Radial growth decline and mortality in Austrocedrus chilensis forests: climate and competition as triggering factors

AMOROSO, MARIANO; VILLALBA, RICARDO; DANIELS, LORI

Conferencia; Second American Dendrochronology Conference – AmeriDendro2013.; 2013

Austrocedrus chilensis forests in northern Patagonia experience stand-level growth decline and mortality. While this disturbance has been subject of detailed study, the role of contributing factors such as climate variation and processes associated with stand development has just begun to be understood. We studied the influence of climatic variation and stand development on the radial growth decline and death of trees to distinguish between the possible causes and the interactions of allogenic (abiotic and biotic factors) and autogenic processes. Radial growth decline onset in overstory trees was strongly related to the occurrence of droughts, while decline in understory trees could be explained by competition. Mortality dates were concentrated in periods of unfavorable conditions but did not exhibit a clear relationship with climate variation; mortality at early stages resulted from competition. Our results emphasize the complexity of this disturbance, and the important role climate and stand development play on it.