boundaryGet: Get values for fitting boundary line.

Description

Get values for fitting boundary line.

Usage

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boundaryGet(data, prior = NULL, change = NULL, m1 = 10, m2 = 10, 
  segment = 0.5, segment2 = 0.5, notop = 10, notop2 = 10, 
  gfun = mean, bfun = mean)

Arguments

data

A data.frame with series as columns and years as rows such as that produced by read.* function of dplR .

prior

Priors.

change

Percentage growth change.

m1

Determines the number of years to be averaged (including target year) for period prior the potential releas.

m2

Determines the number of years to be averaged (including target year) for period prior the potential releas.

segment

Determines length of the segment on which prior growth will be divided

segment2

Determines length of the segment on which first mm of prior growth will be divided.

notop

Number of highest data points for fitting the boundary line.

notop2

Number of highest data points for fitting the boundary line in the segments for first mm.

gfun

Determines if M1 and M2 values are mean or median for selected period.

bfun

Which function use for number of highest data points.

Details

Boundary-line method scales the percent growth change of Nowacki & Abrams (1997) according to growth rate prior to disturbance. In their example, Black & Abrams (2003) defined moderate and major releases as those falling within 20-49.9%, and 50-100% of the boundary line, respectively. Advantage of the boundary-line is standardization, which takes into account the relationships among tree age, size, and canopy class determining radial growth rate (Black et al. 2004). On the downside, Black et al. (2009) suggest approximately 50000 ring width measurements is necessary for boundary line determination for a given species (Black et al. 2009).

Value

Return list object with

bo

Data frame with segments (x-axis) and tops(y-axis).

x

x coordinates of all priors.

y

y coordinates of all priors.

Note

Check reference.

Author(s)

Pavel Fibich <pavel.fibich@prf.jcu.cz>, Jan Altman <altman.jan@gmail.com>, Tuomas Aakala <tuomas.aakala@helsinki.fi>, Jiri Dolezal <jiriddolezal@gmail.com>

References

Black, B.A. & Abrams, M.D. (2003) Use of boundary-line growth patterns as a basis for dendroecological release criteria. Ecological Applications, 13, 1733-1749.
Black, B.A., Abrams, M.D., Gagen, M., Daniels, L.D., Kipfmueller, K.F., Speer, J.H. & Anchukaitis, K.J. (2004) Development and application of boundary-line release criteria. Dendrochronologia, 22, 31-42.
Black, B.A., Abrams, M.D., Rentch, J.S. & Gould, P.J. (2009) Properties of boundary-line release criteria in North American tree species. Annals of Forest Science, 66.

See Also

boundaryFit, plotBoundary

Examples

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data(relData)
bo<-boundaryGet(relData1)
plot(bo)
plotBoundary(bo$bo,bo$x,bo$y,boundary=function(x) {5.0067*exp(-0.664*x)})

Questions? Problems? Suggestions? or email at ian@mutexlabs.com.

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