Governance using the water-food-energy nexus and human-factor measures.

Household water food and energy (WFE) expenditures, reflect respective survival needs for which their resources and social welfare are inter-related. We developed a policy driven quantitative decision-making strategy (DMS) to address the domain geospatial entities' (nodes or administrative districts) of the WFE nexus, assumed to be information linked across the domain nodal-network. As investment in one of the inter-dependent nexus components may cause unexpected shock to the others, we refer to the WFE normalized expenditures product (Volume) as representing the nexus holistic measure. Volume rate conforms to Boltzman entropy suggesting directed information from high to low Volume nodes. Our hypothesis of causality-driven directional information is exemplified by a sharp price increase in wheat and rice, for U.S. and Thailand respectively, that manifests its impact on the temporal trend of Israel's administrative districts of the WFE expenditures. Welfare mass (WM) represents the node's Volume combined with its income and population density. Formulation is suggested for the nodal-network WM temporal balance where each node is scaled by a human-factor (HF) for subjective attitude and a superimposed nodal source/sink term manifesting policy decision. Our management tool is based on two sequential governance processes: one starting with historical data mapping the mean temporal nodal Volumes to single out extremes, and the second is followed by WM balance simulation predicting nodal-network outcome of policy driven targeting. In view of the proof of concept by model simulations in in our previous research, here HF extends the model and attention is devoted to emphasize how the current developed decision-making approach categorically differs from existing nexus related methods. The first governance process is exemplified demonstrating illustrations for Israel's districts. Findings show higher expenditures for water and lower for energy, and maps pointing to extremes in districts' mean temporal Volume. Illustrations of domain surfaces for that period enable assessment of relative inclination trends of the normalized Water, Food and Energy directions continuum assembled from time stations, and evolution trends for each of the WFE components.

The Impact of Roads on the Redistribution of Plants and Associated Arthropods in a Hyper-Arid Ecosystem.

The construction of vehicular roads likely affects the distribution of natural resources. Although the effects of roads on different ecosystem aspects have been extensively studied, studies in arid and, particularly, in hyper-arid ecosystems are scarce. In drylands, where water is the main limiting factor, the effect of roads on the redistribution of water may have strong subsequent effects on the ecosystem, especially when roads cross natural water flow paths. To fill this knowledge gap, we studied the effects of a road that runs across a slope on the distribution of plants and animals in a hyper-arid environment. Changes in shrub cover, below and above the road, were quantified by remote sensing and image classification, while plant-associated arthropods were vacuum-sampled from shrub canopies and from open (inter-shrub) areas. We found that the spatial distribution of shrubs, a vital resource facilitating many other organisms, was affected by the road, with an increase in the shrub cover immediately above the road and a decrease below it. Arthropod abundance generally followed shrub cover, but the exact pattern depended on the specific group sampled. While some arthropod groups (e.g., aphids, parasitic wasps and barklice) thrived under the disturbed conditions above the road, other arthropod groups (e.g., mites and true bugs) were less abundant in the disturbed patches. Our results highlight the strong effects of human-made structures on the distribution of flora and fauna in arid ecosystems.

Evaluating Spatially Resolved Influence of Soil and Tree Water Status on Quality of European Plum Grown in Semi-humid Climate.

In orchards, the variations of fruit quality and its determinants are crucial for resource effective measures. In the present study, a drip-irrigated plum production (Prunus domestica L. "Tophit plus"/Wavit) located in a semi-humid climate was studied. Analysis of the apparent electrical conductivity (ECa) of soil showed spatial patterns of sand lenses in the orchard. Water status of sample trees was measured instantaneously by means of leaf water potential, Ψleaf [MPa], and for all trees by thermal imaging of canopies and calculation of the crop water stress index (CWSI). Methods for determining CWSI were evaluated. A CWSI approach calculating canopy and reference temperatures from the histogram of pixels from each image itself was found to suit the experimental conditions. Soil ECa showed no correlation with specific leaf area ratio and cumulative water use efficiency (WUEc) derived from the crop load. The fruit quality, however, was influenced by physiological drought stress in trees with high crop load and, resulting (too) high WUEc, when fruit driven water demand was not met. As indicated by analysis of variance, neither ECa nor the instantaneous CWSI could be used as predictors of fruit quality, while the interaction of CWSI and WUEc did succeed in indicating significant differences. Consequently, both WUEc and CWSI should be integrated in irrigation scheduling for positive impact on fruit quality.