Responses of Social and Solitary Bees to Pulsed Floral Resources
- 1 October 2013
- journal article
- Published by University of Chicago Press in The American Naturalist
- Vol. 182 (4), 465-473
- https://doi.org/10.1086/671999
Abstract
Pulsed food resources lead to mismatches between distribution of consumers and resources in space and time. Many studies have investigated how pollinators and floral resources covary in space, but few have looked at their covariance among years. I studied responses of two bee taxa, Bombus (a social genus) and Anthophora (a solitary genus), to variation in flowering by Astragalus scaphoides, a perennial herb that flowers in alternate years. First, I quantified the rate at which individual plants were visited by bees. Anthophora showed evidence of a demographic response to resource pulses--that is, more individuals were seen in the year after a high-flowering year--whereas Bombus did not. Second, I quantified pollinator behavior by following individual bees and recording the proportion of visits to A. scaphoides within single foraging bouts. The proportion of visits to A. scaphoides by both taxa increased with A. scaphoides's flowering density. Higher specialization in high-flowering years likely makes both taxa better pollinators in high-flowering years. If these taxa differ in effectiveness as pollinators, then these responses translate into variation in pollination services in space and time, specifically, more activity by Bombus in high-flowering years and more by Anthophora in years following high-flowering years. They also emphasize that pollinator activity depends in part on past-as well as current-floral resources.Keywords
This publication has 35 references indexed in Scilit:
- Timescales, dynamics, and ecological understandingEcology, 2010
- A meta‐analysis of resource pulse–consumer interactionsEcological Monographs, 2010
- How do plants know when other plants are flowering? Resource depletion, pollen limitation and mast‐seeding in a perennial wildflowerEcology Letters, 2009
- Bumblebee Vulnerability: Common Correlates of Winners and Losers across Three ContinentsConservation Biology, 2009
- Mass flowering oilseed rape improves early colony growth but not sexual reproduction of bumblebeesJournal of Applied Ecology, 2009
- Estimating the population size of specialised solitary beesEcological Entomology, 2008
- Pollen and water limitation in Astragalus scaphoides, a plant that flowers in alternate yearsOecologia, 2006
- Empirical Models of Pollen Limitation, Resource Acquisition, and Mast Seeding by a Bee‐Pollinated WildflowerThe American Naturalist, 2005
- Population dynamics of the solitary digger bee Andrena vaga Panzer (Hymenoptera, Andrenidae) studied using mark‐recapture and nest countsPopulation Ecology, 2003
- Pollen Coupling of Forest Trees: Forming Synchronized and Periodic Reproduction out of ChaosJournal of Theoretical Biology, 2000