Initial growth of forest species of different successional groups in response to phosphorus doses

With the aim of evaluating the responses of forest species to phosphorus su pply, an assay under greenhouse conditions was carried out, where seedlings of pioneer tree species (Lithraea molleoides, Schinus terebinthifolius, Pi ptadenia gonoacantha, Mimosa caesalpiniaefolia, Sesbania virgata), a light- demander climax species (Hymenaea courbaril), and the shade-tolerant climax es species (Calophyllum brasiliensis, Tabebuia serratifolia, Myroxylon peru iferum) were cultivated. Five phosphorus doses were used, corresponding to 0, 100, 250, 500 and 800 mg dm(-3) of P. Stem diameter, height, and root, s hoot and total dry matter yield of the plants were evaluated. The pioneers species were more responsive to phosphorus furnishing, indicating the need of phosphorus supply for the adequate development of these species. The cli maxes species showed to have low sensitivity to phosphorus supply, reflecti ng a lower requirement in the initial growth period. The differences in rel ation to growth rate and seed size may be connected to the contrasting beha vior observed for pioneers and climaxes species.