INVESTIGADORES
GHERMANDI luciana
artículos
Título:
Non linear ecological precesses, fires, environmental heterogeneity and shrub invasion in NW Patagonia
Autor/es:
GHERMANDI, L., DE TORRES CURTH M., FRANZESE J. AND GONZALEZ S.
Revista:
ECOLOGICAL MODELLING
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2010 vol. 221 p. 113 - 121
ISSN:
0304-3800
Resumen:
The emergent behaviors of nature are not only the sum of interactions among ecosystem parts but also depend on the organization of these interactions. Fire, climate and vegetation patterns produce non-linear fire propagation across the landscape. Environmental heterogeneity, like outcrop presence and hare density, increases landscape patchiness and makes possible the occupation of fire refuges by plants, like Fabiana imbricata shrubs. We monitored shrub recruitment and cover during nine postfire years in northwestern Patagonia grasslands and we studied the long term population dynamics under different environmental conditions through a matrix model, exploring different fire frequencies and spring precipitation regimes. Both, the field monitoring and the model seem to confirm the relationships between shrub invasion and fire. The climate change forecast predicts an increase in the frequency of El Niño Southern Oscillation phenomena that could causes more coupled fires - rainy springs in northwestern Patagonia, and consequently, more recruitment windows for shrubs, like F. imbricata. The matrix model also indicates that this scenario would be the most favorable for shrub invasion. Our results contribute to the knowledge of the ecosystem properties and processes, providing useful information to improve the grasslands sustainable use.