Bartolomeu Israel de Souza

Contribuição ao estudo da desertificação na Bacia do Taperoá

The phenomenon of desertification in the semi-arid region of Northeast Brazil is studied from the analysis of some variables representative of climate, vegetation, soils and some economic and social aspects in the Taperoa Basin in the State of Paraiba, Brazil. Annual rainfall data from 32 rain gauges was treated by temporal series analysis and a trend map was drawn. All the above listed variables were estimated for Sao Joao do Cariri and Cabaceiras districts. Results show a diferent mode of susceptibility to desertification for both districts, especifically, in the Sao Joao do Cariri district, all the variables treated in this study contributed to the occurrence of a desertification process including a negative trend in annual rainfall.

the Caatinga and desertification

High deforestation in the Caatinga Biome has been generating processes of desertification in several areas, directly altering the biota, the microclimate and the soils, being essential the development of research techniques able to incorporate information which identify the state of natural resources, pointing their relationships and some paths to be taken for an effective intervention which may generate the recovery and sustainable use of land in this environment. The MTLFC consists of a set of techniques used in Brazil for the first time to analyze areas subjected to desertification, presenting biogeographic, climatological, geomorphological and hydrological indicators. By applying the method in an area of the city of Sao Domingos do Cariri (PB), it has been identified a very low plant diversity (13 species and 489 individuals), dominance of a few species (5) and low abundance, with the largest number of individuals in tall shrub and shrub strata, caused by the excessive removal of vegetation, fires and continuous use by the goats. The Water Balance was negative so that it indicated that the vegetative activity depends on hidden precipitation. The soils have presented surface crust of an anthropic origin, making edaphic aridity even more pronounced, associated with low fertility levels, particularly potassium and organic matter.

Tropical forest refuge in peripheral soils of slags in Caatinga

The influence of environmental factors on the structure and composition of plant communities in the Caatinga is complex and poorly explored. Spatial variation of biodiversity in Caatinga is poorly know and strictly attributed to climatic conditions. We investigated the influence of slags on floristic composition and structure of a shrubby-arboreal community in one of the driest region in Brazil. Chemical and physical analyses of soils were performed in samples of seven plots from savannic formations and from forest formations. Vegetation was characterized floristically and structurally in all plots. Habitats were structurally distinct, and diversity differed between peripheral and non-peripheral areas of slags. Nine of the ninety-seven species identified are reported to (sub)humid biomes. Soils are dominantly shallow, eutrophic and sandy loam. However, soils in the periphery of slags are more developed once paludization, melanization and bioturbation were verified. Our results suggest that soil fertility did not influence vegetable cover in Caatinga. The cover of plant species considered exclusive of (sub)humid biomes in Brazil extends beyond highlands in the semiarid, associated with high soil organic carbon content and water retention capacity of more developed soils than the typical of the Caatinga.

BIOGEOGRAFIA: REFLEXÕES SOBRE TEMAS E CONCEITOS

Este artigo traz uma breve analise das producoes cientificas apresentadas no XI Encontro Nacional da Anpege de 2015. Pela primeira vez organizou-se um eixo com o titulo Biogeografia e Geoecologia da Paisagem, revelando que a pesquisa sobre a dimensao espacial da biodiversidade vem ampliando sua producao e espacos de divulgacao academica em eventos da Geografia. Destacam-se tambem as bases conceituais e metodologicas das pesquisas e a apropriacao de tecnologias de geoprocessamento nas analises biogeograficas. A paisagem e os geossistemas aparecem como conceitos estruturadores de variados metodos de estudo. Neste contexto apresenta-se uma caracterizacao do campo de conhecimento da Biogeografia na Geografia e algumas articulacoes conceituais com outros campos cientificos. Em seguida analisa-se a amostra de trabalhos que demonstram esses recortes tematicos e enfoques que atestam, particularmente, o dinamismo da disciplina na contemporaneidade. Por outro lado, percebe-se uma certa diluicao dos conteudos de estudos biogeograficos em varios temas da Geografa Fisica. Outro aspecto importante e o papel das abordagens espaciais e cartografcas, assim como aquelas que sugerem um novo foco geografico da conservacao da natureza. As analises confirmam a necessidade de uma sistematizacao, ainda que preservando a riqueza e diversidade de tendencias, pois ao que parece tem-se neste momento tangencias evidentes em varios campos disciplinares que sempre dialogaram com a biogeografia. Saberes de campos cientifcos, tais como: Botânica, Zoologia, Ecologia da Paisagem, entre outros, estao presentes nos estudos que objetivam de modo geral compreender a espacializacao dos seres vivos. Alem destes campos, que podem ser considerados externos ao campo especifico da Geografia para interpretacao biogeografica, conclui-se que e imprescindivel entrelacar e explorar o grande potencial da Geografia como um dos suportes fundamentais para o estudo de questoes ambientais, associadas principalmente com a Geografia da Conservacao.

Produção Agropecuária e Correlação com a Dinâmica Climática em Caicó-RN (Farming and Agricultural Production and Correlation with Climate Dynamics in Caicó-RN)

O trabalho teve como objetivo principal analisar a producao agropecuaria e sua correlacao com a dinâmica climatica no municipio de Caico/RN, localizado na regiao semiarida, contribuindo para um melhor planejamento economico e para o conhecimento do clima como elemento integrado da organizacao do espaco geografico. No estudo decidiu-se eleger quatro variaveis respostas da producao agropecuaria: (a) producao de carne de sol, (b) producao de leite, (c) producao de feijao e (d) producao de milho. Para cada uma dessas variaveis existem diversas variaveis explicativas e a analise de correlacao definiu quais dessas puderam ser utilizadas para ajudar a prever as variaveis respostas. Correlacionando os dados dos elementos climaticos com a agricultura e a pecuaria, foi observado que as variaveis correlacionadas de forma mais significativa com as variaveis respostas foram a precipitacao, o indice de aridez, a temperatura e a umidade, alem do numero de cabecas bovinas e o numero de vacas ordenhadas para a pecuaria e a area plantada e area colhida para a agricultura. Quanto aos modelos de previsao, estes apresentaram um bom ajuste aos dados observados, sendo possivel pensar em utiliza-los para fazer previsoes futuras a medida que o historico de dados for sendo incrementado com outras variaveis explicativas.

CONVIVENCIA CON LAS REGIONES SEMIÁRIDAS: Desafíos y oportunidades en una comunidad rural .

This research presents the result of a survey of leaders from rural communities in a municipality from the semi-arid Brazilian regions in the state of Paraiba. The goal was to determine the leaders´ perception about the rural and local environment, in order to identify their main strengths and weaknesses. In addition, we attempted to learn some strategies for a better coexistence with the semi-arid. As a methodology, we used a bibliographical and documental research, and a debate in a focus group with 16 leaders, divided into 04 subgroups. The data analysis was performed using an analysis of content according to a thematic axis. By grouping the statements of the respondents, we have elaborated an interpretation of the reality from the rural community in relation with the proposed objectives. Regarding the results, we can highlight a great interest of the leaders in improving the quality of life in the region, upgrading the use of natural resources and preventing environmental degradation. A great concern was noticed about the rural youth, where more investment in public policies was suggested, aimed at education, leisure and professional education. Another aspect was the need for community organization in order to achieve improvements for rural communities. In the statements, we noticed a discomfort with the current situation and the families´ care in rural areas has been a challenge sometimes impassable.

DESERTIFICAÇÃO E SEUS EFEITOS NA VEGETAÇÃO E SOLOS DO CARIRI PARAIBANO

Desertification is the degradation of lands in worldwide dry areas, having the climate influence and human activities as main causes. In Brazil, the cariri r...