Modelling stomatal behavior under soil moisture, light, temperature, and humidity conditions of a Montane Cloud Forest Environment
Abstract
Montane Cloud Forests (MCFs) are extremely biodiverse regions that compromise solely 1% of all the world's woodlands making it critical to understand and preserve these unique ecosystems. Located around headwater streams at elevations ranging from 500 to 4,000 meters, MCFs serve as an essential water source for these regions. During the growing season, MCFs experience low-level clouds and fog for extended periods that results in water deposition on leaves that blocks the stomata (leaf pores) and limits gas exchange. Interestingly, other studies have observed enhanced photosynthesis during periods of cloud immersion for some species of vegetation. It is crucial to understand how vegetation in MCFs exchange water, carbon dioxide, and other gases through the leaf pores, a process described in land-surface models as stomatal conductance. Empirical models of stomatal conductance have been essential in demonstrating the behavior of how water and carbon dioxide are transported through the leaf pores, which ultimately affect estimates of other land surface fluxes including evapotranspiration and latent heat. This study uses a numerical model based on Farquhar's C3 photosynthesis model and a soil-plant-atmosphere continuum (SPAC) model to evaluate how well the Ball-Berry-Leuning (BBL) empirical model for stomatal conductance captures cloud forest vegetation gas exchange processes. A key component of this study is to assess how well the BBL model for stomatal conductance recreates observed photosynthesis rates and leaf water potential observed in a Southern Appalachian MCF using field observations of soil moisture, temperature, incoming soil radiation, and humidity. This work provides a framework to evaluate how future climate change scenarios for MCFs will impact vegetation health and overall ecosystem productivity for these critical regions.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMH068...01G
- Keywords:
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- 1813 Eco-hydrology;
- HYDROLOGY;
- 1836 Hydrological cycles and budgets;
- HYDROLOGY;
- 1894 Instruments and techniques: modeling;
- HYDROLOGY;
- 1895 Instruments and techniques: monitoring;
- HYDROLOGY