SDI.Plot: Plot Level Stand Density Index Function

In ryanmismith/inventoryfunctions: Forestry Inventory Functions

Plot Level Stand Density Index Function

Description

This function computes the Stand Density Index for each plot in your inventory using the summation method.

Usage

SDI.Plot(Stand, Plot, Tree, DBH, EXPF)

Arguments

Stand	Unique Stand ID
Plot	Unique Plot ID
Tree	Unique Tree ID
DBH	Diameter at breast height in cm.
EXPF	Expansion factor for each tree.

Details

This function utilizes the internal SDI.tree function and each tree's expansion factor to provide you with the SDI for each plot in your inventory.

The SDI.Tree function uses the formula (DBH/25.4)^1.605

This index of SDI is obtained through summation (see references). This is a way of determining stand density in uneven-aged stands with non-normal diameter distributions.

This function simplifies obtaining plot level SDI measurements. This SDI value is useful when paired with the SDI.Max function to obtain a Relative Density value using the RD function.

Value

The return value is a numerical vector of length n providing the stand density index for each plot in your inventory.

Author(s)

Ryan Smith

References

Woodall, C. W., Miles, P. D., & Vissage, J. S. (2005). Determining maximum stand density index in mixed species stands for strategic-scale stocking assessments. Forest Ecology and Management, 216(1–3), 367–377. https://doi.org/10.1016/j.foreco.2005.05.050

See Also

SDI.Tree

SDI.Max

Other Plot Level Functions: BA.Larger.Trees(), BAPH(), CCF.Larger(), CrownCompF(), DBHFuns(), HeightPredict(), RD(), SDI.Max(), TPH(), TallestTrees(), Unique.ID()

Other Stand Density Index Functions: RD(), SDI.Max()

Examples

Stand <- c(1,1,1,1,1,1)
Plot  <- c(1,1,1,2,2,2)
Tree  <- c(1,2,3,1,2,3)
DBH   <- c(24, 34, 18, 41, 28, 20)
EXPF <- c(5, 5, 5, 5, 5, 5)
SDI.Plot(Stand, Plot, Tree, DBH, EXPF)

ryanmismith/inventoryfunctions documentation built on Aug. 5, 2022, 2:22 a.m.