238 resultados para 770700 Forest and Wooded Lands
Resumo:
In this paper we present an optimization of the Optimum-Path Forest classifier training procedure, which is based on a theoretical relationship between minimum spanning forest and optimum-path forest for a specific path-cost function. Experiments on public datasets have shown that the proposed approach can obtain similar accuracy to the traditional one but with faster data training. © 2012 ICPR Org Committee.
Resumo:
Many species of tropical amphibians are restricted to very small ranges, and this microendemism coupled with ongoing habitat loss and susceptibility to emerging pathogens imperils the long-term persistence of these species. Incomplete taxonomic and distributional knowledge may obscure conservation assessment, particularly in putatively widespread species that are typically considered to be of Least Concern in Red List assessments, but that in fact may constitute complexes of partly microendemic species. Such is the case in the Steindachner's Robber Frog, Ischnocnema guentheri which, together with the recently recognized Ischnocnema henselii, is thought to occupy most of the Brazilian Atlantic Forest. To test whether these taxa may constitute a species complex of range-restricted and thus potentially threatened species, we analyzed 160 samples of I. guentheri and/or I. henselii for two molecular markers, 16S rRNA (16S) and recombination activation gene 1 (RAG1). To verify the monophyly of the complex, closely related species were also included in the 16S analysis. Congruent evidence from the molecular data and from analyses of advertisement calls support the existence of six distinct species within the complex: I. guentheri and I. henselii as well as four candidate new species. The lineages are distributed as a mosaic in the Atlantic Forest and are sympatric at some localities without indication of admixture. Their phylogeographical pattern partially agrees with paleo-models for the Atlantic Forest, but also suggests the existence of micro-refugia in less stable areas. I. guentheri, previously considered to be widespread, was found only in its type locality, a reserve within the urban area of Rio de Janeiro city. Although none of the species studied appears highly threatened with extinction, we recommend their IUCN threat status to be re-evaluated carefully for the next comprehensive update of the Red List of Brazil's amphibians. © 2013 Springer Science+Business Media Dordrecht.
Resumo:
The recently described taxon Drymoreomys albimaculatus is endemic to the Brazilian Atlantic Forest and its biology and genetics are still poorly known. Herein, we present, for the first time, the karyotype of the species using classical and molecular cytogenetics, which showed 2n=62, FN=62, and interstitial telomeric signals at the sex chromosomes. Nuclear and mitochondrial DNA sequences from the two karyotyped individuals verify the taxonomic identity as the recently described D. albimaculatus and confirm the relationship of the species with other Oryzomyini. Additionally, external morphological information is provided. © Elkin Y. Suárez-Villota et al.
Resumo:
Pós-graduação em Geografia - IGCE
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Pós-graduação em Agronomia (Energia na Agricultura) - FCA
Resumo:
A região onde está inserida a área de estudo, tem sofrido explorações predatórias e má utilização do solo. Áreas antes ocupadas por cerrados, campos sujo e limpo foram substituídas pelos reflorestamentos com eucalipto, devido aos incentivos fiscais e a instalação de companhias reflorestadoras na região, pelo baixo valor das terras e baixa fertilidade do solo; mas com um grande potencial para o desenvolvimento de essências florestais. O presente trabalho visou a elaboração do Diagnóstico Físico Conservacionista da bacia do rio Capivara - Botucatu (SP), baseada no parâmetro ambiental “Coeficiente de Rugosidade”, tendo-se por unidade de estudo 10 microbacias. Os resultados obtidos com a metodologia utilizada, no estudo da bacia do rio Capivara - Botucatu (SP), para o diagnóstico físico conservacionista permitiram mostrar que o grau de deterioração físico ambiental para a bacia foi 44,34%, muito acima do limite de 10% aceitável. O alto valor do grau de deterioração, provavelmente, foi devido ao mau uso da terra que vem provocando erosões, assoreamentos de reservatórios e cursos d’águas. O parâmetro ambiental médio “coeficiente de rugosidade” para as dez microbacias do rio Capivara, permitiu classificá-las para utilização com agricultura e urbanização, pecuária e reflorestamento; ou seja, indicou que a vocação principal desta é para uso com pecuária (Classe B); as classes de declive de 0 a 12% (Classe III) e de 12 a 20% (Classe IV), respectivamente, predominaram em 62,95% e 27,00% da área total das microbacias estudadas, ocorrendo em na sua maior parte nas unidades de solo LVA (46,56%) e RQ (19,86%). A predominância de florestas, capoeiras e pastagens nas microbacias, provavelmente é reflexo da predominância de solos de baixa fertilidade. - As imagens do Sensor TM do LANDSAT 5, permitiram o mapeamento do uso da terra da bacia de maneira rápida, que segundo o índice Kappa foi de boa qualidade (0,45), além de fornecer um banco de dados para futuros planejamentos nessa área. O SIG - IDRISI permitiu constatar através de seus diferentes módulos para georreferenciamento, classificação digital do uso da terra e modelo matemático, as áreas de uso da terra com rapidez. Os parâmetros, coeficientes de forma e circularidade mostraram que as microbacias apresentam baixo perigo de enchentes devido ao seu formato, bem como, o coeficiente de rugosidade permitiu classificar as microbacias 1, 2, 3, 4 e 8 com vocação para agricultura; as 6 e 7 para pecuária; a 5 para pecuária e reflorestamento e as 9 e 10 para floresta e reflorestamento.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Upa Kimsey is a poorly known genus of Tiphiidae with seven species. This genus has records in forest areas and in this paper we present new records to four species. All specimens were collected by malaise traps in four areas of Atlantic Rain Forest and three of Atlantic Semi-deciduous forest, mainly from high and mid-elevations. The new records indicate that species of Upa are not as rare as others genera of Tiphiidae, which are virtually unknown in many Neotropical regions.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Climate change has significantly influenced vegetation dynamics on the Tibetan Plateau (TP). Past research mainly focused on vegetation responses to temperature variation and water stress, but the influence of sunshine duration on NDVI and vegetation phenology on the TP is not well understood. In this study, NDVI time series from 1982-2008 were used to retrieve spatiotemporal vegetation dynamics on the TP. Empirical orthogonal function (EOF) analysis was conducted to understand the spatiotemporal variations of NDVI. The Start of Season (SOS) was estimated from NDVI time series with a local threshold method. The first EOF, accounting for 35.1% of NDVI variations on the TP, indicates that NDVI variations are larger in areas with shorter sunshine duration. The needle-leaved forest and shrub in the southeastern TP are more sensitive to sunshine duration anomalies (p < 0.01) than broad-leaved forest, steppe, and meadow due to spatial and altitudinal distribution of sunshine duration and vegetation types. The decrease in sunshine duration for the growing season on the TP has resulted in a decreased NDVI trend in some areas of southeastern TP (p ranging from 0.32-0.05 with threshold ranging from 0.05 to 0.25) in spite of the overall NDVI increase. SOS dynamics in most parts of the TP were mainly related to temperature variability, with precipitation and sunshine duration playing a role in a few regions. This study enhances our understanding of vegetation responses to climatic change on the TP.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)