Navegando por Orientadores "FERREIRA, Leandro Valle"

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Acesso aberto (Open Access)
Análise do desflorestamento nos municípios do estado do Pará entre os anos de 2000 a 2009 e a importância das áreas protegidas na contenção do desflorestamento
(Universidade Federal do Pará, 2012-10-26) MONTEIRO, Elivelton Ferreira; FERREIRA, Leandro Valle; http://lattes.cnpq.br/8103998556619871
This work aims to demonstrate the process of deforestation in the municipalities of Pará state and the importance of protected areas and indigenous territories in curbing the same. The study area constitutes the state of Para, which has an area of 1,247,690 km², and its 143 municipalities. Data were collected at INPE Monitoring Project in the Brazilian Amazon Forest by Satellite - PRODES. The processing and analysis of vector data was performed using ArcView 3.3 software. Deforestation accumulated by the year 2009, the state of Pará is about 19.6%. Since the remaining forest cover is about 65%. Deforestation in Pará presents itself differently among the twelve regions of integration, deforestation is concentrated mainly in northeastern and southeastern regions of the state, and also along major highways. The proportion of deforestation is varied between the municipalities of Pará Of the 143 municipalities, 31 are between 0 and 15.5% of their lands deforested, represents 21.7% of the total, 16 municipalities (11, 2%) are entre15, 5% and 35.5%, 32 municipalities (22.4%) are between 35.5% and 55.5%, 24 municipalities (11.9%) are between 55.5 and 75, 5% and 40 municipalities are between 75.5% and 95.5% of deforestation their territories, representing 28%. Of the 143 municipalities, 24 are between 0 and 15.5% of their lands deforested, represents 16.8% of the total, 22 municipalities (15.4%) are entre15, 5% and 35.5%, 27 municipalities (18.9%) are between 35.5% and 55.5%, 27 municipalities (18.9%) are between 55.5 and 75.5%, and 43 counties are between 75.5% and 95.5 % of deforested their territories, which represents 30.1%. In the state of Pará today there are 117 protected areas, being a Military Area, occupying 1.7%, 71 Conservation Units (14 Full Protection and Sustainable Use of 57) and 45 indigenous lands, occupying 29.03% and 22 9%, respectively, totaling 53.6% of the total state. The proportion of protected areas varies greatly among municipalities in the state of Pará Of the 143 cities, 16 shows from 55.5% to 93.6% of their territory within protected areas, representing 11.2% of the total, 12 municipalities (8.4%) had between 35.5% to 55.5%, 23 municipalities (16.1%) had between 15.5% - 35.5%, 15 municipalities (10.5%) are between 5, 5% - 16.5%, and the vast majority, 77 municipalities are between 0 and 5.5% of their territory within protected areas, representing 53.8%. There was a significant and negative correlation between the proportion of deforestation and the proportion of protected areas in Pará (r =-0.66). The municipalities that have the highest percentage of protected areas are therefore those with the lowest proportion of deforested their territories. The analysis of deforestation in the inner and outer municipalities of Pará showed the large proportion of vegetation within these areas compared to its exterior.
Acesso aberto (Open Access)
Efeito da fragmentação e o isolamento da paisagem na riqueza e composição de espécies de lagartos no Reservatório de Tucuruí, Pará
(Universidade Federal do Pará, 2008-08-29) LIMA, Crisalda de Jesus dos Santos; FERREIRA, Leandro Valle; http://lattes.cnpq.br/8103998556619871
Appear of many studies published in tropical regions showing the effect on forest fragmentation and landscape isolation in biotic communities most studies have been made in continental regions. The impact of fragmentation and isolation of landscape in hydroelectric artificial reservoir are still poorly studies in the Amazonian. This study was done in island forest remain fragments created by the construction of the Tucurui Hydroelectric dam in the Para State, Brazil. The objectives of the study is to compare the islands on both sides of the reservoir in relation to the total size, total core area size, plot shape and degree of isolation to demonstrated the role of island to protected the local biota in landscape level and assess the species richness, abundance and species composition of the communities of lizard in the islands in local scale. At landscape level were chosen 199 islands in both margin of reservoir using satellite image of 2005. The total size of island varied from 3 to 1,768 hectares, being that 40% of island has less than 10 hectares in size. The islands have a significant loss of size, varying from 22% to 100% in relation to edge effects. There is no significant difference of the total size, total core area size and total edge of islands in relation to reservoir margins. However, the islands situated in the left margin of reservoir have high degree of isolation in compare to island from right margin. Most of the island analyzed in the Tucurui reservoir have small sizes, high loss of total area due to edge effects and irregular plot shape, all contributing. At local scale the lizard community was sampled in five field expedition carried out from January to July of 2005, using two methods of collect, transects and traps of interception and fall. We selected 12 islands based on total size, degree of isolation and position in relation to reservoir margin. We recorded 837 individuals of lizard distributed in 16 species. The most abundant species were Gonatodes humeralis and Coleodactylus amazonicus (Gekkonidae). The curve of total number of species in relation to field expedition reached the asymptote, showing that the five expeditions were sufficient to determine local species richness in the sampled island, corresponding to 84% of the total number of species determined by Jackknife 1 species richness estimator. There is significant difference in the species richness in relation to field expeditions, being highest species richness obtained from the third field expedition carried out from April to May of 2005. There is no significant difference in the species richness and number of individuals in relation to reservoir margins. There is significant and positive difference between the species richness in relation to size of island. There is no significant difference in the abundance of lizards in relation to size of island. There is significant difference in the species richness of lizards in relation to degrees of isolation of island, being the isolation lower in the more remote islands. However, the abundance of lizards in relation to degree of isolation of islands was not significant. There is no significant difference in the species richness in relation to open canopy and volume of litter. There is significant and positive difference between the species richness in relation to density of trunk falls and trees lives. There is no difference in the abundance of lizards in relation to forest structure parameters analyzed in the study. Finally there is no difference in the species composition of lizards in relation to reservoir margins, indicating that the Tocantins River in the sampled area analyzed in the study is not one important biogeography barrier to this group.
Acesso aberto (Open Access)
O efeito da fragmentação insular na paisagem e comunidade arbórea em ilhas na Amazônia
(Universidade Federal do Pará, 2013) BORGES, Cézar Augusto Reis da Fonseca; FERREIRA, Leandro Valle; http://lattes.cnpq.br/8103998556619871
The construction of hydroelectric plants has been a new vector of forest fragmentation on the globe, especially in the Amazon, which has several dams under construction currently planned beyond. The training provides hydroelectric reservoirs in fragmented landscapes, with the creation of artificial islands (fragments), which have the peculiarity of being surrounded by an array tougher for most species, different fragments of land, having a direct effect on reducing biodiversity. This study aimed to evaluate the insular landscape of Lake Tucuruí, by quantifying landscape structure, as a basis for conservation implications. Concomitantly, we assessed the effects of fragmentation on the island tree community, through the structure of the landscape and edge effects, both have been one of the most ecological processes impacting on biodiversity in fragmented landscapes. The results indicated the spatial arrangement may be an approach used for conservation mechanisms in dams, but should consider specific aspects of the islands. In turn, the vegetation is still not responding to the current landscape structure, being in a phase of extinction debt, and the edge effect the main factor for the formation of plant communities.
Acesso aberto (Open Access)
A efetividade das unidades de conservação e das terras indígenas na contenção do desflorestamento na Amazônia Legal
(Universidade Federal do Pará, 2010) NUNES, Tássia do Socorro Serra; FERREIRA, Leandro Valle; http://lattes.cnpq.br/8103998556619871
Was investigated the effectiveness of the Conservation Units of Integral Protection, Conservation Units of Sustainable Use and Indigenous Lands in the inhibition of deforestation in the Amazon. Data analysis was processed in GIS (Geographic Information System) in ArcGIS 9.3. The statistical model developed to test the effectiveness of Protected Areas was based on the difference between the observed deforestation in Protected Areas and deforestation in Protected Areas estimated from the surrounding five kilometers and ten kilometers of Protected Areas. It was found that in forest area by the year 2007, the Protected Areas occupy approximately 40% of the Amazon. Conservation Units of Integral Protection occupied 7.5% of the Amazon, Conservation Units of Sustainable Use occupied 11.2% of the Amazon and Indigenous Lands occupied 21% of the Amazon. Was a significant difference in the proportion of area occupied by the types of Protected Areas among the Amazonian states. It was noted also that the internal rate of deforestation in the Conservation Units of Integral Protection and in the Indigenous Lands was lower than in the Conservation Units of Sustainable Use. The internal rate of deforestation in the Protected Areas was much lower than the rate of deforestation is external to these areas in the states of Mato Grosso, Para and Rondonia. According to the statistical model of effectiveness, 62.3% of the Protected Areas studied were effective in containing the deforestation. This model is an important instrument to direct public policy planning for the conservation of the Amazon, because it indicates the protected areas most threatened by deforestation. It is essential to establish urgently the creation of more Protected Areas in the Amazon and the consolidation of existing protected areas, since it is not known how long these areas will be able to maintain without the minimum necessary for their support.
Acesso aberto (Open Access)
Indicadores ambientais para funcionalidade ecológica em florestas secundárias de diferentes idades na Amazônia Oriental
(Universidade Federal do Pará, 2016-06-17) MEDEIROS, Priscila Sanjuan de; FERREIRA, Leandro Valle; http://lattes.cnpq.br/8103998556619871
Currently secondary forests occupy about 25% of the Amazon region, and have received attention for ecosystemic services they provide. Beyond the role in carbon sequestration, soil protection and water sources, secondary forests can shelter an enormous diversity. However, public policies directed to the maintenance of the succession process these forests are required, so that they can contribute with maintenance of biodiversity and environmental services. The objective of this work was to evaluate the ecological functionality of secondary forests of different ages, using as indicators that successional dynamics vegetation, seed bank, soil macrofauna and arbuscular mycorrhizal fungi. The study was developed in areas of primary forest and secondary upland forest of different ages in Caxiuanã National Forest, in the state of Pará. We applied the Chronosequence method which is to the methodology most used for succession studies. 40 areas were selected, with an average size of 0.75 hectares, three areas of primary forest and 37 of secondary forest (capoeira). The time of abandonment these areas varies between 1 and 40 years and all have similar usage history. In each area it was implanted a permanent plot where vegetables individuals were sampled (understory and forest stratum) and where soil samples were taken to evaluate the seed bank and the density of arbuscular mycorrhizal fungi. In these plots was applied the methodology of Program "Tropical Soil Biology and Fertility" (TSBF) for the sampling of the soil macrofauna and earthworms. Six campaigns were conducted, three in the dry season and three in the rainy season. Were also collected soil moisture data, canopy opening, litter stock, amount of fine roots and soil physicochemical variables (K, P, Na, Ca, Mg, Al, N, pH, sand coarse sand fine , Silt and clay full). For a better compression of the relationships between biotic and abiotic variables data were analyzed and discussed in an approach continues and other categorical, classifying areas into four groups according to age of the secondary forest (stage 1-0 to 10 years; stage 2 – 11 to 25; stage 3 26 to 40; stage 4 primary forest). Vegetation variables and the life forms present in the seed bank showed strong relationship with the age of the secondary forest. The use of macrofauna as bioindicator demonstrated to be an excellent strategy for monitoring of secondary forests, enabling the conservation of these habitats and the correct management of their resources. Already the density and biomass of earthworms have low relationship with the successional process. The arbuscular mycorrhizal fungi showed up to be good indicators in the separation of primary and secondary forest. With this, we have environmental variables of vegetation, seed bank and soil macrofauna that have potential to be used in a quality index of ecosystemic functions in secondary upland forest.