Desertification is one of the major environmental problems that humanity faces today, since it reduces the availability of ecosystem services, increases food insecurity and poverty, and affects the wellbeing of societies. The analysis of the process is extremely complex, since the phenomenon takes place at different temporal and spatial scales, influenced by different factors. It is widely recognized that land use/land cover change (LULC) is one of the main drivers of desertification since environmental degradation is always triggers by the removal of natural vegetation cover. In this study, a LULC change model was calibrated and validated using climate model simulations, demographic data and land susceptibility maps for the historical period 2000-2010. Then, desertification susceptibility of the Northeast of Brazil were estimated by integrating LULC trajectories with three different downscaled climate change scenarios and projection of population growth for the period 2015-2025, 2025-2035, and 2035-2045 for the emission scenarios RCP4.5 and RCP8.5. Results indicated that, between 2010 and 2035-2045, areas of moderate susceptibility decreased 10.34%, while areas of high susceptibility increased 12.28% in the case of the RCP4.5. For the RCP8.5 scenario, those numbers are −16.85% for moderate susceptibility, and +19.62% for high susceptibility. Among all indicators included in the analysis, land management was the main driver of desertification susceptibility, which indicates that mitigation and adaptation strategies for the region should pursue sustainable land use policies.

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The Paraíba Valley in São Paulo, Brazil, is marked by great transformations. The Brazilian economic cycles changed this region and transformed it into a great mosaic of pastures, forest fragments, and urban areas. Temporal studies on land use and cover have given information on these changes and evaluated their impacts. The conversion of extensive areas of the Atlantic Forest into eucalyptus crops is noticeable; this monoculture developed greatly and is expanding steadily in this valley. This land-use conversion has consequences, such as forest fragmentation, and losses in biodiversity, and water and soil quality. Developing future scenarios (2010 to 2050) that simulate changes in land use and cover is essential for an efficient and sustainable public management. Thus, the objective of the present study was to develop future scenarios while considering different social, economic, and environmental issues, based on analyses of the dynamics of forestry expansion in the Paraíba Valley in São Paulo, Brazil. The scenarios developed were classified as Trend, maintaining the same change patterns of the observed period (2000 to 2005); Optimistic, decreasing conversion rates of natural vegetation into forestry and pasture areas; and Pessimist, increasing deforestation rates and increasing eucalyptus and pasture areas. Future scenarios for the period of 2010 to 2050 were developed in the Dinamica Ego software, and it proved to be effective, presenting trends and predispositions of changes in land use. These results can be used for environmental planning focused on sustainability, better management of natural resources, and development of economic activities.

The growth of forestry, mainly eucalyptus, driven by the industry demand for pulp and paper, has significantly changed the landscape around the globe. The so-called agroforestry systems have the advantage of reducing pressure on native forests in different regions of the world. However, this practice can bring impacts to the environment, and contribute to the intensification of agrarian conflicts. The aim of this research is to expose the intrinsic relationship between the dynamic of the forestry expansion in the São Paulo area of the Paraíba Valley, one of the largest agro-producing regions in Brazil, and the regional socioeconomical structure. These results may support further studies in order to define the possibilities and limitations of this type of economic use. With the use of remote sensing techniques using Landsat satellite images, we measured the areas planted with eucalyptus in the study area (Paraíba Valley) between 1986 and 2010. This area was pioneer in this kind of forestry and still is one of the largest producers while still expanding. In the period studied, among positive and negative variations, the planted area increased from approximately 55,000 ha in 1986 to more than 60,000 ha in 2010. This change was driven by industrial demand, as shown by the IBGE data.

Commission VIII, WG VIII/8 KEY WORDS: forestry, remote sensing, Rain Forest, multitemporal assessment ABSTRACT:In this work, we analyze the expansion of forestry activities with Eucalyptus in the Paraiba do Sul basin, region located in Sao Paulo, Brazil, from 1986 to 2010. In this region is situated the most important and largest extension of reminiscent of Mata Atlântica Biome reminiscent. This biome has been one the most exploited Brazilian biome since 1500, when Brazilian colonization begun. To achieve this goal, we use the GIS "SPRING" and images from Landsat 5 Satellite, TM sensor from 1986, 1990, 1995, 2000, 2005 and 2010, distributed by the Brazilian National Institute for Space Research -INPE. The non-supervised-classification was applied to images in order to produce land use and land cover maps. After that, we intersect each classification for each date with the precedent date, so we can analyze the paths of each land use change, focusing forestry expansion in native's Mata Atlântica areas. The results show that eucalyptus plantations in the region have expanded mostly over fragments of Mata Atlântica. About 99.389 hectares of Mata Atlântica were transformed into forestry in 25 years, an average rate of 4000 ha per year. Clear-cut was largest between 1990 and 1995, when 22810 hectares of rain forest were cut, and between 1995 and 2000, when 21430 hectares were cut.