Herbivory mediates the long-term shifts in the relative importance of microsite and propagule limitation

Microsite and propagule limitation are predicted to jointly influence plant community assembly and diversity, with shifts in their relative contributions under different ecological conditions. Mammalian herbivory can also exhibit strong impact on community assembly and diversity. However, to date few studies have considered how herbivory might interact with propagule and microsite limitation and how herbivory might alter their relative importance. Even fewer studies have examined how these processes manifest over time to influence community assembly. In fenced and grazed tundra communities that varied in soil moisture, we manipulated propagule limitation by adding seeds of 14 species, and manipulated microsite limitation through a one-time disturbance treatment which reduced resident community biomass. We then followed these communities for 11 years to assess the long-term impacts of these processes on community assembly and richness. Herbivory interacted with soil moisture to promote l...