Orchards in natural habitats draw bee diversity, improve apple production

Date:  January 17, 2019

Source:  Cornell University

Apple orchards surrounded by agricultural lands are visited by a less diverse collection of bee species than orchards surrounded by natural habitats, according to a new Cornell University-led study, published in the journal Science.

In turn, apple production suffers when fewer, more closely-related species of bees pollinate an orchard. Production improves in orchards surrounded by natural habitats, which then draw a broader selection of species to apple blossoms.

The researchers examined 10 years of data from 27 New York state apple orchards. The study accounted for the types of landscapes that surround these orchards, measured apple production and surveyed the species of bees that visited each orchard.

The researchers also reconstructed the evolutionary history and relatedness of New York native bee species to better understand species patterns that played out across these orchard bee communities. This reconstruction is represented by a branching tree-like diagram of related species, called a phylogeny.

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Bee diversity and richness decline as anthropogenic activity increases, scientists confirm

Date:  November 1, 2018

Source:  Pensoft Publishers

Changes in land use negatively affect bee species richness and diversity, and cause major shifts in species composition, reports a recent study of native wild bees, conducted at the Sierra de Quila Flora and Fauna Protection Area and its influence zone in Mexico.

Having registered a total of 14,054 individual bees representing 160 species, 52 genera, and five families over the span of a year, the scientists conclude that the studied preserved areas demonstrated "significantly greater" richness and diversity.

In their paper, published in the open-access Journal of Hymenoptera Research, a research team from the University of Guadalajara, Mexico, led by Alejandro Muñoz-Urias, compare three conditions within the tropical dry forest study site: preserved vegetation, an agricultural area with crops and livestock, and an urbanised area.

The researchers confirm earlier information that an increase in anthropogenic disturbances leads to a decrease in bee richness and diversity. While availability of food and nesting sites are the key factors for bee communities, changes in land use negatively impact flower richness and floral diversity. Thereby, turning habitats into urbanised or agricultural sites significantly diminishes the populations of the bees which rely on specific plants for nectar and pollen. These are the species whose populations are threatened with severe declines up to the point of local extinction.

According to their data, about half of the bees recorded were Western honey bees (49.9%), whereas polyester bees turned out to be the least abundant (1.2 %).

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