E. L. Cardoso

Atributos biológicos indicadores da qualidade do solo em pastagem cultivada e nativa no Pantanal

The objective of this work was to evaluate the changes in biological attributes soil promoted by substitution native forest cultivated pasture, and submission pasture under continuous grazing Pantanal wetlands. consisted evaluation three forests, Brachiaria decumbens pastures of different formation ages, established in substitution to the native forests and three native pastures, one under continuous grazing and two without grazing for 3 and 19 years. Soil samples were collected at 0-10 and 10-20 cm depths, in the three 100-m transects in each sampled site. Each transect represented one replicate. The following attributes were evaluated: total organic carbon (TOC), soil microbial carbon (Cmic), microbial quotient (qMIC), basal respiration (BR) and metabolic quotient (qCO2). The substitution of the native forest by cultivated pasture reduced TOC, Cmic, and qMIC and increased BR. The continuous grazing on native pasture reduced TOC and Cmic contents. Cmic was the most sensitive attribute to the alterations imposed on soil by the cultivated and native pasture systems, since it was marked by more substantial reductions.

Qualidade química e física do solo sob vegetação arbórea nativa e pastagens no Pantanal Sul-Mato-Grossense

The search for improved productivity of livestock has stimulated deforestation of forested areas in the Pantanal for pasture planting, raising concerns about the sustainability of the natural resources. To study some aspects of land use in the Pantanal of Mato Grosso, Brazil, this study aimed to evaluate the changes in chemical and physical soil properties due to the conversion of native tree vegetation in pasture, and the exposure of native pasture to a continuous grazing system. The environments of the study consisted of three remnants of native vegetation, represented by a semi-deciduous forest (NF) and two Cerrado (CE1 and CE2) areas, three 27, 26 and 11-year-old Brachiaria decumbens pastures, planted to replace FN , CE1 and CE2, respectively, and a native pasture with predominance of Mesosetum chaseae and Axonopus purpusii, under three different grazing systems (continuous and ungrazed for 3 and 19 years). Disturbed and undisturbed soil samples were collected from each study environment, in the layers 0-10 and 10-20 cm, with three replications. The replacement of native tree vegetation by pasture and by continuous grazing of native pasture resulted in a reduction of the soil chemical quality, evidenced primarily by a loss of soil organic matter, particularly in the layer 0-10 cm. Although the soil physical quality also tends to decrease under cultivated and native pasture under continuous grazing, the values of bulk density, total porosity, macroporosity, microporosity, hydraulic conductivity of saturated soil and soil penetration resistance did not reach levels considered critical for root development.

Estoques de carbono e nitrogênio em solo sob florestas nativas e pastagens no bioma Pantanal

The objective of this work was to evaluate the impact of the conversion of native forests into cultivated pasture, and exposure of native pasture to continuous grazing, on the C and N stocks in the soil, in the Brazilian Pantanal wetlands. Three remnants of native forest, three areas with Urochloa decumbens pastures at different ages of formation, and one native pasture submitted to continuous grazing and without grazing for 3 and 19 years were evaluated. Soil samples were collected at 0-10, 10-20 and 20-40 cm depths, with three replications. The conversion of native forests into pastures promoted reduction of organic carbon and microbial carbon stocks in the soil, mainly in cultivated pastures with longer implantation time. However, no alteration in the total N stocks was observed. Carbon stock losses occurred in the three humic fractions but, proportionally, the main losses occurred in the humic and fulvic acid fractions. Cultivated and native pastures under continuous grazing are not capable of accumulating more C in the soil than the natural ecosystems.

Efeitos da queima na dinâmica da biomassa aérea de um campo nativo no Pantanal

Resumo – O objetivo deste trabalho foi avaliar os efeitos da queima na dinâmica da biomassa aerea do estrato herbaceo de um campo nativo do Pantanal com predominância de Andropogon bicornis. A area de estudo foi submetida aos tratamentos sem queima e com queima, ambos sem pastejo. Os dados de biomassa aerea e cobertura do solo foram analisados nos onze meses subsequentes a queima. A biomassa aerea das areas com queima apresentou pequeno incremento linear de materia seca, tornando sua biomassa significativamente menor que a obtida nas areas sem queima. Andropogon bicornis, Axonopus purpusii e outras especies apresentaram menor biomassa apos a queima, enquanto Mesosetum chaseae foi favorecido pela queima, apresentando maior producao de materia seca. A acao do fogo removeu praticamente toda a biomassa; a cobertura do solo, trinta dias apos a queima, foi de aproximadamente 35%. Somente sete meses depois, a cobertura do solo foi restabelecida, tornando-se semelhante a area sem queima. Effects of burning on the aerial biomass dynamics of a native field in the Pantanal

Composição e dinâmica da biomassa aérea após a queima em savana gramíneo-lenhosa no Pantanal

The purpose of this work was to evaluate composition and aerial biomass dynamics after burning of a grassy-woody savanna in the Pantanal wetlands, Brazil. During 11 months, data on species frequency, aerial biomass and soil cover were collected in an area with burning (WB) and another free of burning (FB), both not grazed. Burning reduced the frequency of the most predominant grasses and increased the number of dicotyledons and cyperaceae species. The production of total aerial biomass was lower in the WB area, despite an increase tendency that was similar in both areas. Litter production was strongly affected by burnings. After 11 months its production was approximately 25% of the production exhibited by the FB area. Soil cover was also lower in the WB and only after four months it was similar to the FB area.

Índices de qualidade do solo sob diferentes sistemas de uso e manejo florestal e cerrado nativo adjacente

Existe uma dificuldade em quantificar diferentes atributos do solo que estao relacionados com a sustentabilidade e traduzir estes indicadores na forma de indices de qualidade do solo. Assim, objetivou-se neste trabalho estabelecer tais indices sob diferentes sistemas de uso e manejo florestal e cerrado nativo adjacente atraves da avaliacao integrada de atributos fisicos e quimicos. Para isto, foram desenvolvidos dois indices de qualidade (IQS1 e IQS2) utilizando um banco de dados sobre sistemas de manejo do eucalipto e cerrado nativo em Latossolos de Minas Gerais. No IQS1 os ecossistemas naturais, caracterizados pela minima intervencao antropica e de esperado equilibrio, foram considerados como referencia. O IQS2 foi gerado a partir de um modelo aditivo que considera as funcoes principais do solo e os indicadores de qualidade a elas associados, sendo atribuidos pesos para as funcoes e indicadores. O IQS1 e o IQS2 apresentaram diferentes valores para os solos e sistemas de manejo analisados. Os sistemas sofreram reducoes do IQS1 quando comparados aos sistemas nativos, sendo que apenas os sistemas agrossilvopastoris apresentaram valores superiores de qualidade do solo quando comparados aos sistemas de referencia. Pelo IQS2, os Latossolos Vermelho-Amarelos (LVA1 e LVA2) apresentaram qualidade do solo superior aos Latossolos Vermelhos (LV1 e LV2), sendo este resultado devido as menores limitacoes dos atributos quimicos e fisicos nas funcoes principais dos solos, influenciadas pelos sistemas de manejo daqueles solos. Apenas os sistemas agrossilvopastoris que utilizam eucalipto com arroz e eucalipto com soja proporcionaram melhoria da qualidade do solo pelos dois sistemas analisados.

A fuzzy logic-based tool to assess beef cattle ranching sustainability in complex environmental systems

One of the most relevant issues in discussion worldwide nowadays is the concept of sustainability. However, sustainability assessment is a difficult task due to the complexity of factors involved in the natural world added to the human interference. In order to assess the sustainability of beef ranching in complex and uncertain tropical environment systems this paper describes a decision support system based on fuzzy rule-approach, the Sustainable Pantanal Ranch (SPR). This tool was built by a set of measurements and indicators integrated by fuzzy logic to evaluate the attributes of the three dimensions of sustainability. Indicators and decision rules, as well as scenario evaluations, were obtained from workshops involving multi-disciplinary team of experts. A Fuzzy Rule-Based System (FRBS) was developed to each attribute, dimension and general index. The essential parts of the FRBS are the knowledge database, rules and the inference engine. The FuzzyGen and WebFuzzy tools were developed to support the FRBS and both showed efficiency and low cost for digital applications. The results of each attribute, dimension and index were presented as radar graphs, showing the individual value (0-10) of each indicator. In the validation process using the WebFuzzy, different combinations of indicators were made for each attribute index to show the corresponding output, and which confirm the feasibility and usability of the tool.