Plants and their pollinators form pollination networks integral to the evolution and persistence of species in communities.Previous studies suggest that pollination network structure remains nested while network composition is highly dynamic.However, little is known about temporal variation in the structure and function of plant-pollinator networks, especially inspecies-rich communities where the strength of pollinator competition is predicted to be high. Here we quantify temporalvariation of pollination networks over four consecutive years in an alpine meadow in the Hengduan Mountains biodiversityhotspot in China. We found that ranked positions and idiosyncratic temperatures of both plants and pollinators were moreconservative between consecutive years than in non-consecutive years. Although network compositions exhibited highturnover, generalized core groups – decomposed by ak-core algorithm – were much more stable than peripheral groups.Given the high rate of turnover observed, we suggest that identical plants and pollinators that persist for at least twosuccessive years sustain pollination services at the community level. Our data do not support theoretical predictions of ahigh proportion of specialized links within species-rich communities. Plants were relatively specialized, exhibiting lessvariability in pollinator composition at pollinator functional group level than at the species level. Both specialized andgeneralized plants experienced narrow variation in functional pollinator groups. The dynamic nature of pollination networksin the alpine meadow demonstrates the potential for networks to mitigate the effects of fluctuations in species compositionin a high biodiversity area.
Relative stability of core groups in pollination networks in a biodiversity hotspot over four years
Year: 2012
