, respectively. We demonstrate the suitability of the Planktotrons for food web and biodiversity research. Variation among replicated Planktotrons (n=3 minimum) did not differ from other laboratory systems and field experiments. We investigated population dynamics and interactions among the different trophic levels, and found them affected by the sequence of ciliate and Daphnia addition and the disturbance caused by addition of DOM. Y1 - 2017 U6 - https://doi.org/10.1002/lom3.10196 SN - 1541-5856 VL - 15 SP - 663 EP - 677 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Gerhard, Miriam A1 - Koussoroplis, Apostolos Manuel A1 - Hillebrand, Helmut A1 - Striebel, Maren T1 - Phytoplankton community responses to temperature fluctuations under different nutrient concentrations and stoichiometry JF - Ecology : a publication of the Ecological Society of America N2 - Nutrient availability and temperature are important drivers of phytoplankton growth and stoichiometry. However, the interactive effects of nutrients and temperature on phytoplankton have been analyzed mostly by addressing changes in average temperature, whereas recent evidence suggests an important role of temperature fluctuations. In a laboratory experiment, we grew a natural phytoplankton community under fluctuating and constant temperature regimes across 25 combinations of nitrogen (N) and phosphorus (P) supply. Temperature fluctuations decreased phytoplankton growth rate (r(max)), as predicted by nonlinear averaging along the temperature-growth relationship. r(max) increased with increasing P supply, and a significant temperature x P x N interaction reflected that the shape of the thermal reaction norm depended on nutrients. By contrast, phytoplankton carrying capacity increased with N supply and in fluctuating rather than constant temperature. Higher phytoplankton N:P ratios under constant temperature showed that temperature regimes affected cellular nutrient incorporation. Minor differences in species diversity and composition existed. Our results suggest that temperature variability interacts with nutrient supply to affect phytoplankton physiology and stoichiometry at the community level. KW - carrying capacity KW - growth rate KW - N KW - P ratios KW - phytoplankton composition KW - temperature variability KW - thermal performance Y1 - 2019 U6 - https://doi.org/10.1002/ecy.2834 SN - 0012-9658 SN - 1939-9170 VL - 100 IS - 11 PB - Wiley CY - Hoboken ER -