Evaluation of the impact of an agroecological market garden on carabid beetles, taken as bioindicators

Details

Supervisors

Hance, Thierry

Faculty

Faculté des bioingénieurs

Degree label

Master [120] : bioingénieur en sciences agronomiques, à finalité spécialisée

Abstract

Over the last decades, there has been a growing awareness concerning our food production systems. Agricultural intensification and the loss of semi-natural elements in the landscape have contributed to a diversity loss. Intensive farming is confronted to sustainability issues so numerous alternatives emerged as a response. One of them is agroecology. Among other objectives, agroecology aims to promote synergies between the different components of the agroecosystem, to ensure a more stable and resilient environment. In the perspective of developing knowledge around sustainable farming practices, UCLouvain decided to start a new organic and agroecological market gardening activity. Therefore, one of the permanent grasslands of the farm of Lauzelle underwent a land use change in 2019. Non-crop habitats were integrated to the market garden: flower strips, hedgerows, and grass margins, offering refuges for the fauna. Given the sustainability objectives of the market gardening activity, it seemed important to assess the impact of the land use change on biodiversity. Therefore, carabids were chosen as bioindicators and sampled, once in 2018, before the land use change, and once after it, in 2020 and early 2021. The surroundings of the farm were sampled as well, to allow comparisons with other habitats, which land use remained unchanged: grasslands, forests, and crop fields. This work analyses thus the impacts of the market gardening activity on the carabid communities. We found that the study area was composed of three different carabid communities, one inhabiting the crop field, another the forests and the last one was found in the grasslands as well as in the market gardening field, both before and after the land use change. We did not find a significant impact of the land use change on the carabid community of the market garden. Finally, we found that the flower strips appeared to host an abundant and more species rich carabid assemblage than the other non-crop habitats studied. We suggest that further studies should be hold in the coming years to see if some changes become visible on the long term. Also, other taxa, occupying different niches, could be investigated, for a broader insight on the impact of the agricultural activity on biodiversity.