Diverse landscapes have a higher abundance and species richness of spring wild bees by providing complementary floral resources over bees’ foraging periods
Anthropogenic landscape simplification and natural habitat loss can negatively affect wild bees. Alternatively, anthropogenic land-use change may diversify landscapes, creating complementary habitats that maintain overall resource continuity and diversity.
We examined the effects of landscape composition, including land-cover diversity and percent semi-natural habitat, on wild bee abundance and species richness within apples, a pollinator-dependent crop. We also explored whether different habitats within diverse landscapes can provide complementary floral resources for bees across space and time.
We sampled bees during apple bloom over 2 years within 35 orchards varying in surrounding landscape diversity and percent woodland (the dominant semi-natural habitat) at 1 km radii. To assess habitat complementarity in resource diversity and temporal continuity, we sampled flowers and bees within four unique habitats, including orchards, woodlands, semi-natural grasslands, and annual croplands, over three periods from April–June.
Surrounding landscape diversity positively affected both wild bee abundance and richness within orchards during bloom. Habitats in diverse landscapes had different flower communities with varying phenologies; flowers were most abundant within orchards and woodlands in mid-spring, but then declined over time, while flowers within grasslands marginally increased throughout spring. Furthermore, bee communities were significantly different between the closed-canopy habitats, orchards and woodlands, and the open habitats, grasslands and annual croplands.
Our results suggest that diverse landscapes, such as ones with both open (grassland) and closed (woodland) semi-natural habitats, support spring wild bees by providing flowers throughout the entire foraging period and diverse niches to meet different species’ requirements.
KeywordsPollinator Native bee Land-use change Landscape structure Habitat fragmentation Apples
The authors would like to thank the Ceres Foundation and the United States Department of Agriculture Specialty Crop Block Grant Program for funding, Mike Arduser for help with some bee identifications, apple farmers in southern Wisconsin for participating in this study, and Kiley Friedrich for assistance in the field.
- Biesmeijer JC, Roberts SPM, Reemer M, Ohlemüller R, Edwards M, Peeters T, Schaffers AP, Potts SG, Kleukers R, Thomas CD, Settele J (2006) Parallel declines in pollinators and insect-pollinated plants in Britain and the Netherlands. Science 313:351–354. doi: 10.1126/science.1127863 CrossRefPubMedGoogle Scholar
- Burnham KP, Anderson DR (eds) (2004) Model selection and multimodel inference. Springer, New York, NYGoogle Scholar
- Cane JH, Minckley RL, Kervin LJ (2000) Sampling bees (Hymenoptera: Apiformes) for pollinator community studies: Pitfalls of pan-Trapping. J Kansas Entomol Soc 73:225–231Google Scholar
- ESRI (Environmental Systems Resource Institute) (2009) ArcMap 9.2. ESRI. Redlands, CaliforniaGoogle Scholar
- Gibbs J (2011) Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini). Zootaxa 3073:1–216Google Scholar
- Mallinger R (2015) Cultivating alternative apple pollinators: examining the contribution of wild bees to crop pollination, and the factors that influence their abundance and diversity In Wisconsin’s Orchards. Dissertation, The University of Wisconsin-MadisonGoogle Scholar
- McCracken ME, Woodcock BA, Lobley M, Pywell RF, Saratsi E, Swetnam RD, Mortimer SR, Harris SJ, Winter M, Hinsley S, Bullock JM (2015) Social and ecological drivers of success in agri-environment schemes: the roles of farmers and environmental context. J Appl Ecol 52:696–705. doi: 10.1111/1365-2664.12412 CrossRefGoogle Scholar
- Michener CD (2000) The Bees of the World. JHU Press, Baltimore MDGoogle Scholar
- Mueller UG (1996) Life history and social evolution of the primitively eusocial bee Augochlorella striata (Hymenoptera: Halictidae). J Kansas Entomol Soc 69:116–138Google Scholar
- National Research Council (2007) Status of Pollinators in North America. The National Academies Press, Washington D.CGoogle Scholar
- Pabalan N, Davey KG, Packer L (2000) Escalation of aggressive interactions during staged encounters in Halictus ligatus Say (Hymenoptera: Halictidae), with a comparison of circle tube behaviors with other Halictine species. J Insect Behav 13:627–650. doi: 10.1023/A:1007868725551 CrossRefGoogle Scholar
- Ricketts TH, Regetz J, Steffan-Dewenter I, Cunningham SA, Kremen C, Bogdanski A, Gemmill-Herren B, Greenleaf SS, Klein AM, Mayfield MM, Morandin LA (2008) Landscape effects on crop pollination services: are there general patterns? Ecol Lett 11:499–515. doi: 10.1111/j.1461-0248.2008.01157.x CrossRefPubMedGoogle Scholar
- Steckel J, Westphal C, Peters MK, Bellach M, Rothenwoehrer C, Erasmi S, Scherber C, Tscharntke T, Steffan-Dewenter I (2014) Landscape composition and configuration differently affect trap-nesting bees, wasps and their antagonists. Biol Conserv 172:56–64. doi: 10.1016/j.biocon.2014.02.015 CrossRefGoogle Scholar
- Woodcock BA, Harrower C, Redhead J, Edwards M, Vanbergen AJ, Heard MS, Roy DB, Pywell RF (2014) National patterns of functional diversity and redundancy in predatory ground beetles and bees associated with key UK arable crops. J Appl Ecol 51:142–151. doi: 10.1111/1365-2664.12171 CrossRefGoogle Scholar