An estimate of the number of tropical tree species

The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher’s alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ~40,000 and ~53,000, i.e., at the high end of previous estimates. Contrary to common assumption, the Indo-Pacific region was found to be as species-rich as the Neotropics, with both regions having a minimum of ~19,000–25,000 tree species. Continental Africa is relatively depauperate with a minimum of ~4,500–6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological framework for estimating species richness in trees that may help refine species richness estimates of tree-dependent taxa.

Saved in:
Bibliographic Details
Main Authors: Slik, J.W.F., Bongers, F., Jansen, P.A., Parren, M.P.E., Poorter, L., Tchouto, M.G.P., Venticinque, E.M.
Format: Article/Letter to editor biblioteca
Language:English
Subjects:abundance distributions, area, biodiversity, coverage, global patterns, plant diversity, rain-forests, richness, sample,
Online Access:https://research.wur.nl/en/publications/an-estimate-of-the-number-of-tropical-tree-species
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher’s alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ~40,000 and ~53,000, i.e., at the high end of previous estimates. Contrary to common assumption, the Indo-Pacific region was found to be as species-rich as the Neotropics, with both regions having a minimum of ~19,000–25,000 tree species. Continental Africa is relatively depauperate with a minimum of ~4,500–6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological framework for estimating species richness in trees that may help refine species richness estimates of tree-dependent taxa.