Navegando por Assunto "Solo - Uso - Amazônia"

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Acesso aberto (Open Access)
O Lago Grande do Curuai: história fundiária, usos da terra e relações de poder numa área de transição várzea-terra firme na Amazônia
(Universidade Federal do Pará, 2016-12-07) FOLHES, Ricardo Theophilo; TOURNEAU, François-Michel Le; SANTOS JÚNIOR, Roberto Araújo de Oliveira; http://lattes.cnpq.br/9355107718329833
The aim of this study is to understand the role of the social and environmental order influenced the peopling, land appropriation and the seasonal use of natural resources between floodplains (várzea) and firm land (terra firme) ecosystems in the Brazilian Amazon. I follow an historical and ethnographical approach to examine how social practices and the local power relations influenced the interrelated dynamic between social life and water movements (floods and droughts). The study area is Lago Grande, located in the city of Santarem, Pará State bordering the towns of Óbidos and Juruti. The main question is to investigate if power relations among social groups established and inherited during the colonial living in Lago Grande region are still operating in current times, and how this situation affects the control of transhumance between várzea and terra firme ecosystems. I conclude that the Amazon floodplains are still controlled by local elites, represented by land and livestock owners. The local elite established their socio-political power during colonial times, dominating an increasing process of entering from várzea to terra firme areas (i.e. deforestation). Since 1950, the main economical activity responsible for the expansion of land use from várzea to terra firme was cattle raising through transhumance between both ecosystems. Transumance has received a specific attention in this study, for it is among the main factors encouraging the circulation of local population between várzea and terra firme environments. From 1970‘s, large farmers started the transhumance which was later followed by smaller farmers, and intensified through the 1990‘s. Cattle ranching builds on three local practices which promote transhumance: ―societies‖, ―permissions‖ and land rentals (arrendamentos). A joint analysis allowed me to demonstrate that ―societies‖ between large and small farmers sustain the cattle ranching growth. In 2005, an Agro-extractivist Settlement was created (PAE Lago Grande) to favor land distribution and better economical opportunities among local populations. Though, the territorial unit included terra firme but not the areas of the várzea ecosystem, vital for the local economy part of the year. Additionally, the PAE also did not alter the land tenure, keeping the same historically constructed power structures it aimed to deconstruct.
Acesso aberto (Open Access)
Mudanças de uso da terra em paisagens agrícolas com palma de óleo (Elaeis guineensis Jacq.) e implicações para a biodiversidade arbórea na Amazônia Oriental
(Universidade Federal do Pará, 2015-09-30) ALMEIDA, Arlete Silva de; VIEIRA, Ima Célia Guimarães; http://lattes.cnpq.br/3761418169454490
The expansion of oil palm in the Amazon is associated with a number of public policy, in the form of actions and programs and has provoked economic and ecological changes in the region and challenge the society to monitor and control the palm cultivation expansion on a large scale. The municipalities from the "Palm region" in Pará state, as Moju, intensified cultivation of this palm tree and suffered intense modifications in thier natural ecosystems. In Addition this new frontier of bioenergy challenged the paradigm of sustainability, with social and environmental conflicts and replacement of subsistence farming by the palm. Little is known about the consequences that a large-scale monoculture can cause in the amazonian environment. To follow this new productive dynamic with palm oil are required interdisciplinary studies that contribute to identify how environmental respond to changes associated to the new agricultural frontier with oil palm. In this context, the overall objective of this research is to analyze the changes, the conflicts and the trajectories of land uses, as well as the value of conservation of the biodiversity of the plantations of oil palm and other land uses predominate in eastern Pará. The work is organized into five chapters including the first one which introduce the subject of the thesis. The other four are guided by the following specificobjectives: a) analyze the land use conflicts in Moju county, Pará state, Brazil, within areas of permanent preservation -PPA, according with the Brazilian Forest Code of 2012; b) map and quantify the types of land cover and land use in 2013 in three areas (Ubá, Arauaí e Mamorana), where the implementation of oil palm cultivation is present; c) capture the space-time variability in the changes of trajectories in landscapes of 1991-2013 and identify the effect of changes of land use in the structure of the landscape; and d) investigate the variation in the carbon stock and species richness of trees in different land use and vegetation cover in the three studied areas. For the study of conflicts in APPs in Moju, were used 29 multispectral images of high resolutions by RapidEye satellite of 2010. The results show that the area destined legally for permanent preservation (APP) in Moju is 47,357.06 ha, representing 5.21% of the municipal area. The PPAs with natural vegetation represent 68.60% of the APPs of the municipal area, about 28% of the PPAs have use conflicting with predominance of pasture in 15.6%. Only 0.63% of APPs is occpupied by palm oil. The application of the new recomposition guidelines for APPs according to the new Forest Code will result in the loss of 60.69% of the APP-recovered areas in this municipality. The analysis of vegetation cover and land use in 2013 in the three selected areas (Ubá, Arauaí and Mamorana) was made by the method of decision tree in images of the satellite Landsat-8 year of 2013. The overall performance of the classification was 0.87% (index kappa). The results show greater extension of primary forests in Mamorana, area in the beginning of cultivating oil palm. Agriculture predominate in all areas analysed. For the analyses of trajectories changes of land uses and the effects on the landscape structure i the landscape we made classification using decision tree method in images of the satellite Landsat TM-5 for the years 1991, 1995, 2001, 2005 and 2010, and Landsat-8 for the year 2013, through the ImgToos programs, ENVI and ArcGIS. The landscape structure was carried out through the landscape metrics (PLAND, LPI, PD and PROX-MN) using the FRAGSTATS program. v. 3.3. The classification achieved overall performance of 0.87% for the kappa index. In the period 1991-2013 the conversion of primary forest to other uses occurred in a ratio of 47.82%, while the degraded forest (17%) and oil palm (11%) had the largest increase in occupancy in 2013. We emphasize that the transition of the primary forest to palm oil was 20% in the 22 years under study, which led to a PD (fragments density index) with considerable amounts, attaining a level from 0.3 to 4.5 (number of patches/ 100 ha). Such conversions define the fragmentation intensity of primary forest. The investigation about the biodiversity response and carbon stocks in different forest cover and land uses was made through a floristic inventory of trees greater than or equal to 2 cm DBH in plots ranging from 1, 500 and 2500 m2 on each forest cover/land use analyzed. Intheall 8.55 ha sampling were registered 5,770 individual trees, distributed in 425 species and 74 families. The primary forest presented carbon stock higher than 80 Mg/ha, while palm oil, pasture and secondary forest presented less than 50 Mg/ha, noting that the oil palm retains impoverished communities of trees, and its tree composition is poorer than the pasture, while the stock of carbon is higher. In this study, in 22 years of the analysis we observed that primary forests covers less than 30% of the landscape, a critical level for biodiversity conservation.
Acesso aberto (Open Access)
Recuperação natural da diversidade de espécies de plantas em florestas secundárias na Amazônia Oriental
(Universidade Federal do Pará, 2017-03-30) TAURINO, Tássia Cristina da Conceição Barros; FERREIRA, Joice Nunes; lattes.cnpq.br/1679725851734904
Secondary forests are increasing in area in the tropics, and in the Amazon alone they occupy 23% of deforested areas. These forests are repositories of biodiversity, playing an important role in ecosystem services, and contributing to the livelihoods of local populations. Natural regeneration is an important strategy for the recovery of native Brazilian vegetation, for example, the Forest Code, the National Plan for the Recovery of Native Vegetation (PLANAVEG in portuguese) and the international commitments of forest restoration undertaken by the country. This study describes the natural recovery of plant species diversity in secondary forests of different ages in the Southeast of Pará, Eastern Amazonia. A database of structural and floristic characteristics, collected in 2014 and 2015, was used for 20 fragments of secondary forest in the municipalities of Marabá, Parauapebas, Eldorado dos Carajás and Canaã dos Carajás. The vegetation sampling followed the methodology applied by the Sustainable Amazon Network. In each forest fragment, a transect of 10 x 250 m or 20 x 125 m (0.25 ha) was delimited, subdivided into 25 plots of 10 x 10 m, where the upper stratum (DAP ≥ 10 cm) was sampled. The lower stratum (DAP <10 cm) was sampled in five 5 x 20 m subplots nested in the transect. The phytosociological parameters were calculated using the Fitopac 2.1 software. The dominance pattern was evaluated through species ranking. The similarity among transects was evaluated using non-metric multidimensional scaling in the PCORd 5.15. The phytosociological parameters between two age classes were compared using Anova. Indicator Species Analysis (IndVal) was performed for each class using the R Program. We found 282 species, 61 families and 5509 individuals in the 20 study transects. The natural recovery of species diversity occurs rapidly in the first 10 years of ecological succession. But the recovery trajectory was not linear and was marked by a stabilization of the parameters of structure and diversity between 10 and 20 years. Species diversity was correlated with basal area, although the relationship was not linear. Regeneration was not accompanied by convergence of floristic composition between sites of similar age. However, the similarity in species composition was higher among the nearest sites, suggesting spatial autocorrelation resulting from biotic or environmental processes. The studied forests were separated into two age classes with some species, mainly of the family Fabaceae, indicating the sites in more advanced stages of regeneration. The recovery of plant diversity in the first 20 years of succession provides evidence of high forest resilience in the study region. The findings of this study on the natural regeneration potential of the forests in Southeastern Pará is important to guide the management and conservation strategies underway in the Amazon.