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

In TRADER: Tree Ring Analysis of Disturbance Events in R

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)

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.

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.

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.

Note

Check the reference.

Author(s)

Pavel Fibich <[e-mail]>, Jan Altman <[e-mail]>, Tuomas Aakala <[e-mail]>, Jiri Dolezal <[e-mail]>

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.

See Also

splechtnaALL plotRelease reduceByLB

Examples

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

TRADER documentation built on May 2, 2019, 9:02 a.m.