Getting around: Effects of fragmentation on a bird-pollinated Erica species

Abstract

Small or isolated plant populations might be expected to provide limited nectar resources to attract or sustain pollinators. We determined whether the plant-pollinator mutualism between the obligate out-crossing ornithophilous species Erica discolor, and its pollinators was resilient to habitat fragmentation. To do this we recorded pollinator visitation rates (using % flowers with at least one visit as a proxy) and seed set in patches of different sizes and degree of isolation in the easternmost section of the Cape Floristic Region, South Africa. For E. discolor, there was no negative effect of patch size and isolation on visitation rates. Plants in small patches (< 100 ha) did not have lower proportions of viable seeds compared to plants in large patches (> 240 ha). Our findings suggest that conserving small isolated fragments is important in maintaining ornithophilous plant populations.