XVI International Botanical Congess

From the Cachil forest located in the austral limit of the Peruvian mountain forests the forest has been divided on three layers on the basis of soil types, climatic factors, relief causes and other factors. The layers A, B and C (2400, 2550 y 2700 m.a.s.l.) have been considered for the evaluation with multidisciplinary permanent samples (stratificated ramdom design) in neotropical and subtropical forests. The sample unit size was 10m x 20m, the sample size was estimated to be 20 lotper stratus given 60 lots for the whole forest. The sampling was done through three consecutive samples from May to August of 1997. Spacial disposition, density, dominance, frequency, importance value and Simpson's predominance. Index were determined Podocarpus oleifollus, Pallcourea amethystina, Ruagea glabra, Ilex uniflora and Axinaea sp. are the tree species most representative of the forest. These species slown crouded spacial disposition. A gross species richness was revealed by the Simpson's predominance index although each slown a low predominance. The species Podocarpus oleifollus (112.42%), Ruagea glabra (61.34%), Axinaea sp. (45.82%), Pallcourea amethystina (42.40%) and Ilex uniflora (39.01%), shown as importante values which make them plausible to be catalogued as the most predominance.