Stand development patterns as a consequence of the mortality in Austrocedrus chilensis forests

Temporal patterns of radial growth in declining Austrocedrus chilensis forests in Northern Patagonia: The use of tree-rings as an indicator of forest decline

“…Historically identified in the field using external symptoms including crown condition and tree death, the presence of 'mal del ciprés' was first reported in 1948 (Varsavsky et al, 1975) and 1953 (Hranilovic, 1988). Subsequent studies have reported mortality as early as the 1940s for different areas in Patagonia (Relva et al, 2009;Amoroso and Larson, 2010a). However, our retrospective analyses showed that radial growth rates of some trees showed abnormal patterns of decline as early as the 1920s.…”

“…et Bizarri forests experience stand-level mortality of overstory trees throughout their natural range of distribution in Argentina. This temporally unpredictable process of tree mortality (Amoroso and Larson, 2010a), locally known as 'mal del ciprés' (cypress sickness), was first documented about 60 years ago (Varsavsky et al, 1975;Hranilovic, 1988). Mortality in these forests appears to be the result of complex interactions between biotic and abiotic factors, which has lead to the conclusion that 'mal del ciprés' is a type of forest decline (sensu Manion, 1991;Baccalá et al, 1998;Filip and Rosso, 1999;La Manna and Rajchenberg, 2004;Amoroso and Larson, 2010a).…”

“…This temporally unpredictable process of tree mortality (Amoroso and Larson, 2010a), locally known as 'mal del ciprés' (cypress sickness), was first documented about 60 years ago (Varsavsky et al, 1975;Hranilovic, 1988). Mortality in these forests appears to be the result of complex interactions between biotic and abiotic factors, which has lead to the conclusion that 'mal del ciprés' is a type of forest decline (sensu Manion, 1991;Baccalá et al, 1998;Filip and Rosso, 1999;La Manna and Rajchenberg, 2004;Amoroso and Larson, 2010a). A new species of Phytophthora present in necrotic lesions of symptomatic trees has been associated with the mortality of the trees and suggested to be the primary cause of tree death (Greslebin et al, 2007;Hansen, 2009, 2010).…”

“…Alternatively, it is believed cavitation could be the cause of death in trees and that Phytophthora acts as a secondary agent (El Mujtar, 2009). Other research has suggested that mortality could be influenced by climate variation (Amoroso and Larson, 2010a;Mundo et al, 2010) and inter-tree competition and suppression during early stages of stand development following stand-replacing fires (Amoroso and Larson, 2010a).…”

Temporal progression trends of cypress mortality at permanent plots in a National forest reserve of Austrocedrus chilensis (Patagonia, Argentina)

“…Although biotic agents and soil properties associated with cypress mortality have been studied by several scientific groups (for a review, El Mujtar and Andenmatten, 2007b), information from temporal progression of mortality is scarce and mainly restricted to dendrochronological analysis on individual trees. Recently, the impact of cypress mortality on dynamics of A. chilensis forests was studied using dendrochronological tools to determine temporal development of the radial growth at the tree and stand levels (Amoroso, 2009). This study showed that tree death was preceded by a decline in radial growth that is independent of canopy position and unpredictable in time.…”