INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
Can a natural experiment be used as a tool to design partial cutting regimes? The decline of Austrocedrus chilensis forests, an example
AMOROSO, MARIANO; LARSON, BRUCE
Journal of Forest Research
Año: 2010 vol. 15 p. 38 - 38
The forests of Austrocedrus chilensis in Argentina suffer mortality from what is locally known as mal del ciprés. This disturbance usually appears as aggregations of dead trees of varying sizes. The mortality process seems unpredictable and regeneration establishment is variable under these conditions. The highly variable mortality rates results in a natural experiment that allows the correlation of overstory mortality with regeneration rate. This correlation should then make it possible to estimate the regeneration success which would follow after different levels of partial cutting, allowing the purposeful direction of the regeneration process. We collected data from eight Austrocedrus chilensis- dominated stands and reconstructed overstory mortality over time and correlated it to the regeneration recruitment. Mortality showed two patterns: increasing continuous mortality over time, and pulses of important basal area loss in short periods. Overstory mortality had an effect on the recruitment and composition of the regeneration by allowing different species establishment depending on the degree of mortality. By quantifying mortality basal area and recruitment over time we calculated estimates that can provide partial cutting guidance. Partial cuttings would then, allow the purposeful direction of the regeneration process. Stand reconstruction studies provided a useful tool to help designing regeneration systems using a natural experiment. Some specific management implications for symptomatic A. chilensis forests are given.