Elevational distribution of restricted range forest tree taxa in eastern Tanzania

The forests of eastern Tanzania are a globally important biodiversity hotsp ot. In this study 361 eastern Tanzanian restricted range forest tree taxa w ere assessed. Of these taxa, 223 occurred in the Eastern Arc, 150 in Coasta l forests, 17 in Northern forests and 21 in the Lake Nyasa forests. The maj ority of the taxa had restricted elevational ranges with 76.3% occurring in no more than two 200 m elevational bands out of a total potential elevatio n range of 3000 m. The majority of the taxa occupied a small area in the ea stern Tanzanian forests, with 201 taxa being only found at a few sites. In determining priority areas for conservation, selection of taxon definitions can have important effects. For example, tree size varies with elevation, so if only large trees are used then site selection will be biased towards particular areas.