Peculiar relationships among morphology, burrowing performance and sand type in two fossorial microteiid lizards.

Associations among ecology, morphology and locomotor performance have been intensively investigated in several vertebrate lineages. Knowledge on how phenotypes evolve in natural environments likely benefits from identification of circumstances that might expand current ecomorphological equations. In this study, we used two species of Calyptommatus lizards from Brazilian Caatingas to evaluate if specific soil properties favor burrowing performance. As a derived prediction, we expected that functional associations would be easily detectable at the sand condition that favors low-resistance burrowing. We collected two endemic lizards and soil samples in their respective localities, obtained morphological data and recorded performance of both species in different sand types. As a result, the two species burrowed faster at the fine and homogeneous sand, the only condition where we detected functional associations between morphology and locomotion. In this sand type, lizards from both Calyptommatus species that have higher trunks and more concave heads were the ones that burrowed faster, and these phenotypic traits did not morphologically discriminate the two Calyptommatus populations studied. We discuss that integrative approaches comprising manipulation of environmental conditions clearly contribute to elucidate processes underlying phenotypic evolution in fossorial lineages.

Espacialidade de atributos de solos cultivados com cana-de-açúcar no Pontal do Paranapanema, SP / Spatiality of attributes of soils cultivated with sugar cane in Pontal do Paranapanema, SP

A pesquisa teve como objetivo organizar e analisar um banco de dados geoespacial de informações pedológicas e aplicar técnicas de geoestatística para avaliar a dependência espacial de atributos físicos e químicos do solo. Para tanto, buscou-se confeccionar uma base de dados com 473 pontos amostrais pertencentes a uma grade não regular, coletados em duas profundidades, 0,00 a 0,25m, e 0,25 a 0,50m, devidamente georeferenciados. Estas amostras foram coletadas sob a cultura da cana-de-açúcar em diferentes idades de corte, sendo a amostragem realizada no meio da entrelinha da cultura, com o auxílio de um trado holandês e posteriormente submetido às determinações analíticas químicas e físicas em laboratório. Baseado nesses resultados, determinou-se, ainda, o potencial de produção de cana de açúcar para a região de estudo. Em seguida realizou-se a análise descritiva dos dados, estabelecendo-se correlações lineares, simples e múltiplas, entre os atributos. Foram modelados semivariogramas, obtendo-se as respectivas krigagens e validações cruzadas. Também foram estabelecidas as cokrigagens de interesse. Os atributos Ca, Mg, K e MO apresentaram forte dependência espacial na camada superficial. A variável ambiente relacionou-se negativamente com todos os atributos e camadas, exceto argila, areia fina e alumínio.(AU)

The present work aimed to organize and analyze a geospatial database of pedological information and to apply geostatistics techniques to evaluate the spatial dependence of physical and chemical attributes of the soil. In order to do so, a database was designed with 473 sampling points belonging to a non-regular grid, collected at two depths, 0.00 to 0.25m, and 0.25 to 0.50m, duly georeferenced. The samples were collected in a region with predominance of Oxisols and Ultisols, mostly very sandy, low acid, clay poor and of great depth, under sugarcane culture at different ages of cut, being the sampling performed in the middle of the culture line, with the help of a Dutch translator and later submitted to chemical and physical analytical determinations in the laboratory. Based on these results, the sugarcane production potential for the study region was also determined. Then, the descriptive analysis of the data was performed, establishing simple and multiple linear correlations between the attributes. Semivariograms were modeled, obtaining the respective krigagens and cross validations. Cokrigagens of interest were also established. The attributes Ca, Mg, K and MO presented strong spatial dependence on the surface layer. The environment variable was negatively related to all attributes and layers except clay, fine sand and aluminum.(AU)

Espacialidade de atributos de solos cultivados com cana-de-açúcar no Pontal do Paranapanema, SP / Spatiality of attributes of soils cultivated with sugar cane in Pontal do Paranapanema, SP

A pesquisa teve como objetivo organizar e analisar um banco de dados geoespacial de informações pedológicas e aplicar técnicas de geoestatística para avaliar a dependência espacial de atributos físicos e químicos do solo. Para tanto, buscou-se confeccionar uma base de dados com 473 pontos amostrais pertencentes a uma grade não regular, coletados em duas profundidades, 0,00 a 0,25m, e 0,25 a 0,50m, devidamente georeferenciados. Estas amostras foram coletadas sob a cultura da cana-de-açúcar em diferentes idades de corte, sendo a amostragem realizada no meio da entrelinha da cultura, com o auxílio de um trado holandês e posteriormente submetido às determinações analíticas químicas e físicas em laboratório. Baseado nesses resultados, determinou-se, ainda, o potencial de produção de cana de açúcar para a região de estudo. Em seguida realizou-se a análise descritiva dos dados, estabelecendo-se correlações lineares, simples e múltiplas, entre os atributos. Foram modelados semivariogramas, obtendo-se as respectivas krigagens e validações cruzadas. Também foram estabelecidas as cokrigagens de interesse. Os atributos Ca, Mg, K e MO apresentaram forte dependência espacial na camada superficial. A variável ambiente relacionou-se negativamente com todos os atributos e camadas, exceto argila, areia fina e alumínio.

The present work aimed to organize and analyze a geospatial database of pedological information and to apply geostatistics techniques to evaluate the spatial dependence of physical and chemical attributes of the soil. In order to do so, a database was designed with 473 sampling points belonging to a non-regular grid, collected at two depths, 0.00 to 0.25m, and 0.25 to 0.50m, duly georeferenced. The samples were collected in a region with predominance of Oxisols and Ultisols, mostly very sandy, low acid, clay poor and of great depth, under sugarcane culture at different ages of cut, being the sampling performed in the middle of the culture line, with the help of a Dutch translator and later submitted to chemical and physical analytical determinations in the laboratory. Based on these results, the sugarcane production potential for the study region was also determined. Then, the descriptive analysis of the data was performed, establishing simple and multiple linear correlations between the attributes. Semivariograms were modeled, obtaining the respective krigagens and cross validations. Cokrigagens of interest were also established. The attributes Ca, Mg, K and MO presented strong spatial dependence on the surface layer. The environment variable was negatively related to all attributes and layers except clay, fine sand and aluminum.