BDM in operation

At the landscape level, biodiversity is surveyed by fieldworkers walking a track (transect) predefined on a map for each 1-km2 sampling area, recording each species they find.

Regarding vascular plants and butterflies, each BDM transect is 2.5 kilometers. Surveying breeding birds, however, requires tracks to be laid out in such a way as to cover the major part of each sampling area. At three up to no more than five kilometers, these tracks are considerably longer than plant and butterfly transects.

Visiting a sampling area once is generally not enough: As a rule, sampling areas are being surveyed two or three times a year in order to take seasonal differences in species composition into account. For butterfly surveys, sampling areas even must be walked up to seven times.

Surveying step by step

This series of images shows a BDM fieldworker surveying species in a sampling area. For a larger view and information on what happens in each step, please click on the images. 


Surveying in motion

The roughly three-minute video allows you to accompany BDM fieldworkers surveying species diversity in landscapes. Please be patient: After clicking the start button, it takes a few seconds for the video to start. 

For more information on the “Species Diversity in Landscapes” indicator please click
> here