Evolution of Plant Niche Construction Traits in Biogeomorphic Landscapes

By virtue of niche construction traits, plants play a significant role in shaping landscapes. The resultant outcome is a change in the selective environment, which influences the evolution of these same plants. So far almost all biogeomorphic models have assumed that niche construction traits are invariant in time. On the other hand, niche construction studies have assumed that independent abiotic changes are either nonexistent or are simply linear. Here, I considered the concomitant evolution of plant niche construction traits during landscape development. I constructed a geo-evolutionary model that couples a population genetic module with a landscape development module. Allowing plants to evolve always results in landforms different from those that appear when evolution is not accounted for. The topographic difference between cases with and without evolution ranges from a small difference in the steady-state topography, to drastic differences in landforms. The amount of difference is contingent upon forms of landscape development and the strength of geo-evolutionary coupling. Allowing the landscape to develop while evolution occurs changes evolutionary trajectories for niche construction traits. The landscape can even develop spatial structures that suppress selection. Model results clearly support the need to integrate niche construction theory and biogeomorphology to better understand both.