|Title||Tropical tree a-diversity: Results from a worldwide network of large plots|
|Publication Type||Journal Article|
|Year of Publication||2005|
|Authors||Condit, R, Ashton, P, Balslev, H, N. V. L. Brokaw|
Tropical forests are known for high a-diversity, with hundreds of tree species found on single hectares. This diversity hinders the understanding of diversity, though, because small plots are poor at uncovering the rare species. Single hectares are filled with singletons – species occurring only once – and clearly miss many local species. The Center for Tropical Forest Science has sought to remedy this by much larger-scale studies at a few key sites (Condit 1995, 1998, Ashton 1998). These large plots are expensive and labour-consuming, and cannot be done in many places, but they provide a window into the details of tropical tree diversity. Here we present a comparison of species abundance and diversity at 13 sites where large inventories are complete. We focus on two basic issues. First, how well to the typical small inventories, 0.1 or 1 ha, represent adversity at a site? By how much do they underestimate local diversity? Given the underestimate, can they be used to predict patterns of diversity across sites? This is crucial to studies of variation in diversity, since all are based on small plot inventories (Gentry 1992, Phillips et al. 1994, ter Steege et al. 2000). Second, how do forests compare in diversity at higher taxonomic levels? Few studies have considered this topic before (Enquist et al. 2002), but recommendations to utilize criteria based on phylogeny, not just species, for assessing conservation needs are now surfacing (Webb et al. 2002, Mace et al. 2003). Moreover, hypotheses about evolutionary patterns and the origin of diversity depend on deep phylogenic divisions (Richardson et al. 2001, Bermingham & Dick 2001, Enquist et al. 2002).