Composi??o e estrutura em trecho de floresta no M?dio Para?ba do Sul, RJ

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2020-08-12T15:54:47Z No. of bitstreams: 1 2001 - Maria Lucila Chicarino Varaj?o Spolidoro.pdf: 2165212 bytes, checksum: c6a73e8ca0de4c06c8b5918ac565ea14 (MD5) Made available in DSpace on 2020-08-12T15:54:48Z (GMT). No. of bitstreams: 1 2001 - Maria Lucila Chicarino Varaj?o Spolidoro.pdf: 2165212 bytes, checksum: c6a73e8ca0de4c06c8b5918ac565ea14 (MD5) Previous issue date: 2001-01-04 A preliminary study of floristic and phytosociologycal was accomplished in a forest passage in the Experimental Field Santa M?nica (CEFSM) (22?22'S and 43?42'W), belonging Embrapa Gado de Leite, located in Bar?o of Juparan?, district of Marqu?s de Valen?a, middle section of the Basin of Rio Para?ba do Sul, RJ. The total area sample was of 0,3 ha subdividing in three areas of 1.000m2 each, with approximately 60, 80 and 120 years of natural regeneration starting from different occupation reports and abandonment. It was used the method of parcels and criterion of inclusion of diameters the height of the chest (DAP) equal or larger than 5cm. In the soil analysis it was observed that in a general way, the tenors of Ca+Mg, K, P, N and C came with superior values in the 120 year-old parcel, decreasing according to the age of the portions, in compensation, the litter stock as well as the tenors of Ca, P, N, C and the relationship C/N had been significantly equal for the three parcels used as a sample, despite that, discreet variation was observed as for the individuals of Leguminosae presence with nodules in their roots among the portions of 60 and 120, however the inadequacy parcels suggests larger investigation. The medium values of the litter stock can be considered low inside of the strip of variation occurred in other areas of Forest Atl?ntica.Com relationship to the measures of diversity of fauna of the soil, these they are with very close values among the three portions, suggesting larger investigation. As for the composition and structure was observed that the 60 year-old portion presented the lowest number of individuals (108), trunks still died in foot (1), however the number of goods (26) and species (31) as well as larger diversity index (3,02) and eq?ability (0,87) they were above the sampled in the 80 year-old parcel, however, medium DAP and basal area, they are the more bass in relation to the portions of 80 and 120 years. In this portion the species Piptadenia gonoacantha, Miconia cinnamomifolia and Dalbergia nigra, for different attributes were the ones that obtained larger values of importance and they are representative of this portion. The high number of individuals (88%) with maximum height of up to 10m, being among these species as Xylopia brasiliensis and X. sericea that occupy emerging position in the dossal of forests in other Atlantic forest places, this allied observation to the parameters observed above suggest that this portion is in intermediate phase of successional development. The 80 year-old portion presented the highest number of individuals comparatively (172), low number of families (14), smaller number of goods (24) and species (27), consequently smaller diversity index (2,78) and eq?ability (0,84). This portion presented medium DAP a little below to the observed for the one of 60 years and intermediate basal area among the three analyzed portions, these data suggest that disturbances that active and/or act are influencing unfavorably composition and structure. The species Siparuna guianensis, Piptadenia gonoacantha and Apuleia leiocarpa, can be considered as representative of this parcel. The 120 year-old parcel presented the largest number of trunks died (15), of goods and species, larger H' and eq?ability, as well as smaller number of families and intermediate number of individuals, high number of exclusive species as well as the largest values of medium DAP and basal area, if compared with the others two parcels. In this parcel the species with larger VI?s were Vochysia oppugnata and Inga capitata, due to the high DoR, a little below is Lauraceae sp and Roupala longipetiolata, followed by Guapira opposita and Bauhinia forficata that presented larger number of individuals. Possibly, the access difficulty and time of permanence might have favored the largest complexity of this formation, suggesting that this it is in phase of advanced development of development, reinforced by the largest number of exclusive species, they put these data should be observed with reservation, due to the analysis species/area to have if shown insufficient. The floristic similarity (0,5) it was obtained between the parcels of 60 and 80 years, fact this favored possibly by the proximity age, space and historical of occupation also similar. The species G. opposita, C. sylvestris, C. oblongifolia, M. rostrata and P. gonoacantha are common to the three analyzed parcels. The vegetation of the Experimental Field Santa M?nica presented similarity, at the level of 0,24 in the index of Jaccard, with the forest formation of the Dam of Ribeir?o of Lages, RJ, suggesting that the existent formations in the area of Medium Para?ba of the South possess peculiar characteristics. This initiative and with these results, allies the historical pressure antropic that has been suffering the forest remainders and the proven shortage of floristic and phytosociologia studies indicate the conservation need and preservation of the fragments of this area that still keep own species of these formations and the incentive to futures studies in the region Um estudo preliminar de flor?stico e fitossociol?gico foi realizado em um trecho de floresta no Campo Experimental Santa M?nica (CEFSM) (22?22'S e 43?42'W), pertencente a Embrapa Gado de Leite, localizado em Bar?o de Juparan?, distrito de Marqu?s de Valen?a, setor M?dio da Bacia do Rio Para?ba do Sul, RJ. A ?rea total amostrada foi de 0,3 ha subdivididos em tr?s parcelas de 1.000m2 cada, com aproximadamente 60, 80 e 120 anos de regenera??o natural a partir de diferentes hist?ricos de ocupa??o e abandono. Utilizou-se o m?todo de parcelas e crit?rio de inclus?o de di?metros a altura do peito (DAP) igual ou maior que 5cm. Na an?lise de solo observou-se que de maneira geral, os teores de Ca+Mg, K, P, N e C se apresentaram com valores superiores na parcela de 120 anos, decrescendo conforme a idade das parcelas, em contrapartida, o estoque de serrapilheira assim como os teores de Ca, P, N, C e a rela??o C/N foram significativamente iguais para as tr?s parcelas amostradas, apesar disso, observou-se discreta varia??o quanto ? presen?a de indiv?duos de Leguminosae com n?dulos em suas ra?zes entre as parcelas de 60 e 120, entretanto a insufici?ncia amostral sugere maior investiga??o. Os valores m?dios do estoque de serrapilheira podem ser considerados baixos dentro da faixa de varia??o ocorrente em outras ?reas de Mata Atl?ntica.Com rela??o ?s medidas de diversidade de fauna do solo, estas se encontram com valores muito pr?ximos entre as tr?s parcelas, sugerindo maior investiga??o. Quanto ? composi??o e estrutura observou-se que a parcela de 60 anos apresentou o mais baixo n?mero de indiv?duos (108), troncos mortos ainda em p? (1), entretanto o n?mero de g?neros (26) e esp?cies (31) como tamb?m maior ?ndice de diversidade (3,02) e equabilidade (0,87) foram acima do amostrado na parcela de 80 anos, entretanto, o DAP m?dio e ?rea basal, s?o os mais baixos em rela??o ?s parcelas de 80 e 120 anos. Nesta parcela as esp?cies Piptadenia gonoacantha, Miconia cinnamomifolia e Dalbergia nigra, por diferentes atributos foram as que obtiveram maiores valores de import?ncia e s?o representativas desta parcela. O elevado n?mero de indiv?duos (88%) com altura m?xima de at? 10m, estando entre estas esp?cies como Xylopia brasiliensis e X. sericea que ocupam posi??o emergente no dossel de florestas em outras localidades de Mata Atl?ntica, esta observa??o aliada aos par?metros observados acima sugerem que esta parcela encontra-se em fase intermedi?ria de desenvolvimento sucessional. A parcela de 80 anos apresentou comparativamente o mais alto n?mero de indiv?duos (172), baixo n?mero de fam?lias (14), menor n?mero de g?neros (24) e esp?cies (27), consequentemente menor ?ndice de diversidade (2,78) e equabilidade (0,84). Esta parcela apresentou DAP m?dio um pouco abaixo ao observado para a de 60 anos e ?rea basal intermedi?ria entre as tr?s parcelas analisadas, estes dados sugerem que perturba??es que atuaram e/ou atuantes v?em influenciando desfavoravelmente sua composi??o e estrutura. As esp?cies Siparuna guianensis, Piptadenia gonoacantha e Apuleia leiocarpa, podem ser consideradas como representativas desta parcela. A parcela de 120 anos apresentou o maior n?mero de troncos mortos (15), de g?neros e esp?cies, maior H? e equabilidade, como tamb?m menor n?mero de fam?lias e n?mero intermedi?rio de indiv?duos, alto n?mero de esp?cies exclusivas como tamb?m os maiores valores de DAP m?dio e ?rea basal, comparado-a com as outras duas parcelas. Nesta parcela as esp?cies com maiores VIs foram Vochysia oppugnata e Inga capitata, devido ao alto DoR, um pouco abaixo est?o Lauraceae sp e Roupala longipetiolata, seguidas de Guapira opposita e Bauhinia forficata que apresentaram maior n?mero de indiv?duos. Possivelmente, a dificuldade de acesso e tempo de perman?ncia podem ter favorecido a maior complexidade desta forma??o, sugerindo que esta se encontra em fase de desenvolvimento avan?ado de desenvolvimento, refor?ado pelo maior n?mero de esp?cies exclusivas, porem estes dados devem ser observados com reserva, devido ? an?lise esp?cies/?rea ter se mostrado insuficiente. A similaridade flor?stica (0,5) foi obtida entre as parcelas de 60 e 80 anos, fato este favorecido possivelmente pela proximidade et?ria, espacial e hist?rico de ocupa??o tamb?m similar. As esp?cies G. opposita, C. sylvestris, C. oblongifolia, M. rostrata e P. gonoacantha s?o comuns ?s tr?s parcelas analisadas. A vegeta??o do Campo Experimental Santa M?nica apresentou similaridade, ao n?vel de 0,24 no ?ndice de Jaccard, com a forma??o florestal da Represa de Ribeir?o das Lages, Rio de Janeiro, sugerindo que as forma??es existentes na regi?o do M?dio Para?ba do Sul possuem caracter?sticas peculiares. Esta iniciativa e com estes resultados, aliados a hist?rica press?o antr?pica que tem sofrido os remanescentes florestais e a comprovada escassez de estudos de flor?stica e fitossociologia indicam a necessidade de conserva??o e preserva??o dos fragmentos desta regi?o que ainda guardam esp?cies pr?prias destas forma??es e o incentivo a futuros estudos na regi?o.