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Quantifying forest stand diversity using stand structure Staudhammer, Christina Lynn
Abstract
Stand structure is an important component of the overall description of biological diversity in a stand. The diversity of tree sizes within a stand affects tree growth and yield, and is highly correlated with the biodiversity of a stand. Four measures of stand diversity based on the stand distribution of basal area by height, diameter, and species were proposed, assuming a baseline of maximum diversity corresponding to a uniform distribution. First, the Extended Shannon Index (ESI), a measure based on Shannon's Index, was derived. Second, a measure based on fitting the univariate and bivariate distributions of diameter and height was investigated. The third measure, STRI, was derived as a modified R-squared, based on the fit of the distribution to that of a uniform distribution. The fourth measure, STVI, was derived based on comparing the variance of a distribution to that of a uniform distribution. The four measures were evaluated with simulated data and inventory data from the Malcolm Knapp Research Forest (MKRF). The ESI and STVI resulted in logical orderings of both the simulated data and the MKRF data. The advantages of the ESI include its known sampling distribution and accepted use in forestry; however, the ESI depends on allocating data to arbitrary classes. The STVI does not require classifying data; however, its sampling distribution is unknown. Since the measures derived require only normally collected inventory plot data, they are relatively inexpensive to use. However, a thorough investigation of the properties of each should be undertaken. Since evaluating structural diversity is becoming an increasingly important part of forest assessment, a quantitative measure is needed to measure diversity. These measures provide a starting point toward finding an inexpensive, practical measure of structural diversity which gives reasonable results.
Item Metadata
Title |
Quantifying forest stand diversity using stand structure
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1999
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Description |
Stand structure is an important component of the overall description of biological
diversity in a stand. The diversity of tree sizes within a stand affects tree growth and
yield, and is highly correlated with the biodiversity of a stand.
Four measures of stand diversity based on the stand distribution of basal area by
height, diameter, and species were proposed, assuming a baseline of maximum diversity
corresponding to a uniform distribution. First, the Extended Shannon Index (ESI), a
measure based on Shannon's Index, was derived. Second, a measure based on fitting the
univariate and bivariate distributions of diameter and height was investigated. The third
measure, STRI, was derived as a modified R-squared, based on the fit of the distribution
to that of a uniform distribution. The fourth measure, STVI, was derived based on
comparing the variance of a distribution to that of a uniform distribution.
The four measures were evaluated with simulated data and inventory data from the
Malcolm Knapp Research Forest (MKRF). The ESI and STVI resulted in logical
orderings of both the simulated data and the MKRF data. The advantages of the ESI
include its known sampling distribution and accepted use in forestry; however, the ESI
depends on allocating data to arbitrary classes. The STVI does not require classifying
data; however, its sampling distribution is unknown.
Since the measures derived require only normally collected inventory plot data, they
are relatively inexpensive to use. However, a thorough investigation of the properties of
each should be undertaken. Since evaluating structural diversity is becoming an
increasingly important part of forest assessment, a quantitative measure is needed to
measure diversity. These measures provide a starting point toward finding an
inexpensive, practical measure of structural diversity which gives reasonable results.
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Extent |
5030504 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-07-07
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0075007
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
2000-05
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.