title: Detecting insect pollinator declines on regional and global scales.
abstract: Recently there has been considerable concern about declines in bee communities in agricultural and natural habitats. The value of pollination to agriculture, provided primarily by bees, is >$200 billion/year worldwide, and in natural ecosystems it is thought to be even greater. However, no monitoring program exists to accurately detect declines in abundance of insect pollinators; thus, it is difficult to quantify the status of bee communities or estimate the extent of declines. We used data from 11 multiyear studies of bee communities to devise a program to monitor pollinators at regional, national, or international scales. In these studies, 7 different methods for sampling bees were used and bees were sampled on 3 different continents. We estimated that a monitoring program with 200-250 sampling locations each sampled twice over 5 years would provide sufficient power to detect small (2-5%) annual declines in the number of species and in total abundance and would cost U.S.$2,000,000. To detect declines as small as 1% annually over the same period would require >300 sampling locations. Given the role of pollinators in food security and ecosystem function, we recommend establishment of integrated regional and international monitoring programs to detect changes in pollinator communities.
authors.affiliation: Department of Biology, San Francisco State University, San Francisco, CA 94132, USA. lebuhn@sfsu.edu
authors.forename: Gretchen
authors.initials: G
authors.lastname: Lebuhn
authors.forename: Sam
authors.initials: S
authors.lastname: Droege
authors.forename: Edward F
authors.initials: EF
authors.lastname: Connor
authors.forename: Barbara
authors.initials: B
authors.lastname: Gemmill-Herren
authors.forename: Simon G
authors.initials: SG
authors.lastname: Potts
authors.forename: Robert L
authors.initials: RL
authors.lastname: Minckley
authors.forename: Terry
authors.initials: T
authors.lastname: Griswold
authors.forename: Robert
authors.initials: R
authors.lastname: Jean
authors.forename: Emanuel
authors.initials: E
authors.lastname: Kula
authors.forename: David W
authors.initials: DW
authors.lastname: Roubik
authors.forename: Jim
authors.initials: J
authors.lastname: Cane
authors.forename: Karen W
authors.initials: KW
authors.lastname: Wright
authors.forename: Gordon
authors.initials: G
authors.lastname: Frankie
authors.forename: Frank
authors.initials: F
authors.lastname: Parker
mesh_terms: D000818:Animals; D001516:Bees / Q000502:physiology*; D003247:Conservation of Natural Resources; D004784:Environmental Monitoring; D007313:Insecta / Q000502:physiology; D054817:Pollination; D011156:Population Density; D011157:Population Dynamics