Research of the past decades has shown that biodiversity promotes ecosystem functions including primary productivity. However, most studies focused on experimental communities at small spatial scales, and little is known about how these findings scale to nonexperimental, real-world ecosystems at large spatial scales, despite these systems providing essential ecosystem services to humans.

Climate warming is altering the diversity of plant communities but it remains unknown which species will be lost or gained under warming, especially considering interactions with other factors such as herbivory and nutrient availability. Here, we experimentally test effects of warming, mammalian herbivory and fertilization on tundra species richness and investigate how plant functional traits affect losses and gains.