Remote sensing of canadian grasslands: using vegetation biochemistry to monitor grassland health

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Assessment of vegetation biochemical and biophysical properties can lead to a better understanding of grassland conditions and further improve performance of ecosystem modeling. Some key vegetation biophysical parameters have been estimated from remote sensing data and used as inputs to ecosystem process models at various spatial and temporal resolutions. However, vegetation biochemical variables that control ecosystem biogeochemical processes, are not always available in a spatially-explicit format and have to be held constant in the models due to a lack of appropriate data with high spectral and spatial resolutions across a broad area. Recent developments in the field of hyperspectral remote sensing have opened new ways for estimating vegetation's biochemical properties. Consequently, I propose to explore and develop cutting-edge remote sensing methods to estimate spatially-explicit grassland biochemical properties (e.g. chlorophyll concentrations and carotenoid concentrations) at multiple spatial scales. Specifically, the research will 1) develop index-based approach to accurately estimate grassland biochemical properties at the canopy level; 2) investigate the capability of physical modelling approach to accurately estimate grassland biochemicals at the canopy level; 3) scale up from the canopy level to the landscape level using space-borne hyperspectral data and assess the dependence of the index-based and the physical modeling based biochemical estimations on confounding factors (i.e. exposed soil and non-photosynthetic vegetation) at the landscape level. The proposed work will address the significant knowledge gap concerning remote sensing biochemistry and grassland ecosystem. It is anticipated that the output from this work will be an essential input for carbon sequestration studies, grassland ecosystem sustainable development, and climate change and variability impact studies in the Canadian mixed and tall grassland ecosystems, as well as a decision making tool for stakeholders.