Modelling of carbon cycle in grassland ecosystems of diverse water availability using Biome-BGCMuSo.

Abstract

Grassland ecosystems have an important role in agriculture, and at the same time, are highlysensitive to changes in land use and climate change. Simulation of the biogeochemical cycles ofmanaged grasslands may help in identifying and quantifying the main processes contributing tochanges in their productivity. In our work we used the latest version of Biome-BGCMuSo model,the modified version of the widely used biogeochemical Biome-BGC model, with structuralimprovements to simulate herbaceous ecosystem carbon and water cycles more faithfully.Our sampling areas were in diverse grasslands in the Kiskunság, Hungary. Different soil textureand changing water table level, consequently highly different water conditions are characteristicin these ecosystems, influencing the development and productivity of vegetation, and also thepotential for animal husbandry. Hence, for the meadows and the marshland ecosystems weincluded mowing management in the simulations. In order to compare the ecosystems and studytheir functions we simulated ecosystem variables, such as ecosystem respiration, standing andharvested aboveground biomass etc.We found that ecosystems with higher water availability are more sensitive to changes in waterconditions, and their productivity is more variable between years. By calibration processes usingleaf area and aboveground biomass we aim to further specify our findings.Biome-BGCMuSo is available as a standalone model, but also through virtual laboratoryenvironment and Biome-BGC Projects database (http://ecos.okologia.mta.hu/bbgcdb)developed within the BioVeL project (http://www.biovel.eu). Scientific workflow management,web service and desktop grid technology can support model optimization in the so-called"calibrated runs" within MACSUR.