Crescimento, acúmulo de fósforo e fra??es fosfatadas em mudas de sete espécies arbóreas nativas

摘要

This work aimed to compare growth, phosphorus (P) uptake and distribution of P-fractions in seedlings of seven tree species classified as pioneers (Lithraea molleoides, Shcinus terebinthifolius, Mimosa caesalpiniaefolia, Sesbania virgata) or climaxes (Hymenaea courbaril, Calophyllum brasiliensis, Myroxylon peruiferum) and cultivated under five doses of P (0, 100, 250, 500 and 800 mg dm-3 of P) in a greenhouse. Up to ninety days after germination, the plants were harvested, and dry matter, P-content and P-fractions (total-P, inorganic-P and organic- P) in the leaves were determined. The tree species presented a wide behavior variation regarding P-fertilization, with the pioneer species being more efficient in producing dry matter and absorbing P. The biomass production of the pioneer species Lithraea molleoides was directly related to P accumulation. Its proportions of inorganic-P and organic-P remained unaffected by the increased availability of P. The growth of the Shcinus terebinthifolius, Sesbania virgata and Hymenaea courbaril did not keep up with P uptake, which was mainly accumulated as inorganic-P in the first species and as organic-P in the two last ones. Climax species Calophyllum brasiliensis and Myroxylon peruiferum presented a larger proportion of organic-P, however, the P uptake and plant growth were little affected by P-fertilization.