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

Intervalo hídrico ótimo num nitossolo vermelho distroférrico irrigado Least limiting water range of an irrigated dystroferric red nitosol

O manejo da irrigação tem-se baseado no controle do potencial da água no solo (&#936;) como fator limitante do crescimento das plantas. Entretanto, outras variáveis podem influenciar a cultura mesmo que o &#936; não seja limitante. O Intervalo Hídrico Ótimo (IHO) é um conceito de disponibilidade de água no solo que leva em consideração a porosidade de aeração e a resistência do solo à penetração em adição ao &#936;. O objetivo deste estudo foi quantificar o IHO num Nitossolo Vermelho distroférrico irrigado e utilizá-lo no estabelecimento de critérios para o manejo de água e do solo em áreas irrigadas. A resistência do solo à penetração foi a variável que limitou o IHO com maior frequência, diminuindo sua magnitude com o aumento da densidade do solo (Ds). Com o aumento da Ds, ocorreu redução na frequência com que &#952; manteve-se dentro dos limites do IHO. A Ds crítica (Dsc) foi de 1,40 Mg m-3, indicando severa degradação física do solo para Ds > Dsc. Para Ds < 1,28 Mg m-3, o &#936; de -800 hPa utilizado frequentemente para o controle da irrigação por meio de tensiômetros caracterizou o limite inferior do IHO. Para 1,28 < Ds < 1,40 Mg m-3, o limite inferior do IHO foi determinado pela RP e, nestas condições, a adoção de &#936; igual a -800 hPa como limite para a aplicação de água estabelece restrições físicas às plantas devido à elevada RP. Neste caso, o mapeamento de áreas com Ds uniformes poderia ser utilizado para o manejo do &#936; para a manutenção da RP < 2,0 MPa. Nas áreas em que a Ds < 1,28 Mg m-3 pode ocorrer maior secamento do solo sem que ocorra RP > 2,0 MPa; para 1,28 < Ds < 1,40 Mg m-3 deve-se manter &#936; > -800 hPa visando ao controle da RP. Para áreas em que Ds > Dsc, medidas que visem a redução da Ds poderiam ser tomadas em função da severa degradação física do solo.<br>The establishment of irrigation management has been based on the soil water potential (&#936;) as a limiting factor for plant growth. However, other variables can affect crop growth even when &#936; is not limiting. The least limiting water range (LLWR) is a concept of available water that take account the influence of aeration and soil resistance to penetration (SR) in addition to &#936;. The objective of this study was to quantify the LLWR in an irrigated Dystroferric Red Nitosol and to use it to determine the soil and water management for irrigated areas. Soil penetration resistance limited LLRW most often, reducing its magnitude with the increase of soil bulk density (Bd). Therefore, the higher Bd, the less often &#952; was inside the limits of LLWR. The critical Bd (Bdc) was 1.40 Mg m-3, indicating severe soil physical degradation when Bd > Bdc. For Bd < 1.28 Mg m-3 , the &#936; = -800 hPa, which is frequently used for irrigation management using tensiometers, characterized the lower limit for LLWR. For 1.28 < Bd < 1.40 Mg m-3 the lower limit was determined by SR, and under these conditions &#936;=-800 hPa as a limit for water application results in physical restrictions for plants due to the high SR. In this case, the mapping of areas with homogenous Bd could be used for the management of &#936; to maintain SR < 2.0 MPa. In areas where Bd < 1.28 Mg m-3 soil drying can be higher without SR > 2.0 MPa; for areas in which 1.28 < Bd < 1.40 Mg m-3 &#936; should be maintained at > -800 hPa to maintain adequate SR. For areas where Bd > Bdc measures to reduce Bd could be taken due to the severe soil physical degradation in this situation