Dendrochronological study of the xeric and mesic Araucaria araucana forests of northern Patagonia: implications for the ecology and conservation

HADAD M. A.; ARCO MOLINA J. G; ROIG JUÑEN,FIDEL ALEJANDRO

Latin American Dendroecology - Combining tree-ring sciences and ecology in a mega diverse territory

Springer

Año: 2020; p. 283 - 315

The identification of the forest structure could give insights of the processes that determine certain aspects of the population dynamics over time. To address this concern in the Araucaria araucana forests of northwestern Patagonia in Argentina, fourteen forest stands distributed along a strong precipitation gradient were analyzed. A suite of components of the forest structure were considered in order to determine: 1) the relationship between the climate and tree growth variability, 2) the age structure of each study site by defining age classes through the tree ring analysis, 3) the relationship between tree age, tree height and stem diameter, and 4) the sex ratio. Xeric forests were affected significantly and negatively by the temperature of the current growing season, while mesic forests were more affected during winter months. Precipitation showed a positive effect on the growth at the beginning of the growing season in all forests. Age distribution in the xeric and mesic environments showed a preponderance of trees between 51 and 300, and 51 and 250 years old, respectively. Broadly, male and female trees were more abundant in xeric and mesic forests, respectively. The tree age-diameter and tree height-diameter relationships were significantly positive in both mesic and xeric environments. Through these elements, some aspects of the dynamic of the A. araucana trees in their natural distribution area were revealed, which consolidates a better understanding of the ecology and dynamic of these endemic forests and provides tools for designing proper conservation strategies.