This dataset measures the total amount of above-ground live biomass in forested systems, which is an important attribute of forested communites and an indicator of successional development, and an important habitat attribute for many forest-associated wildlife species. The dataset is derived from a combination of remote sensing products derived from multi-temporal Landsat TM data and Forest Inventory and Analysis (FIA) plot data and forest succession models derived from FIA plot data. It is expected this dataset will be useful for distinguishing early successional from mature forests as they existed in approximately 2012. Units are in kilograms/meters squared times 10.

To create this dataset, the Woods Hole North American Carbon Program (NACP) Aboveground National Biomass and Carbon Baseline Data (NBCD 200) Version 2 (Kellndorfer et al. 2013) was updated with the High-Resolution Global Maps of 21st-Century Forest Cover Change (Hansen et al. 2013) to generate the current biomass grid.

Development of the NBCD 2000 data set used an empirical modeling approach that combined USDA Forest Service Forest Inventory and Analysis (FIA) data with high-resolution InSAR data acquired from the 2000 Shuttle Radar Topography Mission (SRTM) and optical remote sensing data acquired from the Landsat ETM+ sensor. Three-season Landsat ETM+ data were systematically compiled by the Multi-Resolution Land Characteristics Consortium (MRLC) between 1999 and 2002 for the entire U.S. and were the foundation for development of both the USGS National Land Cover Dataset 2001 (NLCD 2001) and the Landscape Fire and Resource Management Planning Tools Project (LANDFIRE). Products from both the NLCD 2001 (landcover and canopy density) and LANDFIRE (existing vegetation type) projects as well as topographic information from the USGS National Elevation Dataset (NED) were used within the NBCD 2000 project as spatial predictor layers for canopy height and biomass estimation. The response variables (canopy height and biomass) used in model development and validation were derived from the FIA database (FIADB). See:

http://daac.ornl.gov//NACP/guides/NBCD_2000_V2.html for a complete description of the NBCD 2000 dataset.

Hansen’s team used Earth observation satellite data to map global forest loss and gain from 2000 to 2012 at a spatial resolution of 30 meters. ‘Forest Loss’ is defined as a stand-replacement disturbance, or a change from a forest to non-forest state. ‘Forest Gain’ is defined as the inverse of loss, or a non-forest to forest change entirely within the study period. ‘Forest Loss Year’ is a disaggregation of total ‘Forest Loss’ to annual time scales. See:

http://www.sciencemag.org/content/342/6160/850.full for a complete description of these datasets.

We used the Woods Hole NACP Aboveground National Biomass and Carbon Baseline Data (NBCD 2000) V.2 (Kellndorfer et al. 2013) and updated it with the High-Resolution Global Maps of 21st-Century Forest Cover Change (Hansen et al. 2013) and forest succession models to generate the current biomass grid. Briefly, FIA plot data were used to develop an estimate of biomass for the year 2000 (Kellndorfer et al. 2013). Next, we fit a non-linear regression model that describes how above-ground live biomass changes in response to stand age and a suite of ecological settings variables (growing degree days, growing season precipitation, soil pH, soil available water supply and soil depth) based on FIA plot data in forested systems (see DSL_documentation_succession.pdf for details). Next, based on this regression model we converted the 2000 biomass layer to stand age and grew the stands by adding 12 years to the stand age. Next, we subtracted the year of disturbance based on the Hansen et al. (2013) map of recent (2000-2012) stand-replacing disturbances. Lastly, we applied the regression model to convert 2012 stand age to biomass.

This dataset was developed as part of the Designing Sustainable Landscapes project led by Professor Kevin McGarigal of UMass Amherst and sponsored by the North Atlantic Landscape Conservation Cooperative; for more information about the entire project see: http://www.umass.edu/landeco/research/dsl/dsl.html

Literature cited:

Hansen, M. C., P. V. Potapov, R. Moore, M. Hancher, S. A. Turubanova, A. Tyukavina, D. Thau, S. V. Stehman, S. J. Goetz, T. R. Loveland, A. Kommareddy, A. Egorov, L. Chini, C. O. Justice, and J. R. G. Townshend. 2013. “High-Resolution Global Maps of 21st-Century Forest Cover Change.” Science 342 (15 November): 850–53. Data available on-line from: http://earthenginepartners.appspot.com/science-2013-global-forest.

Kellndorfer, J., Walker, W., LaPoint, E., Bishop, J., Cormier, T., Fiske, G., Hoppus, M., Kirsch, K., and Westfall, J. 2012. NACP Aboveground Biomass and Carbon Baseline Data (NBCD 2000), U.S.A., 2000. Data set. Available on-line at http://daac.ornl.gov from ORNL DAAC, Oak Ridge, Tennessee, U.S.A. http://dx.doi.org/10.3334/ORNLDAAC/1081