Climate and habitat management are two key drivers for patterns of biodiversity, but little is known about relative importance, interactions and nonlinear effects of climate and management on species richness and trait variation of plants.

Alps (Germany).

We studied patterns of species richness and pollination types in 34 alpine grasslands along an altitudinal climatic gradient comparing grazed, mown and non-managed grasslands. Two vegetation assessments were conducted in 2009 on ten 4-m² plots per study site and per survey.

In total, 484 vascular plant species were recorded. Species richness peaked at intermediate temperatures and was highest in grazed grasslands compared with mown and non-managed grasslands. No significant interaction between management effects and climate was found. Species richness of insect-pollinated plants peaked at lower temperatures (higher altitudes) than species richness of wind-pollinated plant species. The proportion of wind-pollinated plants decreased with decreasing temperature, but the vegetation cover of wind-pollinated plants increased with decreasing temperature.

Our results indicate that managing alpine grasslands by extensive grazing maintains high plant diversity over the full subalpine gradient. Rising temperatures with climate change and an upward shift of the diversity peak of plants might result not only in reduced overall diversity because of reduced grassland area at higher altitudes but also in changed species composition and adaptive potential of pollination types.