Deforestation in Lacandonia (southeast Mexico): evidence for the declaration of the northernmost tropical hot-spot

To assess the conservation status of Lacandonia, a megadiversity area in Me xico, rates of deforestation were calculated for the periods 1974-1981 and 1981-1991, using a random sample of 38 5 x 5 km sites. We evaluated: (i) th e overall magnitude of, and spatial and temporal variation in deforestation ; (ii) how spatial variation relates to human population density, terrain s lope and the presence of the Montes Azules Biosphere Reserve; (iii) the mag nitude of potential plant species loss associated with deforestation. Overa ll deforestation was greater in the former than in the second period (1412 vs. 744 ha/year), although mean rates (2.1 and 1.6%/year) were statisticall y indistinguishable due to a considerable spatial variation. The greatest s patial variation was related to the presence of the Montes Azules Reserve: deforestation outside the reserve was 20 and 6 times greater in the first a nd second period, respectively. Population density and terrain slope were r elated to deforestation but the relationship was considerably poor. Estimat es of plant species committed to extinction (out of the expected total flor a of 4314 species) were as high as 22% by year 2035, and 55% by year 2135. Such levels of potential species extinction associated to deforestation, an d the great biological diversity of Lacandonia provide evidence to declare it as the northernmost tropical hot-spot and a priority goal in conservatio n efforts.