Abstract

Global environmental changes are ranked among the major drivers of biodiversity loss in different types of ecosystems. While there have been numerous studies that examined the impact of biodiversity loss on ecosystem functioning and community dynamics, it is still not much known about the underlying mechanisms behind the biodiversity-ecosystem functioning relationship. In recent years, studies started to follow a trait-based approach, i.e. examining the role of species and taxon specific functional traits, such as resource uptake or biochemical composition. Loss of such traits has been shown to alter key processes of ecosystems, such as productivity and sustainability. In aquatic ecosystems, pigment composition of the phytoplankton community determines the community’s light-use efficiency. Hence, a change in pigment composition may lead to alterations of the phytoplankton community’s productivity. We hypothesize that pigment composition of the phytoplankton community might be one of the links between biodiversity and ecosystem functioning. To examine this, we performed a large-scale field experiment in three lakes along a trophic gradient (oligotrophic to eutrophic) where we manipulated natural phytoplankton communities to establish a diversity gradient. Additionally, we estimated the pigment composition of seston samples via HPLC. We demonstrate that the pigment composition is highly correlated with phytoplankton species richness. This indicates that photopigments are a key functional trait that links the utilization of an abiotic resource to biodiversity.

Dr. Maja Ilić

Data Analyst/R Programmer in Ecology