Pollination plays a critical role in the plant reproduction and also the maintenance of biodiversity. However, the interaction of plant-pollinator appears quite vulnerable to global change, which may threaten native plant biodiversity, ecosystem stability and food security. To date, it is not clear that to which degree environment change will decrease plant reproductive success through alterations in pollination service, especially at the community level. Pollination study across environment gradients can be used to investigate the effects of non-random species loss in response to global change, whereas most previous research has been based on randomly assembled communities. For example, regions with natural and human-generated landscape gradients are emerging as an ideal system to assess whether and how land use affect pollinator-plant interactions and thus plant reproduction. In this study, we assessed pollination network, pollen limitation and thus plant reproductive success across a natural-agriculture environment gradient at Qizimei Mountains Nature Reserve, Hubei Province, China. At each gradient level, plots were sampled both in the natural community and in the semi-natural community near the crops. Field observation were conducted during August in 2017. If possible, we tracked each pollinator’s foraging in the plot during each 30min observation.
Results/Conclusions
As expected，there were more plant species，more groups of pollinators visited. There were more flowers/inflorescences, more pollinator individuals approached. Our results detected significant gradient effects on pollinator diversity and pollinator approaches. Pollinator diversity decreased and then increased along the gradient from the Reserve to the agriculture area. Habitat effects differed among gradients. Pollinator diversity and approaches were much higher in natural community than those in semi-natural community at the Reserve-area gradient level. At the nearest-agriculture-area gradient level, however, significant fewer pollinator individuals were found in the natural community while no significant difference in pollinator groups. Our study also revealed that the visitation rate per flower/inflorescence was only affected by plant species and its interaction with gradient level. Visitation rate varied significantly among plots across the gradient, resulting in significant different reproduction success. However, plant species had different response to the effects of gradient level, which mostly depending on its community context such as co-flowering species composition and their relative abundance. In a conclusion, interactions between plant and pollinators did vary across the gradient level. Human activity in the Nature Reserve especially influenced the pollination network, highlighting the implications in environment managements.