Estrutura da vegetação arbórea de dois fragmentos florestais na Zona da Mata Norte de Pernambuco.

Abstract

This study has the purpose to analyze the arboreal structure and the composition floristic of two forest fragments remainders of Atlantic Forest in the North Forest Zone of State of Pernambuco. The surrounding head office of the fragments is, mainly, the cultivation of the sugarcane. One of the fragments presents characteristic vegetation of Seasonal Forest Semideciduous, in the coordinates 07° 30' 12 '' S and 35° 10' 30 '' W, known like Forest of the Engenho Guararema with area of 46,58 ha. The other presents characteristic vegetation of Forest Dense Ombrophylous, in the coordinates 07° 25' 54 '' S and 35° 11' 31 '' W, known like Forest of the Pau Amarelo, with area of 52,54 ha. Both fragments are placed in Itambé- PE. The distance among the two fragments is of only 10 km (in straight line). In agreement with the classification of Köppen, the predominant climate in the area is of the type As' hot and humid with autumn-winter rains higher to 1.600 annual mm, with temperature varying between 20 and 26° C. It was located 40 plots of 10 x 25 m (20 plots in each fragment), totaling an area of 10.000 m². Each plot was marked with pickets of inoxidable pipe and surrounded by plastic narrow ribbon, being halfway one of the other for 20 m. They were counted and done measure all of the individual trees with CBH ≥ 15,0 cm, being usedmeasuring tape. The height was esteemed with aid of the modules of the aluminum. Each individual received a plaque of aluminum, with growing numbering, and it was identified, in the field, for the popular name, with aid of a practical of the place. The botanical material, fertile and/or sterile collected, was pressed and send for identification to the Herbário Sérgio Tavares, of the Department of Forest Science of UFRPE and to the Herbário Dárdano de Andrade-Lima of IPA. The analysis of the data was accomplished, through the estimate of the phytosociological parameters: absolute and relative values of density, frequency and dominancy; Value of Importance and Shannon Diversity Index (H’). The rising resulted in 1.344 arboreal individuals, being 708 showed in Engenho Guararema's Forest and 636 in the Forest of the Engenho Pau Amarelo. These individuals are distributed in 20 families, 34 genus and 39 species in Engenho Guararema's Forest and 24 families, 37 genus and 45 species in the Forest of the Engenho Pau Amarelo. With this analysis, it was verified that the two fragments are considered young, they are in initial process of establisliment and, due to that, they should be protected and more studied hereafter.