Sustanis Horn Kunz

Analysis of floristic similarity between forests of the Upper Xingu River and forests of the Amazon Basin and of the Planalto Central

Recent studies have showed that the phytogeographic identity of the Upper Xingu River is as Seasonal Evergreen Forest. The region has peculiar physical and floristic characteristics, located at the contact area between the rain forest and the Brazilian Savannah (Cerrado). This study shows the floristic similarity between deciduous and semideciduous seasonal forests, cerrado of Middle Brazil and Amazonian tropical rain forests, aiming to interpret the relationship of the Seasonal Evergreen Forest of the Upper Xingu with one of these formations. Thirty-two lists of arbustive-arboreal species were taken from floristic and phytosociologic studies. The floristic similarity was estimated by Jaccards index and the construction of dendrogram based on group mean values. The analysis of similarity allowed the identification of the clear floristic distinction between the Cerrado and the Amazon Forest biomes, as well as the areas of ecological tension between these biomes. The areas of seasonal evergreen forest were more similar to the monodominant semideciduous seasonal forest, which may be a consequence of their location in the ecotone between the Cerrado and the Amazon Forest. The low similarity between the Seasonal Evergreen Forest and the other forest types confirme the unique flora possessed by this phytophysiognomy, that demonstrates its recognition in a region considered as the transition area.

Aspectos florísticos e fitossociológicos de um trecho de Floresta Estacional Perenifólia na Fazenda Trairão, Bacia do rio das Pacas, Querência-MT

The southern border of the Amazon region presents a peculiar type of forest called Seasonal Evergreen Forest, which has currently undergone several environmental impacts due to the agriculture frontier expansion from the Northern state of Mato Grosso. Due to the lack of studies on this type of forest, the objective of this study was to identify the floristic composition and phytosociological structure of the arborous component from a forest area in the Trairao Farm, Querencia - MT, Brazil. The vegetation sampling was composed of the distribution of 200 quadrant-points in which the four individuals closest to each point, with DAP (diameter to height breast) equal or superior to 10 cm were considered. The total density of the sampled area was 728 ind./ha distributed into 49 species, 39 genera and 24 families. The species presenting the highest richness was Fabaceae (five species), followed by Burseraceae and Euphorbiaceae, with four species each, and considered as the richest in some Amazon forest areas. The species of highest Importance Value (IV) were Ocotea leucoxylon (Sw.) Laness., Xylopia amazonica R.E. Fr. and Myrcia multiflora (Lam.) DC., Chaetocarpus echinocarpus (Baill.) Ducke and Protium pilosissimum Engl., but did not present the same representativity as in other Seasonal Evergreen Forest area, evidencing structural differences within this phytogeographic unit. The majority of individuals from this community present slender size, with diameter ranging from 10 to 14.9 cm and height from 10.6 to 16.5 m. The Shannon index (3.17) may be considered as low in relation to the Amazon Forest in which the diversity is above 4.0.

Transposição do banco de sementes do solo como metodologia de restauração florestal de pastagem abandonada em Viçosa, MG

This study had as its objective to compare the transposition of the soil seed bank of two successional stages of Seasonal Semideciduous Forest for a Melinis Minutiflora P. Beauv site, in an abandoned pasture of the Mata do Paraiso Forest Reserve, Vicosa, MG. Ten parcels had been placed in each successional site of forest and withdrawals of the center of each parcel sample of 1 m² and 5 cm of superficial depth of soil, being carried afterwards to the abandoned pasture site. Two hundred and thirty one individuals had been registered in the two treatments (initial forest and mature forest), consisting of 31 shrubs and 200 trees. The individuals are distributed by 13 families, 17 kinds and 22 species. The most abundant species had been Vernonia polyanthes, with 108 individuals and Senna multijuga, with 39 individuals. The soil seed bank coming from the site of initial secondary forest (Fi) registered more individuals (120) than the bank coming from the site of the mature forest (Fm), with 111 individuals. The parcels witnesses had been colonized by herbaceous and mainly by the exotic grass Melinis Minutiflora. The number of germinated seeds was only greater in the Fm treatment in the months of july/2008 and january/2009. Significant differences were observed with 1% probability, between the treatments, for the variable wealth of species and density of individuals. The present study showed that it is recommendable and viable to adopt the technique of transposition of the seed bank as a methodology of forest restoration of abandoned pasture.

Estrutura fitossociológica de um trecho de floresta estacional perenifólia, Bacia do Rio Das Pacas, Querência - MT

A borda sul da regiao amazonica apresenta um tipo peculiar de floresta, denominada de Floresta Estacional Perenifolia. Diante da falta de conhecimento deste tipo florestal, objetivou-se desenvolver um estudo relacionado a estrutura fitossociologica na bacia do rio das Pacas, em Querencia-MT. A amostragem da vegetacao consistiu na distribuicao de 200 pontos-quadrantes, nos quais foram considerados os quatro individuos mais proximos de cada ponto, que tivessem diâmetro a altura de 1,30 m do solo (DAP) > 10 cm. A densidade total da area amostrada foi 761 ind./ha, distribuidos em 53 especies, 37 generos e 27 familias. Das especies de maior Valor de Importância, Ocotea leucoxylon, Myrcia multiflora, Pouteria gardneri, Sloanea eichleri, Miconia pyrifolia e Amaioua guianensis, ocorreram em outros trechos de Floresta Estacional Perenifolia, mas nao com a mesma representatividade, evidenciando diferencas estruturais desta unidade fitogeografica. O indice de Shannon (3,38) pode ser considerado medio e a equabilidade de Pielou (0,85) indica heterogeneidade floristica do componente arboreo.

Síndromes de dispersão de diásporos das espécies de trechos de vegetação ciliar do rio das Pacas, Querência - MT

The adaptations of plants, as its agents dispersers correlated with the morphological characteristics of each specie and family, and with the region in which it dominates, and the seeds progressed according to the dispersors. The zoochory is the most frequent seed dispersal in the tropical forest, hence the importance in the conservation of ecological corridors, which allowed the spread of species of a fragment to another. Given the fact, this study aimed to trace the major processes of the seed dispersal of species occurring in the Riparian Evergreen Seasonal Forest areas of the Pacas river, Querencia - MT, to identify the main dispersal type. The informations on dispersal syndromes were collected in the field during the sampling the vegetation, wich was divided in strata, according to the eight of the individuals sampled. We identified 69 species, belonged 51 genera and 31 botanic families. The families with the greatest richness were Annonaceae and Fabaceae, which showed the greatest variety syndromes. The zoochory were syndrome the more important, with 86% the total species, followed by anemochory (10%), autochory (3%) and barochory (1%). The lower (understory) and intermediate (canopy) strata have percentage zoochoric species higher than upper stratum (emergente), where the anemochory was the more important. These results demonstrate the strong relationship between the vegetation and animals in the maintenance of plant populations in the riparian environment and the importance of maintaining ecological corridors between forest fragments.

Fitossociologia de uma área de floresta estacional perenifólia na fazenda Amoreiras, Querência, MT

The Southern Amazon forests, where the Seasonal Perennial Forest occurs, has great influence on the maintenance of the regional physical equilibrium and they are among forests most threatened by anthropic action and are little known in relation to their structure. In this context, the objective of this work was to study phytosociological structure of a Seasonal Perennial Forest area in the Rio das Pacas Basin at Querencia, state of Mato Grosso, Brazil. The vegetation sampling was composed of the distribution of 200 center quarter points, all individuals with DAP (diameter to height breast) equal or superior to 10 cm were considered. The total density of the sampled area was 736 ind./ha distributed into 58 species, 45 genera and 31 families. The species of highest Importance Value (IV), Ocotea leucoxylon (Sw.) Laness., Trattinickia glaziovii Swart, Ouratea discophora Ducke, Xylopia amazonica R.E. Fr. and Myrcia multiflora (Lam.) DC. corresponded to 28.45% of the total IV and occurred in other Seasonal Perennial Forest areas in Gaucha do Norte, state of Mato Grosso; however, not with the same representativity. The Shannon index (3.51) may be considered as low in relation to the Amazon Forest; however, the Pielou equability (0.86) suggests that this arborous community presents high floristic heterogeneity. mudancas morfologicas nas raizes relacionadas ao metabolismo secundario, constituindoThe Southern Amazon forests, where the Seasonal Perennial Forest occurs, has great influence on the maintenance of the regional physical equilibrium and they are among forests most threatened by anthropic action and are little known in relation to their structure. In this context, the objective of this work was to study phytosociological structure of a Seasonal Perennial Forest area in the Rio das Pacas Basin at Querencia, state of Mato Grosso, Brazil. The vegetation sampling was composed of the distribution of 200 center quarter points, all individuals with DAP (diameter to height breast) equal or superior to 10 cm were considered. The total density of the sampled area was 736 ind./ha distributed into 58 species, 45 genera and 31 families. The species of highest Importance Value (IV), Ocotea leucoxylon (Sw.) Laness., Trattinickia glaziovii Swart, Ouratea discophora Ducke, Xylopia amazonica R.E. Fr. and Myrcia multiflora (Lam.) DC. corresponded to 28.45% of the total IV and occurred in other Seasonal Perennial Forest areas in Gaucha do Norte, state of Mato Grosso; however, not with the same representativity. The Shannon index (3.51) may be considered as low in relation to the Amazon Forest; however, the Pielou equability (0.86) suggests that this arborous community presents high floristic heterogeneity. mudancas morfologicas nas raizes relacionadas ao metabolismo secundario, constituindo-sistema-modelo para o estudo da genetica, da fisiologia e dos processos morfogeneticos envolvidos na formacao de ectomicorriza entre Pisolithus e Eucalyptus.