Indicator bee biomass Pan Trap Monitoring of Bee Communities

In 2025, 16 sites in Saxony-Anhalt and Lower Saxony were sampled at five phenologically defined dates throughout the year. A general decrease in the recorded activity density of wild bees was observed from spring onwards. This development likely follows a general annual phenological trend also observed in other studies. However, unlike in 2024, the highest observation values for the year were recorded in July. Over 30% of the total bee biomass for the year was determined in this month.

With the data collected up to the present point, the identification of medium- and long-term trends is not yet possible. Further years of data collection are needed to adequately account for interannual variance in the time series.

Each year, 16 monitoring sites in agricultural landscapes of Saxony-Anhalt and Lower Saxony are sampled at several phenologically determined dates. The bee communities are surveyed representatively using fluorescent blue, yellow, and white pan traps. These arable and grassland-dominated sites are among the nationally representative sample plots used by the Federal Agency for Nature Conservation for the Ecosystem Monitoring and for the Monitoring of High Nature Value Farmland. Local flowering is recorded concurrently with the pan trap sampling.