HABITAT FRAGMENTATION AND PLANT POLLINATOR INTERACTIONS

Habitat fragmentation is one of the most apparent forms of environment al degradation and is often considered to be one of the greatest threa ts to terrestrial biodiversity. We examine plant-pollinator relationsh ips as one example of a vital interaction that may be affected by frag mentation. All available evidence shows that pollinator abundance and diversity decline with fragmentation. For some plants, this decline ca uses reduced pollination and seed set. For both pollinators and plants , specialization for mutualistic partners appears to be a key characte ristic that increases their risk of local extinction in fragments. For more generalized species, substitutability of available partners will be necessary for their success. However, relatively little evidence e xists for evaluating the importance of these or other characteristics in causing species loss in fragments. Potentially, the loss of one mut ualistic partner could cause cascading extinctions, but this process r emains to be documented for plant-pollinator communities. More studies on the biologies of key plant-pollinator mutualisms would be valuable for habitat management and would also provide insights into how plant -pollinator interactions influence demographic and genetic processes.