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Berhe, Leakemariam, 1999. Spatial continuity in tree diameter distribution. Second cycle, A1E. Umeå: SLU, Dept. of Forest Resource Management



Investigation for spatial continuity in tree diameter distribution is attempted.
Parametric and non-parametric approaches are employed to see whether tree diameter
distribution acts as regionalized variable or not. Tree diameter at breast height (dbh)
with size five ems or greater is recorded in circular plot along with the relative geo­
referenced co-ordinates of the plot center at compartment level. For the parametric
approach, truncated two parameter Weibull distribution is found best fit for plot data
and that an overlook of truncated data may result in wrong inference. From the
truncated Weibull distribution, the maximum likelihood scale and shape parameter
estimates of each plot data is obtained. Consequently, both parameter estimates, as
attributes of tree dbh distribution, are subjected to spatial variation study usmg
omnidirectional semivariogram and associated models at compartment level.
Computation of cumulative distribution function of dbh at selected cutoff ( cdf) in the
plots is followed by investigation for spatial continuity in the non-parametric case. The
spatial continuity study of the number of stems per hectare greater or equal to the
selected cutoff is also considered.
The variograms and cross validation study of the Weibull parameter estimates, cdf and
number of stems as attributes of tree dbh distribution seem to be very indicative to
suggest that tree diameter distribution exhibits spatial continuity in the same fashion to
regionalized variable.

Main title:Spatial continuity in tree diameter distribution
Authors:Berhe, Leakemariam
Supervisor:Holm, Sören
Series:Arbetsrapport / Sveriges lantbruksuniversitet, Institutionen för skoglig resurshushållning och geomatik
Volume/Sequential designation:64
Year of Publication:1999
Level and depth descriptor:Second cycle, A1E
Student's programme affiliation:Other
Supervising department:(S) > Dept. of Forest Resource Management
Keywords:Spatial continuity, Geostatistics , Regionalized variable, Truncated distribution function, Variogram, Kriging, Cross validation
Permanent URL:
Subject. Use of subject categories until 2023-04-30.:Forestry production
Mathematical and statistical methods
Deposited On:21 Jun 2012 11:04
Metadata Last Modified:08 Oct 2012 10:33

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