Monitoring of avian biodiversity, conservation and restoration project of a 268ha domain of mixed hardwood forest and agricultural land in Silty Wallonia

Details

Supervisors

Nieberding, Caroline M.

Faculty

Faculté des sciences

Degree label

Master [120] en biologie des organismes et écologie, à finalité approfondie

Abstract

Our era is marked by a serious decline in biodiversity. With 21,000 described species, they are experiencing an extinction rate of 48 million species-years (E/MSY), which is 20 to 40 times higher than the average rate of the Cenozoic history of 1 to 2 E/MSY. Birds are obviously not spared. The main cause is the 1.58 billion hectares of natural ecosystems that have been converted into cultivated land in 2014 worldwide. This conversion is associated with unfavorable conditions for species in agricultural environments, with ¾ of the risk related to reduced food quantity and quality and ¼ of the risk related to nesting success rates. Within 28 years in Wallonia, farmland birds have lost 60% of their abundance. In our field, we estimate that generalist species are 4 times more abundant for a share of specific diversity almost identical to farmland birds. In Wallonia, generalist species are already the most widespread with a total of 42 species: among their population trend, 31% are increasing, 45% are declining and 24% are stable. For farmland birds, 24% are increasing, 65% are declining and 12% are stable. We can thus observe the signs of a biotic homogenization, where generalist species are replacing the declining specialist species. This report is therefore part of a transdisciplinary dynamic, with cooperation between field actors and academic bodies, in a 268ha arable domain comporting 97ha of hardwood forest. A monitoring of the avian biodiversity was carried out during spring-summer 2021 to establish the cumulative diversity present in the field, in collaboration with an experienced forester. Subsequently, different habitat conservation, restoration measures and AESs (agri-environmental schemes) are proposed for this agroforestry area of Hesbaye, targeting species absent or in decline compared to previous and actual inventories. A certain holistic vision has been undertaken, targeting the agricultural, forest and hydromorphic habitats of the area. The implementation of AESs is one of the main tools to stop the decline of biodiversity in agricultural areas and is proving to be effective to some extent. However, to truly reverse the decline, it is essential to apply them in large numbers and especially in the most intensive farming areas, in order to constitute a concrete ecological network. Regarding the adherence of farmers to at least 1 AES in Wallonia, the rate has decreased from 54% in 2013 to 45% in 2018, probably due to the evolution of the subsidies linked to these AESs. This shows the effort to reach in the future to convince farmers to implement these measures, especially via landowners already convinced of their importance, and by offering attractive subsidies to compensate for possible yield losses.