Native-species seed additions do not shift restored prairie plant communities from exotic to native states

作者：Martin Leanne M^*; Wilsey Brian J

来源：Basic and Applied Ecology, 2014, 15(4): 297-304.

DOI：10.1016/j.baae.2014.05.007

• Alternate states
• Community assembly
• Dispersal limitation
• Exotic species
• Invasive species
• Novel ecosystem
• Species diversity
• Seed addition
• Restoration

Exotic- and native-dominated communities can exist as alternate states in landscapes, but whether exotic-dominated states are persistent in the face of propagule pressure from native species is not well known. Here, we asked whether adding native seeds to low diversity, exotic-dominated patches would shift them to a more diverse, native state by using a long-term experiment with tallgrass prairie species in Iowa, USA. Previous work established that community assembly history led to alternate exotic or native states of perennial species. We added native seeds to plots in the spring after removing aboveground biomass with fire. We found that an experimental seed addition did not cause a shift from exotic to native states. Plots seeded eight years earlier in spring and without a priority effect continued to have the highest abundance and diversity of native species and lowest proportion of exotics. Our results suggest that exotic-dominated states in restorations can persist in the face of native species propagule pressure. Thus, assembly history can play a strong role in generating and maintaining alternate states over long time frames that are relevant to restoration. New restoration projects in exotic-dominated landscapes should maximize effort toward establishing native species during initial stages of restoration.

• 出版日期2014