project {rconifers}R Documentation

Projects a sample.data object using the CONIFERS forest growth model

Description

Projects a CONIFERS sample.data object.

Usage

project( x,years=1,control=list(rand.err=0,
                        rand.seed=0,
                        endemic.mort=0,
                        sdi.mort=0) )

Arguments

x a sample.data object.
years number of years to project the sample.data
control A list of control parameters. See *Details*

Details

The project function returns a sample.data object that contains the projected plant list. The plot data are simply copied from the input sample.data object, and the x0 member is updated if the sample has been projected past the point where stand growth becomes limited by competition.

By default this function projects the sample.data one year, with the default control parameters. The defaults project the sample with a random error component added to the height increment, with endemic mortality turned on and the stand density index induced mortality turned on as well.

The 'control' argument is a list that can supply any of the following components:

rand.err
Non-negative integer. If 0, no random error will be applied in the height growth function. If 1, then a random error will be added to each plant, in each year to the height growth. This is where you include some explanation regarding the random error.
rand.seed
Non-negative integer. If 0, the random number generator will be seeded with the time. If >0, the random number generator will be seeded with this value. To use random error for each projection, you only need to initialize the random number generator once. If you wish to repeat the randomness, you need to reseed with the same seed, in the same sequence.
endemic.mort
Non-negative integer. If 0, no endemic mortality will be applied to the sample.data. If 1, the default mortality in the mortality settings table will be applied to the sample.data for each growth cycle.

sdi.mort
Non-negative integer. If 0, no stand density index mortality will be applied to the sample.data. If 1, stand density index mortality will be applied to the sample.data for each growth cycle. This operation is applied independently of the endemic mortality.

Value

returns a projected sample.data object.

Author(s)

Jeff D. Hamann jeff.hamann@forestinformatics.com,
Martin W. Ritchie mritchie@fs.fed.us

References

Hann, D.W. and C.H. Wang. 1990. Mortality equations for individual trees in southwest Oregon. Oregon State University, Forest Research Laboratory, Corvallis, Oregon. Research Bulletin 67. 17p.

Ritchie, M. and J. Hamann. 2006. Modeling dynamics of competing vegetation in young conifer plantations of northern California and southern Oregon, USA. Canadian Journal of Forest Research 36(10): 2523-2532.

Ritchie, M. and J. Hamann. 2008. Individual-tree height-, diameter- and crown-width increment equations for young Douglas-fir plantations. New Forests 35(2):173-186.

Ritchie, M.W. 2008. User's Guide and Help System for CONIFERS: A Simulator for Young Conifer Plantations Version 4.10. See http://www.fs.fed.us/psw/programs/ecology_of_western_forests/projects/conifers/

Vaughn, Nicholas. 2007. An individual-tree model to predict the annual growth of young stands of Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) in the Pacific northwest. M.S. Thesis, University of Washington. 91p.

See Also

calc.max.sdi, impute, rand.seed, rconifers, sample.data, set.species.map, set.variant, smc, swo, thin

Examples

library( rconifers )

## set the variant to the SWO variant and set species map
set.species.map( set.variant(0) )

## grow the data SWO variant test data
# load and display CONIFERS example plots
data( plots.swo )
print( plots.swo )

# load and display CONIFERS example plants
data( plants.swo )
print( plants.swo )

# create the sample.data list object
sample.swo.3 <- list( plots=plots.swo, plants=plants.swo, age=3, x0=0.0 )
class(sample.swo.3)  <- "sample.data"

# now, project the sample forward for 20 years
# with all of the options turned off
sample.swo.23 <- project( sample.swo.3, 20,
          control=list(rand.err=0,rand.seed=0,endemic.mort=1,sdi.mort=1))

## print the projected summaries
print( sample.swo.23 )

# now, project the sample forward for 20 years
# with random error on and duplicate run 100 times, finish by calculating
#summaries of DF basal area
reps<-100
dfba<-vector(mode="double", length=reps)
for ( i in 1:reps){
sample.swo.23wr <- project( sample.swo.3, 20,
          control=list(rand.err=1,rand.seed=0,endemic.mort=1,sdi.mort=1))
          
#do a sp.sums of each run
summi<-sp.sums(sample.swo.23wr)

# select the Douglas-fir basal area
dfba[i]<-summi["DF","ba"]
}
summary(dfba)


[Package rconifers version 1.0.0 Index]