Elias Silva

Diagnóstico ambiental no contexto da paisagem de fragmentos florestais naturais "ipucas" no município de Lagoa da Confusão, Tocantins

RESUMO - Este estudo foi conduzido em uma area localizada no municipio de Lagoa da Confusao, Estado do Tocantins, com os objetivos de diagnosticar fragmentos florestais naturais, denominados regionalmente de “ipucas”, e mapear as diferentes feicoes fisionomicas e o uso antropico da area. Para realizacao deste estudo utilizou-se um sistema de informacoes geograficas, IDRISI 2.0. O principal resultado obtido foi o historico de perturbacao que se intensificou a partir da criacao do Estado do Tocantins e da implantacao do Projeto Rio Formoso para o cultivo de arroz irrigado; em relacao a classificacao fisionomica e ao uso antropico foram individualizadas 73 “ipucas”. A partir das variaveis consideradas verificou-se que, em relacao a area, 56,16% dos fragmentos possuem areas de ate 5,00 ha e apenas quatro apresentaram areas superiores a 100,00 ha. Aproximadamente 50% destas possuem formas alongadas, o que indica alta relacao perimetro/area. Apenas tres “ipucas” apresentaram indice de circularidade (C) proximo de 1. Foram identificadas oito feicoes circunvizinhas as “ipucas”. Destas, cinco sao ambientes naturais (varjao-sujo, varjao-limpo, pastagem natural, corpos d’agua e afloramento rochoso) e as demais resultantes de acoes antropicas (area agricola, pastagem plantada e rede viaria).

Identificação de conflito de uso da terra em áreas de preservação permanente no entorno do parque nacional do Caparaó, Estado de Minas Gerais

The objective of this work was to prepare a map of land use based on the IKONOS II sattelite images, to automatically determine the permanent preservation areas and to identify the occurrence of use conflicts, using as legal reference the Forest Code and the no 303 Resolution of the CONAMA. The research was developed around the Caparao National Park, in lands of the municipalities of Alto Jequitiba, Alto Caparao, Caparao and Espera Feliz, all of them located in the State of Minas Gerais. Using the resources available in the geographic processing, it was possible to map 8 classes of land use and to delimitate the permanent preservation areas located in regions above 1,800 meters of altitude (8.42 ha), the third upper part the hills (18.67 ha); an hillsides with slopes above 45 degrees (92.96 ha); water course margins with width below 10 meters (3,957.19 ha); and the upper third part the sub basins totalizing 12,098.22 ha (48.06%) of the basin total area. The area of improper use corresponds to 8,922.91 ha (45.49 %), being the classes coffee crop (5,183.43 ha) and clear pasture (3,650.74 ha) the main occurrences in these areas. Only 2,160.69 ha (18.40 %) of the permanent preservation areas are protected by natural vegetation.

Avaliação temporal da florística arbórea de uma floresta secundária no município de Viçosa, Minas Gerais

RESUMO - Avaliou-se a composicao floristica, por um periodo de nove anos, em um fragmento de Floresta Estacional Semidecidual Secundaria localizada no Municipio de Vicosa, Minas Gerais, com o objetivo de se avaliar a dinâmica da vegetacao arborea. A coleta dos dados dessa vegetacao, com diâmetro a altura do peito (DAP a 1,3 m) igual ou superior a 5 cm, foi realizada em 10 locais, em parcelas permanentes. As especies amostradas foram identificadas, sempre que possivel, em niveis de familia, genero e especie. Em nove anos de estudo foram amostradas 161 especies, 114 generos e 48 familias, sendo as familias Leguminosae, Lauraceae, Euphorbiaceae, Myrtaceae, Flacourtiaceae e Meliaceae, as que tiveram a maior riqueza de especies. O indice de diversidade de Shannon-Weaver variou de 2,26 a 3,65, quando analisado para cada local, e de 4,22 a 4,26 para o fragmento como um todo, ao longo de nove anos. O grupo ecologico que mais se destacou foi o das secundarias iniciais, seguido pelas secundarias tardias ou pelas pioneiras, a depender da abertura do dossel do local estudado, indicando que o fragmento se encontrava em estadio medio de sucessao. A variabilidade na composicao floristica em funcao dos locais estudados e na proporcao de especies em cada grupo ecologico era resultante das variacoes na intensidade da acao antropica, bem como das condicoes fisiograficas, em especial exposicao e declividade do terreno. Planos de manejo para essas florestas devem levar em conta essa variabilidade de condicoes ambientais.

Análise da dinâmica de fragmentos florestais no município de Carandaí, MG, para fins de restauração florestal

The knowledge on forest patches in rural properties allows the application of a correct environmental administration, promoting their conservation and restoration in degraded areas. By using the softwares SPRING and FRAGSTATS, the landscape was characterized with emphasis on the patches of secondary Seasonal Semidecidual Forest, located in the municipal district of Carandai, MG, and the area around it, considering its evolution from the period of 1984 to 2007. It could be concluded that progressive increase in the total area of native forest occurred due to the appearance of new patches, and the individual area of each patch presented reduction tendency, what provided increase of the edge area, reducing the percentage of each patch which is the core area during the gap of the evaluated time. Despite the advantage of predominance of patches in simple geometric ways, with reduction of the edge effect, the quality of the landscape got threatened because it was predominantly constituted by small patches. The forest patches were still so distant one from the others (more than 200 meters), presenting small gathering tendency (result of the increase of the number of patches), however, still insufficient. Therefore, although the covering of native forest has presented increase of total area, in general, it lost in quality in the gap of the time considered.

Mapeamento dos fragmentos de vegetação florestal nativa da bacia hidrográfica do rio Alegre, Espírito Santo, a partir de imagens do satélite IKONOS II

The main objective of this study was to create land use and diagnosis maps, at landscape level, of the native forest fragmentation through visual classification using IKONOS II data. The study was conducted in the river Alegre watershed, situated in the south region of State of Espirito Santo, Brazil. Twelve land use classes were mapped, pointing out 475 forest fragments. The classes of coffee plantation (2,086.2 ha), pasture (14,130.1 ha) and forest fragmentation (2,978.9 ha) occupied 92.16% (19,195.2 ha) of the total study area, which was about 20,819.8 ha. The majority of the forest fragments presented strongly elongated shapes, with an average of 6.3 ha. It was also noticed that most of them presented a high level of disturbance, with 452 and 166 forest fragments neighboring the pasture and coffee plantation classes, respectively.

Perfil ambiental qualitativo da extração de areia em cursos d'água

RESUMO – As atividades de extracao de areia sao de grande importância para o desenvolvimento social, mas igualmente responsaveis por impactos ambientais negativos, alguns inclusive irreversiveis. Nesse sentido, este trabalho teve como objetivo central avaliar qualitativamente os impactos ambientais decorrentes desse tipo de empreendimento. A identificacao e caracterizacao qualitativa dos impactos ambientais foram feitas, utilizandose o metodo do “check-list”. Os resultados por meio do metodo do “check-list” possibilitaram identificar 49 impactos, sendo 36 negativos (73,47%) e 13 positivos (26,53%). A principal conclusao e a de que este estudo pode ser utilizado como referencial teorico para subsidiar o processo de licenciamento ambiental desse tipo de empreendimento.

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.

Estrutura do componente arbóreo de um trecho de Floresta Atlântica na Área de Proteção Ambiental da Serra da Capoeira Grande, Rio de Janeiro, RJ, Brasil

The Area de Protecao Ambiental Serra da Capoeira Grande is a 80 ha site and one of the last forest remnants in Rio de Janeiro municipality where Caesalpinia echinata Lam. (brazilwood) occurs naturally. Trees were sampled according to the point-centered-quarter method. The inclusion criteria was PBH ³ 15 cm and a total of 200 points were surveyed. 44 species were identified, belonging to 36 genera and 22 botanical families The families with the higher importance value indices (VI) were Solanaceae (34.1%), Leguminosae (Mimosoideae with 16.4%, Papilionoideae with 7.9% and Caesalpinioideae with 2.1%), Nyctaginaceae (13.0%), Anacardiaceae (6.5%) and Flacourtiaceae (6.1%). The species with greater number of individuals were the same with higher VI. They are: Metternichia princeps Mik. with 40.4% of the individuals and 33.7% of the total VI, Pseudopiptadenia contorta G.P. Lewis & M.P. Lima (9.3 and 12.6%), Guapira hirsuta (Choisy) Lundell (7.5 and 7.8%), Astronium fraxinifolium Schott ex Spreng. (5.6 and 5.7%). Caesalpinia echinata Lam. followed with 2.4% of the individuals and 2.1% of the total VI. Trunk diameters of the individuals are concentred in the smallest classes diameter distribution of the most important species sampled indicate abundant regeneration.

Diagnóstico do uso do fogo no entorno do Parque Estadual da Serra do Brigadeiro (PESB), MG

The use of fire slash and Burn is a common alternative practice in the rural area, seen by many farmers as an efficient technique for various purposes. However, this technique should be carefully employed so as not to cause environmental disasters, such as forest fires. The objective of this work is to make a diagnosis of the use of fire by farmers nearby the Parque Estadual da Serra do Brigadeiro (PESB), in Minas Gerais and verify their perception of forest fire. The use of fire is still a common practice among farmers since it is economically viable and presents fast results. However, there is a consensus concerning its harmful effects on the soil, human life and the environment.