Fragmentation effects on pollinator guilds and wildflower seed set in an oak-savannah ecosystem

Fragmentation is generally considered to negatively affect biodiversity. Concern over pollinator declines has highlighted the lack of understanding of fragmentation effects on pollinators. As many plant species depend on insect pollination, changes in pollinator communities may result in inadequate pollen receipt (pollen limitation) and depressed seed set. In a fragmented oaksavannah ecosystem, I assessed pollinator diversity and abundance, seed set of seven wildflower species and pollen limitation in Camassia quamash. I also measured fragment characteristics including area, local disturbance, proximity to urbanization, floral resources and proximate habitat. Overall diversity and abundance of pollinators did not respond to fragmentation. Proportional abundance of guilds changed among sites, but guilds responded to different fragment characteristics. Pollen limitation was weakly related to high flowering plant diversity and abundance, but fragment characteristics did not predict seed set of wildflower species. Pollinators and pollination services in this ecosystem may be less affected by fragmentation than expected.