Identification of hotspots of crop wild relatives in Germany to promote their in situ conservation in a network of genetic reserves.

Background: Crop wild relatives (CWR) represent a valuable resource for ensuring food security. Although they are negatively affected by the loss of habitats due to climate change and land use change, they are underrepresented in conservation programmes. The establishment of genetic reserve (GR) networks has been put forward as an approach to protect CWR. The objective of this study was to identify CWR hotspots in Germany, which are suitable candidates for the establishment of GRs. CWR observation data were collected on a national scale from various sources and a hotspot analysis was performed to identify potential GR sites. A number of these sites were visited and the plant species occurring were recorded.

Results: 76 GR candidate sites were identified. The sites are distributed across the biogeographic regions of Germany and could conserve 73% of all CWR and 85% of the CWR that were assigned a conservation priority for Germany. Our on-site surveys for 27 GR candidates found discrepancies between the species records available and the species currently occurring.

Conclusions: We propose five hectares as an appropriate size for GRs, as such an area can be monitored and the number of stakeholders involved is usually low. The discrepancies concerning species records highlight the need for more frequent, regular nationwide CWR monitoring as a prerequisite for their conservation. Our results further suggest that GRs should also be set up outside of protected areas to protect CWR efficiently.