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Epiphyte Ecology
Monitoring Change
Species Discovery

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Dr Brian Coppins
Ms Sally Eaton
Dr Christopher Ellis
Ms Louise Olley
Dr Rebecca Yahr

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This page makes available some simple R code which has been developed to support our research:

Resampling and the Accumulation of Species Richness.
It is possible to calculate the exact richness among a set of samples if two properties are known: species density (number of species per unit area or effort = richness per sample), turnover among added samples - see Appendix 3 and Appendix 4A from Ellis & Ellis 2013. However, estimation of richness for a sub-set of samples, or extrapolation to an asymptote (total community richness) depends on the order in which samples are accumulated, and resampling procedures are commonly used to make these estimations. Furthermore, in making these analyses for epiphyte samples, the consistent unit area of a quadrat placed against a tree should be adjusted to take account of variable bark roughness (see Appendix 5 from Ellis & Ellis 2013), which will cause different areas to be sampled per quadrat. One option to overcome this problem is an adjustment to calculate the species density per mean area sampled within a set, followed by randomisation to resample and average across multiple accumulation curves (Appendix 4B from Ellis & Ellis 2013).

We provide the R code which was used to estimate asymptotes based on resampling epiphyte communities, along with an example spreadsheet, as implemented by Ellis & Ellis 2013.

Ellis, C.J. & Ellis, S.C. (2013) Signatures of autogenic epiphyte succession for an aspen chronosequence. Journal of Vegetation Science, 24: 688-701.