A truly exceptional research paper is in press for the Journal of Geophysical Research. It is
Steyaert, L. T., and R. G. Knox (2007), Reconstructed Historical Land Cover and Biophysical Parameters for Studies of Land-Atmosphere Interactions within the Eastern United States, J. Geophys. Res., doi:10.1029/2006JD008277, in press. [those of you with AGU subscriptions can view the entire paper (see)].
The abstract reads,
“Over the past 350 years, the eastern half of the United States experienced extensive land cover changes. These began with land clearing in the 1600s, continued with wide-spread deforestation, wetland drainage, and intensive land use by 1920, and then evolved to the present-day landscape of forest regrowth, intensive agriculture, urban expansion, and landscape fragmentation. Such changes alter biophysical properties that are key determinants of land-atmosphere interactions (water, energy, and carbon exchanges). To understand the potential implications of these land use transformations, we developed and analyzed 20-km land cover and biophysical parameter datasets for the eastern United States at 1650, 1850, 1920, and 1992 time-slices. Our approach combined potential vegetation, county-level census data, soils data, resource statistics, a Landsat-derived land cover classification, and published historical information on land cover and land use. We reconstructed land use intensity maps for each time-slice and characterized the land cover condition. We combined these land use data with a mutually-consistent set of biophysical parameter classes, to characterize the historical diversity and distribution of land surface properties. Time-series maps of land surface albedo, leaf area index, a deciduousness index, canopy height, surface roughness, and potential saturated soils in 1650, 1850, 1920, and 1992 illustrate the profound effects of land use change on biophysical properties of the land surface. Although much of the eastern forest has returned, the average biophysical parameters for recent landscapes remain markedly different from those of earlier periods. Understanding the consequences of these historical changes will require land-atmosphere interactions modeling experiments.”
This study is the most in-depth analysis ever completed on the transformation of the landscape of the eastern half of the United States, and is a truly seminal paper on this subject. The study also presents the landscape variables in a form that can be directly used within climate models. We are in the process of completing a paper which uses this information;
Strack, J., R.A. Pielke Sr and L. T. Steyaert, 2007: Sensitivity of near-surface temperatures and precipitation in the eastern United States to historical land cover changes since European settlement. Water Resources Res., Special Issue on Impacts of Land-Use Change, In Final preparation
which will be posted soon.