Composición de la flora de praderas andinas en la reserva nacional alto bío-bío (Lonquimay-Chile) y su relación con el régimen de pastoreo
Composición de la flora de praderas andinas en la reserva nacional alto bío-bío (Lonquimay-Chile) y su relación con el régimen de pastoreo
Authors
Fuentes Ramírez, Andrés.
Pauchard Cortes, Aníbal.
Hauenstein Barra, Enrique
Pauchard Cortes, Aníbal.
Hauenstein Barra, Enrique
Authors
Date
2012-02-07
Datos de publicación:
Gayana. Botánica, Vol. 68, N°1, 28-39, 2011
Keywords
Veranadas - Sobrepastoreo - Riqueza de especies
Collections
Abstract
Las praderas andinas de la Región de La Araucanía son usadas estacionalmente por comunidades Pehuenches como forraje para sus animales. El pastoreo es una de las principales perturbaciones que afectan a las praderas naturales, pudiendo generar cambios a nivel comunitario en la composición y en la riqueza de especies. Con el objetivo de determinar la composición de la flora de las praderas andinas de la Reserva Nacional Alto Bío-Bío (37° S y 70° O) y su relación con la carga animal que soporta cada una, se estudiaron cinco sitios al interior de la reserva: Cuchares Grande, Cajón Chileno, Tralilhue, Cuchares Chico y Mancha de Pinos. En cada sitio se realizaron 20 parcelas al azar, registrándose todas las especies presentes y su cobertura relativa. En total se registraron 89 especies de plantas vasculares. La riqueza taxonómica está representada por dos especies de Pteridophyta y 87 de Magnoliophyta, de las cuales 25 son Liliopsida y 62 Magnoliopsida. Las 89 especies se distribuyen en 72 géneros y 37 familias, siendo las más numerosas Asteraceae (13), Poaceae (11), Cyperaceae (6) y Rosaceae (6). De las especies determinadas, un 88% son nativas y 12%, introducidas. Las formas de vida están representadas principalmente por hemicriptófitos con un 53%, criptófitos (17%) y caméfitos (15%). Las praderas que tienen mayor carga ganadera son las que presentan mayor proporción de especies introducidas y hemicriptófitas, existiendo mayor similitud florística entre ellas, mientras que las que tienen menor carga ganadera presentan mayor proporción de especies nativas. Estos resultados sugieren que el uso ganadero podría tener efectos importantes en el cambio de la composición de la flora de las praderas andinas. A pesar de la baja proporción de especies introducidas en total, el alto porcentaje de hemicriptófitos indicaría un grado medio de perturbación.
Andean grasslands of the La Araucanía Region are used every year by Pehuenches communities as forage resources for their livestock. Grazing is one of the most important disturbances which affect natural meadows and can produce changes at community level in the species richness and plant composition. With the aim of determining the floristic composition of the Andean grasslands in the Alto Bío-Bío National Reserve (37° S y 70° W) and its relationship with the cattle load, we studied five sites within the reserve: Cuchares Grande, Cajón Chileno, Tralilhue, Cuchares Chico and Mancha de Pinos. In each site, we sampled 20 random plots recording all the species and their relative cover. We recorded a total of 89 species of vascular plants. Taxonomic richness is represented by two Pteridophyta and 87 Magnoliophyta species. In this last group, 25 species are Liliopsida and 62 are Magnoliopsida. All flora is distributed in 37 families and 72 genera. Greatest families, in species number, are Asteraceae (13), Poaceae (11), Cyperaceae (6) and Rosaceae (6). About the origin, 88 species are native and only 11 are introduced, representing 88% and 12%, respectively. Life forms are represented mostly by hemicryptophytes with 53%, then cryptophytes arround 17% and finally chamaephytes (15%). Grasslands wich have greater livestock density, have a higher proportion of introduced species and hemicryptophytes and a greater floristic similarity between them, while those with lower livestock densities have a higher native species proportion. These results suggest that cattle use could have a significant impact in the floristic composition of Andean grasslands. Even though, the low proportion of introduced species found, the high percentage of hemicryptophytes indicates an intermediate level of disturbance.
Andean grasslands of the La Araucanía Region are used every year by Pehuenches communities as forage resources for their livestock. Grazing is one of the most important disturbances which affect natural meadows and can produce changes at community level in the species richness and plant composition. With the aim of determining the floristic composition of the Andean grasslands in the Alto Bío-Bío National Reserve (37° S y 70° W) and its relationship with the cattle load, we studied five sites within the reserve: Cuchares Grande, Cajón Chileno, Tralilhue, Cuchares Chico and Mancha de Pinos. In each site, we sampled 20 random plots recording all the species and their relative cover. We recorded a total of 89 species of vascular plants. Taxonomic richness is represented by two Pteridophyta and 87 Magnoliophyta species. In this last group, 25 species are Liliopsida and 62 are Magnoliopsida. All flora is distributed in 37 families and 72 genera. Greatest families, in species number, are Asteraceae (13), Poaceae (11), Cyperaceae (6) and Rosaceae (6). About the origin, 88 species are native and only 11 are introduced, representing 88% and 12%, respectively. Life forms are represented mostly by hemicryptophytes with 53%, then cryptophytes arround 17% and finally chamaephytes (15%). Grasslands wich have greater livestock density, have a higher proportion of introduced species and hemicryptophytes and a greater floristic similarity between them, while those with lower livestock densities have a higher native species proportion. These results suggest that cattle use could have a significant impact in the floristic composition of Andean grasslands. Even though, the low proportion of introduced species found, the high percentage of hemicryptophytes indicates an intermediate level of disturbance.