Anne Sophie Sergent obtained her PhD in forest biology at Val de Loire University – France - in 2011 before joining the National Scientific and Technical Research Council CONICET - Argentina. Her research activities are conducted within the ecology, ecophysiology, and wood laboratory (LEEMA) of IFAB, UEDD INTA-CONICET in Bariloche. Her research interests are forest tree ecophysiology and dendro-ecology, focusing on the relationships between wood structure, growth rate, and physiological mechanisms involved in drought resistance. Her current project aims to assess the geographical and genetic variations of wood traits involved in the adaptability of Austrocedrus chilensis to drought.

The enigma of the Cordilleran cypress dieback: insights from the study of xylogenesis

The Cordillera cypress (Austrocedrus chilensis) is a dioecious conifer native to the Andes-Patagonia region of South America. In the current context of global warming, including reduced annual rainfall and increased pathogens attacks, this species is experiencing severe die-offs that are still poorly understood. The process of xylogenesis, which is crucial for the functioning of trees and their response to the environment, has never been described for the Cordillera cypress. The objective of this study is to address this knowledge gap by initially examining the impact of dioecia on the processes of wood formation. Our study was conducted in a closed forest in San Carlos de Bariloche, Argentina, during the 2018-2019 southern growing season (November to May). It involved weekly micro-coring of 11 dominant trees (5 males and 6 females) to describe xylogenesis and compare sexes. The findings indicate that the male Cordilleran cypress produces two to three times the quantity of wood cells as the female, and exhibits a growth rate that is twice as high over a growing period that is one-third longer. This discrepancy may be attributed to the prioritization of resources towards reproductive processes over wood production in female individuals. Further research is required to ascertain the impact of climatic and environmental factors on the xylogenesis of this species.

Co-authors: Boussaroque L., Adikurnia I, Diez J., Martinez-Meier A. and Rathgeber C.