Estrutura, riqueza, diversidade e grupos funcionais da comunidade arb?rea em um remanescente de floresta estacional semidecidual no Espinha?o Meriodional

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-06T10:47:28Z No. of bitstreams: 2 laura_araujo_garcia_santos.pdf: 2256828 bytes, checksum: c1830193f40ba15c0f686de05bafc34c (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-06T10:48:01Z (GMT) No. of bitstreams: 2 laura_araujo_garcia_santos.pdf: 2256828 bytes, checksum: c1830193f40ba15c0f686de05bafc34c (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-06T10:47:54Z (GMT) No. of bitstreams: 2 laura_araujo_garcia_santos.pdf: 2256828 bytes, checksum: c1830193f40ba15c0f686de05bafc34c (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-06T10:48:17Z (GMT) No. of bitstreams: 2 laura_araujo_garcia_santos.pdf: 2256828 bytes, checksum: c1830193f40ba15c0f686de05bafc34c (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)Made available in DSpace on 2015-01-06T10:48:17Z (GMT). No. of bitstreams: 2 laura_araujo_garcia_santos.pdf: 2256828 bytes, checksum: c1830193f40ba15c0f686de05bafc34c (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2013Este trabalho teve como objetivo conhecer a estrutura da comunidade arb?rea, diversidade, riqueza e fun??es ecol?gicas das esp?cies de um fragmento de Floresta Estacional Semidecidual. O estudo foi conduzido em uma ?rea de Reserva Legal pertencente ? empresa Anglo Ferrous Minas-Rio Minera??o S.A no munic?pio de Dom Joaquim (MG), nas coordenadas 19?00'09'' S e 43?11'38'' W e com altitude m?dia de 738m. O fragmento possui aproximadamente 105 ha e encontra-se disposto em encostas com declividades acentuadas, com pequenos cursos d??gua entre as mesmas.Foram observados sinais de impactos naturais causados pela alta intensidade dos ventos, que ocasionam quedas de ?rvores e aberturas do dossel. Para o invent?rio florestal foram alocadas trinta parcelas de 20 ? 20 m (400 m?) totalizando ?rea amostral de 1,2 hectare.Nestas foram amostrados todos os indiv?duos arb?reos com circunfer?ncia ? altura do peito (CAP) > 15,7 cm, exceto lianas e indiv?duos mortos. As esp?cies amostradas foram classificadas em quatro sistemas de guildas (dispers?o, poliniza??o, toler?ncia ? desseca??o e densidade da madeira). Foram mensurados 2056 indiv?duos distribu?dos em 156 esp?cies, 104 g?neros e 46 fam?lias.A distribui??o por classes diam?tricas dos indiv?duos da comunidade arb?rea obteve uma tend?ncia de J-invertido, comportamento esperado para florestas inequi?neas. Por?m, a an?lise para algumas esp?cies isoladas n?o possu?ram esse padr?o, fato este relacionado com a ecologia populacional de cada esp?cie ou com limita??es no recrutamento.Foi verificado um alto valor de H?, o que indica uma ?rea com diversidade relativamente alta e uma fraca domin?ncia ecol?gica de esp?cies verificada tanto pelo elevado valor de J? como pela reduzida porcentagem do somat?rio das dez principais esp?cies para todos par?metros fitossociol?gicos. No fragmento tamb?m foram levantadas esp?cies que est?o inseridas na lista das esp?cies amea?adas de extin??o do IBAMA, sendo estas Euterpe edulis, Zeyheria tuberculosa, Apuleia leiocarpa, Dalbergia nigra, Melanoxylon bra?na, Syagrus macrocarpa, Ocotea odorifera e Almeidea coerulea. Na guilda de dispers?o a ?nica s?ndrome considerada significativa foi a anemoc?rica (indiv?duos foram mais frequente que o esperado nos estratos intermedi?rio e superior), o que ocorreu devido nestes locais haver uma maior a??o do vento e aus?ncia de obst?culos. A s?ndrome de dispers?o zooc?rica, predominou em todos os estratos, por?m estatisticamente n?o houve diferen?as significativas. Este resultado parece estar fortemente relacionado ao habitat dos animais, j? que s?o nessas ?reas que a fauna encontram maior prote??o contra preda??o. Para poliniza??o tamb?m foi constatado uma domin?ncia de indiv?duos polinizados por animais em todos os estratos, por?m tamb?m sem diferen?as significativas. Esse predom?nio sugere a import?ncia do papel da fauna na garantia do fluxo g?nico. J? a guilda toler?ncia a desseca??o apresentou em todos os estratos analisados diferen?as significativas entre as categorias de toler?ncia, onde indiv?duos com sementes recalcitrantes foram mais frequente que o esperado nos estrato inferior e emergente, sugerindo que no fragmento ocorreu algum dist?rbio a m?dio prazo de tempo e que este se encontra em pleno processo de sucess?o secund?ria, j? que h? indiv?duos de sementes recalcitrantes (est?gio sucessional avan?ado) jovens que substituir?o os indiv?duos situados nos estratos superiores. Corroborando com a toler?ncia ? desseca??o, a densidade da madeira apresentou um predom?nio de indiv?duos madeira pesada (est?gio sucessional mais avan?ado) no estrato inferior, evidenciando mais uma vez a substitui??o de indiv?duos de est?gio sucessional intermedi?rio.Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013.ABSTRACT This study aimed to know the structure of the tree community, the richness, diversity and ecological functions of the species in a Seasonal Semideciduous Forest fragment. The study was conducted in a Legal Reserve area belonging to the company Anglo Ferrous Minas-Rio Minera??o S.A. in the municipality of Don Joaquim (MG), at coordinates 19? 00'09'' S and 43? 11'38'' W and average altitude of 738 m. The fragment has approximately 105 ha and is arranged on slopes with steep slopes, with small streams between them. Signs of natural impacts caused by the high intensity of the winds, which cause falling trees and canopy openings were observed. For the forest inventory were allocated thirty plots of 20 ? 20 m (400 m?) of the total sampled area of 1.2 hectare. In these, were sampled all the trees with circumference at breast height (CBH) > 15.7 centimeters, except lianas and dead individuals. Sampled species were classified into four guilds systems (dispersal, pollination, desiccation tolerance and wood density). 2056 individuals were measured, distribuite in: 156 species 104 genus and 46 families. The distribution by diameter classes of individuals of the tree community, obteined a trend of inverted-J behavior, expected for uneven aged forest. However, the analysis of some isolated species did not possess this pattern, a fact related to the population ecology of each species or the limitations in recruitment. A high value of H' was found, which indicates an area with relatively high diversity and low ecological dominance of species, verified by the high value of J' and for the small percentage of the sum of the ten major species for all phytosociological parameters. In the fragment were collected species that are also included in the list of endangered species of IBAMA, such as Euterpe edulis, Zeyheria tuberculosa, Apuleia leiocarpa, Dalbergia nigra, Melanoxylon brauna, Syagrus macrocarpa, Ocotea odorifera and Almeidea coerulea. In the dispersion guild, the only syndrome that was considered significant was the anemocoric (individuals were more frequent than expected in the intermediate and superior stratas), which occurred because these sites have a higher wind action and absence of obstacles. The zoochoric dispersion syndrome, predominated in all stratas, but statistically there were no significant differences. This result appears to be strongly related to the habitat of the animals, since these are areas that the fauna found a greater protection against predation. For pollination, have been found the predominance of individuals pollinated by animals in all strata, but also without significant differences. This predominance suggests the importance of the role of fauna in ensuring the gene flow. The guild presented desiccation tolerance in all stratas analyzed significant differences between categories of tolerance, where individuals with recalcitrant seeds were more frequent than expected in emerging and inferior strata, suggesting that in the fragment occured some disturbance in the medium and long term that this is in the process of secondary succession, since there are individuals of young recalcitrant seeds (late successional state) that will replace individuals on the superior strata. Corroborating with desiccation tolerance, the wood density showed a prevalence of individuals with heavy wood (more advanced successional stage) in the lower stratum, showing once again the replacement of individuals of intermediate successional stage