Estudio fitosociológico de los bosques de Kewiña (Polylepis spp., Rosaceae) en la cordillera de Cochabamba

Abstract

FITOSOCIOLOGICAL STUDY OF THE KEWINA FORESTS (Polylepis spp., ROSACEAE) IN THE CORDILLERA OF COCHABAMBA El trabajo se refiere a la tipificaci6n de los bosques remanentes de kewiiya (Polylepis spp.) presentes en la cordillera de Cochabamba, entre los 2 900 Y 4 100 msnm aproximadamente y realizado desde enero de 1995 a junio de 1996. Se utiliz6 el metodo fitosociol6gico de BRAUN-BLANQUET, actualiza- do por GEHU y RIVAS-MARTINEZ (1981), habiendose identificado 2 asociaciones:Berberido commutatae-Polylepidetum besseri (piso supratropical subhumedo a humedo inferior); Citharexylo punctati- Polylepis lanatae (piso supratropical humedo a subasociaci6n); una subasociaci6n citharexyllotosum punctati (piso supratropical humedo a hiperhumedo) y 2 comunidades fitosociol6gicas: una de Polylepis tomentella subsp. nana (piso supratropical subhumedo) y otra de Polylepis tomentella subsp. inca- noides (piso supratropical subhumedo). La principal conclusi6n es la existencia de vegetaci6n potencial climacica constituIda por especies de Polylepis en todo el piso supratropical de la cordillera de Co- chabamba, entre los 2 900 -4 100 m. Palabras clave: bosques andinos, fitosociologla, Polylepis, Cochabamba. Bolivia. ABSTRACT The objective of this study was to investigate the phytosociology of the remaining Kewiiya (Polylepis spp.), forests, located at approximately 2 900 -4100 m on Cochabamba's mountain range. The study took place between January 1995 and June 1996. The phytosociology method, developed by BRAUN-BLANQUET and updated by GEHU and RIVAS-MARTINEZ (1981), was used. Two associations, Berberido commutatae-Polylepidetum besseri (supratropical subhumid to inferior humid floor) and Citha-rexylo punctati-Polylepidetum lanatae (supratropical humid floor), were identified. Furthermore, one subassociation, citharexyllotosum punctati (supratropical humid to hiperhumid floor), and two phytoso- ciology communities, Polylepis tomentella subsp. nana (supratropical subhumid floor) and Polylepis to- mentella subsp. incanoides (supratropical subhumid floor), were detected. The most important finding was the presence of a climax community, consisting of Polylepis species, which is distributed around the entire supratropical floor of the Cochabamba mountain range at an altitude of 2 900 -4 100 m. Key words: Andean forests, phytosociology, Polylepis, Cochabamba. Bolivia.