Vegetation

Baksh-Comeau, Yasmin S., Maharaj, Shobha S., Adams, Dennis, Harris, Stephen A., Filer, Denis L. & Hawthorne, William D., 2016, An annotated checklist of the vascular plants of Trinidad and Tobago with analysis of vegetation types and botanical ‘ hotspots’, Phytotaxa 250 (1), pp. 448-450 : 448-450

3a Vegetation classification

The RBS sample plot data managed in BRAHMS, were exported and analysed by ordination (nonmetric multidimensional scaling and detrended correspondence analysis) using PC-ORD software, version 6 (MjM Software Design, Gleneden Beach, OR, USA, McCune & Mefford 1999) and the DECORANA program ( Hill 1994, http://www.ceh.ac.uk/products/software/cehsoftware-decoranatwinspan.htm); or merged with other data to produce bioquality results in BRAHMS. Canopy tree composition was assessed by normalising the tree counts for each species to a percentage of all tree stems occurring in each sample plot, prior to ordination. Beard’s (1946) published stand tables of tree populations were also normalised and included in a separate analysis, to help compare his classes with the RBS vegetation classes

For analysis of the flora in the RBS samples, the normalised tree counts were also converted to abundance scores where:>67% of trees in the canopy = abundance score 3; 33–66% = abundance score 2; <33% = abundance score 1. The maximum abundance score was then taken per species per sample plot, including these tree abundances and the independent assessments of abundance of each species in each plot.