DYNAMICS OF NATURAL REGENERATION IN THE UNDERSTORY OF Pinus caribaea Morelet. var. caribaea IN BIOLOGICAL RESERVE SALTINHO, TAMANDAR\uc9 - PE

O estudo da estrutura e din\ue2mica da regenera\ue7\ue3o natural em sub-bosque de plantios com esp\ue9cies ex\uf3ticas, como as do g\ueanero Pinus, possibilita dar informa\ue7\uf5es para manejo, conserva\ue7\ue3o e reestabelecimento das esp\ue9cies nativas de uma comunidade vegetal. O objetivo deste trabalho foi identificar e quantificar a din\ue2mica da regenera\ue7\ue3o natural das esp\ue9cies arbustivo-arb\uf3reas ocorrentes no sub-bosque do povoamento de Pinus caribaea , na Rebio de Saltinho, em Pernambuco. Foram medidas as esp\ue9cies regenerantes de 10 parcelas permanentes, de 1 x 50 m, e inclu\ueddos os indiv\uedduos com circunfer\ueancia na base a 30 cm do solo (CAB 0,30m) 64 15 cm e altura superior a um metro. A altura foi classificada em: Classe 1, indiv\uedduos arbustivoarb\uf3reos, com altura 1 64 H 64 2; Classe 2 com altura 2 < H 64 3; e Classe 3, com altura > 3 m e CAP 64 15 cm. Calcularam-se os par\ue2metros fitossociol\uf3gicos, a din\ue2mica da regenera\ue7\ue3o e os \uedndices de Shannon (H\u2019) e a equabilidade (J\u2019) por Pielou. Protium heptaphyllum teve maior n\ufamero de indiv\uedduos e valor de import\ue2ncia (VI), e Miconia prasina a melhor frequ\ueancia nos dois levantamentos. Quanto ao \uedndice H\u2019 de 3,32 nats.ind-1 (2007) passou a 3,07 nats.ind-1 (2012), e a equabilidade de J\u2019 de 0,85 a 0,62, havendo decr\ue9scimo tanto para a diversidade, quanto para a distribui\ue7\ue3o. O levantamento de 2012 registrou aumento de 12,5% do n\ufamero de indiv\uedduos, e os regenerantes de 2007 tiveram 48,31% de mortalidade. Com rela\ue7\ue3o ao n\ufamero de indiv\uedduos e \ue1rea basal, os percentuais de ganhos foram superiores ao das perdas. Conclui-se que a sucess\ue3o ecol\uf3gica da regenera\ue7\ue3o do sub-bosque do povoamento estudado, encontra-se em modifica\ue7\ue3o positiva, e o povoamento de Pinus caribaea, n\ue3o est\ue1 impedindo o surgimento de novos indiv\uedduos e esp\ue9cies.The study of the structure and dynamics of natural regeneration in the understory of plantations with exotic species, such as those of the genus Pinus , makes it possible to provide information to management, conservation and re-establishment of native species in a plant community. The aim of this study was to identify and quantify the dynamics of natural regeneration of woody tree species occurring in the understory of Pinus caribaea in Rebio of Saltinho, Pernambuco state, Brazil. Regenerating species were measured for 10 permanent plots, 1 x 50 m, and included individuals with circumference at the base to 30 cm from the ground (CAB 0, 30 m) 64 15 cm and height of more than one meter. The height was classified in: Class 1, shrubby tree, individuals with height 1 64 H 64 2; Class 2 with 2 height < H 64 3; and Class 3, with height > 3 m and 64 15 cm CAP. Phytosociological parameters were calculated, the dynamics of the regeneration and the Shannon index (H \u2018) and evenness (J \u2018) by Pielou. Protium heptaphyllum had as many individuals and value of importance (VI) and Miconia prasina the best frequency in the two surveys. How to index H \u2018 of 3,32 nats. ind-1 (2007) went to 3,07 nats. ind-1 (2012), and the evenness of J \u2018 of 0,85 to 0,62, and decrease for both the diversity and the distribution. The 2012 survey recorded 12,5% increase in the number of individuals, and the regenerating of 2007 had 48,31% mortality. With respect to the number of individuals and basal area, the percentage gains were greater than the losses. It is concluded that the ecological succession of understorey regeneration of the population studied, lies in positive modification, and the settlement of Pinus caribaea, is preventing the emergence of new individuals and species