Monitoring the biological diversity in agricultural landscapes in Germany with Copernicus – Concept and key indicators for policy evaluation

The European Biodiversity Strategy together with the Farm-to-Fork strategy and the Common Agriculture Policy (CAP) provide the legislative boundaries and incentives for a long-term preservation of biodiversity by facilitating actions and measures (e.g., ecoschemes) for a more sustainable agriculture. The abandonment and intensification of agricultural land-use, however, are recognized as key drivers of biodiversity loss. At the same time, biodiversity supports the provision of ecosystem function and services (e.g., pollination) that maintain and enhance the quality and quantity of food production in agroecosystems. There is broad evidence from ecological studies that the enhancement of farmland heterogeneity and reduction of land-use intensity at multiple spatial and temporal scales fosters biodiversity in agricultural landscapes. In order to assess the impact of upcoming agri-environmental measures related to the CAP and further strategies on farmers' decision, there is a need for a nationwide data basis on the state and development of land-use. So far, in Germany, where approximately 47% of the area is used for agricultural purpose, such a data basis is still lacking. Monitoring biodiversity in agricultural landscapes therefore requires a robust data basis in order to demonstrate the development of agricultural land-use and evaluate the relations of trends in land-use to trends in the distribution and diversity of different organism groups. With the free and global availability of the Copernicus data, especially the Sentinel-missions Sentinel 1 and -2, satellite remote sensing is able to record the land surface repeatedly and comprehensively and to generate information about land use and its changes. This includes information on the status quo, on short-term changes as well as on trends in land use. The Sentinel-data provide a basis for the collection of Essential Biodiversity Variables (EBV) that are suitable for the assessment of the state and condition of ecosystems (Skidmore et al. 2016). However, for a long-term integration into policy implementation and evaluation processes, those variables have to be translated into measurable and reportable biodiversity indicators. The national monitoring of biodiversity in agricultural landscapes in Germany (MonViA) is intended to provide a scientific and representative data base for the evaluation of biological diversity in open agricultural landscapes under the influence of agricultural production, of land use, and agricultural structural change. A fundamental pillar of the monitoring is the availability of area-wide, repeatable measurements of land use, use intensity and habitat heterogeneity in the agricultural landscape from satellite data and other geodata time series like weather or phenological information (Schwieder et al. 2021, Blickensdörfer et al. 2021, Möller et al. 2019). Those measurements will contribute to the definition and Germany-wide computation of a set of national biodiversity indicators describing the state and development of the land-use through simple and intuitive pressure and state indicators. These indicators are foreseen to inform policy makers and the public about the changes in land use related to agri-environmental policy instruments. We here present the overall monitoring approach to describe area-wide agricultural land-use and changes based on Copernicus and third-party mission data in Germany as part of the MonViA project. We will further propose how land-use and changes can be reported within a national monitoring system through a set of satellite-based key biodiversity indicators. In the third part, we will introduce the technical implementation of the indicator concept for two selected indicators (grassland use intensity, crop rotation diversity) on the basis of area-wide state variables that are available for Germany. Finally, we will discuss possible linkages to European approaches.