Consequences of subpopulation isolation for pollination, herbivory, and population growth in Clarkia concinna concinna (Onagraceae) Original Research Article

The importance of the spatial arrangement of populations for long-term persistence has been debated. Plant species will be influenced mostly by the responses of their pollinators and herbivores to changes in population isolation, making it hard to predict how habitat fragmentation may affect a plant species. I have used a common annual to examine how population isolation may affect reproductive success and ultimately population growth and persistence. Clarkia concinna concinna exhibits considerable pollen limitation when small populations are isolated, although it also endures less herbivory. For this plant, isolation appears mostly to depress population growth and therefore to enhance risks of extinction. Experimental investigations on common species such as C. concinna concinna can be used to better diagnose threats to endangered taxa, and to design appropriate restoration activities.