Forest Cover, Windspeed and Precipitation: A South American Case Study of the Impact of Forest Ecosystems on Wind and Rainfall Patterns (unpub.)
Emory Ellis,1,2 Ronny Meier,3 David Ellison*, 4-6
1 Hampshire College, Amherst, Massachusetts, USA
2 University of British Columbia Okanagan, Earth and Environmental Sciences, Kelowna, British Columbia, Canada
3 ETH, Zurich, Switzerland
4 Land Systems and Sustainable Land Management Unit, Institute of Geography, University of Bern, Switzerland,
5 Department of Forest Resource Management, Swedish University of Agricultural Sciences, Umeå, Sweden,
6 Ellison Consulting, Baar, Switzerland
Abstract
Gaps persist in our comprehension of forest-water interactions and how forest cover potentially alters and sustains precipitation at continental scales. We analyze high-resolution, remote sensing data on forest cover, annual average windspeed and total annual precipitation amounts in order to better understand how forest cover interacts with and impacts windspeed and how the forest impact on windspeed can influence the transport and potential re-deposition of atmospheric moisture as rainfall. In this first look at these interactions over the South American continent, our analysis suggests forests slow windspeed, providing greater opportunity for the accumulation and aggregation of incoming atmospheric moisture and local evapotranspiration, and thereby contributing to its increased potential re-deposition as rainfall. In slowing windspeed, greater forest cover appears to intensify the hydrologic cycle, providing more opportunities for atmospheric moisture and evapotranspiration to condense and re-precipitate, as well as re-evaporate and re-transpire back to the atmosphere, thereby increasing the potential for terrestrial rainfall recycling, as well as the availability of water resources across continental surfaces. We are hopeful improved understanding of how forest cover, windspeed and rainfall interact can help motivate future study and promote the development of a more rigorous approach to preserving the hydrologic cycle through the pursuit of Nature-based Solutions to forest landscape restoration.