Project Details
Projekt
Diversity loss and trait dynamics in natural plankton communities
Subject Area
Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
Term
from 2014 to 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 257418649
The project's objective is to assess the impact of a loss of traits from natural communities with shared evolutionary history on trait dynamics and their effect on consumer fitness and productivity. In such a context of trait diversity and their impact on producer and consumer community dynamics, this general objective can be particularly well addressed through species specific traits (pigment and fatty acid composition) at the phytoplankton-zooplankton interface in lake food webs. Our proposed work programme aims to investigate the following research question: Are traits that are responsible for biodiversity - ecosystem functions in laboratory plankton communities also relevant for natural field populations of plankton and show these traits more complex dynamics in "wild nature"? Consequences of losses of important ecophysiological traits can then not easily be predicted from laboratory studies alone, in particular, if complex interactions and feed-back loops occur. Investigations of evolved field communities manipulated in species diversity are therefore urgently needed. We will address this research question with a chain of testable hypotheses (A-C) using natural phytoplankton communities. We will investigate these hypotheses at two different loss scenarios (loss of rare species, loss of stress sensitive species) and along a trophic gradient (oligotroph to eutroph) in the field and in controlled laboratory experiments. A) Ecologically relevant, dynamic and functional traits affecting plankton dynamics in "wild nature" are e.g. the taxon specific pigment composition of phytoplankton and the taxon-specific composition of essential lipids (in particular fatty acids) in the phytoplankton community. B) The taxon and thereby functional trait diversity of natural phytoplankton (pigments, fatty acids) is correlated with the nutritional complementarity of this community for herbivorous zooplankton. C) Different zooplankton groups (e.g. different Daphnia genotypes) differ in their susceptibility to limitations by the availability of essential fatty acids. A loss of trait diversity (fatty acids) can thus affect competitive interactions between zooplankton. This can in turn affect the genetic and/or taxonomic composition of the zooplankton community resulting on dynamic feedback effects on phytoplankton community composition and the corresponding functional traits. These hypotheses will be addressed in a dual approach, using laboratory and field experiments. By answering the above stated research questions, we will be able for the first time to estimate the importance of trait losses in natural pelagic communities and to link mechanistically the dynamics of individual ecophysiological traits to ecosystem functioning.
DFG Programme
Priority Programmes
International Connection
France, USA
Participating Persons
Privatdozent Dr. Philippe Pondaven; Professor Val H. Smith, Ph.D.
