Plant isolation reduces outcross pollen receipt in a partially self-compatible herb

Abstract

1 Few studies of pollination success in fragmented systems measure stigmatic pollen load, and those that do often find it unrelated to plant or population density, size or isolation. Reduced reproductive output, however, is commonly reported, probably because incompatible pollen is contributing substantially to pollen loads of isolated flowers. 2 We used manipulated floral arrays of a bee-pollinated species (Dianella revoluta) to investigate isolation effects on deposition of outcross pollen, while precluding self-pollen transfer. 3 Outcross pollen receipt declined significantly over short distances up to approximately 50 m but even the most isolated flowers received some pollen grains. In c..