ulations exist as small forests (core areas ' 3 ha), where Fitzroya forms nearly pure stands. We established permanent plots in each of these five stands, determining tree ages and recording species composition. Multivariate analyses performed on both understory and tree species composition separated one stand from the remaining four, the differences being a function of stand ages and disturbance histories. Given their small size and isolation (from each other and from Fitzroya populations of the Coastal and Andean Cordilleras), these stands represent an extreme example of habitat fragmentation. A combination of conservation efforts is being undertaken to ensure their persistence in the Central Depression.