rli.sampled {red}

Sampled Red List Index.

Description

Calculates accumulation curve of confidence limits in sampled RLI.

Usage

rli.sampled(spData, tree = NULL, p = 0.05, runs = 1000)

Arguments

spData

A vector with species assessment categories for a single point in time. Values can be text (EX, EW, RE, CR, EN, VU, NT, DD, LC) or numeric (0 for LC, 1 for NT, 2 for VU, 3 for EN, 4 for CR, 5 for RE/EW/EX).

tree

An hclust or phylo object (used when species are weighted by their unique contribution to phylogenetic or functional diversity).

p

p-value of confidence limits (in a two-tailed test).

runs

Number of runs for smoothing accumulation curves.

Details

The IUCN Red List Index (RLI) (Butchart et al. 2004, 2007) reflects overall changes in IUCN Red List status over time of a group of taxa. The RLI uses weight scores based on the Red List status of each of the assessed species. These scores range from 0 (Least Concern) to Extinct/Extinct in the Wild (5). Summing these scores across all species and relating them to the worst-case scenario, i.e. all species extinct, gives us an indication of how biodiversity is doing. Yet, in many groups, it is not possible to assess all species due to huge diversity and/or lack of resources. In such case, the RLI is estimated from a randomly selected sample of species - the Sampled Red List Index (SRLI; Stuart et al. 2010). This function allows to calculate how many species are needed to reach a given maximum error of the SRLI around the true value of the RLI (with all species included) for future assessments of the group.

Value

A vector with the accumulation of the error of the SRLI around the true value of the RLI (with all species included).

References

Butchart, S.H.M., Stattersfield, A.J., Bennun, L.A., Shutes, S.M., Akcakaya, H.R., Baillie, J.E.M., Stuart, S.N., Hilton-Taylor, C. & Mace, G.M. (2004) Measuring global trends in the status of biodiversity: Red List Indices for birds. PLoS Biology, 2: 2294-2304.

Butchart, S.H.M., Akcakaya, H.R., Chanson, J., Baillie, J.E.M., Collen, B., Quader, S., Turner, W.R., Amin, R., Stuart, S.N. & Hilton-Taylor, C. (2007) Improvements to the Red List index. PLoS One, 2: e140.

Stuart, S.N., Wilson, E.O., McNeely, J.A., Mittermeier, R.A. & Rodriguez, J.P. (2010) The barometer of Life. Science 328, 117.

Examples

rliData <- c("LC","LC","EN","EN","EX","EX","LC","CR","CR","EX")
rli.sampled(rliData)