splechtna: Splechtna et al. 2005 type of releases analysis.

Description

Splechtna is a combination of radial-growth averaging and boundary-line technique.

Usage

splechtna(data, change = NULL, prior = NULL, m1 = 10, m2 = 10, 
  boundary = NULL, buffer = 2, criteria = 0.2, criteria2 = 0.5, 
  segment = 0.5, gfun = mean, length = 2, segment2 = 0.5, 
  notop = 10, notop2 = 10, storedev = pdf, prefix=NULL )

Value

Return list object with

releases: By length and buffer filtred scaled percent growth change (PGC).
years: Release years per tree.
change: Original PGC.
pgc: Reduced releases values per tree and year.
years_list_total: Number of releases per year.
all_releases: All PGC above criteria.

Arguments

data: A data.frame with series as columns and years as rows such as that produced by read.* function of dplR .
change: Precomputed percent growth change.
prior: Precomputed priors.
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.
boundary: Boundary line function of one argument, eg. boundary=function(x) {5.0067*exp(-0.664*x)}
buffer: Number of years determining how close to one another two releases can be.
criteria: Threshold for detection of moderate release
criteria2: Threshold for detection of major release.
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.
gfun: Determines if M1 and M2 values are mean or median for selected period.
length: Determines how many years have to be given critera exceeded to be considered as release.
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.
storedev: Format for saving the graphical outputs, eg. pdf or jpeg.
prefix: Prefix of saved files.

Author

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

Details

Splechtna is a combination of radial-growth averaging and boundary-line technique. This method was developed by Splechtna, Gratzer & Black (2005) and as a potential release accepts only growth pulses exceeding 50% growth change according to Nowacki & Abrams (1997). Only these potential releases were then scaled relative to the boundary line.

References

Splechtna, B.E., Gratzer, G. & Black, B.A. 2005. Disturbance history of a European old-growth mixed-species forest - A spatial dendro-ecological analysis. Journal of Vegetation Science, 16, 511-522.

Examples

Run this code

data(relData)
rel<-splechtna(relData1)
 plotRelease(relData1,rel$change,rel,1,method="Splechtna")

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