Sampling methods

There was a lot of learning in the beginning, but once they got the methods down, they went out in groups of two to conduct the sampling. They would conduct a transect walk where there were usually three transects per farm. The transects were 150 meters long and 2 meters wide and were sampled for 15 minutes. A sampler would slowly walk the transect looking for bees, butterflies or hoverflies that were visiting a flower or flying through. If they spotted a flower visitor, the partner would stop the time for them to process the sample. Insects that could be identified in the field were released. The farms were sampled three time during the summer and during one of the sampling periods, they also conducted a vegetation survey.

Sampling at the farms

The BiodivNetz field sites are diverse and consist of different land use types, varying from annual crop plants (e.g., wheat, corn, and beans), pastures (e.g., grasses and wildflowers) to perennial crops (e.g., wine grapes and apples). At the first farm that I visited, the team sampled within the rows of apple trees, where lots of flowers were blooming. They caught quite a few bees and hoverflies. At the second farm, the next day, there was a workshop with various stakeholders to present the biodiversity measures implemented on the farm and how to identify indicator species. The ALU-FR team was able to give a spontaneous short pitch about RestPoll to the participants. The stakeholders seemed enthusiastic about the work and its integration into the BiodivNetz program. Anecdotally, it seemed that when high floral cover is available, different bee species, hover fly species, and butterflies are much more abundant and diverse. In measures where flowering plants were interspersed within crops (e.g., wheat fields and inter-row flower strips in apple orchards), the abundance and diversity seemed much higher than in control sites, which is an encouraging observation!