The response of xylem pressure potential of Engelmann spruce (Picea engelmannii Engelm.) to environmental factors was studied in the natural subalpine environment. Data were analyzed in the context of a leaf water potential model based upon the van den Honert model for water transport through the soil-plant-atmosphere continuum. At soil temperatures of 10 to 15 C, xylem pressure potential decre...

expansive soils are considered a worldwide problem as they cause extensive damage tocivil engineering structures. an important characteristic of expansive soils is theirsusceptibility to volume change due to the phenomenon of wetting and drying. this paperpresets the effect of pore water quality on the swelling and shrinkage behavior of anexpansive soil during wetting and drying cycles. thirty ...

Due to climate change, heat waves and drought are ex­ pected to increase in frequency and intensity in Central Europe. Thus, assessments of critical constraints of water supply in forest trees are needed to develop adequate for­ est adaptation measures. We present a novel ‘critical limit’ approach to soil water availability (SWA) for the major central European forest tree species based on the p...

One of soil microbiology's most intriguing puzzles is how so many different bacterial species can coexist in small volumes of soil when competition theory predicts that less competitive species should decline and eventually disappear. We provide evidence supporting the theory that low pore connectivity caused by low water potential (and therefore low water content) increases the diversity of a ...

The biogeographic distribution of plant species is inherently associated with the plasticity of physiological adaptations to environmental variation. For semi-arid shrublands with a legacy of saline soils, characterization of soil water-tolerant shrub species is necessary for habitat restoration given future projection of increased drought magnitude and persistence in these ecosystems. Five dom...

Effects of soil and atmospheric drought on whole-tree transpiration (E(T)), leaf water potential (Ψ(L)) and whole-tree hydraulic conductance (K(T)) were investigated in mature rubber trees (Hevea brasiliensis, clone RRIM 600) during the full canopy stage in the rainy season in a drought-prone area of northeast Thailand. Under well-watered soil conditions, transpiration was tightly regulated in ...

Climate modelling studies predict that the rain forests of the Eastern Amazon basin are likely to experience reductions in rainfall of up to 50% over the next 50-100 years. Efforts to predict the effects of changing climate, especially drought stress, on forest gas exchange are currently limited by uncertainty about the mechanism that controls stomatal closure in response to low soil moisture. ...

The effect of drought on forest water use is often estimated with models, but comprehensive models require many parameters, and simple models may not be sufficiently flexible. Many tree species, Pinus species in particular, have been shown to maintain a constant minimum leaf water potential above the critical threshold for xylem embolism during drought. In such cases, prediction of the relative...

Spores of three Glomus species were examined to compare the effect of long term storage under three different soil water conditions ( -0.04 MPa, -0 .8 MPa or dried) on their infective capacity. After 6 months of incubation, the infectivity tests showed that spores were affected in their potential as inoculum by soil water potential during storage. Spores from G. mosseae and G. deserticola were ...