From a site in Israel that had high pollinator biodiversity (Mt. Carmel), Potts and colleagues (2003) discovered that fire initially was catastrophic to plant and bee communities, but that recovery was rapid. Within 2 years of the fires there was a peak in plant and bee diversity that was followed by a long and steady decline over the next 50 years. They reported that bee pollinator communities closely matched the plant community in recovery and regeneration (Potts et al., 2001, 2003).

Like mowing and grazing, fire is an important management tool that can be used to reset the successional sequence and maintain the diverse and heterogeneous mosaic landscapes that include early successional stages (oldfields) and late primary stages (climax forests). Resetting the successional sequence provides resources for a wider array of species (Pickett and White, 1985; Smallidge and Leopold, 1997). More information is needed on the short- and long-term effects of fire—and its use as a management technique—on diverse North American plant and pollinator communities.

Nesting Habitat

Although solid expanses of grasses and forbs are not productive nesting habitats for bees, they do provide nest sites (larval host plants) for a variety of Lepidoptera. Thus, grassland management protocols that are well adapted for Lepidoptera also should consider provisions for bee-nesting sites. Nesting sites can be provided by creating patches of bare ground or sand-loam mixes for ground-nesting bees; by maintaining a landscape mosaic of wooded and grassy areas, protecting some dead wood and standing snags and drilling holes in some dead wood; putting out trap nests for twig-nesting bees; and putting out bumble bee nest boxes, buried or above ground (Box 6-4). Large-scale herbicide applications, such as are applied in the southwestern United States to remove undesirable scrub and brush (mesquite and Prosopis plants), should be discouraged because they remove not only nesting sites and refuges, but also pollen and nectar sources for native bees, honey bees, and other pollinators (Buchmann and Nabhan, 1996).

MAINTAINING POLLINATION SERVICES

Maintaining commercial pollinator stocks and the diversity of wild pollinator communities differs from maintaining pollination services provided by pollinators, because pollination services could be enhanced without an increase in pollinators. This section presents strategies for maintaining pollination services to crops by commercial pollinators and pollination services to crops and wild native plant populations by wild pollinators.



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