Skip to main content
U.S. flag

An official website of the United States government

Estimating botanical composition by the dry-weight-rank method in California's annual grasslands

Author(s):

Raymond D. Ratliff
William E. Frost

Year:

1990

Publication type:

Research Note (RN)

Primary Station(s):

Pacific Southwest Research Station

Source:

Res. Note PSW-RN-410. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 5 p

Description

The dry-weight-rank method of estimating botanical composition on California's annual grasslands is a viable alternative to harvesting and sorting or methods using points. Two data sets of sorted species weights were available. One spanned nine years with quadrats harvested at peak of production. The second spanned one growing season with 20 harvest dates. Two existing sets of coefficients for the first, second, and third ranked species and one calculated from our data were used to estimate dry-weight composition. We tested the differences between the estimates and actual values. Differences were found (using the basic ranking method) for data from moderately grazed grassland, but one set of coefficients did not appear better than the others. The cumulative ranking correction produced more differences than the basic ranking method on ungrazed grassland with one dominant species. For the dominant species, cumulative ranking, nevertheless, produced more accurate estimates. Cumulative ranking with coefficients of 70 (rank one), 20 (rank two), and 10 (rank three) should serve well for most applications. Calculating coefficients for each new area should not be necessary.

Citation

Ratliff, Raymond D.; Frost, William E. 1990. Estimating botanical composition by the dry-weight-rank method in California's annual grasslands. Res. Note PSW-RN-410. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 5 p.

Cited

Publication Notes

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
https://www.fs.usda.gov/treesearch/pubs/32546