Auswirkungen von anthropogen bedingten Umweltveränderungen (Biodiversitätsverlust, erhöhrte CO2-Konzentration in der Luft, erhöhte Stickstoffdeposition und Klimaerwärmung) auf die Funktionsweise und Rückkopplungseffekte von Bodennahrungsnetzen und Mikroorganismen.
Zusammenfassung der Projektergebnisse
The projects of my DFG research scholarship aimed at investigating the impacts of global change processes on soil organisms and functioning. The project integrated the composition of soil organisms as response variable and driving force of plant communities of different diversity and aimed at a more comprehensive understanding of aboveground-belowground interrelationships in consideration of important global change phenomena. The results show that considering aboveground-belowground interactions is essential to realistically predict the consequences of current global change phenomena in terrestrial ecosystems. In the long term, soil feedback effects on plant performance and other ecosystem processes become apparent and of great biological significance. For instance, positive plant diversity effects on ecosystem functioning are most pronounced in the presence of a diverse community of soil mutualists. My results thus underline the need to perform long-term experiments in order to appreciate delayed responses of the soil subsystem. Further, my results indicate that global change agents interactively affect ecosystem processes questioning the explanatory value of single-factor experiments. Thus, I got involved in two kicking-in projects investigating such interactive global change effects in grassland and forest ecosystems. Global change effects on soil organisms, such as plant diversity loss, elevated atmospheric CO2 concentrations and N deposition, seem to be mainly mediated by changes in rhizodeposition and bottom-up effects. In addition to the planned research, I got involved in several projects on the effects of invasive European earthworms which profoundly change the biotic composition and functioning of North American ecosystems previously devoid of earthworms. Earthworm effects were strongest at the peak of the invasion wave, after what ecosystems likely have altered biotic compositions and functions. Further, the analysis of two of the longest running plant diversity experiments revealed that plant diversity effects on primary productivity become less saturating and more linear over time, suggesting that even moderate loss of species at high diversity leads to significant deteriorations of ecosystem functions.
Projektbezogene Publikationen (Auswahl)
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(2011) The wave towards a new steady state: effects of earthworm invasion on soil microbial functions. Biological Invasions 13: 2191-2196
Eisenhauer N, Schlaghamerský J, Reich PB and Frelich LE
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(2012) Above- and belowground inputs both fuel soil food webs. Soil Biology and Biochemistry 45: 156-160
Eisenhauer N and Reich PB
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(2012) Aboveground-belowground interactions as a source of complementarity effects in biodiversity experiments. Plant and Soil 351: 1-22
Eisenhauer N
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(2012) Global change below ground: impacts of elevated CO2, nitrogen and summer drought on soil food webs and biodiversity. Global Change Biology 18: 435-447
Eisenhauer N, Cesarz S, Koller R, Wonm K and Reich PB
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(2012) Interactive effects of global warming and 'global worming' on the initial establishment of native and exotic herbaceous plant species. Oikos
Eisenhauer N, Fisichelli NA, Frelich LE and Reich PB
