Biodiversity and carbon sequestration: a field study simulating loss of plant species from Mediterranean grassland

biogeochemical cycles

The current loss of biodiversity on a global scale may be a major threat to the composition and functioning of ecosystems, and to the services mankind derives from nature. Most terrestrial ecosystems are based on vegetation as the main autotrophic component, and, therefore, functioning of these systems depends to a high degree on plant diversity. Many recent studies investigated effects of biodiversity loss on carbon dynamics by focusing on biomass accumulation and primary productivity. However, field data are rare that provide means for predicting carbon sequestration (the full carbon balance) as influenced by loss of plant diversity. This project proposed a field study in Mediterranean grassland to investigate effects of diversity loss on carbon sequestration. Reduction in diversity was simulated by establishing replicated experimental plant assemblages of decreasing species richness in old-field soil. Carbon sequestration was quantified by measuring net ecosystem CO2 fluxes with a static chamber technique. The main objectives of this study were

1) to quantify the effect of plant diversity loss on net ecosystem carbon balance in Mediterranean grassland, and assess potentially functional mechanisms;

2) to determine plant diversity effects on components of net ecosystem productivity, mainly net primary production and decomposition of soil organic matter;

3) to analyze the relationship between diversity effects on the carbon cycle and functional traits of the plant species involved;

4) to estimate the impact of plant diversity loss on microclimatic factors (water availability, temperature), and consequently on C balance and its components.

Partner organizations: Israel Science Foundation