View Single Post
Old 03-14-2013, 07:28 PM   #1
Cirsium's Avatar
Join Date: Nov 2008
Location: Midwest
Default Sit-and-Wait Pollination in the Spring Flowering Woodland Plant, Trillium Grandiflorum


Journal of Pollination Ecology
Emily S. Darling 1,* and Spencer C.H. Barrett 2
1 Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6
2 Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2
Abstract—In animal-pollinated plants, reproductive success is commonly limited by pollen availability, which can occur in environments where pollinator activity is scarce or variable. Extended floral longevity to maximize a plant’s access to pollinators may be an adaptation to such uncertain pollination environments. Here, we investigated the effects of flower exposure time to pollinators on female fertility (fruit and seed set) in the bee-pollinated woodland herb Trillium grandiflorum, a species with long-lived flowers (~17-21 d) that blooms in early spring when pollinator activity is often variable. We experimentally exposed flowers to pollinators for different amounts of time to determine the extent to which floral longevity influenced reproductive success. The amount of time that flowers were exposed to pollinators significantly increased fruit set and seed set per flower, but not seed set per fruit. Our results provide experimental evidence that long floral life spans may function as a ‘sit-and-wait’ pollination strategy to increase the amount of exposure time to pollinators and promote seed set in the unpredictable pollination environments often experienced by early spring ephemerals. In large populations with infrequent pollinator visitation, as commonly occurs in T. grandiflorum, pollination may be a largely stochastic process.
Trillium grandiflorum is a perennial, non-clonal herb that occurs in the deciduous forest understory of eastern North America (Case & Case 1997). Populations flower for approximately three weeks in early spring and are pollinated largely by pollen-foraging bees (Case & Case 1997; Irwin 2000; Sage et al. 2001). Flowers produce no nectar and are weakly protandrous (Irwin 2000; S.C.H. Barrett unpubl. observations).[]=112&path[]=17
"We abuse land because we regard it as a commodity belonging to us.
When we see land as a community to which we belong, we may begin to use it with love and respect."
Aldo Leopold

Cirsium is offline   Reply With Quote