Quantifying Ecosystem Responses to Changes in Climatic and Management Factors using Field Observations, Remote Sensing Data and Process-Based Modelin

Rajen Bajgain

Climatic and management factors in isolation or in combination influence the ecosystem properties and the flows of energy, water, and elements. Knowledge gap persists regarding how the change in climatic factors will affect the interactions of ecosystems and feedbacks of ecosystems with climate, under diverse land management conditions. In this presentation, I will focus on quantifying biophysical and biogeochemical feedbacks of ecosystems to climate and management variability using field observations (eddy covarian ce and automated chamber), remote sensing data, and process-based modeling approaches. A new drought algorithm was developed and tested to understand the response of tallgrass prairie to drought. Eddy covariance data showed that grassland converted to winter wheat was a net source of carbon at an annual scale. Management practices in pasture altered the biophysical properties and ecosystem biogeochemistry resulting into higher greeenhouse gas emissions. Our results highlight the importance of quantifying vegetation feedbacks to changes in climatic and management factors, and this information can be used to reduce the uncertainty of model projections.