National land cover monitoring using large, permanent photo plots

Abstract

A study in the State of North Carplina, U.S.A. demonstrated that large, permanent photo plots (400 hectares) can be used to monitor large regions of land by using remote sensing techniques. Estimates of area in a variety of land cover categories were made by photointerpretation of medium-scale aerial photography from a single month using 111 photo plots. Many of these area estimates compared favorably with the most recent data from the traditional forest inventory, although sampling errors of the new system are at least eight times larger due to the small sample size. The new system detected what appears to be significant conversion of harvested forestland to planted pine plantations between 1983 and 1985. An inexpensive monitoring system based on remote sensing and large photo plots, which uses a variety of aerial photography and low-cost analog satellite imagery might be useful for detecting rapid changes in land cover and management practices. To detect slower changes in land cover and to monitor variables impossible to measure reliably using remote sensing (e.g. wood volume and quality, tree growth, and mortality), the more precise and expensive traditional techniques must still be used.

Citation

Czaplewski, Raymond L.; Catts, Glenn P.; Snook, Paul W. 1987. National land cover monitoring using large, permanent photo plots. In: Land and Resource Evaluation for National Planning in the Tropics: An International Conference and Workshop; Chetumal, Mexico; January 25-31, 1987. General Technical Report WO-39. Washington, DC: U.S. Department of Agriculture, Forest Service. p. 197-202.