THE NEED FOR “EXTENDED CARE” IN CONSERVATION: EXAMPLES FROM STUDIES OF RARE PLANTS IN THE WESTERN UNITED STATES

Critical habitat of rare Angiosperms may extend well beyond the actual area occupied because of the dependence of many plant species on pollinators.
Indeed, because of their need for sexual servicing, rare plants may be regarded as uncharismatic “umbrella” species.
Most of the 26 species of rare plants we have studied in the western U.S. since 1988, set fruit only when visited by pollinators, primarily native bees.
Thus, management plans to conserve these plants must also acknowledge their pollinators.
Such plans introduce factors not usually considered in rare plant conservation.
First, managers must find and defend that nesting habitat of bee populations (usually in the ground or in decaying wood), which is not conterminous with the rare plants that these bees pollinate.
Second, to maintain healthy native bee populations may also require the encouragement of populations of other plant species with floral rewards that complement or supplement those of the rare species.
And third, in areas with rare species whose pollinators have long flight periods, such as Bumblebees and species with more than one generation per year, acceptable floral rewards must be available throughout the growing season.
We illustrate the need for such “extended care” of rare plants with examples from our field work.
Application of the “extended care” concept would increase the size of areas set aside for rare plants, and would preserve larger chunks of communities and ecosystems.

VII International Symposium on Pollination

V.J. Tepedino, S.D. Sipes, J.L. Barnes, L.L. Hickerson

native bees, pollinators, plant reproduction, Spiranthes, Mirabilis, Arctomecon, Pediocactus, Astragalus

https://doi.org/10.17660/ActaHortic.1997.437.27