Age effect of Austrocedrus chilensis trees on the quality of the climate signal contained in the rings growth

GALLARDO, V; HADAD M

Mendoza

Otro; XXXVI Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2018

Tree growth is a biological process influenced by internal and external factors, where the climate is the most influentialclimate being one of the most influential. In addition, trees may experience changes in climatic sensitivity, given that during the growth from seedlings to adults there might occur variations in the structure and interactions of the invdividualsindividuals with the environment. Because of this tThe objective of this work was to identify the quality of the climatic signal contained in the growth rings of Austrocedrus chilensis (cypress) as a functionin different of age classes. More thanWe collected 90 wood samples of trees were collected in two forests of A. chilensis in the Patagonian steppe. The samples were mounted and polished for their posterior observation under looking glass and cross-datinged datation. Samples were classified in two age groups: young (less than 100 years), and adult (more than 101 years). The measurements of ring widths were standardized obtaining three chronologies (regional, adults and young). Pearson´s correlation coefficient, mobile correlation and spatial correlation was calculated for distinctbetween monthly climatic variables (precipitation, mean temperature, maximum temperature, minimum temperature) and radial growth of A. chilensis. We used the cross-wavelet spectral, to detection of periodic significant signals Overmore a wave analysis was made, with which the prescence of tree growth influential cycles can be detected. Correlation coefficient between tree growth and the precipitation was similar for both age classThe relationship between the chronologies of the two age classes and the rainfall showed no difference. However, the correlation shown some difference between age class when compare with temperature (mean, maximum and minimum temperature). The adults trees are more sensitive than juvenile in the previous and current period of growth.While the Climatic signal sensitivity was different between the age/etary classes when mean, maximum and minimum temperature was taken into account, being the adults more sensitive in the previous and current period of growth. The analysis of the mobile correlation showed that growth was variable in two age class and which in the last decades with a negative and significative correlation.The analysis of the mobile correlation allowed to see that the relationship between the climatic variables and the radial increase of the cypress was variable in all the chronologies in the last century. Wavelet analysis showed a higher sensitivity of adult trees in cycles of 4, 6, 8, 11 and 64 years. A. chilensis forests showed a differential sensitivity with age, being adult trees more sensitive to temperatures. In the context of climate change, is important to understand better the forest ecology?climate interactions in order to make better management and conservation decisions