Crecimiento de plántulas y árboles de seis especies de Quercus

Résumé

The main objectives of this work were: a) to describe some important features relative to the functional traits of seedlings of species belonging to the genus Quercus, b) to calculate biomass allocation patterns in leaf, stem and root in adults, and c) to calculate the relative growth rates (RGR) of these species for seedlings and adults. To do this, we used data of experiments with seedlings under controlled conditions, the National Forest Inventory (IFN2 and IFN3) and the allometric equations developed by Montero et al. (2005). Quercus species were characterized by large seeds, and the seedlings had a low RGR and specific leaf area (SLA) and a high proportion of root (RMR). One of the most important factors explaining differences in growth rates among seedlings and adults of Quercus species was the difference in SLA. Considering data of tree biomass, the proportion of biomass in leaves (LMR) and roots (RMR) decreases with tree size, while the proportion of biomass in stem (SMR) increases with tree size. Considering an average tree with trunk diameter of 20 cm, the values of LMR are only between 1-5 % and SMR range from 50 to 80 %. Considering the IFN data, within each species the RGR values were highly variable. Still, when the RGR of seedlings were compared with those of adults a significant and positive relationship was observed. One of the factors that significantly affected RGR was tree size, so that bigger trees grew more slowly.