Isolation limits spring pollination in a UK fragmented landscape

Abstract

Abstract Context Animal-mediated pollination is a key factor that determines the reproductive success of the most flowering plants; this process however can be disrupted by environmental degradation, with habitat fragmentation highlighted as a key driver of pollinator declines. Despite habitat fragmentation being one of the most pervasive anthropogenic stressors worldwide, we still have rather limited empirical evidence on its effects on pollination, especially for early spring pollination syndromes. Objectives We experimentally study the effect of patch area and isolation on the pollination of English Bluebell (Hyacinthoides non-scripta), a species largely pollinated in spring by queen bumblebees. Methods In a fragmented landscape in Bristol, United Kingdom, we selected 51 woodland patches which vary in both size and distance from each other, and placed 153 bluebell plants in those selected patches for c.4 weeks to measure pollination. Results Measuring pollination through the number of seeds produced and seed capsules formed, we show that while patch area had no effect, the main determinate of overall reproductive success of plants was patch isolation which negatively correlated with both seed number and capsules. Conclusion Our results highlight the importance of connectivity in maintaining pollination services in fragmented landscapes.