The pupal development of Aethina tumida Murray (Coleoptera: Nitidulidae) was studied at various combinations of thermo-hygrometric soil conditions (temperatures of 16, 18, and 20 degrees C and soil water content levels of 0.37, 0.56, and 0.73 m3 water per cubic meter of dry soil) representative of southeastern Canada. Survivorship and development duration of A. tumida pupae, as well as sex rati...

A new multispectral image classification method is presented. The method is based on dividing the Near Infrared “NIR” and Visible Red “VR” scatterplot diagram into regions corresponding to their reflectance values. The best line discriminating the Soil’s components from the vegetated area is recognized by utilizing the least square fitting criterion. The vegetate line which differentiate the fu...

Inadvertent soil ingestion, especially by young children, can be an important route of exposure for many environmental contaminants. The introduction of exterior soil into the interior environment is a significant element of the exposure pathway. The unintentional collection of outside soil on footwear followed by subsequent deposition indoors is a principal route of soil ingress. Here we have ...

Shear strength of aggregates and the bulk soil matrix in two Haploxeroll of central Chile was assessed in order to determine: (1) the effect of previous tillage on shear parameters between aggregates and in the soil matrix and (2) the effects of structure development on differences between dry-wet mechanical parameters. Undisturbed soil cylinders and single aggregates (0-10 cm layer) were colle...

Three independent surface soil moisture datasets for the period 1979–87 are compared: 1) global retrievals from the Scanning Multichannel Microwave Radiometer (SMMR), 2) global soil moisture derived from observed meteorological forcing using the NASA Catchment Land Surface Model, and 3) ground-based measurements in Eurasia and North America from the Global Soil Moisture Data Bank. Time-average ...

Orifice-weir structures are being used to reduce peak drainage rates and to store water during the growing season in poorly drained pine plantations. Earlier studies have demonstrated their effectiveness in reducing drainage outflows while conserving water during the growing season. This study reports on criteria and preliminary guidelines for designing such structures. The guidelines were deve...

[1] N2O, CH4 and CO2 soil-atmosphere exchange and controlling environmental factors were studied for a 3-month period (dry-wet season transition) at the Kakamega Rain forest, Kenya, Africa, using an automated measurement system. The mean N2O emission was 42.9 ± 0.7 mg N m 2 h 1 (range: 1.1–324.8 mg N m 2 h ). Considering the duration of dry and wet season the annual N2O emission was estimated a...

In a 2-year field study, we quantified lateral root growth patterns and soil water depletion dynamics in the invasive annual Centaurea solstitialis and two native perennials, Elymus glaucus and Grindelia camporum. Centaurea solstitialis produced lateral roots most actively from early April to mid-June, during the late rosette to spiny seedhead stage while both root growth and water depletion we...

Terrestrial biosphere-atmosphere carbon dioxide (CO(2)) exchange is dominated by tropical forests, where photosynthetic carbon (C) uptake is thought to be phosphorus (P)-limited. In P-poor tropical forests, P may also limit organic matter decomposition and soil C losses. We conducted a field-fertilization experiment to show that P fertilization stimulates soil respiration in a lowland tropical ...