Abstract
Procedures and methodologies for evaluating the quality and uniformity of seedlings are essential for homogenizing lots in forest nurseries and successful planting for reforestation. A study was made in order to evaluate the correlations between the allocation of biomass and the Dickson Quality Index (IQD) for seedlings from six native tree species of the Atlantic Forest as well as to select quality indicators that most affect the IQD and which can be used in a practical and precise fashion for the evaluation of native forest seedlings. Seedlings from six tropical forest species were used: Calophyllum brasiliense, Eriotheca macrophylla, Inga laurina, Psidium cattleyanum, Roupala montana and Sloanea obtusifolia. The following characteristics were evaluated: dry leaf (MSF), dry stem (MSC) and dry root (MSR) mass, as well as the aerial part height (H) and the stem diameter (D). Based on these variables, the following calculations were made: ratios of root (RMR), stem (RMC) and leaf (RMF) mass, as well as the total dry mass (MST), that of the aerial part (MSPA), the ratio of the aerial part dry mass to the dry root mass (MSPA/MSR), and that of the aerial part height to the stem diameter (H/D), and the IQD. The results were analyzed via correlation analyses. Based on the conditions of this study it is possible to conclude that: (a) the differences between the average IQD values of the species studied were not explained by the allocation pattern of biomass characterizing each species; (b) the MSR, MST and the D are the best variables for predicting the IQD of the seedlings from the forest species analyzed in this study; and (c) because it is a non-destructive method, D can be considered the best practical indicator for estimating IQD values for Atlantic Forest seedling species lots.
Keywords:
Dickson quality index; Brazilian Atlantic Forest; Forest nurseries; Forest restoration