Ecological Variability Prediction Based on Functional Characteristics of an Urban Rainforest

Abstract

The relation among basal area, light and functional characteristics variation is still an unexplored issue, especially in rainforests with different disturbance regimes. The following hypotheses were tested: 1) basal area of arboreal plants and light availability is a good predictor of the functional characteristics, once it is believed that in forest environments with a lower basal area and much light, functional characteristics values linked to the fast light resources utilization are found in leaves, stem and roots; 2) environments where there is greater light availability, the standard deviation values of the leaf characteristics will be greater. The functional characteristics values were not influenced by the geographic distance (spatial autocorrelation) neither by the species phylogeny. The prediction that in the areas with the lower basal area, values of characteristics associated with the rapid use of the light resource were confirmed for five characteristics: dry leaf matter (LMDC), stem (SDMC) and root (RDMC), the density of wood stem (WDC) and root (WDR). Significant investment was not found in structural carbon (greater dry matter values of leaf and wood) in environments with the greater basal area. It is considered that in urban fragments the disturbances are frequent, it is possible to suppose that plants with lower values of LDMC, DWC, DWR, SDMC, and RDMC have also "established" in the two areas with a greater basal area. It is concluded that in fragments in urban rainforest studied, perturbations may change the succession path due to population dynamics, especially in the area with more abundant light availability and lesser basal area (A4<AB). the study suggests that this greater light input in the A4<AB environment, due to the greater perturbations, would lead plants with the strategy of using a slow resource, favoring those with fast use of the resource, and as a result, there would be less variability of the leaf characteristics in A4<AB. The basal area and light intensity are not good predictors of variations of functional characteristics in the urban fragments studied.