DIAMETRIC DISTRIBUTION MODELING OF WOODY SPECIES IN CAATINGA, SEMI- ARID REGION OF PERNAMBUCO STATE

O objetivo deste estudo foi ajustar e selecionar fun\ue7\uf5es de densidade de probabilidade que descrevam a distribui\ue7\ue3o diam\ue9trica das esp\ue9cies Poincianella bracteosa Tul, Mimosa ophthalmocentra Mart. ex Benth, Manihot carthaginensis subsp. glaziovii (Muell. Arg.) Allem e para o conjunto de esp\ue9cies lenhosas ocorridas em uma \ue1rea de Caatinga, no munic\uedpio de Floresta, semi\ue1rido pernambucano. O estudo foi realizado em uma \ue1rea com hist\uf3rico de perturba\ue7\ue3o com aproximadamente 10 ha, na qual foram instaladas 20 parcelas de (20 x 20 m), de forma sistem\ue1tica. Os indiv\uedduos lenhosos com circunfer\ueancia a altura do peito (CAP) 65 6 cm, foram identificados botanicamente e tiveram seus di\ue2metros e alturas mensuradas. Foram testadas as fun\ue7\uf5es probabil\uedsticas de Weibull 3 par\ue2metros, Sb Johnson, Normal, Log-normal, Gamma, Beta e Meyer, utilizando-se um intervalo de classe de 2 cm e o teste de Kolmogorov-Smirnov foi empregado como crit\ue9rio de sele\ue7\ue3o. Verificou-se que a fun\ue7\ue3o de Weibull 3 par\ue2metros, foi a que melhor descreveu a distribui\ue7\ue3o diam\ue9trica de Mimosa ophthalmocentra e Manihot carthaginensis, al\ue9m de melhor descrever tamb\ue9m o conjunto total de esp\ue9cies. Para Poincianella. Bracteosa, a fun\ue7\ue3o ideal foi Sb Johnson. A exist\ueancia de forte perturba\ue7\ue3o, observada na \ue1rea de estudo, \ue9 explicada pela distribui\ue7\ue3o unimodal, refletida nas tr\ueas esp\ue9cies, portanto, a referida \ue1rea merece devida aten\ue7\ue3o para que tal processo cesse.The objective of this study was to adjust and select probability density functions that describe the diametric distribution of Poincianella bracteosa Tul, Mimosa ophthalmocentra Mart. ex Benth e Manihot carthaginensis subsp. glaziovii (Muell. Arg.) Allem species, and for this species as whole, which occured in Caatinga biome, in the municipality of Floresta, in the semiarid region of Pernambuco state. The study was conducted in an area with disturbance history with approximately 10 ha, where it was installed 20 plots (20 x 20m), in a symmetric way, where all the trees with circumference at the breast right (CBH) 65 6cm were identified and their diameters and heights were measured. It was tested the probabilistic functions such as: Weibull 3 parameters, Jonson\u2019s Sb, Normal, Log-nomal, Gamma, Beta and Meyer. A class interval of 2 cm was used and Kolmogorov-Smirnov test was used as the selection criterium. It was found that the Weibull 3 parameters was the best function described the diametric distribution for Mimosa ophthalmocentra e Manihot carthaginensis. For Poincianella bracteosa Johnson\u2019s Sb was the ideal one. The existence of strong disturbance observed in the study area, is explained by a unimodal distribution, reflected in the three species, so that the area deserves due attention so that this process ceases