The relationships between hydraulic and photosynthetic properties in plants have been widely studied, but much less is known about how these properties are linked to water-source partitioning, the spatial and temporal separation of water sources in ecosystems. Plant water-source partitioning is often influenced by the proximity of groundwater from the natural surface. We studied the water acqui...

The Arya-Paris model is an indirect method to estimate the soil water characteristic from particle-size data. The scaling parameter, a, in the original model was assumed constant for all soil textures. In this study, a is defined as a, = (logJV//log«,-), where n, is the number of spherical particles in the ith particle-size fraction (determined by the fraction solid mass, wh and mean particle r...

Evidence is increasing to suggest that a major activity of roots is to redistribute soil water. Roots in hydraulic contact with soil generally either absorb or lose water, depending on the direction of the gradient in water potential between root and soil. This leads to phenomena such as "hydraulic lift" where dry upper soil layers drive water transfer from deep moist layers to the shallow rhiz...

Permafrost is tightly coupled to the organic soil layer, an interaction that mediates permafrost degradation in response to regional warming. We analyzed changes in permafrost occurrence and organic layer thickness (OLT) using more than 3000 soil pedons across a mean annual temperature (MAT) gradient. Cause and effect relationships between permafrost probability (PF), OLT, and other topographic...

This study was conducted to investigate surface characteristics of sand particles. Surface topography of sand particles was determined in 3-D using a commercially available optical profiler. Measurements were made on areas that had side dimensions on the order of 0.1 mm at a lateral resolution of 0.3 Ilm and height resolution of less than 6 nm. The 3-D representation of a surface obtained using...

BACKGROUND Infiltration is a key process in determining the water balance, but so far effects of earthworms, soil texture, plant species diversity and their interaction on infiltration capacity have not been studied. METHODOLOGY/PRINCIPAL FINDINGS We measured infiltration capacity in subplots with ambient and reduced earthworm density nested in plots of different plant species (1, 4, and 16 s...

Sub-surface irrigation with porous clay pipe can be an efficient, water saving method of irrigation for many less developed arid and semi-arid regions. Maximizing the efficiency of clay pipe irrigation requires guidelines and criteria for system design and operation. In this study, experimental and simulated (with HYDRUS (2D/3D)) soil wetting patterns were investigated for sub-surface pipe syst...