Reproductive success in fragmented habitats: Do compatibility systems and pollination specialization matter?

Abstract

This paper explores whether plant breeding system and pollination specialization influence the reproductive response of plants to habitat fragmentation. It is meaningful for conservation to predict a plant species' extinction risk. We found 25 studies in the literature assessing the effects of habitat fragmentation on either pollination or reproductive success of 46 plant species to answer the following questions: 1. Are pollination and reproductive success of self-incompatible species more likely to decline with habitat fragmentation than the pollination and reproductive success of self-compatible species? Although most of the species showed statistically significant negative effects, the pollination and reproduction of self-incompatible species were as likely to decline with fragmentation as those of self-compatible species. 2. Are pollination and reproductive success of specialist plants more affected than the pollination and reproduction of generalist plants? Comparisons of fragmentation-related changes in pollination and reproductive success between specialists and generalists do not support the hypothesis that specialization in pollination increases the risk of plant extinction. 3. Can self-incompatible species offset their expected higher vulnerability to fragmentation by being, on average, more pollination generalist than self-compatible species? In a larger data set on 260 species, we did not find significant differences in either the mean number or frequency distribution of numbers of flower-visiting species or orders between self-compatible and self-incompatible species. Our review suggests that no generalizations can be made on susceptibility to fragmentation based on compatibility system and pollination specialization.