Regeneração natural de espécies arbóreas de floresta ombrófila densa em sub-bosque de Eucalyptus saligna Smith. e Pinus caribaea Morelet var. caribaea e estudo alelopático na Zona da Mata Sul de Pernambuco

Abstract

The natural regeneration was evaluated in busy occupied by plantings of exotic species, in the municipal districts of Tamandaré and Rio Formoso - PE, and the effect allelopatic of Eucalyptus saligna Smith was verified. and Pinus caribaea Morelet. var. caribaea, about the germination of Lactuca sativa L. To analysis of the estimate of the natural regeneration of the arboreal species five stand of Pinus caribaea var. caribaea Morelet were selected and thrown 2 portions of 1,0 x 50 m, in three stand of Eucalyptus saligna Smith portions of 1,0 x were thrown 50 m, totaling 10 subunities. The inclusion level for the natural regeneration of the arboreal native species belong to individuals with CAP≤15,0 cm and with Circumference of the Base to 30 cm of the soil - CAB0,30m. the natural regeneration was evaluated through classes of heights (H) which had the following widths: Class 1 with arboreal individuals with height (H) 1,0 ≤ H ≤ 2,0 the Class 2 with height (H), 2 < H ≤ 3 and the Class 3 with height (H)> 3. For the calculations phytosocioliogies and for the natural regeneration the a software called Mata Nativa was used. They were shown 297 individuals alive were shown, belonging to 38 families, 45 goods and 54 species, in the talhões of P. caribaea, and for the stands of E. saligna they were shown 302 alive individuals, belonging to 23 families, 31 goods and 39 species. The diversity of the studiedspecies was from 3,31 nats/ind. and 2,86 nats/ind. to the stand of P. caribaea and E. saligna respectively. The allelopatic experiments were driven at laboratory, with aqueous extracts of the acículas and leaves of P. caribaea and E. saligna respectively, in the concentrations 0, 25%, 50%, 75% and 100%. For the germination tests four repetitions of 25 seeds were used distributed in gerbox and maintained to the temperature of 30°C. the evaluation was compared by the test of Tukey to 5% of probability. It can be concluded that the aqueous extracts of P. caribaea and E. saligna present effects inibitórios in the lettuce germination. It can be verified that the extracts elaborated starting from the leaf of P. caribaea and E. saligna presented effect inhibitories in the germination of lettuce seeds, however the existent conditions in the studied stand, they are making possible the individuals' of species development of common species of the area, and the presence of the trees of E. saligna and P. caribaea doesn't disable the growth of native species in his sub-forest.