redlistr (version 1.0.1)

getDeclineStats: Change statistics.

Description

getDeclineStats calculates the Proportional Rate of Decline (PRD), Absolute Rate of Decline (ARD) and Absolute Rate of Change (ARC), given two areas at two points in time. Also provides the total area difference. Inputs are usually the results from getArea.

Usage

getDeclineStats(A.t1, A.t2, year.t1, year.t2, methods)

Arguments

A.t1

Area at time t1

A.t2

Area at time t2

year.t1

Year of time t1

year.t2

Year of time t2

methods

Method(s) used to calculate rate of decline. Either 'PRD', 'ARD', and/or 'ARC'. See vignette to see a more detailed explanation for each of them.

Value

A dataframe with total area difference, and a selection of:

• Proportional Rate of Decline (PRD)

• Absolute Rate of Decline (ARD)

• Absolute Rate of Change (ARC)

References

Bland, L.M., Keith, D.A., Miller, R.M., Murray, N.J. and Rodriguez, J.P. (eds.) 2016. Guidelines for the application of IUCN Red List of Ecosystems Categories and Criteria, Version 1.0. Gland, Switzerland: IUCN. ix + 94pp. Available at the following web site: https://iucnrle.org/ Puyravaud, J.-P. 2003. Standardizing the calculation of the annual rate of deforestation. Forest Ecology and Management, 177, 593-596.

See Also

Other Change functions: getAreaLoss, getArea

Examples

# NOT RUN {
a.r1 <- 23.55
a.r2 <- 15.79
decline.stats <- getDeclineStats(a.r1, a.r2, year.t1 = 1990, year.t2 = 2012,
                                 methods = c('ARD', 'ARC'))
# }