Changes in wild bee fauna of a grassland in Brazil reveal negative effects associated with growing urbanization during the last 40 years

By A. C. Martins, R. B. Gonçalves, G. A. Melo. 2013

88 citations recorded by the source corpus.

Bee fauna and associated flora from a grassland site in Brazil, surveyed 40 and 20 years ago, were newly surveyed with comparable methodology to evaluate changes in the bee fauna of this site, considering that human population and urbanization has exponentially increased in the last 40 years. In general, bee species richness has declined in 22%, as well as their abundance. Some of the previously abundant species are now absent, including Bombus bellicosus Smith, 1879, Gaesischia fulgurans (Holmberg, 1903) and Thectochlora basiatra (Strand, 1910). No particular trend of differential decrease among either taxonomic or functional groups was observed, except for a minor increase in the proportion of oligolectic species and a 50% reduction in the number of large species. The first two surveys were more similar to each other in species richness per bee genus, while the two most recent grouped together based on measures of anthropogenic impact. Furthermore, the number of plant species visited by bees increased, with a pronounced increase in ruderal and exotic species. Crop cultivation, competition with honeybees and climate changes may all be related to bee decline. Nevertheless, the effects of urbanization, in particular intense land occupation and few preserved natural areas can be pointed as the main causes of species decline. Due to continuing increase in human population, increased erosion in diversity is expected. Habitat protection is an additional challenge to bee conservation in the region, with no local conservation units set aside for grasslands. State and municipal agencies should urgently consider the establishment of reserves for the few remaining patches of natural grasslands.

Subfields: Ecology, Evolution, Behavior and Systematics, Insect Science

View Paper: https://www.semanticscholar.org/paper/59e6de270dfd81a54335c862694941c8e9a0d758

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In Ecology, Evolution, Behavior and Systematics

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Citations in the corpus

Further evidence for a global decline of the entomofauna (2020, background): “Loss of natural habitat by conversion to urbanised landscapes and agriculture is thought to be the main cause of the changes, although the extirpation of Bombus bellicosus could be due to climate warming (Martins et al. 2013).”
The relative performance of sampling methods for native bees: an empirical test and review of the literature (2020, background): “…is a significant form of land-use change and is set to increase (United Nations 2015), with the potential for adverse consequences to bee abundance and diversity and through the associated loss of natural habitat and other aspects of the built environment (Martins et al. 2013, Potts et al. 2016).”