Water Availability

Biochar addition to agricultural soil has been suggested to mitigate climate change through increased biogenic carbon storage and reduction of greenhouse gas emissions. We measured the fluxes of N2O, CO2, and CH4 after adding 9 t ha−1 biochar on an agricultural soil in Southern Finland in May 2009. We conducted these measurements twice a week for 1.5 months, between sowing and canopy closure, to capture the period of highest N2O emissions, where the potential for mitigation would also be highest. Biochar addition increased CH4 uptake (96% increase in the average cumulative CH4 uptake), but no statistically significant differences were observed in the CO2 and N2O emissions between the biochar amended and control plots. Added biochar increased soil water holding capacity by 11%. Further studies are needed to clarify whether this may help balance fluctuations in water availability to plants in the future climate with more frequent drought periods.▶ Biochar addition to boreal agricultural soil increases CH4 uptake. ▶ Biochar addition to boreal agricultural soil increases water holding capacity. ▶ Biochar addition to boreal agricultural soil had no effect on N2O or CO2 fluxes.

Photon flux density (PFD) and water availability, the daily and seasonal factors that vary most in tropical environments, were examined to see how they influenced expression of crassulacean acid metabolism (CAM) in 3year-old Clusia shrubs native to Panama. Instead of the commonly used single-leaf approach, diel CO 2 exchange was measured for whole individual canopies of plants in large soil containers inside a naturally illuminated 8.8 m 3 chamber. In well-watered C. rosea, a mainly constitutive CAM species, nocturnally fixed CO 2 contributed about 50% to 24 h carbon gain on sunny days but the contribution decreased to zero following overcast days. Nonetheless, CO 2 fixation in the light responded in such a way that 24 h carbon gain was largely conserved across the range of daily PFDs. The response of C. rosea to drought was similarly buffered. A facultative component of CAM expression led to reversible increases in nocturnal carbon gain that offset drought-induced reductions of CO 2 fixation in the light. Clusia cylindrica was a C 3 plant when well-watered but exhibited CAM when subjected to water stress. The induction of CAM was fully reversible upon rewatering. C. cylindrica joins C. pratensis as the most unambiguous facultative CAM species reported in the genus Clusia.

Trenbolone acetate (TBA) is a synthetic androgenic steroid hormone administered as a subcutaneous implant for growth promotion in beef cattle. The primary metabolite excreted in manure from implanted cattle is 17a-trenbolone with lesser amounts of 17b-trenbolone and trendione also present. At 22°C and favorable moisture conditions in a controlled laboratory environment, trenbolone degrades to trendione in a few hours; however, these conditions are often not what exist in the field. Therefore, aerobic degradation rates of 17a-trenbolone, 17b-trenbolone and trendione were determined in a sandy soil and silty clay loam under a range of temperature and water availability combinations that may be expected in the field. A first-order exponential decay model was used to estimate rates and generally resulted in good model fits to the data. Degradation rates decreased with decreasing water availability (i.e., more negative soil matric potential) and decreasing temperature. However, when water availability was substantially reduced (À1.0 MPa), hotter temperatures (35°C) significantly reduced trenbolone degradation rates. Once temperature was low enough to limit microbial activity, no further changes were observed with decreasing matric potential. Trendione also exhibited similar moisture and temperature dependent degradation, but persisted longer than the parent trenbolone. The latter was discussed in light of extracellular versus intracellular enzymatic degradation and sorption. Half lives at colder temperatures (5°C) even under favorable moisture conditions were 2-3 d for the trenbolone isomers and approached 10 d for trendione.

Contrary to irrigated agriculture thet use blue water, rainwater haNesting that use green water in forms of the direct rain and runoff, has been accorded little importance in terms of economic research, investment, technology transfer and management. This bias happens whereas 60-70 per cent of food production is rain fed and based on green water. The perception by majority of our water planners has been that, water haNesting in the upper watersheds would reduce blue water flows downstream. Improved management of rainwater in the upper watersheds for agriculture, livestock and domestic use would reduce pressure on the blue water downstream. However, the promotion of rainwater haNesting in the upper watersheds requires an ex-ante analysis related aspects of economic benefits, eco-hydrology and human dynamics. This paper demonstrates the economic benefits of rainwater management for crop production in a semi-arid Makanya Watershed in the Pangani river basin. The results from a two-seasons yield monitoring done between 2002 to 2004 for maize and lablab show that, rainwater haNesting has the potential for poverty reduction through improved yields, returns to land and labour. These findings justify investment and technology transfer1n rainwater haNe~ting for crop production in the upper watersheds of our major river basins.

O ur ohjective is to descrihe a multi-layer model of C.r canopy processes that effectively simulates houri)' C02 :uul latent ener gy (U~) lluxcs in a mixed deciduous Quercus-Acer (oak-maple) st'.111d in c~ntral l\ l~1ssac~1u selts, US/\. The key hy pothesis J!OVe rnmg the b1oloA1cal component of the model is Urnt stomata! conductance (g,.) is var ied s o that d ail y carbon uptake per unit of foliar nit r oj:!en is maximized wit hin the limitations of ca1101>Y water avr1ilability. T he h ydraulic system is modelled as :m a nalo~ue to simple electr ical circuits in parallel. includinJ! a separate soil hydraulic resistance. plant resistance and plant capacitance for each c:m op y layer. Stomata! openin(! is initially controlled to conserve plant water stores and delay the o nset or water stress. Stomata! clos ure at :i threshold minimum l~1f water potential prevents xyle m cavitation and contr ols the maximum r:itc of wate r llux through the h ydraulic system. We show a strong correlat ion between predicted hourly C0 2 exchange rate (r2 = 0•86) and LE (r 2 = 0•87) with independent whole-forest measurements made by the eddy correlation method during the s ummer of 1992. Our theoretical derivation s hows that observed relationships between C0 2 assimilation a nd LE nux can he explained on the basis of s tomata! behaviour 01>timizing c:irhon gain, and provides mt exi>licit link hetwecn canopy structure, soil pro1>erties. atmos pheric conditions and stomatal conductance.

Background: Ziziphus lotus, wild jujube, is a xerophytic shrub of the Rhamnaceae family widely distributed in arid and semiarid regions of Tunisia, where it occupies most soil types. Phenological patterns of desert plants are strongly affected by the seasonality of water availability and phreatophytes represent a particularly interesting case for studying such relationships. Aim: This study aims to investigate the relationship between phenological traits and water potential patterns of the wild jujube as a tool for understanding how plants cope with extreme drought. Methods: Phenophases and predawn (Y pd ) and midday (Y md ) xylem water potentials of wild jujube were studied monthly (Nov 2007-Oct 2008 at Samaâliate and Oued El Hallouf in southern Tunisia. These sites receive164 mm and 191 mm of annual rainfall, respectively, and differ in slope and soil type.

Chemical analysis of volatile organic compounds (VOCs) and semivolatiles (SVs), including pesticides, was performed on 623 and 568 samples, respectively, of household drinking water, as well as on 113 samples from 71 brands of bottled water available in Kuwaiti markets. The analysis was performed according to United States Environmental Protection Agency (US-EPA) Methods 524.2 and 525.2. Nine VOCs and eight SVs were found in household water. Furthermore, between one and seven of 12 VOCs were detected in 93% of the bottled water brands. All bottled waters were found to be completely free of SVs. Styrene was the main pollutant found in all brands packaged in polystyrene containers of sizes 200-mL and 250-mL, with levels generally higher than the WHO guideline value of 20 microg/L. The levels of styrene, toluene, ethyl benzene and xylenes were found to increase with storage time, which indicates that these VOCs were migrating from the container material. No effect was detected due to changes in the storage temperature. All detected VOCs and SVs in household and bottled waters, except styrene, were found at concentrations much lower than those established as safe by WHO guidelines and US-EPA maximum contaminant levels (MCLs), respectively.

work has been done on the Naqchu region in northern Tibet. This region is the most important pasturing area in Tibet. The grassland is greatly influenced by climate, especially drought. Therefore, palaeoclimatic records are needed to examine the full range of past drought variability, including magnitude and duration, to better anticipate future climate change. In addition, drought is a main factor limiting tree growth at the ecotone between the grassland and the forest at Nachqu region in northern Tibet. Climate change models predict higher temperatures and increased variability in precipitation in the future for the Tibetan Plateau (Zhang et al., 1996), which may increase the frequency and intensity of drought. The Palmer Drought Severity Index (PDSI) is the most prominent index of meteorological drought to measure departures from

This paper focuses on artificial groundwater recharge study in 'Ayyar basin', Tamil Nadu, India. The basin is covered by hard crystalline rock and overall has poor groundwater conditions. Hence, an artificial recharge study was carried out in this region through a project sponsored by Tamil Nadu State Council for Science and Technology. The Indian Remote Sensing satellite 1A Linear Imaging Self Scanning Sensor II (IRS 1A LISS II) satellite imagery, aerial photographs and geophysical resistivity data were used to prioritize suitable sites for artificial recharge and to estimate the volume of aquifer dimension available to recharge. The runoff water available for artificial recharge in the basin is estimated through Soil Conservation Service curve number method. The land use/land cover, hydrological soil group and storm rainfall data in different watershed areas were used to calculate the runoff in the watersheds. The weighted curve number for each watershed is obtained through spatial intersection of land use/land cover and hydrological soil group through GeoMedia 3.0 Professional GIS software. Artificial recharge planning was derived on the basis of availability of runoff, aquifer dimension, priority areas and water table conditions in different watersheds in the basin.

In arid and semi-arid ecosystems, water availability is discontinuous, highly variable, and characterized by discrete pulse events separated by long periods of limited resource availability. Plant recruitment in these ecosystems is also episodic and dependent on the water available during and after these discrete rainfall events. Precipitation thresholds for plant establishment have been estimated mainly for herbaceous plants and tree seedlings, but extrapolation of short-term results based on seedlings to natural tree populations is difficult. Nevertheless, estimations of water availability thresholds for tree recruitment are essential for successful policies on forest conservation and restoration. We propose a methodology to estimate precipitation thresholds for adult tree populations using tree-ring series and precipitation data. We used this methodology with two Prosopis species from South America: Prosopis pallida and Prosopis chilensis. Results indicate a precipitation threshold of around 85 mm for the establishment of P. pallida trees, whereas the threshold for P. chilensis is likely to be much higher. r

Watershed programme is an important intervention in dryland areas to improve livestock productivity through increased feed and fodder supply. The present study has focused on the impact of watershed interventions on crop-livestock linkages with particular emphasis on how the interventions have affected the quantity of stovers/straws as livestock feeding materials in bridging the demand-supply gap. The study has been carried out in three typical Shivalik foothill watersheds (two treated and one untreated) in the Panchkula district of Haryana state. The impact of watershed development programme has been estimated by adopting both with and without approach and before and after approach. The untreated watershed has derived 65 per cent of its total income from animal husbandry. On the contrary, this sector has contributed 42 per cent and 20 per cent in two treated watersheds. The availability of supplemental irrigation enabled the villagers to step up cropping intensity. The number of go...

Runoff generation processes in the Canadian Shield were investigated to reconcile the considerable variability of runoff ratios noted by previous studies. Four bedrock plots near Yellowknife, Northwest Territories, Canada were studied between May 1999 and September 2000. Surface runoff increases with rainfall and snowmelt intensity because higher values of the latter can exceed fracture in®ltration capacities. The size distribution of fractures affects in®ltration while the fracture network controls the direction of surface¯ow. Frost has no effect on in®ltration since the fractures are seldom ice ®lled. Storms of long duration and intermittent rainfall provide intervals between rainfalls during which evaporation can reduce the water available to runoff. Available storage in bedrock depressions, both empty and soil ®lled, retard surface¯ow and lengthen residence time, in turn enhancing evaporation and in®ltration at the expense of runoff. The further downslope available storage is on the slope the more control it has on plot runoff magnitude. These ®eld results show that rainfall±runoff relationships for bedrock slopes in the Canadian Shield should be considered in terms of microtopography, bedrock and soil characteristics and climate. q

Small livestock (goats, sheep, llamas, camels…) like other agricultural activities could have to face dramatic social, economical and environmental challenges. These challenges are identified underlining that these activities are often important and well present in countries with low incomes or in less favored areas. Although they are often low input production systems with lower environmental impacts, they face desertification and less water availability, genetic erosion, soil degradation and degradation of rangelands, competitions for land use. The needs of policy on more research, education, micro credits, organization and extension are enhanced. A global review of publications in the main scientific journals shows that relatively few works are still dedicated to marketing, Economic development, management and productions systems. The main subjects related to these challenges are the control of emergent diseases and parasites, the improvement of nutrition in harsh conditions, the genetic characterization of local breeds. But these results confirm that most articles have few links with the demand for innovation. The several journals in social science publish relatively few works on these livestock activities. To face these challenges, the discussion proposes new forms of governance in which priority is given to the participation of all stakeholders and the confrontation between local and scientific knowledge. This would have consequences on educational programs and training. The awareness of the public powers on these questions has to be improved by a coordinated and argued active communication. At short term, new types of events and conferences at local and international levels have to be created to manage innovation and transitions towards the necessary destabilizing changes

Refeeding syndrome encompasses fluid and electrolyte imbalances and metabolic, intestinal, and cardiorespiratory derangements associated with appreciable morbidity and mortality. Although refeeding syndrome has been well documented in concentration-camp subjects, and more recently during parenteral therapy of critically ill patients, little is known about the importance of refeeding syndrome during recovery from a hunger strike. Thus, we studied the response to a four-step dietary replenishment routine in eight hunger strikers who refused food for 43 d. In this retrospective, observational study, we assessed the safety and efficacy of the refeeding procedure and analyzed the clinical and nutritional course of the cohort during both starvation and refeeding, mainly on the basis of clinical as well as a few biochemical determinations. During starvation, average weight loss was about 18% and, with the exception of occasional oral vitamins and electrolytes, the subjects consumed only water. Available body-composition and biochemical profiles showed no clinically significant changes during starvation, but one-half of the group displayed spontaneous diarrhea at some time before refeeding. Stepwise nutritional replenishment lasted for 9 d, after which all patients tolerated a full, unrestricted diet. Only one episode of diarrhea occurred during this phase, and both clinical and biochemical indexes confirmed a favorable clinical course, without any manifestation of refeeding syndrome. In conclusion, we observed the following: 1) Hypophosphatemia and other micronutrient imbalances did not occur, nor was macronutrient intolerance detected. 2) Despite some episodes of diarrhea, nutritional replenishment was not associated with significant enteral dysfunction. 3) There was some fluid retention, but this was mild. 4) Acute-phase markers were abnormally elevated during the refeeding phase, without associated sepsis or inflammation.

Human life quality and preservation of ecosystems are two major topics that depend on environmental quality. In this paper particular attention is dedicated to water conductivity assessment in estuarine zones. Estuarine zones are generally surrounded by people concentration, that use those places as residential zones, and also by industrial plants that take advantage of water availability to generally cool, and sometimes warm (e.g., liquid natural gas plants), their industrial equipments. At the same time boats, particularly those that transport hydrocarbons, represent also a danger that can affect water quality. This paper includes the design and implementation of a low-cost conductivity sensor, its metrological characterization and a detailed description of the calibration techniques used to compensate errors caused by temperature variation.

North American coastal sandplain heathlands are unique in species composition and vegetation, but the extent to which edaphic factors influence the structure of these communities is currently debated. It was hypothesized that salt spray and edaphic factors maintain the dwarf stature and community composition of heathlands by limiting plant growth and excluding competitively dominant woody species close to the ocean. Field surveys were carried out to investigate the spatial patterns of salt spray accumulation, soil salt and soil moisture. High salt spray correlated significantly with increased leaf necrosis and water stress in Myrica pensylvanica and with decreased plant height. Plant community composition changed across a salt spray and soil gradient, as well. Distinctive sub-communities were identified that separated according to soil salt and soil moisture but salt spray was the main factor affecting sites occupied only by heathland vegetation. Results from this study suggest that salt spray suppresses the growth of heathland plants in close proximity to the ocean, and therefore maintains the low stature in these dwarf shrublands. This research also demonstrates that the physical environment influences the community structure in heathlands, particularly by limiting tree species from growing in high salt spray, low water availability sites.

As contribution to the 'Second Ghana Dams Forum of the National Dialogue on Dams and Development' scientists of the GLOWA Volta Project (GVP) of the Center for Development Research (ZEF, University of Bonn) have undertaken a hydrological assessment of the likely impact of climate change on Black Volta River and the Bui Dam. Two different studies that investigate the impact

The reclamation of effluent from wastewater treatment plants to be applied as an alternative water source is usually linked to reasons of water scarcity in the sense of unmatched temporary or structural water demand. Uneven spatial distribution and seasonal variations in water demand and in the hydrological cycle make the semi-arid coastal planes and islands of the Mediterranean particularly indicated for the use of reclaimed water as a useful droughtproof conservation measure. In the moderate climates of northern Europe, however, at first sight, one may think that there should be sufficient amounts of water available to support all possible water uses. However, the reuse of water in northern Europe can be an important asset to preserve or improve the quality of the existing water bodies. In simplified terms, 'reuse' of water in Northern Europe is dictated by quality aspects rather than by quantity. The main reason for the use of reclaimed water today is to conserve good quality (ground)water resources to applications requiring high-quality water such as the make-up of potable water. The water management in Flanders, the northern region of Belgium, is a good example of this situation, and will be discussed in the following paper.

Although some invasive plants are cosmopolitan, not all ecosystems are invaded to the same degree. Yet there is little experimental work on how ecosystem resistance to invasion at the establishment phase differs among ecosystems. We conducted two field sowing experiments in two consecutive years to examine establishment of the deciduous tree Ailanthus altissima , the succulent subshrub Carpobrotus spp. and the annual geophyte Oxalis pes-caprae in coastal dunes, shrublands and oldfields in more than 200 sites across six Mediterranean Basin islands differing in climatic conditions and local species richness. Establishment success (i.e. percentage of plots with at least one seedling) and rates (i.e. seedling to sown seed ratio) were low, especially for Ailanthus even when accounting for differences in seed viability. Oxalis was capable of producing a new cohort of seedlings the year following planting. By contrast, all Ailanthus seedlings and half the Carpobrotus seedlings died following the first summer. Differences in establishment success and rates among ecosystems were species-, island-and year-dependent. Differences in precipitation and mean temperature were associated with differences in establishment rates across sites. Establishment rates tended to be positively correlated with cumulative precipitation and negatively with mean T a. Unexpectedly, native species richness was not a good predictor of seedling establishment, except for higher Oxalis establishment success in species rich habitats. By conducting field sowing tests at multiple sites across a region we found that except for Oxalis , Mediterranean island ecosystems are quite resistant to invader establishment. These results suggest that differences in the degree of invasion between ecosystems and islands might be more dependent upon the influence of invasion event factors (e.g. propagule pressure) or factors acting at a later life-history stages rather than differences in the resistance imposed by ecosystems to invader recruitment. Moreover, our results support the notion that in Mediterranean ecosystems invasions are highly idiosyncratic events and strongly dependent on water availability conditions.

SUMMARY - It is nowadays widely accepted that the increasing concentration of the so-called greenhouse gases in the atmosphere is altering the Earth's radiation balance and causing the temperature to rise. This process in turn provides the context for a chain of events which leads to changes in the different components of the hydrological cycle, such as evapotranspiration rate, intensity

The effects of climate change and variability on water availability in Ghana is being felt throughout the country. Coping with water scarcity has become a major issue. Most communities in the Offin River basin are rural with no pipe-borne water, and consist predominantly of farmers who depend on irrigation for their crops. The basin provides the communities with water for drinking, and for other economic activities. Benjamin Apraku Gyampoh, Monica Idinoba and Steve Amisah look at livelihood options to cope with water scarcity as the climate situation worsens in the coming years.

Crop-pasture rotations (CPR) are unusual around the world but have been the predominant cropping system in Uruguay since the 1960s. Uruguay has a temperate sub-humid climate, 80% of its landscape (16 Mha) is climax grasslands C 3 and C 4 species. Beef, wool, and dairy are the main commodities. Crops occupy a portion of the remaining 20% land area, primarily on Argiudolls and Vertisols, rotated with seeded grass and legume pastures. Continuous cropping (CC) with conventional tillage (CT) has proven unsustainable due to decreased soil productivity. Seeded pasture periods increased soil productivity. CPR adoption created less variable inter-annual economic results, but soil degradation remained a major concern during the crop cycle using CT. Farmers and technicians became interested in no-till (NT) to reduce erosion and production cost. Currently, approximately 52% of crop producing farms and 25% of dairy farms have adopted NT. This paper synthesizes research results (mainly from long-term experiments) contrasting CC versus CPR with CT (1960CT ( -1990 and NT (from 1990). Soil erosion was reduced more than six times with NT in CC, and almost three times in CPR compared with CC using CT; but combining the use of CPR and NT resulted in the same low erosion rate as under natural pasture. The transition from CT to NT is not always easy. The time between herbicide application to pasture and planting of the first crop of the rotation crop cycle with NT is a critical transition factor to optimize N and water availability, and soil tilth. Chiseling or paraplowing can alleviate plow-pans inherited by NT from previous CT; but higher soil strength at the soil surface under NT contributes to better forage utilization under grazing. Soil organic carbon (SOC) content in CC decreased with CT, and was maintained with NT only if grain was harvested. In CC systems with harvested forage, SOC decreased even with NT. CPR with NT maintained or increased the original SOC content. The paper concludes with a discussion on the relative sustainability of CC versus CPR with NT. Both are sustainable from the soil quality and productivity standpoints. But compared with CC, CPR is a more economically and climatically buffered system, due to higher diversity. Also, CPR systems are more environmentally sustainable since fuel and agrochemicals usage is reduced approximately 50%.

Freshwater availability has been recognized as a global issue, and its consistent quantification not only in individual river basins but also at the global scale is required to support the sustainable use of water. The WaterGAP Global Hydrology Model WGHM, which is a submodel of the global water use and availability model WaterGAP 2, computes surface runoff, groundwater recharge and river discharge at a spatial resolution of 0.58. WGHM is based on the best global data sets currently available, and simulates the reduction of river discharge by human water consumption. In order to obtain a reliable estimate of water availability, it is tuned against observed discharge at 724 gauging stations, which represent 50% of the global land area and 70% of the actively discharging area. For 50% of these stations, the tuning of one model parameter was sufficient to achieve that simulated and observed long-term average discharges agree within 1%. For the rest, however, additional corrections had to be applied to the simulated runoff and discharge values. WGHM not only computes the long-term average water resources of a country or a drainage basin but also water availability indicators that take into account the interannual and seasonal variability of runoff and discharge. The reliability of the modeling results is assessed by comparing observed and simulated discharges at the tuning stations and at selected other stations. The comparison shows that WGHM is able to calculate reliable and meaningful indicators of water availability at a high spatial resolution. In particular, the 90% reliable monthly discharge is simulated well. Therefore, WGHM is suited for application in global assessments related to water security, food security and freshwater ecosystems. q

About 600 earthen small dams were constructed in southern Zimbabwe during the last 40 years. A large number of the small dams are in poor physical condition. Therefore most of the dams are likely to fail threatening security of water availability and livelihoods in the area. To assist those involved in maintenance, repair and rehabilitation of small dams, a risk of failure evaluation tool was developed. The tool helps to systematically and objectively classify risk of failure of small dams, hence assist in the ranking of dams to prioritise and attend to first. This is important where resources are limited. The tool makes use of factors such as seepage, erosion and others that are traditionally used to assess condition of dams. In the development of the tool, the factors were identified and listed according to guidelines for design and maintenance of small dams. Inspection of the physical condition of 44 small dams was carried out in Mzingwane catchment. The description of the extent to which the factors affect the physical condition of small dams was then standardised. This was mainly guided by similar methods used in other countries but mostly for large dams and by HR Wallingford's methodology for estimating risk of soil erosion. Cause-effect diagrams were used to determine the stage at which each factor is involved in contributing to dam failure. Weights were then allocated to each factor depending on its stage in the process of causing dam failure. Scores were allocated to each factor based on its description and weight. Design and maintenance guidelines were also used to guide the ranking and weighting of the factor. The tool was used to classify 7 small dams in Mzingwane catchment. The risk of failure was moderate for one dam, high for four and very high for two dams. The results were similar to findings from physical condition assessments. It was concluded that the tool could be used in ranking of the risk of failure of small dams in semi arid communal areas. The tool needs to be tested in a wider geographical area to improve its usefulness.

The expansion of the Prosopis genus from the sub-humid Chaco towards colder and drier zones such as Monte, Prepuna and Patagonia .biogeographical regions would have implied the acquisition and/or adjustment of morphological and physiological adaptations to stressful environments. In this chapter, we discuss the phenological, morphological and physiological features of seven Prosopis species native to Argentinean arid regions that allow them to avoid or tolerate water stress, salinity, and other environmental stress factors in arid lands. Some of these adaptations appear to be spread over the genus and should confer the capability to deal with the most common stressful factor of arid lands (i.e. water availability); however, other morphological or physiological adaptations appear to be specific to each species, and should be the cause of niche differentiation among species and the occupation of particular environments within arid lands (e.g. sand dunes, salive environments). Finally, we díscuss some consequences of these adaptations for the management of Prosopis species. The inter-and intra-specific variability observed in their adaptation to stressful factors suggest that some Prosopis species may be a good option to be used in the restoration of degraded areas or in afforestation projects with productive objectives.

Conversion of natural habitats to human settlements creates an alternative habitat with different bio-physical characteristics such as micro-climatic conditions and resource availability. Deserts are especially sensitive to such effects due to generally low nutrient levels and water availability. Gardens in human settlements in the desert are often a main source of alien plant species that provide ample foraging resources year round. These changes in floral composition and availability may alter pollinator community composition and foraging behaviour, as well as pollination network characteristics. We investigated the effects of desert gardening on pollinator communities and pollination networks in the Jordan Rift Valley (Israel), an arid agro-natural landscape south of the Dead Sea. We studied seasonal diversity patterns of plants and wild bees in natural habitats and in gardens in settlements. Wild bees and blooming plants were sampled from February to July in 2007 and in 2008. We constructed plant-pollinator networks and compared bee communities between the two habitat types along the season. We found that bee abundance was greater in the gardens, and that rarefied bee species richness was greater in the natural habitat. Bee species richness and abundance exhibited contrasting seasonal patterns between habitats. Bee community composition also differed greatly between habitats, and species in the gardens had a generally wider geographical range in comparison to species in the natural habitat. We also found a higher level of generalisation of the pollination network in the gardens compared to the natural habitat, which may indicate a response to a disturbed and unstable environment. We conclude that gardening in deserts although promoting overall bee abundance, negatively affects species richness and changes community composition and network characteristics, with possible implications on the composition of native flora in the natural habitat surrounding the gardens. A. Gotlieb et al. / Basic and Applied Ecology 12 (2011) 310-320 311 2008 erfasst. Wir konstruierten Diagramme der Pflanzen-Bestäuber-Netzwerke und verglichen die Bienengemeinschaften der beiden Habitattypen im Laufe der Saison. Wir fanden, dass die Bienenabundanz in den Gärten größer war und dass die rarefizierte Artenzahl in den natürlichen Habitaten höher war. Artenreichtum und Abundanz der Bienen zeigten unterschiedliche jahreszeitliche Muster. Die Zusammensetzung der Bienengemeinschaften der beiden Habitattypen war ebenfalls unterschiedlich. Die Arten der Gärten hatten ein größeres geographisches Verbreitungsgebiet als die Arten des natürlichen Habitats. Im Vergleich zum natürlichen Habitat fanden wir auch einen höheren Grad der Generalisierung im Pollinationsnetzwerk der Gärten. Dies könnte ein Indikator für eine gestörte, instabile Umwelt sein. Wir folgern, dass das Anlegen von Gärten in Wüsten, obwohl die Gesamtbienenabundanz erhöht wird, den Artenreichtum negativ beeinflusst sowie Artenzusammensetzung und Netzwerkeigenschaften verändert, was Auswirkungen auf die einheimische Flora der natürlichen Habitate in der Umgebung von Gärten haben kann.

Alterations in VO(2) or VCO(2) are amongst the more polemical physiological adaptations ascribed to insects. Generally, metabolic rate is thought to be lowered in response to arid conditions, and elevated in species from cold environments compared to their more temperate relatives. However, most studies have rarely addressed the influence of both environmental factors in unison. To this end, standard metabolic rate and its temperature dependence were measured (at 4 degrees C intervals from 16 to 32 degrees C) in six Scarabaeus dung beetle species (three flightless, three volant) from a variety of habitats (warm, arid to cool, mesic) in southern Africa using flow-through respirometry. Mass specific VCO(2) varied from 0.0158 ml g(-1) h(-1) at 16 degrees C to 0.1839 ml g (-1) h(-1) at 32 degrees C. The slopes of the rate temperature curves were similar for all species (Q(10)s of 2.14-2.84), although the intercepts differed significantly in the direction (warm arid to cool mesic): S. gariepinus<S. hippocrates<S. striatum<S. galenus<S. rusticus<S. westwoodi. General linear models were fitted to the VCO(2) data with treatment temperature, wing status, mean annual rainfall and mean annual temperature as the independent variables. For all six species, the best fit model included treatment temperature and wing status only. Flightless species had significantly lower VCO(2)s than did winged ones. Amongst the flightless species, S. gariepinus, from the driest area, had the lowest VCO(2). Among the winged species it was impossible to determine whether environmental temperature or water availability were most important in influencing VCO(2); both were significant. We conclude that investigations of metabolic rate modulation, and especially metabolic cold adaptation, in insects must take both temperature and water availability into account.

Groundwater and surface flow depletions are altering riparian ecosystems throughout the southwestern United States. Due in large part to hydrologic alterations and land use changes, forests of the pioneer trees Populus fremontii (Fremont cottonwood) and Salix gooddingii (Goodding willow) have declined. In many areas these forests have been replaced by shrublands and woodlands of Tamarix ramosissima (salt cedar). Previous work has focused on the physiological responses of these riparian plant species to decreases in water availability, but little attention has been given to shifts in community and population structure (size class diversity, canopy cover, basal area, vegetation volume, and stem density) in response to declines in surface flow duration and groundwater levels. This study identified hydrologic thresholds above which P. fremontii-S. gooddingii maintain tall dense stands with diverse age classes, and above which they are more abundant than T. ramosissima stands along the San Pedro River in Arizona. Populus fremontii and S. gooddingii were dominant at sites where average maximum depth to groundwater was less than 2.9 meters (m), annual groundwater fluctuation was less than 0.6 m, and surface flow was present more than 73% of the months during a two-year period of data collection. Because T. ramosissima is a shrub species with smaller leaves and lower canopy heights than P. fremontii and S. gooddingii, these shifts in species composition corresponded to decreases in maximum canopy height and upper stratum (above 8 m) vegetation volume as site water availability declined. Sites with deeper water tables and lower flow frequencies had greater areal coverage of shrublands and less woodland coverage. The altered vegetation structure along dewatered rivers may provide poorer quality wildlife habitat. This study provides river managers with quantitative hydrologic guidelines for conserving tall dense P. fremontii-S. gooddingii stands and emphasizes the importance of maintaining long-term hydrologic conditions that are favorable to these species. This project has four components with each addressing an aspect of how humanimposed drought stress, as well as subsequent rewatering of rivers, influences competitive abilities and relative abundances of native (Fremont cottonwood and Goodding willow) and exotic (salt cedar) riparian tree species.

Soil erosion is a growing problem in southern Greece and particularly in the island of Crete, the biggest Greek island with great agricultural activity. Soil erosion not only decreases agricultural productivity, but also reduces the water availability. In the current study, an effort to predict potential annual soil loss has been conducted. For the prediction, the Revised Universal Soil Loss Equation (RUSLE) has been adopted in a Geographical Information System framework. The RUSLE factors were calculated (in the form of raster layers) for the nine major watersheds which cover the northern part of the Chania Prefecture. The R-factor was calculated from monthly and annual precipitation data. The K-factor was estimated using soil maps available from the Soil Geographical Data Base of Europe at a scale of 1:1,000,000. The LS-factor was calculated from a 30-m digital elevation model. The C-factor was calculated using Remote Sensing techniques. The P-factor in absence of data was set to 1. The results show that an extended part of the area is undergoing severe erosion. The mean annual soil loss is predicted up to *200 (t/ha year -1 ) for some watersheds showing extended erosion and demanding the attention of local administrators.

Water is critical to paper production and increasing competition from other users has reduced water availability to paper mills in recent years. The study was conducted at a large-scale integrated pulp and paper industry. The study conducted at laboratory for recycling of effluents was aimed at reducing water foot print of the paper mill. Paper machine section effluent was identified for treatment and reuse based on the flow and characteristics. Chemical aided clarification and simple membrane filtration systems were used for water recovery. Closing the water loop through suitable treatment for reuse of wastewater in the paper mills provides an assured and continuous source of water. Pollutant reductions at the rate of 87.5%, 75% and 89% were obtained on SS, COD and turbidity, respectively. Operational and capital costs were delineated for selection of treatment option and enhanced water recovery. Feasibility of micro/ultra filtration combination was assessed to reduce costs for water recovery. This combination removed up to 93% and 91.7% of SS and COD from the effluents. The treatment options assessed for water recovery reduced freshwater consumption by about 40% and the excess treated water was stored in ponds for process use during the lean season.

In this review, we provide an overview of the role of glucosinolates and other phytochemical compounds present in the Brassicaceae in relation to plant protection and human health. Current knowledge of the factors that influence phytochemical content and profile in the Brassicaceae is also summarized and multi-factorial approaches are briefly discussed. Variation in agronomic conditions (plant species, cultivar, developmental stage, plant organ, plant competition, fertilization, pH), season, climatic factors, water availability, light (intensity, quality, duration) and CO(2) are known to significantly affect content and profile of phytochemicals. Phytochemicals such as the glucosinolates and leaf surface waxes play an important role in interactions with pests and pathogens. Factors that affect production of phytochemicals are important when designing plant protection strategies that exploit these compounds to minimize crop damage caused by plant pests and pathogens. Brassicaceous pl...

Water resources of a country constitute one of its vital assets. India receives annual precipitation of about 4000 km 3 . The rainfall in India shows very high spatial and temporal variability and paradox of the situation is that Mousinram near Cherrapunji, which receives the highest rainfall in the world, also suffers from a shortage of water during the non-rainy season, almost every year. The total average annual flow per year for the Indian rivers is estimated as 1953 km 3 . The total annual replenishable groundwater resources are assessed as 432 km 3 . The annual utilizable surface water and groundwater resources of India are estimated as 690 km 3 and 396 km 3 per year, respectively. With rapid growing population and improving living standards the pressure on our water resources is increasing and per capita availability of water resources is reducing day by day. Due to spatial and temporal variability in precipitation the country faces the problem of flood and drought syndrome. Overexploitation of groundwater is leading to reduction of low flows in the rivers, declining of the groundwater resources, and salt water intrusion in aquifers of the coastal areas. Over canal-irrigation in some of the com-mand areas has resulted in waterlogging and salinity. The quality of surface and groundwater resources is also deteriorating because of increasing pollutant loads from point and non-point sources. The climate change is expected to affect precipitation and water availability. So far, the data collection, processing, storage and dissemination have not received adequate attention. The efforts initiated under the Hydrology Project Phase-I and the development of the Decision Support System proposed under Hydrology Project Phase-II are expected to bridge some of the gaps between the developed advanced technologies of water resources planning, designing and management and their field applications. The paper presents availability and demands of water resources in India as well as describes the various issues and strategies for developing a holistic approach for sustainable development and management of the water resources of the country. It also highlights integration of the blue and green flows and concepts of virtual water transfer for sustainable management of the water resources for meeting the demands of the present, without compromising the needs of future generations.

The Upper Barremian deposits of La Huérguina Limestone Formation in the Serranía de Cuenca (Iberian Ranges, Spain) contain rich continental fossil associations preserved under a great diversity of taphonomic conditions in alluvial and lacustrine deposits. The vertebrate association retrieved from the Buenache de la Sierra Subbasin is described in detail and compared to other localities of La Huérguina Formation (Uña and Las Hoyas). The association was found at El Inglés Quarry, in a level composed of grey to ochre slabby marly siltstones, sometimes slightly sandy, with abundant plant macroremains sedimented in a small stagnant pond. The pond was part of a complex and mixed (siliciclastic and carbonatic) depositional system, controlled by a seasonal subtropical climate. It consisted of distal alluvial plains grooved by narrow channels with scattered ponds, small shallow lakes and palustrine marshy areas, fed by superficial water and groundwater. These underwent seasonal floods followed by slow draining and evaporation and finally a seasonal period of desiccation.

In order to characterize the main areas of natural forest on Terceira Island ͑Azores͒, some of the most interesting European forests due to their rich and diverse flora of endemic as well as relict species, six forest stands were studied and their flora inventoried using 226 randomized quadrats, which revealed one anthocerote, 64 liverworts, 41 mosses and 16 macrolichen taxa. The alpha-diversity of the samples is particularly species-rich, some quadrats ͑30 ϫ 30 cm͒ including more than 25 bryophyte species. A quantitative analysis of the vegetationenvironment relationships consistently showed that the distributions of the native forest bryophytes and lichens of Terceira are governed by a complex set of factors related to water availability, the status of the substrata and the influences of the vascular plant community. Considering the generally high values of the Sørensen indices and the low number of specialist species found with Lloyd's index, the differences are more in terms of dominance of species than in terms of species composition. In fact, substratum type was clearly important in the DCA and TWINSPAN analysis using species cover abundance values, largely explaining the distribution of bryophyte species between Juniperus brevifolia ͑Seub.͒ Antoine and Laurus azorica ͑Seub.͒ Franco bark. The eight putative plant community type groupings achieved with these multivariate methods were able to elucidate some major bryophyte -substratum relationships, that had not previously been considered and they offer a framework for future research. 1953;, and the communities present have not been the main focus. Previous studies ͑Hübschmann 1974; suggest that the bryophyte veg-

Wetland ecosystems are important habitats for flora and fauna and hence are of national and international importance for conservation. Wetlands can be defined as areas of high groundwater environments that are characterised by permanent (shallow water bodies) or temporary inundation, or soils having hydric properties. They provide a number of critical ecological functions, including the regulation of water regimes, and support a significant percentage of the world's biodiversity that have adapted to life in saturated conditions. Wetland ecosystems depend on water levels and therefore climate change, especially changes in precipitation, is likely to have a significant impact on these habitats and associated species. A modelling assessment of water balance was undertaken for the UK and Ireland using current and future climate scenarios. Results showed that water availability could increase in winter across the whole region, and northwest Ireland and northwest Scotland could have a small increase in water availability in the summer. Other regions would experience little change or have decreased water availability during the summer months; this being most severe in southeast England. A local-scale study of a wetland habitat in East Anglia indicated that significant seasonal stresses could occur due to climate change and the associated lowering of water levels.

This paper provides discussion of ways in which an interdisciplinary approach can be taken to produce an integrated assessment of water stress and scarcity, linking physical estimates of water availability with socioeconomic variables that reflect poverty, i.e., a Water Poverty Index. It is known that poor households often suffer from poor water provision, and this results in a significant loss of time and effort, especially for women. By linking the physical and social sciences to address this issue, a more equitable solution for water allocation may be found. For the purpose of initiating discussion, a summary of different approaches to establishing a Water Poverty Index is discussed. Ó