The Three Exploratories
Functional biodiversity research will be conducted in three exploratories in Germany:
Biosphere Reserve Schorfheide-Chorin in the State of Brandenburg
National Park Hainich and its surroundings in the State of Thuringia and
Biosphere Reserve Schwäbische Alb in the State of Baden-Württemberg.
Basic hierarchic design
We selected plots to vary substantially in land use but to be as similar as possible in other regards. Our approach is therefore a planned comparison between land use types and intensities, not just an observational approach.
To do this, we used a hierarchical sampling approach to select the study plots. First, we compiled a large inventory of more than 3000 plots, which we called grid plots (GP). These included all types of grassland and forests that could be found in a particular region. For the grid plots, we then conducted a soil inventory, a systematic forest inventory to describe the management types and main tree species in forests, and a grassland inventory to assess land use intensity from interviews with farmers and land owners.
Based on this information, we selected and permanently marked a total of 300 plots (100 per region, 50 in forests and 50 in grasslands) for further research, called the experimental plots (EP). These experimental plots serve for more thorough biodiversity assessment, environmental monitoring, and manipulative experiments. The selection of these plots was randomly stratified to include the entire range of land use and management types found in a region whilst minimizing differences in soil type and other confounding variables.
In 2015, we selected a subset of 150 plots (50 per regions, 25 in forest and 25 in grasslands) for more laborious research which we called medium-intensively studied plots (MIP). These plots were selected to cover the whole gradient of land-use intensities in both forests and grassland.
Finally, for very laborious measurements and elaborate experiments, we selected a subset of 54 + 3 plots from the experimental plots (18 per region, 9 in forest and 9 in grasslands), which we called very intensively studied plot (VIP). In the Hainich-Dün region, we included three additional plots of managed, continuous cover forestry because that type of management is of particular regional importance.