fsi: Estimate the Forest Stability Index from the FIADB

In hunter-stanke/rFIA_TX: Duplicate rFIA for TX

Description

Estimate forest population performance from the FIADB using the Forest Stability Index. This function is experimental, please check back soon for updated documentation.

Usage

fsi(db, grpBy = NULL, polys = NULL, returnSpatial = FALSE,
    bySpecies = FALSE, bySizeClass = FALSE,
    landType = "forest", treeType = "live", method = "sma",
    lambda = 0.5, treeDomain = NULL, areaDomain = NULL,
    totals = TRUE, variance = TRUE, byPlot = FALSE,
    useSeries = FALSE, scaleBy = NULL, betas = NULL,
    returnBetas = FALSE, nCores = 1)

Arguments

db	FIA.Database object produced from readFIA; Function requires that PLOT, TREE, COND, POP_PLOT_STRATUM_ASSGN, POP_ESTN_UNIT, POP_EVAL, POP_STRATUM, POP_EVAL_TYP, POP_EVAL_GRP tables exist in FIA.Database object.
grpBy	variables from PLOT, COND, or TREE tables to group estimates by (NOT quoted). Multiple grouping variables should be combined with c(), and grouping will occur heirarchically. For example, to produce seperate estimates for each ownership group within ecoregion subsections, specify c(ECOSUBCD, OWNGRPCD).
polys	sp or sf Polygon/MultiPolgyon object; Areal units to bin data for estimation. Seperate estimates will be produces for region encompassed by each areal unit.
returnSpatial	logical; if TRUE, return sf spatial object (polys must also be specified).
bySpecies	logical; if TRUE, returns estimates grouped by species.
bySizeClass	logical; if TRUE, returns estimates grouped by size class (2-inch intervals, see makeClasses to compute different size class intervals).
landType	character ('forest' or 'timber'); Type of land which estimates will be produced for. Timberland is a subset of forestland (default) which has high site potential and non-reserve status (see details).
treeType	character ('all', 'live', 'dead', or 'gs'); Type of tree which estimates will be produced for. All (default) includes all stems, live and dead, greater than 1 in. DBH. Live/Dead includes all stems greater than 1 in. DBH which are live or dead (leaning less than 45 degrees), respectively. GS (growing-stock) includes live stems greater than 5 in. DBH which contain at least one 8 ft merchantable log.
method	character; Method used for annual panel combination (see details). One of: 'TI' (temporally indifferent), 'annual' (annual panels), 'SMA' (simple moving average), 'LMA' (linear moving average), or 'EMA' (exponential moving average)
lambda	numeric (0,1); if method == 'EMA', the decay parameter used to define weighting scheme for annual panels. Low values place higher weight on more recent panels, and vice versa. Specify a vector of values to compute estimates using mulitple wieghting schemes, and use plotFIA with grp set to lambda to produce moving average ribbon plots.
treeDomain	logical predicates defined in terms of the variables in PLOT, TREE, and/or COND tables. Used to define the type of trees for which estimates will be produced (e.g. DBH greater than 20 inches: DIA > 20, Dominant/Co-dominant crowns only: CCLCD %in% c(2,3)). Multiple conditions are combined with & (and) or | (or). Only trees where the condition evaluates to TRUE are used in producing estimates. Should NOT be quoted.
areaDomain	logical predicates defined in terms of the variables in PLOT and/or COND tables. Used to define the area for which estimates will be produced (e.g. within 1 mile of improved road: RDDISTCD %in% c(1:6), Hard maple/basswood forest type: FORTYPCD == 805). Multiple conditions are combined with & (and) or | (or). Only plots within areas where the condition evaluates to TRUE are used in producing estimates. Should NOT be quoted.
totals	logical; if TRUE, return population estimates (e.g. total area, total biomass) along with ratio estimates (e.g. mean biomass per acre).
variance	logical; if TRUE, return estimates of uncertainty as variance instead of sampling error (default). Sampling error cannot be used to estimate confidence intervals.
byPlot	logical; if TRUE, returns estimates for individual plot locations (population totals not returned).
useSeries	logical; If TRUE, use multiple remeasurements to estimate change in TPA & BA on each plot, when available.
scaleBy	variables from PLOT or COND tables to use as 'random effects' in model of size-density relationships.Multiple variables should be combined with c(), and grouping will occur heirarchically. For example, to produce seperate estimates for each ownership group within ecoregion subsections, specify c(FORTYPCD, SITECLCD).
betas	more soon.
returnBetas	more soon.
nCores	numeric; number of cores to use for parallel implementation. Check available cores using detectCores. Default = 1, serial processing.

Details

Please check back soon for more details

Value

Dataframe or SF object (if returnSpatial = TRUE). If byPlot = TRUE, totals are returned for each plot. All variables with names ending in SE represent the estimate of sampling error (%) of the variable. All variables with names ending in TOTAL represent the population total of the variable.

• YEAR: reporting year associated with estimates

• SI: estimate of forest stability index

• SI_STATUS: indication of the forest stability index (i.e., decline, stable, or expand)

• SI_INT: width of 95% confidence interval of mean FSI

• TPA_RATE: standardized estimate of annual change in TPA

• BAA_RATE: standardized estimate of annual change in BAA

Note

All sampling error estimates are returned as percentages, and represent ~68% confidence (1 standard deviation). To compute sampling error percent with 95% confidence, multiply by 1.96.

Author(s)

Hunter Stanke and Andrew Finley

References

FIA Database User Guide: https://www.fia.fs.fed.us/library/database-documentation/

Bechtold, W.A.; Patterson, P.L., eds. 2005. The Enhanced Forest Inventory and Analysis Program - National Sampling Design and Estimation Procedures. Gen. Tech. Rep. SRS - 80. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 85 p. https://www.srs.fs.usda.gov/pubs/gtr/gtr_srs080/gtr_srs080.pdf

See Also

tpa, vitalRates, growMort

Examples

## Load data from the rFIA package
data(fiaRI)
data(countiesRI)

## Most recents subset
fiaRI_mr <- clipFIA(fiaRI)

## FSI for all forestland 2018 in RI
fsi(fiaRI_mr, method = 'sma')

hunter-stanke/rFIA_TX documentation built on Jan. 1, 2021, 3:22 a.m.