NUÑEZ martin Andres
congresos y reuniones científicas
Early post-fire regeneration on Matorrals and Ponderosa pine plantations in Northwestern Patagonia.
NUÑEZ, M. A. & E RAFFAELE
Congreso; Southeastern Ecology And Evolution Conference; 2004
Georgia Institute Of Technology
Exotic conifer plantations represent an important contribution for the economy in several countries; however, this extensive practice is associated with negative impacts on natural communities. In northwestern Patagonia, planted area is increasing annually, with a consequent rise in accumulated fuel and a possible increase in number and intensity of fires. The aim of this work is to study post-fire successional changes in matorral zones that were replaced by exotic conifer plantations. We surveyed four sites in ChallHuaco valley, Argentina. Each site was a vegetation mosaic composed of: an unburned Ponderosa pine plantation, a Ponderosa pineplantation burned in 1996 (BP), a matorral not burned for at least 10 years, and a matorral burned by the same fire (BM). In summer 2000 and 2001, we censused the vegetation at each site and the spatial distribution of woody plants at one site. Total cover was similar in BM and BP, though the predominant life forms showed significant differences. Woody species cover and number were significantly higher in BM, while herbal species cover and number, as well as proportion of exotic species were significantly higher in BP. Woody species established in patches by resprouting in BM, while spatial distribution was random and the reproduction by seeds in BP. The structural changes that plantations produce on native communities are important not only for biodiversity losses but also because they affect fire recolonization processes. Thesechanges alter native species establishment and possibly successional trajectories during recolonization.