The Pacific Northwest region vegetation and monitoring system.

Timothy A. Max; Hans T. Schreuder; John W. Hazard; Daniel D. Oswald; John Teply; Jim Alegria

doi:10.2737/PNW-RP-493

Treesearch

The Pacific Northwest region vegetation and monitoring system.

Informally Refereed

Authors:

Timothy A. Max, Hans T. Schreuder, John W. Hazard, Daniel D. Oswald, John Teply, Jim Alegria

Year:

1996

Type:

Research Paper

Station:

Pacific Northwest Research Station

DOI:

https://doi.org/10.2737/PNW-RP-493

Source:

Res. Pap. PNW-RP-493. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 22 p.

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Abstract

A grid sampling strategy was adopted for broad-scale inventory and monitoring of forest and range vegetation on National Forest System lands in the Pacific North-west Region, USDA Forest Service. This paper documents the technical details of the adopted design and discusses alternative sampling designs that were considered. A less technical description of the selected design will be given elsewhere. The grid consists of a regular, square spacing with 5.47 kilometers (3.4 mi) between grid points. The primary sampling unit (PSU), established at each grid sampling point, consists of a circular, 1-hectare (2.47-acre) plot. The PSU is subsampled with a set of different-sized fixed-area subplots, as well as line transects, to assess all components of vegetation. The design is flexible and can be used with many types of maps. The theory of point and change estimation is described, as well as estimates of variation that assess the statistical precision of estimates.

Keywords

Keywords Sampling, plot design, fixed-area plots, line intersect sampling, monitoring, National Forest System, Pacific Northwest

Citation

Max, Timothy A.; Schreuder, Hans T.; Hazard, John W.; Oswald, Daniel D.; Teply, John; Alegria, Jim. 1996. The Pacific Northwest region vegetation and monitoring system. Res. Pap. PNW-RP-493. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 22 p.