Risch Anita Christina
Impacts of different-sized herbivores on root biomass in subalpine grassland
Project Number: CH-4655
Grassland ecosystems are the largest biome on earth. Besides being a remarkable source of biodiversity, they provide important goods and services. Herbivores can strongly influence the function and structure of these ecosystems, namely altering biomass, woody and herbaceous plant diversity and soil characteristics. To identify the effects of grazing on belowground plant properties is valuable for the understanding of how sustainable a system is or how likely it is to change with altered grazing pressure. Although belowground biomass can be three to four times greater than aboveground biomass, belowground processes remain understudied in grasslands. Root biomass, length, elongation and distribution can be altered by regular defoliation, and its reduction can be connected with the intensity and frequency of defoliation.
The present thesis focuses on the effects of grazing by different-sized herbivores on root biomass. It is part of a larger scope experiment sited in the Swiss National Park, in the south-eastern part of Switzerland. The exclusion of different-sized herbivores is an important aspect of this experiment, since the spatial and temporal scales at which plants and soil organisms operate change depending on the body size and life history of the organism concerned and the size of its habitat unit or domain.
After the second year of the exclusion experiment, root biomass was, however, not yet affected by altered grazing regimes. This result suggests that belowground responses on aboveground changes in high altitude grasslands might be delayed and that an enlarged temporal scale should be considered.
Vera Alexandra da Silva Lopes Baptista, 2011: Impacts of different-sized herbivores on root biomass in subalpine grassland. Master thesis ETH Zurich.pdf Masterthesis
Last update: 7/18/17
Source of data: ProClim- Research InfoSystem (1993-2020)
Update the data of project: CH-4655