6533b833fe1ef96bd129b3ed

RESEARCH PRODUCT

Parameterizing the "grassland" module in the multispecific model FlorSys

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EAEcolDurCT1; The multispecies model FlorSys can predict the effects of cropping systems on the dynamics of weed communities in annual crops ; however, it is not configured to predict the fate of weeds in permanent cover such as grasslands. We realized the simulation of a weed seed rain in controlled conditions to estimate the percentage of weed seeds intercepted by a grass cover. Parameters of this linear model will be used to develop a new sub model in FlorSys to be able to simulate weed dynamics in temporary grasslands. We used twelve weed species selected on the basis of specific morphological characteristics and observations made in the experimental set up of SOERE ACBB (Observatory Environmental Research, Agro-ecosystems, Biogeochemical Cycles, and Biodiversity). Weed seeds have a probability to reach the ground which depends on the height of the cover, but also on seed characteristics. So, we determined the favorable traits in the weed seed interception by a grass cover whatever the species considered. The next steps will consist of integrating the interception equation in FlorSys and of analyzing the sensitivity of the modified model. We will compare the model simulations with the observations of weed dynamics in SOERE ACBB, to explain the changes observed in cropping systems with temporary grasslands.