INVESTIGADORES
CARRERA analia Lorena
artículos
Título:
Estructura de la vegetación y funcionamiento de los ecosistemas del Monte austral
Autor/es:
BERTILLER, MB; BISIGATO, AJ; CARRERA, AL; DEL VALLE, HF
Revista:
BOLETíN DE LA SOCIEDAD ARGENTINA DE BOTáNICA
Editorial:
Sociedad Argentina de Botánica
Referencias:
Año: 2004 vol. 39 p. 139 - 158
ISSN:
0373-580X
Resumen:
Structure and functioning of vegetation in ecosystems of the ?Monte Chubutense?. In this work, the most significant results of studies in recent years on structural and functional aspects of vegetation, soil, and their interrelations in the Monte Chubutense are presented. The dominant plant functional groups of vegetation (perennial grasses and shrubs) exhibit different ability to colonize the soil, and this is related to their functional asyncronism, their capacity to explore the soil depth, and their strategies of nitrogen conservation in the plant. Shrubs may be identified as colonizers or initiators of small plant patches in areas of bare soil while the establishment of grasses is more successful  in areas associated with established vegetation. Thus, both functional groups play key roles in the initiation and dynamics of vegetation patches and in the dynamics of soil nitrogen, being these aspects of great importance in the functioning of these ecosystems. Shrubs are important for the conservation and restoration of nitrogen fertility in soil since they have low nitrogen requirements but they contribute with nitrogen-rich litter to the soil. Nitrogen accumulation in the soil of patches dominated by shrubs promotes the establishment of perennial grasses in their periphery. Perennial grasses have high nitrogen requirements and low capacity to return nitrogen to the soil. Degradation of plant patches by grazing use, leads to the decrease of patch cover and the subsequent patch fragmentation and losses of soil resources by wind and water erosion. These changes have effects on germination, emergence, and seedling establishment and consequently on the architecture, floristic composition, and spatial distribution of plant patches. These patch characteristics can be used as indicators of the state of conservation when evaluating alternative managements within the frame of sustainable use.