Land Change Science Program
Biofuel, biomass, and carbon
Biofuels represent an opportunity to reduce dependency on foreign oil, improve domestic viability, and improve air quality (when used as an oxidizer in gasoline blends). We assess environmental and future sustainability of biofuel crop (e.g., switchgrass) developments based on carbon flux (sink or source) and biomass productivity information. Our focus is native grasslands and croplands in the Great Plains (GP). This project helps guide efficient and sustainable biofuel land uses in productive grasslands and marginal croplands in the GP.
Data driven carbon
The balance of carbon dioxide emissions (from soils and plants; sources) and photosynthetic carbon dioxide uptake (sink) play an important role in the condition of our climate. Carbon flux towers data quantify atmospheric carbon dioxide fluxes related to photosynthesis (gross primary production) and respiration and decomposition (ecosystem respiration) at a 30 minute time step. We seek to understand the dynamics of these carbon dioxide fluxes through regional synthesis of grassland and cropland flux towers. We incorporate remote sensing, GIS, and machine learning to extend flux tower carbon flux dynamics through time and space to quantify regional carbon sinks and sources.
Dynamic monitoring of ecosystem performance (cheatgrass)
Cheatgrass invades Great Basin ecosystems and provides fine fuels that increase fire frequency and severity. It also replaces native shrub steppe species after disturbances, reducing species richness and creating a positive feedback loop with fire. Our study monitors recent cheatgrass dynamics (i.e., beginning of spring growth, percent cover, and dieoff) by developing spatially-explicit ecological models that integrate satellite data, geophysical data, and biophysical data into regression-tree software. The presence of cheatgrass in this ecoregion seems inevitable; therefore, understanding recent and future cheatgrass dynamics can help land managers develop management plans that consider areas most vulnerable or resistant to persistent and increasing cheatgrass percent cover.