NPP Boreal Forest: Superior National Forest, U.S.A., 1983-1984

Data Citation

Cite this data set as follows:

Hall, F. G. 1997. NPP Boreal Forest: Superior National Forest, U.S.A., 1983-1984. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.

Description

Productivity of a boreal forest was determined at 31 spruce and 30 aspen forest stands in the Superior National Forest (SNF) near Ely, Minnesota, U.S.A., in 1983 and 1984 by the National Aeronautics and Space Administration. The purpose of the experiment was to investigate the ability of remote sensing to provide estimates of biophysical properties of ecosystems, such as leaf area index (LAI), biomass and net primary productivity (NPP). These ground-based estimates of above-ground biomass and NPP are available; more ground measurements plus the satellite, aircraft, and helicopter observations for the study site.

The study area covered a 50 x 50 km area centered at approximately 48 N 92 W in northeastern Minnesota at the southern edge of the North American boreal forest. Sites for biophysical measurements were chosen to be pure spruce or aspen stands. The SNF is mostly covered by boreal forest. Boreal forests were chosen for this project because of their relative taxonomic simplicity, their great extent, and their potential sensitivity to climatic change.

At each site, five circular subplots of 16 meters in diameter were sampled within a large plot of 60 meters in diameter. Within the subplots, all woody stems over 2 meters in height were tallied by species, diameter, and height. Thirty each of black spruce and aspen trees from outside the plots were sacrificed and measured. Climate data were collected, including insolation data measured by Donald Baker, Department of Soil Science, University of Minnesota. Dimension analysis of these sampled trees was used to develop equations linking the convenience measurements taken at each site and the biophysical characteristics of interest, including LAI, biomass, and NPP. NPP was estimated for each sacrificed tree from the average radial growth over 5 years measured from the segments cut from the boles and the terminal growth measured as the height increase of the tree. Allometric equations were used to find the height and radial increment as a function of crown height and diameter at breast height. Spruce stands used an additional parameter of stem density. The models were used to project back for 5 years and determine biomass at that time. The average change in biomass per year over that 5-year time was used to determine the above ground NPP.

Contact Information

Contact: Dr. Forrest G. Hall
NASA Goddard Space Flight Center
Code 923
Greenbelt, Maryland
U.S.A.

Telephone +1 (301) 286-2974
Fax +1 (301) 286-0239
E-mail: fghall@ltpmail.gsfc.nasa.gov

There are two data files for this site. Abstracts and references are available, as is a more complete set of Superior National Forest Data.

Recent research findings based on the SNF data have been published by Dr. Scott Goetz, University of Maryland.