Skip to main content
hyi
Banner
banner
bn

Collaborative Research: Restricted Plasticity of Canopy Stomatal Conductance: A Conceptual Basis for Simpler Spatial Models of Forest Transpiration

0405381<br/>Ewers<br/><br/>It is clear from recent reports by the water and carbon groups associated with the United States Global Change Research Program that accurate predictions of canopy stomatal conductance in forested systems are critical for the understanding of land surface - atmosphere fluxes and how they are affected by climate and land use changes. Indeed, land use changes are producing more fragmented landscapes and these are not readily represented in current land surface models. Current forest flux models were developed under the paradigm of research in which uniform forest stands are identified, flux measurements are made in the centers of these stands, and then what is learned here is extrapolated to the entire stand and beyond. This approach is neither necessary nor justified given the spatial complexity of vegetative communities. This project<br/>seeks to develop a conceptual model of forest transpiration that embraces the inherent spatial variability of stomatal control while retaining a tractable measure of generalizability that is the hallmark of empirical models of stomatal conductance. Our conceptual model is based on the idea that canopy stomatal conductance is regulated primarily by water potential when water fluxes are high and of significant hydrologic import. We propose that species plasticity in canopy stomatal conductance, which determines its spatial variability and challenge for quantifying, follows a linear relationship that is keyed off of an easily quantifiable reference conductance<br/>0405381<br/>Ewers<br/><br/>It is clear from recent reports by the water and carbon groups associated with the United States Global Change Research Program that accurate predictions of canopy stomatal conductance in forested systems are critical for the understanding of land surface - atmosphere fluxes and how they are affected by climate and land use changes. Indeed, land use changes are producing more fragmented landscapes and these are not readily represented in current land surface models. Current forest flux models were developed under the paradigm of research in which uniform forest stands are identified, flux measurements are made in the centers of these stands, and then what is learned here is extrapolated to the entire stand and beyond. This approach is neither necessary nor justified given the spatial complexity of vegetative communities. This project<br/>seeks to develop a conceptual model of forest transpiration that embraces the inherent spatial variability of stomatal control while retaining a tractable measure of generalizability that is the hallmark of empirical models of stomatal conductance. Our conceptual model is based on the idea that canopy stomatal conductance is regulated primarily by water potential when water fluxes are high and of significant hydrologic import. We propose that species plasticity in canopy stomatal conductance, which determines its spatial variability and challenge for quantifying, follows a linear relationship that is keyed off of an easily quantifiable reference conductance

Status
In progress
Type
Project
Project URL
http://www.research.gov/research-portal/appmanager/base/desktop
Project Database
Start Date
End Date

The Great Lakes - St. Lawrence Research Inventory is an
interactive, Internet-based, searchable database created as a tool to collect and disseminate
up-to-date information about research projects in the
Great Lakes - St. Lawrence Region.