Disturbance of forest areas, much of which has been cleared by human means around the world, has become one of the more challenging and pertinent aspects of global environmental change. The condition of a forested watershed has a direct impact in the quantity and quality of water that is available for human and ecosystem uses. Various aspects of the forest ecosystem affect the surface energy balance and the partitioning of precipitation to runoff, stream flow and groundwater recharge. The operating hypothesis of this work considers that the wide variety of forest disturbances (e.g. drought, defoliation, windthrow, fire, thinning or partial harvest, and clear-cutting) produces a spectrum of such impacts on the land-based hydrologic cycle. Each of these disturbances types is tied closely, by numerous and complex pathways, to climate and weather conditions and anthropogenic influences. The overall hydrologic impacts of these disturbances arise from similarly varied signatures in the feedback of the land surface to the atmosphere, responses that may initially be observed as subtle changes in the local energy balance and the exchange of heat and moisture within the disturbed forest area. The goal of this work is to provide, using existing and new tools in novel combinations, some physical explanation for the observed spectrum of impacts on the local and regional hydrologic cycle due to various observed forest disturbances.Feedback welcome, and there's more to come!
Scientists, researchers, and natural resource managers seek to understand the hydro-ecological impacts of anthropogenic disturbance and climate variability while the economic needs of the community, the spread of invasive species, and the threat of catastrophic forest fires persist. Significant attention has been given to the loss of tropical forest cover in the past several decades, but concern is also rising for the health and fate of temperate and boreal forests. Expanding urban areas, agricultural land use, resource extraction, land and timber management, natural ecological cycles, and climate change have all shaped forest health for far longer than we have given our attention to the issues and problems of such influences. Valuable previous work has considered these problems from varied and often disjoint aspects, but we now have the tools and the methods that can provide a successful approach to such issues in combination. Specifically, I propose to demonstrate the hydrologic impacts of forest disturbances by the combination of several tools that are now available: remote sensing products and analytical methods for the estimation of forest disturbance severity and vegetation health, ecological models of forest disturbance and succession, and coupled land–atmosphere models.
We can witness these changes as they occur using many methods, from local hydrological and climatological observations to space-based remote sensing platforms, but we often wonder about the ultimate source and mechanism of the change that has been found. We are similarly curious about the ways that projected future climate conditions will become apparent at the local scale, but we must recognize in our approach to this problem that the states and processes of the atmosphere and the land surface are necessarily and closely intertwined. Changes at the land surface, broadly as land cover and use and in such narrow categories as the treatment of a fire-scarred hillside above a drinking water reservoir, are finally being recognized as significant management decisions. These are efforts that require the consideration of detailed and far-reaching impacts on both the natural and built environments, the resilience of ecological and human systems, and the sustainability of biodiversity, ecosystem services, and human health. It is vital that we incorporate the best available science in decision-making efforts in order to ensure progress on these goals.
07 December 2012
Dissertation Proposal Excerpt
The paragraphs below are excerpted from my Ph.D. Dissertation Proposal, currently in preparation. I'll be using parts of the dissertation proposal for some upcoming fellowship proposals too...