Navegando por Assunto "Agricultura mecanizada"

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Acesso aberto (Open Access)
Análise da dinâmica da transição do regime de fogo na Amazônia brasileira
(Universidade Federal do Pará, 2023-06-21) TAVARES, Paulo Amador; FERREIRA, Joice Nunes; http://lattes.cnpq.br/1679725851734904; BARLOW, Bernard Josiah; http://lattes.cnpq.br/8559847571278134
The Amazon biome has undergone significant changes in land use and land cover, and it is also being affected by global climate change. Consequently, the fire occurrence has become more frequent in the Amazon. Therefore, it is important to understand how the fire regime in this region occurs and its interactions with land use and climate. For these reasons, this study analyses the fire transition in the Brazilian Amazon. In Chapter 1, we investigated the temporal fire transition in the Brazilian Amazon, considering changes in land use and forest cover. We collected annual data on fire occurrence, forest cover, deforestation rates, and soybean cultivation areas. Generalized linear mixed models and linear models were used to analyse the data and identify the key factors influencing this transition. We found that there is a fire transition process in the forest, and a quadratic model provided a better prediction of fire occurrence behaviour. Furthermore, the peak of fire occurrence is shifting towards more forested landscapes over time. Deforestation rates and the expansion of cultivation areas were found to be related to this transition, with deforestation having a greater impact on fire occurrence and cultivation expansion being more relevant in predicting the transition to more forested areas. In Chapter 2, we investigated the fire transition in forest landscapes of the Brazilian Amazon, aiming to understand how this transition occurs and which variables best explain the process. We used Latent Trajectory Analysis (LTA) and generalized linear mixed models to identify latent trajectories representing different patterns of land use over time. Two main latent trajectories were identified: the "Consolidated" trajectory, characterized by a longer history of deforestation, and the "Transition" trajectory, characterized by a more recent land occupation pattern. Forest cover and deforestation were the main predictors of forest fires in both trajectories, followed by water deficit. Mechanized agriculture did not show significant influence on either trajectory. An increase in burned forest areas was observed from 2015 onwards in both trajectories. Overall, these findings highlight the importance of the fire transition in the Brazilian Amazon and its relationship with land use changes and forest cover. They underscore the need to develop public policies that strengthen forest cover through initiatives like forest restoration and reduce deforestation in the Amazon region to ensure biodiversity conservation and carbon stocks.
Acesso aberto (Open Access)
Análise espacial das mudanças na cobertura e uso da terra em Santarém e Belterra, Pará, Brasil
(Universidade Federal do Pará, 2008) CASTRO, Williams Martins; VENTURIERI, Adriano; http://lattes.cnpq.br/8968863324073508; BATISTELLA, Mateus; http://lattes.cnpq.br/1337579164863601
Through a case study, this work tests how the delimitation of the study area may influence the results of multiscale analyses in spatial processes of land-use and landcover change in the Amazon. Within the municipal limits of Santarém and Belterra in western Pará State, three levels of analysis were defined. The first level encompasses a rectangular region that was arbitrarily defined as the Santarém subregion. The second level, which encompasses part of the first level, corresponds to an established agricultural settlement, defined by the set of limits of property lots designed by INCRA in the 1970’s. The third level corresponds to the zones of influence of four different roads located within the established agricultural settlement, subdivided into sub areas North and South, comprising a total of eight sub areas within the second level of delimitation. For each level of analysis, landscape metrics were calculated based on land-use and land-cover thematic maps for 1986, 1997, and 2005, also analyzed with basis on field surveys. The results show that the peculiarities of the occupation dynamics in each level allow for a better identification of patterns and processes revealed by the landscape structure. In particular, it is clear there is a continuation of processes of landscape fragmentation and expansion of intensive agriculture at different rates in distinct portions of the study area. The results obtained for the three levels of analysis are complementary, allowing for a better understanding of land-use and land-cover changes as well as their driving forces.