Dendroecological investigation of the Araucaria araucana xeric forest and its implications for conservatio

MARTÍN HADAD; FIDEL ROIG; GABRIEL GATICA

Medellín

Simposio; LOTRED-SA 3rd International Symposium ?Climate change and human impact in Central and South America over the last 2000 years: Observation and Models?; 2014

LOTRED-SA - Long-Term climate REconstruction and Dynamics of South America and Universidad EAFIT

Climate variability is an important factor affecting the regeneration dynamics and successional processes in forest communities. It is argued that the increased sensitivity in the development of tree populations is towards the limits of natural distribution, where the climate is expected to be one of the main obstacles to the recruitment of trees. A transitional environment, such as that between the Andean forest and the Patagonian steppe, is often affected by changes in disturbance regimes of natural or anthropic origin. The main aims of our research are: a) determined the age structure of A. araucanaandb) to document temporal and spatial variation of total ring width (TRW). Wood samples of all trees located in random plots, were collected at 1.3 m above ground at each study. This resulted in 287 wood samples that were processed through traditional dendrochronological techniques.We used Generalized Linear Mixed Models (GLMMs) to analyzing temporal and spatial variation of total ring width.The sites exhibit a higher concentration of individuals between 76 and 375 years of biological age, but these forests have been recruiting during for the 600 years last. However, trees younger than 75 years are poorly represented. The GLMMs show that the tree growth is significantly different between sites in the 1600, 1800 and 1900 (p< 0.001) and the interactions growth among site and time was significative (p> 0.001). On forecasts of changes in climate, achieving a better understanding of the structure, replying features and growth responses to environmental variability of these ecosystems will optimize not only compression of the ecology of these forests, but also promote conservation strategies and streamline forest management.