Data from: The effect of repeated, lethal sampling on wild bee abundance and diversity

1. Bee pollinators provide a critical ecosystem service to wild and
agricultural plants but are reported to be declining world-wide due to
anthropogenic change. Long-term data on bee abundance and diversity are
scarce, and the need for additional quantitative sampling using repeatable
methods has been emphasized. Recently, monitoring programmes have begun
using a standardized method that employs a combination of pan traps and
sweep netting, resulting in lethal sampling of bees. This standardized
method can remove a large number of bees from sites during each sampling
day, raising concern that the sampling itself could have a negative effect
on bee populations. 2. We conducted an experiment to assess whether lethal
sampling for bees using pan traps and netting affected bee abundance and
diversity when done every two weeks throughout a season and over multiple
years. We compared bee abundance, richness, evenness and functional group
composition between sites that had been sampled every two weeks from 2009
to 2012 to similar sites not previously sampled. 3. We found that the
standardized method for sampling bees, with specimens from 132
morphospecies, did not affect bee communities in terms of abundance,
rarefied richness, evenness, or functional group composition. Thus, our
results indicate that the bee communities we sampled are robust to such
sampling efforts, despite removing an average of 2862 bees per season. 4.
We discuss several explanations for why sampling did not affect bee
abundance or community structure, including a density-dependent response
to reduced competition for resources. 5. These results suggest that bee
monitoring programmes sampling once every two weeks with pan traps and
netting will not affect bee community structure. We urge researchers
monitoring bees to utilize standardized protocols so that results can be
compared across space and time.