BREEDING BIOLOGIES FOR CHAENACTIS DOUGLASII (ASTERACEAE) AND BEE COMMUNITY FATES IN A CHRONOSEQUENCE OF PAST WILDFIRES
Pollinating Insects-- Biology, Management and Systematics Research
2012 Annual Report
1a.Objectives (from AD-416):
1) The breeding biology of the Great Basin wildflower Chaenactis douglasii will be characterized experimentally to inform prospective seed growers of this plant’s pollination needs when farming it to produce restoration seed.
2) The post-fire fates of native bee communities across the northern Great Basin will be sampled from a chronosequence of past wildfires. This knowledge is important for the reproductive success of large seedings of wildflowers meant to rehabilitate recently burned sage-steppe and juniper habitats.
1b.Approach (from AD-416):
1) The breeding biology of C. douglasii will be studied in a common garden by comparing achene and seed sets at caged flowers, openly visited flowers, and manually self- and cross-pollinated flowers in our common garden. Combined with flower production, we can then estimate seed production per plant by each treatment.
2) A chronosequence of accessible large Great Basin wildfires will be visited during spring bloom and the bee faunas of 1-2 target wildflower species will be quantitatively sampled in and outside of the fire perimeter. Bloom density, forb diversity, shrub density and densities of the dominant wildflowers will be characterized by standard plant community measures.
The flower called dusty maiden, Chaenactis douglasii, is desirable for restoring western rangelands after wildfires in the Great Basin. ARS conducted manual pollination experiments in a common garden to determine pollination requirements, thus to assisting farmers in seed production. The plant was found to be weakly self-incompatible and primarily sets seed through outcrossing. ARS also collected bees, providing a collection probable pollinators across three states, and showed that this plant is mostly visited by native floral generalists, as well as by honey bees. One native cavity-nesting specialist, Osmia californica, can reproduce on this floral host; it and the honey bee are the pollinators we recommended for on-farm seed production.