17 research outputs found
NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics
Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset
Qualidade física de um Latossolo Vermelho sob sistemas de integração lavoura-pecuária no Cerrado Soil physical quality under crop-livestock management systems in a Cerrado Oxisol
O objetivo deste trabalho foi avaliar o impacto de sistemas de integração lavoura-pecuária sobre atributos físico-hídricos do solo e avaliar o potencial uso desses atributos como indicadores da qualidade física de um Latossolo. As amostras de solo foram coletadas nas camadas 0-5, 10-15, 20-25 e 40-45 cm. Todos os sistemas de uso e manejo do solo alteraram significativamente a densidade, umidade volumétrica, resistência à penetração, porosidade total, macroporosidade, microporosidade efetiva e água prontamente disponível do solo. Foram observados incrementos na resistência à penetração e na densidade do solo em todos os sistemas em comparação ao cerrado nativo. A compactação resultante do pisoteio animal durante quatro anos da fase pastagem, nos sistemas de integração lavoura-pecuária, não atingiu valores críticos, que pudessem limitar cultivos anuais subseqüentes. A porosidade total e a macroporosidade foram maiores no cerrado e nos sistemas em plantio direto em relação aos em preparo convencional. Os atributos avaliados são indicadores confiáveis da qualidade físico-hídrica do solo.<br>The objective of this work was to analyze the effect of integrated crop-livestock systems on soil hydraulic properties, and test the potential use of these properties as physical quality indicators of a Cerrado Oxisol. The field study was conducted at Embrapa Cerrados, Planaltina, DF, Brazil, considering soil layers of: 0-5, 10-15, 20-25 and 40-45 cm. Crop-livestock systems caused significant changes in soil bulk density, volumetric soil-water content, soil penetration resistance, total porosity, macroporosity, effective microporosity, unsaturated pores and available water. An increase was observed in both soil resistance and bulk density for all systems in comparison to the cerrado. However, higher soil resistance did not appear as a limiting factor for annual crops growth in a rotation sequence. Total porosity and macroporosity were higher in the cerrado, and in the systems with no-tillage in relation to conventional tillage. Soil penetration resistance, macroporosity, bulk density and available soil-water properties are reliable indicators of the soil physical quality
Intervalo hídrico ótimo e porosidade de solos cultivados em área de proteção ambiental do sul de Minas Gerais Least limiting water range and porosity of cultivated soils in an environmental protection area in the south of Minas Gerais
Condições físicas restritivas ao adequado desenvolvimento das plantas reduzem a capacidade produtiva dos solos e a sustentabilidade ambiental. Um importante parâmetro para expressar essas restrições é o intervalo hídrico ótimo (IHO), por representar, conjuntamente, atributos físicos do solo que influenciam o desenvolvimento de plantas. Com o objetivo de avaliar o IHO e a porosidade de solos cultivados com café e pastagem na microbacia do ribeirão Capituvas, local representativo da APA Coqueiral, coletaram-se amostras indeformadas no Latossolo Vermelho distrófico típico (LVd), no Argissolo Vermelho eutrófico típico (PVe) e no Cambissolo Háplico distrófico típico (CXbd), nas camadas de 0-5, 20-25 e 40-45 cm, respectivamente. Os poros com diâmetro > 145 µm foram os mais afetados pelo manejo. Apesar de não haver diferenças entre os microporos (poros com diâmetro < 50 µm, responsáveis pela água potencialmente disponível para as plantas), observaram-se variações no IHO, sendo no LVd > CXbd > PVe. Conclui-se que o IHO é um parâmetro que pode ser utilizado com segurança na quantificação das alterações que ocorrem na disponibilidade de água dos solos submetidos a diferentes usos e manejos.<br>Restrictive physical conditions for an adequate plant development reduce the productive capacity of soils and environmental sustainability. An important parameter to express these restrictions is the least limiting water range (LLWR), which is used in combination with soil physical properties that influence plant development. To evaluate the LLWR and porosity of soils under coffee and pasture in the Capituvas River microbasin, a representative area of the Coqueiral Resereve was chosen. Undisturbed samples of a typical Dystrophic Red Latosol (LVd- Oxisol), typical Eutrophic Red Argisol (PVe-Ultisol) and typical Dystrophic Haplic Cambisol (CXbd- Inceptisol) were collected from the layers 0-5, 20-25 and 40-45 cm. Pores with a diameter of > 145 µm were most affected by the management. Although no statistical differences were verified among the micropores (pores < 50 µm), variations occurred in LLWR, in the following order: LVd > CXbd > PVe. It is possible to conclude that LLWR is a reliable parameter that could be used to quantify alterations that occur in the water availability of soils under different use and management systems
Soil loss risk and habitat quality in streams of a meso-scale river basin Risco de perda de solo e qualidade do habitat numa bacia hidrográfica de meso-escala
Soil loss expectation and possible relationships among soil erosion, riparian vegetation and water quality were studied in the São José dos Dourados River basin, State of São Paulo, Brazil. Through Geographic Information System (GIS) resources and technology, Soil Loss Expectation (SLE) data obtained using the Universal Soil Loss Equation (USLE) model were analyzed. For the whole catchment area and for the 30 m buffer strips of the streams of 22 randomly selected catchments, the predominant land use and habitat quality were studied. Owing mainly to the high soil erodibility, the river basin is highly susceptible to erosive processes. Habitat quality analyses revealed that the superficial water from the catchments is not chemically impacted but suffers physical damage. A high chemical purity is observed since there are no urban areas along the catchments. The water is physically poor because of high rates of sediment delivery and the almost nonexistence of riparian vegetation.<br>Expectativa de perda de solo e possíveis relações entre erosão, vegetação ripária e qualidade da água foram estudados na bacia do rio São José dos Dourados (SP). Através de recursos de geoprocessamento e da Equação Universal de Perda de Solos, os dados sobre expectativa de perda de solo foram levantados. Para a área de drenagem total e a faixa tampão dos corpos d'água de 22 sub-bacias aleatoriamente selecionadas, analisou-se a cobertura do solo predominante e qualidade do habitat. Devido principalmente à alta erodibilidade do solo, a área estudada é altamente suscetível ao processo erosivo. As análises de qualidade da água revelaram que as águas superficiais das sub-bacias estão quimicamente não impactadas, mas fisicamente degradadas. A alta pureza química deve-se, possivelmente, à ausência de áreas urbanizadas ao longo das sub-bacias e as alterações nas características físicas são, possivelmente, decorrentes das altas taxas de transferência de sedimento aos corpos d'água e à quase ausência de mata ciliar