Albedo and Bioenergy at the Great Lakes Bioenergy Research Center

Albedo—the ratio of reflected solar radiation to total incident radiation for a given area of land surface—is crucial in understanding energy fluxes on the Earth’s surface, and is an important parameter for modelling climate and weather. Research on albedo can provide information on biophysical characteristics of the land surface, including its role in land surface energy balance, the structure of vegetation canopies, soil moisture, effects of urbanization, etc. However, little is known about how albedo affects different biofuel cropping systems, nor about temporal variability, land use legacies, or the effects of management changes such as fertilization. This study will seek to understand the changes in albedo during bare-ground, peak growing, and senescence seasons, and thereby contribute to assessing the global warming potentials of each type of biofuel cropping system used within our study.

This study will be conducted at the Great Lakes Bioenergy Research Center (GLBRC), Michigan, USA (W.K. Kellogg Biological Station). Change in albedo of different bioenergy crops of corn, sorghum, switchgrass, miscanthus, native grasses, early successional and restored prairie will be quantified.

Research Question 1:
How does albedo vary over time, between different cropping ecosystems, different treatment sites, and changing climate and growing seasons?

Research Question 2:
How can we use drone imagery and sensor-derived albedo to analyze the spatial variability of crop ecosystems, and to scale up to a regional scale?

Research Question 3:
How can we utilize ancillary data from scale-up and MLE sites to provide validation for models to scale up to landscapes?

We propose to use the eddy covariance (EC) method as our primary tool (see Chen et al. 2008) in making intensive, continuous measurements of NEP, water loss through evapotranspiration (ET) and energy balance at the six KBS-GLBRC “Scale-Up Fields”: switchgrass, restored prairie and continuous corn fields (two replicates of each system). A combination of dynamic chambers and microclimatic and biometric measurements will also be used to collect various needed data on soil C, resource use (water, light and N), carbon gain (photosynthesis) and loss (respiration) and changes in major biophysical variables as well as heat energy to achieve our study objectives.

We hypothesize that significant differences exist in ecosystem production, biophysical regulations and belowground carbon allocation among the three biofuel production systems. These differences are clearly reflected at multiple temporal scales.

The data and results produced from this study will be posted on an open Webpage in order to best promote their uses (e.g., modeling research of the Thrust 4 toward the missions of the DOE-BRC.

Objective 1:
Examine the magnitudes and dynamics of net ecosystem production (NEP) and soil C at the six “Scale-Up Fields” that have been identified at the Kellogg Biological Station (KBS).

Objective 2:
Investigate the biophysical regulations and resource use limitations for maximizing NEP and soil C at these sites.

Acknowledgements

Funded by the DOE

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