Wind dynamics in corridors

When thinking about the forces that shape species’ response to corridors, how many people think to look off the ground and into the sky?  With so many plant species dispersed by wind, the question of how wind dynamics are altered in corridors may have big implications for species movement and diversity.  Damschen et al., in their recent paper in PNAS, set out to determine how wind-dispersed species fare in corridors through both model simulations and empirical testing at one of the largest experimental corridors, Savannah River Site in South Carolina.  Using models of seed dispersal under varying wind dynamics scenarios, combined with releases of artificial seeds in corridors that control for area, shape and connectivity, the authors were able to predict and observe how corridors change wind dynamics and ultimately long distance dispersal for many species.  With 12 years of data, they were also able to examine how species richness of wind dispersed plants has changed under different connectivity scenarios.

Models predicted that that open corridors tend to alter wind dynamics by redirecting wind flow, accelerating wind speed, and increasing turbulence so that there is a higher probability of seeds being uplifted and moving longer distances.  Empirical data supported these predictions, showing that corridors increased wind speed and rotated wind direction to be more in line with the long axis of the patch.  In addition, patches connected by corridors showed significantly higher richness in wind-dispersed species.  Conservation planning, especially for open habitats, might do well to consider wind dynamics when designing corridors to promote long distance dispersal of seeds, especially if those seeds are for rare or endangered plants.