Plant Community Establishment in Restoration: Effects of Seed Source Across Reciprocal Common Gardens in Three States

Humankind is undertaking an unprecedented manipulation of the globe's climate, land cover, and species distributions. This has been especially true for temperate grasslands, where the disparity between habitat loss and protection is vast. In temperate grasslands agriculture, urban development, invasive species, and woody encroachment continue to replace or transform native grassland ecosystems, and restoration has become increasingly critical for the conservation of biodiversity and ecosystem functioning. However, the feasibility of restoration, which traditionally targets historical conditions, is questionable in the context of anthropogenic alteration of biophysical conditions.

This is the focus of my research, which investigates the effects of propagule source and variation (mixing among propagule sources) on restoration establishment and the generality of restoration outcomes across variable environments using reciprocal common gardens in three states (Nebraska, Kansas, Oklahoma), which differ markedly in their biophysical conditions. After two growing seasons, the productivity and density of native, seeded plants differed among sites and among seed sources within sites. Seed sources local to individual sites did not exhibit a general establishment advantage, and individual sown species exhibited differential establishment patterns, yielding plant communities that differed in structure, even where overall establishment densities were similar. Sourcing propagules across geographical gradients may ensure that seed mixtures possess traits both within and among species for establishment under altered and changing biophysical conditions across variable environments using reciprocal common gardens in three states (Nebraska, Kansas, Oklahoma), which differ markedly in their biophysical conditions. After two growing seasons, the productivity and density of native, seeded plants differed among sites and among seed sources within sites. Seed sources local to individual sites did not exhibit a general establishment advantage, and individual sown species exhibited differential establishment patterns, yielding plant communities that differed in structure, even where overall establishment densities were similar. Sourcing propagules across geographical gradients may ensure that seed mixtures possess traits both within and among species for establishment under altered and changing biophysical conditions.