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The Caatinga is an important ecosystem in the semi-arid region of northeast Brazil and a natural laboratory for the study of plant adaptation to seasonal water stress or prolonged droughts. The soil water availability for plants depends on plant root depth and soil properties. Here, we combined for the first time the remote sensing classification of Caatinga physiognomies with soil information derived from geostatistical analysis to relate vegetation distribution with physico-chemical attributes of soils. We evaluated the potential of multi-temporal data acquired by the MultiSpectral Instrument (MSI)/Sentinel-2 for Random Forest (RF) classification of seven physiognomies. In addition, we analyzed the contribution of airborne LiDAR metrics to improve classification accuracy compared to six vegetation indices (VIs) and 10 reflectance bands from the MSI instrument. Using a detailed soil survey, the spatial distribution of the vegetation physiognomies mapped by RF was associated with the variability of 20 physico-chemical attributes of 75 soil profiles submitted to principal components analysis (PCA) and ordinary kriging. The results showed gains in overall classification accuracy with use of the multi-temporal data over the mono-temporal observations. Gains in classification of arboreous Caatinga were also observed after the insertion of LiDAR metrics in the analysis, especially the percentage of vegetation cover with height greater than 5 m, the terrain elevation and the standard deviation of vegetation height. Overall, the most important metrics for classification were the VIs, especially the Enhanced Vegetation Index (EVI), Normalized Difference Infrared Index (NDII-1), Optimized Soil-Adjusted Vegetation Index (OSAVI) and the Normalized Difference Vegetation Index (NDVI). The most important MSI/Sentinel-2 bands were positioned in the red-edge spectral interval. From PCA, soil attributes responsible for most of the data variance were related to soil fertility, soil depth and rock fragments in the surface horizon. The amounts of gravels and pebbles were factors of physiognomic variability with shrub and sub-shrub Caatinga occurring preferentially over shallow and stony soils. By contrast, arboreous Caatinga occurred over soils with total profile depth greater than 1 m. Finally, areas of sub-shrub Caatinga had greater values of cation exchange capacity (CEC) and water retention at field capacity than areas of arboreous Caatinga. The differences were statistically significant at 95% confidence level, as indicated by Mann-Whitney U tests.

Drylands are predicted to become more arid and saline due to increasing global temperature and drought. Although species from the Caatinga, a Brazilian tropical dry forest, are tolerant to these conditions, the capacity for germination to withstand extreme soil temperature and water deficit associated with climate change remains to be quantified. We aimed to evaluate how germination will be affected under future climate change scenarios of limited water and increased temperature. Seeds of three species were germinated at different temperatures and osmotic potentials. Thermal time and hydrotime model parameters were established and thresholds for germination calculated. Germination performance in 2055 was predicted, by combining temperature and osmotic/salt stress thresholds, considering soil temperature and moisture following rainfall events. The most pessimistic climate scenario predicts an increase of 3.9 °C in soil temperature and 30% decrease in rainfall. Under this scenario, soil temperature is never lower than the minimum and seldomly higher than maximum temperature thresholds for germination. As long as the soil moisture (0.139 cm3 cm3) requirements are met, germination can be achieved in 1 day. According to the base water potential and soil characteristics, the minimum weekly rainfall for germination is estimated to be 17.5 mm. Currently, the required minimum rainfall occurs in 14 weeks of the year but will be reduced to 4 weeks by 2055. This may not be sufficient for seedling recruitment of some species in the natural environment. Thus, in future climate scenarios, rainfall rather than temperature will be extremely limiting for seed germination. Made available in DSpace on 2020-02-21T18:10:31Z (GMT). No. of bitstreams: 1 Rainfallnotsoiltemperaturewilllimittheseedgerminationofdry2020.pdf: 3202683 bytes, checksum: 1a6594dd57f074a3945a09b035657ac6 (MD5) Previous issue date: 2020

Analises uni e multivariada foram utilizadas para a construcao do Indice de Priorizacao Tecnologica (IPT) visando a geoespacializacao de tecnologias de convivencia com aridez, para 38 comunidades quilombolas do Estado da Paraiba. As localidades foram definidas em funcao do universo das familias recenseadas in loco, sendo a unica fonte de referencia para o conhecimento das atividades socioeconomicas e ecologicas. A geoespacializacao tecnologica por comunidade foi realizada atraves do cruzamento de dados e informacoes espaciais em seus recortes territoriais internos no Sistema de Informacao Geografica. Os resultados indicaram a importância dos indicadores da matriz ambiental, na percepcao da vulnerabilidade socioeconomica e ecologica das comunidades quilombolas, o que evidencia a necessidade premente de se priorizar as tecnologias produtivas por ocasiao da implementacao de politicas publicas local. A pesquisa comprovou que as comunidades localizadas nos setores censitarios da Zona Rural, sao mais vulneraveis que as de Area Urbanizada de cidade ou vila. Independentemente da situacao do setor censitario as comunidades com indicadores favoraveis ao abastecimento de agua de uso domestico, solos e clima sem maiores restricoes aos sistemas produtivos, sao as menos vulneraveis, muito embora, nao as isente da priorizacao tecnologica, uma vez que, o indicador de pobreza e altamente significativo. Nas 38 comunidades estudadas identificou-se a necessidade de politicas publicas voltadas para o desenvolvimento sustentavel local que promovam a seguranca hidrica e alimentar, atraves de incentivo a agricultura familiar, diminuindo a dependencia de programas sociais. A B S T R A C T The technologies geospatialization of coexistence with aridity at maroon communities of the State of Paraiba was used to construct the Technological Prioritization Index. Locations were defined on basis of the households surveyed, as the only source of reference for knowledge of socioeconomic and ecological activities. Technological geospatialization by the community was carried out by crossing data and spatial information in its internal territorial clippings in Geographic Information System. The results indicated the importance of the environmental matrix indicators, in the perception of socio-economic and ecological vulnerability of maroon communities, which highlights the urgent need to prioritize productive technologies during the implementation of local public policies. Their research shows that communities located in census tracts in the rural zone, are more vulnerable than those of city or town of urbanized area. Regardless of the situation, the census tract communities with good indicators of household water supply, soil and climate without major restrictions on production systems are less vulnerable, though, not exempt from technological prioritization, since the indicator poverty is highly significant. In the 38 communities studied identified the need for public policies for local sustainable development that promote water and food security by encouraging family farming, reducing dependency on social programs. Keywords : quilombo community, public policy, geospatialization, technological diffusion.

O estudo teve como objetivo a construcao do Indice de Priorizacao Tecnologica (IPTe_Qsc), que possibilitou a geoespacializacao das tecnologias de Convivencia com o Semiarido para 38 comunidades quilombolas do Estado da Paraiba. O algoritmo estatistico associado ao Sistema de Informacao Geografica, por setor censitario, permitiu definir as prioridades tecnologicas socioambientais fundamental, primaria, secundaria e terciaria para esta populacao. A pesquisa comprovou que as comunidades localizadas nos setores censitarios da Zona Rural, sao as mais vulneraveis a priorizacao tecnologica que as de Area Urbanizada de cidade ou vila. A Comunidade Quilombola de Vila Teimosa, pertencente ao municipio de Livramento foi considerada a mais vulneravel. O IPTe_Qsc sugeriu prioriza-la com: agricultura irrigada, areas de preservacao e/ou conservacao ambiental, construcao de barreiros para uso com irrigacao de salvacao e/ou pequenas barragens de terra, exploracao das terras agricultaveis com tecnicas de captacao de agua de chuva in situ e turismo. As demais comunidades foram agrupadas em classes de vulnerabilidade: alta (3), media (21) e baixa (13), seguindo-se tecnicas, metodos e procedimentos similares.

Na regiao Semiarida do Estado de Pernambuco existe grande diversidade na paisagem natural, onde a vegetacao, os solos e o clima geram uma multiplicidade de situacoes que concorrem para formacao de diferentes ecossistemas e habitats com grande potencial ecologico e ambiental. Nesta regiao, a vegetacao e caracterizada por diferentes fisionomias, variando de areas com formacoes arbustivas, com cobertura do solo muito escassa e quase ausente, a formacoes arboreas com niveis de cobertura bastante densas. De modo analogo, nesta regiao ocorre uma grande variedade de solos, que por suas caracteristicas, manejo e situacao no relevo podem potencializar os processos erosivos, determinantes no desencadeamento da desertificacao. Considerando as interrelacoes destas duas variaveis ambientais, este trabalho tem o objetivo de realizar um diagnostico das areas susceptiveis a desertificacao da Regiao de Desenvolvimento Sertao do Sao Francisco - RDSF, tendo como base o cruzamento das informacoes da cobertura vegetal natural e das classes de solos. Para tanto, foram utilizados o recorte do mapeamento da cobertura vegetal e uso do solo e o recorte do mapeamento de solos da RDSF. Foram estabelecidos criterios para susceptibilidade da cobertura vegetal, assim como para as classes de solos presentes na area. Executou-se a interseccao destas duas bases de informacao para o perfil da sensibilidade a desertificacao. Os resultados mostram que a RDSF tem os seguintes valores das areas em processos de desertificacao: 1,77% na classe ausente ou fraca; 74,74% na classe moderada; 0,35% na classe acentuada e 23,14% na classe severa. Deste modo, observa-se que aproximadamente 98% da RDSF encontram-se na situacao de sensibilidade a desertificacao em que predominam as classes de Moderada a Severa. 800x600 Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} In the semiarid region of the state of Pernambuco there are plenty of biophysics where vegetation , climate, soils, and the various faces and the relationships and processes that take place among them generate the formation of different ecosystems and habitats with great potential ecological and environmental . There are a range of vegetation types, ranging from shrubby coverage areas up to very sparse and mostly absent vegetation areas, which demonstrated high desertification process occurring . Similarly, a variety of soils that is in the region along with vegetation makes this a region of great variation from the viewpoint of environmental supply . This article deals with the realization of a diagnosis of environmental sensitivity to desertification of Sao Francisco Development Region seeking spatialize the different situations in which the environment fulfills a greater or lesser extent , its role as provider of environmental services . For this, we used the cutting mapping of existing vegetation and soil mapping of the state and the established criteria , as well as edaphic vegetation cover , featuring the susceptibility to degradation and performed the intersection of these two bases of information to profile the sensitivity to desertification . The results show that Sao Francisco Development Region has the following values of areas undergoing desertification : 1.77% in weak class ; 74.74 % in the moderate class ; 0.35% in sharp class, and 23.14% in severe class. Keywords : desertification, Sao Francisco, Semi-arid region, soils.

A paisagem do Submedio do Vale do Sao Francisco tem, ao longo dos anos, passado por constantes alteracoes devido as atividades antropicas, onde a vegetacao original da Caatinga hiperxerofila foi gradativamente sendo eliminada pelo processo extrativista e parte cedendo espaco ao processo de uso agricola. Dessa maneira, muitas areas sem aptidao ou de aptidao restrita para o uso agricola sao cultivadas, aumentando o risco de degradacao pelo efeito da erosao que atinge, inclusive, a vegetacao ciliar. A recuperacao desta vegetacao e um grande desafio, haja vista as dificuldades de conciliar a garantia do sustento das familias ribeirinhas e de torna-las parte integrante deste processo de reconstituicarrro da mata ciliar. O objetivo geral deste estudo foi avaliar o uso e ocupacao dos solos e integrar e fortalecer estudos ambientais para a preservacao da vegetacao ciliar. Tambem visou contribuir com a recuperacao de areas degradadas, florestamento, reflorestamento e ecossistemas agrossilviculturais, encaminhados ao Programa de Revitalizacao da Bacia do Rio Sao Francisco, para os municipios de Curaca no Estado da Bahia. Inicialmente foram realizados estudos basicos que indicaram o municipio de Curaca apresentou a maior percentagem de areas degradadas (13,21%). As areas com vegetacao de Caatinga arbustiva se destacam na maior parte do municipio estudado. De um modo geral, pode-se dizer que no municipio, praticamente toda a vegetacao ciliar foi retirada e que a grande maioria dos solos relacionados aos sedimentos fluviais encontra-se em via ou com elevado grau de salinizacao e degradacao. Palavras – Chave: Zona riparia ; Estudos edafo-ambientais ; Recuperacao de areas degradadas . Current Use and Quantification of Degraded Areas at the Right Riverside of Sao Francisco River at Curaca Municipality (Bahia, Brazil) ABSTRACT Over the years the landscape of the of the lower half of Sao Francisco Valley has undergone constant change due to anthropogenic activities where the original hyperxerophilous Caatinga vegetation has been gradually eliminated by the extractivist process and partially given over to space for agricultural use. In this way several areas without suitability or of limited suitability for agricultural use have been cultivated, increasing the risk of degradation by the effect of erosion, which affects the vegetation, including the riparian vegetation. The recuperation of this vegetation has been a great challenge in face of the difficulties to conciliate the guarantee of the livelihood of riverside families and turning them into an integral part of this reconstitution process of the riparian forest. The general objective of this study was to evaluate the use and occupation of the soils and to integrate and strengthen environmental studies for the preservation of the riparian vegetation. It also intended to contribute to the recuperation of degraded areas, forestation, reforestation and agroforestry ecosystems directed towards the Revitalization Program of the Sao Francisco River Basin at the municipalities of Curaca, in the State of Bahia, Brazil. Initially, basic studies indicated that the municipality of Curaca presented the largest proportional percentage of degraded areas studied (13,21%). The areas with shrub Caatinga vegetation cover the major part of the municipality which was studied. In a general, it can be said that in the municipality, practically the whole riparian vegetation has been removed and the majority of the soils related to fluvial sediments are, either in process of salinity and degradation, or present an elevated degree of both. Keywords: Riparian zone, edapho-environmental studies, Recuperation of degraded areas.