Pollinator Studies: Willamette Valley, OR
Project ID: W912HZ-19-2-0009
Federal Agency: U.S. Army Corps of Engineers
Partner Institution: Center for Natural Lands Management
Fiscal Year: 2019
Initial Funding: $55,995
Total Funding: $112,906
Project Type: Research
Project Disciplines: Biological
Principal Investigator: Waters, Susan
Abstract: Interactions with pollinators can be important drivers of reproductive success for rare and endangered plant species. Worldwide, the vast majority of land plants require an animal (usually an insect) to transfer pollen in order to reproduce (Ollerton et al. 2011). Studies measuring pollinator dependence in Willamette Valley prairies (OR) are minimal, but our data for closely related south Puget Sound prairies (WA) suggest that >85% of prairie plant species are dependent on insect pollination to set seed (Waters et al., unpublished data 2017). Thus, pollination services are probably key for conservation and recovery of federally endangered Erigeron decumbens (Willamette daisy or
ERDE). To best understand how pollination of E. decumbens influences recovery of the species, two factorsare important: the intrinsic pollination biology of ERDE itself and the effect of the surrounding plant community on ERDE pollination. The plant community context is important because it influences what pollinator taxa are available and their behavior while foraging (i.e., which flowers they choose to visit).
This context is a critical piece of the picture, since the same plant species can receive many pollinator visits or very few pollinator visits depending on the surrounding floral neighborhood (e.g., floral density and diversity; Waters et al., 2014).
Our research will focus on determining key aspects of the plant community context for pollination and identifying E. decumbens pollinators, complementing work by others that will focus on ERDE’s mating system and pollination biology. With few ERDE populations remaining, opportunities to observe ERDE across the full range of conditions under which its life history traits evolved are limited, but assessing plant community effects in large, well-established ERDE populations and in small remnant populations (i.e., low density/low abundance) will provide useful comparisons. Our research will provide key information for management and conservation by:
1. Building site-specific plant-pollinator networks to visualize and analyze interdependencies
between E. decumbens, its pollinators, and other plants.
2. Inventorying E. decumbens pollinators by identifying pollinator specimens captured during timed
observations of E. decumbens.
3. Comparing plant-pollinator network characteristics between two large Willamette Valley ERDE
sites and a site with a small remnant ERDE population.
4. Producing a pollen “reference library”.
5. Piloting a strategy to determine pollen competition and facilitation of E. decumbens.