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Drought
Kinds of Drought Terms modified by Drought Selected AbstractsTOWARDS CHARACTERIZING AND PLANNTNG FOR DROUGHT IN VERMONT-PART II: POLICY IMPLICATIONS,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2001Lesley-Ann Dupigny-Giroux ABSTRACT: Vermont is one of approximately half a dozen states for which no official drought mitigation plan exists. Given the recurring nature of this natural hazard, current contingency measures should be expanded upon into a coherent mitigation framework. The types of drought and impacts resulting from the 1998 to 1999 event were the focus of a previous article in this volume. The present article builds on the understanding of drought characteristics specific to the Vermont context and introduces the rationale behind a proposed drought planning framework. Pivotal organizations and institutions that should be involved in this process are also presented. [source] NATURE, MARKETS AND STATE RESPONSE: THE DROUGHT OF 1939 IN JAPAN AND KOREAAUSTRALIAN ECONOMIC HISTORY REVIEW, Issue 1 2010Janet Hunter drought; hydroelectricity; Japan; Korea; rice production Large areas of Northeast Asia experienced drought in 1939. Agricultural production in Korea decreased significantly, but the drought did not cause famine in Japan despite its dependence on rice imports from Korea. The paper analyses the impact of the 1939 drought on the markets for rice and electricity in Japan. The authorities were ill-prepared for such a disaster but willing to use it for the purpose of covering for other problems. The drought thus accelerated the move of Japan's economic system towards a managed economy. A lower total rainfall in Japan in 1940 did not generate similar problems, suggesting that the broader political, economic, and social context is crucial to the identification of short-term climatic fluctuations as crises. [source] Coping with Crisis,Smoke, Drought, Flood and Currency: Iban Households in West Kalimantan, IndonesiaCULTURE, AGRICULTURE, FOOD & ENVIRONMENT, Issue 1 2002Professor Reed L. Wadley First page of article [source] Drought, Domestic Budgeting and Wealth Distribution in Sahelian HouseholdsDEVELOPMENT AND CHANGE, Issue 5 2000Matthew Turner Over the past twenty-five years, Sahelian households have experienced recurrent harvest failure and greater reliance on remittances from migratory wage labour. Household subsistence has become less dependent on household grain stores and more on the liquidation of individual wealth stores. This study investigates how these broader changes have affected struggles between household members over obligations to support the household in the Zarmaganda region of western Niger. As the land-derived leverage of male patriarchs has declined and household dependence on individual wealth stores has increased, domestic budgeting has become more contested. Household heads make case-by-case moral claims on other household members during times of grain shortage. Women and subordinate males invoke Islamic law, which accords primary provisioning responsibility to the household head, to protect their individual wealth in times of grain deficit. This article investigates the nature of these budgetary struggles, showing how individuals' decisions to contribute individual wealth to support the household are best understood as highly situated, affected not only by the specific material conditions of the household but also the interplay of the moral, structural, and individualistic imperatives that derive from one's position within the household. Using reconstructed livestock wealth histories for the members of fifty-four households in western Niger, this study investigates the material consequences of these struggles. Male heads of corporate households, the historic managers of the household's land and agricultural labour, have lost wealth relative to their wives and married male subordinates since the drought of 1984. [source] Changing household responses to drought in Tharaka, Kenya: vulnerability, persistence and challengeDISASTERS, Issue 2 2008Thomas A. Smucker Drought is a recurring challenge to the livelihoods of those living in Tharaka District, Kenya, situated in the semi-arid zone to the east of Mount Kenya, from the lowest slopes of the mountain to the banks of the Tana River. This part of Kenya has been marginal to the economic and political life of Kenya from the colonial period until the present day. A study of more than 30 years of change in how people in Tharaka cope with drought reveals resilience in the face of major macro-level transformations, which include privatisation of landownership, population growth, political decentralisation, increased conflict over natural resources, different market conditions, and environmental shifts. However, the study also shows troubling signs of increased use of drought responses that are incompatible with long-term agrarian livelihoods. Government policy needs to address the challenge of drought under these new macro conditions if sustainable human development is to be achieved. [source] Destocking as a Drought,mitigation Strategy: Clarifying Rationales and Answering CritiquesDISASTERS, Issue 3 2002John Morton The idea of externally assisted emergency destocking of pastoralists has gained currency in recent years: increasing the incentives for pastoralists to sell animals, or removing the constraints to selling animals in the early stages of drought. We identify two separate rationales put forward by proponents of destocking: environmental benefits and purchasing power/welfare benefits. We consider whether specific recent critiques of ,new range ecology' and specifically of ,tracking policies' do in fact provide arguments against emergency destocking in pastoralist areas. We illustrate some of these themes with a case study of a successful destocking exercise in northern Kenya where a very specific form of support was requested and received by pastoralists themselves. The sorts of destocking that work are likely to have significant effects on pastoralist purchasing power at key points of the drought cycle, but minimal effects on the environment. Clarifying these points will make it easier to promote destocking as a drought,mitigation policy. [source] Gender and Drought: Experiences of Australian Women in the Drought of the 1990sDISASTERS, Issue 1 2000Daniela Stehlik A unique collaborative, sociological study undertaken during 1995,7, explored the social construction of drought as a disaster, with farm families in two Australian states: Queensland (beef producers) and New South Wales (sheep/wheat producers). A decision was made to interview the women and men separately to test our hypothesis that there would be gender issues in any analysis of a disaster, but particularly one which has such a long-term impact on individuals, families and communities, such as drought. Interviews were conducted with over 100 individuals male and female. We conclude that drought as a disaster is a gendered experience. The paper draws on the narratives of some women involved in the study to identify ,themes of difference' which confirm the necessity to maintain gender as a variable in all studies of the social impacts of disaster. [source] Drought changes phosphorus and potassium accumulation patterns in an evergreen Mediterranean forestFUNCTIONAL ECOLOGY, Issue 2 2007J. SARDANS Summary 1Climate models predict more extreme weather in Mediterranean ecosystems, with more frequent drought periods and torrential rainfall. These expected changes may affect major process in ecosystems such as mineral cycling. However, there is a lack of experimental data regarding the effects of prolonged drought on nutrient cycling and content in Mediterranean ecosystems. 2A 6-year drought manipulation experiment was conducted in a Quercus ilex Mediterranean forest. The aim was to investigate the effects of drought conditions expected to occur over the coming decades, on the contents and concentrations of phosphorus (P) and potassium (K) in stand biomass, and P and K content and availability in soils. 3Drought (an average reduction of 15% in soil moisture) increased P leaf concentration by 18·2% and reduced P wood and root concentrations (30·9% and 39·8%, respectively) in the dominant tree species Quercus ilex, suggesting a process of mobilization of P from wood towards leaves. The decrease in P wood concentrations in Quercus ilex, together with a decrease in forest biomass growth, led to an overall decrease (by approximately one-third) of the total P content in above-ground biomass. In control plots, the total P content in the above-ground biomass increased 54 kg ha,1 from 1999 to 2005, whereas in drought plots there was no increase in P levels in above-ground biomass. Drought had no effects on either K above-ground contents or concentrations. 4Drought increased total soil soluble P by increasing soil soluble organic P, which is the soil soluble P not directly available to plant capture. Drought reduced the ratio of soil soluble inorganic P : soil soluble organic P by 50% showing a decrease of inorganic P release from P bound to organic matter. Drought increased by 10% the total K content in the soil, but reduced the soil soluble K by 20·4%. 5Drought led to diminished plant uptake of mineral nutrients and to greater recalcitrance of minerals in soil. This will lead to a reduction in P and K in the ecosystem, due to losses in P and K through leaching and erosion, if the heavy rainfalls predicted by IPCC (Intergovernmental Panel on Climate Change) models occur. As P is currently a limiting factor in many Mediterranean terrestrial ecosystems, and given that P and K are necessary for high water-use efficiency and stomata control, the negative effects of drought on P and K content in the ecosystem may well have additional indirect negative effects on plant fitness. [source] Hydraulic differentiation of Ponderosa pine populations along a climate gradient is not associated with ecotypic divergenceFUNCTIONAL ECOLOGY, Issue 4 2002H. Maherali Summary 1.,Pinus ponderosa occurs in a range of contrasting environments in the western USA. Xeric populations typically have lower leaf : sapwood area ratio (AL/AS) and higher whole-tree leaf specific hydraulic conductance (KL) than mesic populations. These climate-driven shifts in hydraulic architecture are considered adaptive because they maintain minimum leaf water potential above levels that cause xylem cavitation. 2.,Using a common garden study, we examined whether differences in biomass allocation and hydraulic architecture between P. ponderosa populations originating from isolated outcrops in the Great Basin desert and Sierran montane environments were caused by ecotypic differentiation or phenotypic plasticity. To determine if populations were genetically differentiated and if phenotypic and genetic differentiation coincided, we also characterized the genetic structure of these populations using DNA microsatellites. 3.,Phenotypic differentiation in growth, biomass allocation and hydraulic architecture was variable among populations in the common garden. There were no systematic differences between desert and montane climate groups that were consistent with adaptive expectations. Drought had no effect on the root : shoot and needle : stem ratio, but reduced seedling biomass accumulation, leaf area ratio, AL/AS and KL. Stem hydraulic conductance (KH) was strongly size-dependent, and was lower in droughted plants, primarily because of lower growth. 4.,Although microsatellites were able to detect significant non-zero (P < 0·001) levels of differentiation between populations, these differences were small and were not correlated with geographic separation or climate group. Estimates of genetic differentiation among populations were low (<5%), and almost all the genetic variation (>95%) resided within populations, suggesting that gene flow was the dominant factor shaping genetic structure. 5.,These results indicate that biomass allocation and hydraulic differences between desert and montane populations are not the result of ecotypic differentiation. Significant drought effects on leaf : sapwood allocation and KL suggest that phenotypic differentiation between desert and montane climates could be the result of phenotypic plasticity. [source] Effects of drought on avian community structureGLOBAL CHANGE BIOLOGY, Issue 8 2010THOMAS P. ALBRIGHT Abstract Droughts are expected to become more frequent under global climate change. Avifauna depend on precipitation for hydration, cover, and food. While there are indications that avian communities respond negatively to drought, little is known about the response of birds with differing functional and behavioural traits, what time periods and indicators of drought are most relevant, or how response varies geographically at broad spatial scales. Our goals were thus to determine (1) how avian abundance and species richness are related to drought, (2) whether community variations are more related to vegetation vigour or precipitation deviations and at what time periods relationships were strongest, (3) how response varies among avian guilds, and (4) how response varies among ecoregions with different precipitation regimes. Using mixed effect models and 1989,2005 North American Breeding Bird Survey data over the central United States, we examined the response to 10 precipitation- and greenness-based metrics by abundance and species richness of the avian community overall, and of four behavioural guilds. Drought was associated with the most negative impacts on avifauna in the semiarid Great Plains, while positive responses were observed in montane areas. Our models predict that in the plains, Neotropical migrants respond the most negatively to extreme drought, decreasing by 13.2% and 6.0% in abundance and richness, while permanent resident abundance and richness increase by 11.5% and 3.6%, respectively in montane areas. In most cases, response of abundance was greater than richness and models based on precipitation metrics spanning 32-week time periods were more supported than those covering shorter time periods and those based on greenness. While drought is but one of myriad environmental variations birds encounter, our results indicate that drought is capable of imposing sizable shifts in abundance, richness, and composition on avian communities, an important implication of a more climatically variable future. [source] Study of indices for drought characterization in KBK districts in Orissa (India)HYDROLOGICAL PROCESSES, Issue 12 2008R. P. Pandey Abstract Drought is a temporary, random and regional climatic phenomenon, originating due to lack of precipitation leading to water deficit and causing economic loss. Success in drought alleviation depends on how well droughts are defined and their severity quantified. A quantitative definition identifies the beginning, end, spatial extent and the severity of drought. Among the available indices, no single index is capable of fully describing all the physical characteristics of drought. Therefore, in most cases it is useful and necessary to consider several indices, examine their sensitivity and accuracy, and investigate for correlation among them. In this study, the geographical information system-based Spatial and Time Series Information Modeling (SPATSIM) and Daily Water Resources Assessment Modeling (DWRAM) software were used for drought analysis on monthly and daily bases respectively and its spatial distribution in both dry and wet years. SPATSIM utilizes standardized precipitation index (SPI), effective drought index (EDI), deciles index and departure from long-term mean and median; and DWRAM employs only EDI. The analysis of data from the Kalahandi and Nuapada districts of Orissa (India) revealed that (a) droughts in this region occurred with a frequency of once in every 3 to 4 years, (b) droughts occurred in the year when the ratio of annual rainfall to potential evapotranspiration (Pae/PET) was less than 0·6, (c) EDI better represented the droughts in the area than any other index; (d) all SPI, EDI and annual deviation from the mean showed a similar trend of drought severity. The comparison of all indices and results of analysis led to several useful and pragmatic inferences in understanding the drought attributes of the study area. Copyright © 2007 John Wiley & Sons, Ltd. [source] Tree-ring reconstructions of precipitation and streamflow for north-western TurkeyINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 2 2008Ünal Akkemik Abstract We describe tree-ring reconstructions of spring (May-June) precipitation and spring-summer (May-August) streamflow for north-western Turkey, both beginning in AD 1650. These are among the first such reconstructions for the region, and the streamflow reconstruction is among the first of its kind for Turkey and the entire Middle East. The reconstructions, which both emphasize high-frequency variations, account for 34 and 53% of their respective instrumental variance. Comparison to precipitation and runoff data provides some means of verification for the instrumental streamflow record, which is very short (30 years). Drought and flood events in the reconstructions are compared to historical archives and other tree-ring reconstructions for Turkey. The results reveal common climatic extremes over much of the country. Many of these events have had profound impacts on the peoples of Turkey over the past several centuries. Copyright © 2007 Royal Meteorological Society [source] Distributional Patterns of Diatoms and Limnodrilus Oligochaetes in a Kenyan Dry Streambed Following the 1999,2000 Drought ConditionsINTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 2 2005Jude M. Mathooko Abstract Drought is a natural phenomenon experienced by many intermittent and also seasonal lotic systems. It has diverse effects on the structure and distribution of biological communities through habitat transition from wetted to terrestrial conditions. The Njoro River, a tropical stream, was drought-stressed between late 1999 and mid 2000, providing an opportunity to sample and describe the distributional patterns of diatoms and Limnodrilus oligochaetes in the vertical sediment profile. The dispersion of Limnodrilus oligochaetes with sediment depth profile varied from quasi-random (i.e. exponent k of the negative binomial distribution >2.0 or <0) at the surface to strong aggregation (0 < k < 1.0) in the deeper sediments. Diatoms were heterogenous, with most species contributing less than 1% of all the diatoms collected from the riverbed. Contagious dispersion was a common feature among the diatom species. The distribution of Fragilaria ulna was largely quasi-random in all sites, with Nitzschia amphibia and Cocconeis placentula demonstrating quasi-random distribution in the Kerma vertical sediment profile. Escape from stranding to deeper sediment strata as the drought progressed was not a universal response among the diatom species. Our results showed that drought-stress altered the structure of biological assemblages and also emphasized the need for the management of tropical lotic systems and their catchments for flow permanence. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Response of Oryzacystatin I Transformed Tobacco Plants to Drought, Heat and Light StressJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 2 2010K. Demirevska Abstract Transformed tobacco plants expressing a rice cysteine proteinase inhibitor (OC-I) and non-transformed plants were grown in a controlled environment and subjected to various stresses. Two-month-old transformed and non-transformed plants were exposed for 5 days to drought conditions by withholding watering. High temperature (40 °C) was applied additionally at day 6th for 5 h either individually or in combination with drought. All stress treatments were applied under low (150 ,mol m,2 s,1 PPFD) and high light intensity (HL) of 1000 ,mol m,2 s,1 PPFD to determine if OC-I expression might provide protection under combination of stresses usually existing in nature. Drought stress led to diminution in leaf relative water content, photosynthesis inhibition, decrease in chlorophyll content and accumulation of malondialdehyde and proline. Heat stress alone did not affect the plants significantly, but intensified the effect of drought stress. HL intensity further increased the proline content. OC-I transformed plants grown under low light intensity had significantly higher total superoxide dismutase and guaiacol peroxidase activities as well as their isoforms than non-transformed control plants under non-stress and stress conditions. Catalase activity was not highly affected by OC-I expression. Results indicate that OC-I expression in tobacco plants provides protection of the antioxidative enzymes superoxide dismutase and guaiacol peroxidise under both non-stress and stress conditions. [source] Different Patterns of Physiological and Molecular Response to Drought in Seedlings of Malt- and Feed-type Barleys (Hordeum vulgare)JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 1 2010M. Rapacz Abstract A number of physiological and molecular characteristics are proposed as selection criteria for drought tolerance. This study measured the associations between physiological and molecular characteristics of drought response in malting and fodder spring barleys. Plants of 13 malt- and 14 feed-type Polish genotypes were exposed to drought at the four-leaf stage for 7 days. Drought susceptibility indexes (DSI) were calculated for membrane integrity, water status, gas exchange and PSII photochemical activity. Accumulation of HVA1 and SRG6 transcripts in drought was measured with real-time PCR. A wide range of variation in the drought response was observed among studied genotypes. Malting barleys were less sensitive to drought than feed-barleys according to all the traits studied. In both groups, different patterns of relationships between traits were observed. In malting genotypes only, CO2 assimilation rates in drought, as well as PSII efficiency were related to both water content and the accumulation of HVA1 transcript in leaves. On the other hand the SRG6 expression was highly correlated in both groups of barley with the photochemical efficiency of PSII. The results suggest that different physiological, biochemical and molecular characteristics should be applied in the selection towards drought resistance in the case of malting and fodder barleys. [source] Exogenously Applied Nitric Oxide Enhances the Drought Tolerance in Fine Grain Aromatic Rice (Oryza sativa L.)JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 4 2009M. Farooq Abstract Drought stress is a severe threat to the sustainable rice production, which causes oxidative damage and disturbs plant water relations, while exogenously applied nitric oxide (NO) may have the potential to alleviate these effects in rice plants. In this study, the role of NO to improve drought tolerance in fine grain aromatic rice (Oryza sativa L. cv. Basmati 2000) was evaluated. Sodium nitroprusside, a NO donor, was used at 50, 100 and 150 ,mol l,1 both as seed priming and foliar spray. To prime, the seeds were soaked in aerated NO solution of respective solution for 48 h and dried back to original weight. Primed and non-primed seeds were sown in plastic pots with normal irrigation in a greenhouse. At four leaf stage, plants were subjected to drought stress except the controls, which were kept at full field capacity. Drought was maintained at 50 % of field capacity by watering when needed. Two controls were maintained; both receiving no NO treatments as foliar application or seed treatment, one under drought conditions and the other under well-watered conditions. Drought stress seriously reduced the rice growth, but both methods of NO application alleviated the stress effects. Drought tolerance in rice was strongly related to the maintenance of tissue water potential and enhanced capacity of antioxidants, improved stability of cellular membranes and enhanced photosynthetic capacity, plausibly by signalling action of NO. Foliar treatments proved more effective than the seed treatments. Among NO treatment, 100 ,mol l,1 foliar spray was more effective. [source] Effects of Post-Anthesis Drought and Waterlogging on Accumulation of High-Molecular-Weight Glutenin Subunits and Glutenin Macropolymers Content in Wheat GrainJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 2 2009D. Jiang Abstract Drought and flooding during grain filling have become major constraints to wheat quality and yield. The impacts of water deficits and waterlogging during the grain filling on contents of high-molecular-weight glutenin subunits (HMW-GS) and of glutenin macropolymers (GMP) in grains of the winter wheat cultivar Yumai 34 with high grain protein content (GPC) and Yangmai 9 with low GPC were studied. At maturity, GPC was higher under drought and lower under waterlogging compared to the control, while contents of GMP and HMW-GS were reduced by the two water-stress treatments. The contents of both HMW-GS and GMP were higher in Yumai 34 than in Yangmai 9. A drought event after anthesis increased the accumulation of HMW-GS during the early grain filling stage. By contrast, waterlogging reduced the accumulation of HMW-GS during the whole grain filling phase. At maturity, the HMW-GS and GMP to protein ratios were also depressed under the two water-stress events, while the HMW-GS to GMP ratio was very close between the three treatments in Yumai 34 and much higher under the control than the drought and waterlogging treaments in Yangmai 9. It is concluded that the variation in GMP content with various water-stress treatments is attributed to the changing in accumulation of HMW-GS in the grain. [source] Root Distribution of Drought-Resistant Peanut Genotypes in Response to DroughtJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 2 2008P. Songsri Abstract The ability of a plant to modify its root distribution to exploit deeper stored soil water may be an important mechanism to avoid drought. This study aimed at assessing root distributions, variations in root length density (RLD) and percentage of root distribution, and the relevance of root traits for yield of drought-resistant peanut genotypes under different available soil water levels. The experiment was conducted in the dry season during the years 2003/04 and 2004/05. Eleven peanut genotypes (ICGV 98300, ICGV 98303, ICGV 98305, ICGV 98308, ICGV 98324, ICGV 98330, ICGV 98348, ICGV 98353, Tainan 9, KK 60-3 and Tifton-8) and three soil moisture levels [field capacity (FC), 2/3 available soil water (AW) and 1/3 AW] were laid out in a split-plot design with four replications. Roots were sampled by a core sampler at 37, 67 and 97 days after sowing (DAS). Root length was determined by a scanner and the WINRHIZO Pro 2004a software. RLD was calculated as the ratio of root length (cm) and soil volume (cm3). Graphical illustration of root distribution was constructed by merging RLD in the first and second soil layers (0,40 cm) as upper roots and pooling RLD at the third, fourth and fifth layers (40,100 cm) as lower roots. Pod yield, biomass and harvest index (HI) were recorded at harvest. A drought tolerance index (DTI) was calculated for each parameter as the ratio of the parameter under stress treatment to that under well-watered conditions. Variations in RLD in 40 to 100 cm layer (RLD40 to 100 cm) were found under well-watered conditions, and the peanut genotypes could be readily identified as high, intermediate and low for this trait. Changes in RLD in the 40 to 100 cm soil layer were found at 2/3 AW and were more evident at 1/3 AW. ICGV 98300, ICGV 98303, ICGV 98305, ICGV 98308 and KK 60-3 were classified as drought responsive as they increased RLD in the deeper subsoil level in response to drought. In general, RLD under drought conditions was not related to biomass production. The ability to maintain the percentage of RLD (DTI for %RLD) was related to pod yield, DTI for pod yield and DTI for HI. ICGV 98300, ICGV 98303, ICGV 98305 exhibited high DTI (RLD40 to 100 cm) which may explain their high pod yield, DTI (PY) and DTI (HI). Based on these observations we classified them as drought-avoiding genotypes. [source] ECONOMIC TRENDS: Drought and Floods: Central and West AfricaAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 7 2010Article first published online: 1 SEP 2010 No abstract is available for this article. [source] Burundi: In the Grip of DroughtAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 2 2010Article first published online: 1 APR 2010 No abstract is available for this article. [source] East Africa,Drought: Escalating HungerAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 9 2009Article first published online: 2 NOV 200 No abstract is available for this article. [source] Drought, dispersal, and distribution in the inner tropicsJOURNAL OF BIOGEOGRAPHY, Issue 11 2007Oliver L. Phillips No abstract is available for this article. [source] Drought and salinity: A comparison of their effects on mineral nutrition of plantsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 4 2005Yuncai Hu Abstract The increasing frequency of dry periods in many regions of the world and the problems associated with salinity in irrigated areas frequently result in the consecutive occurrence of drought and salinity on cultivated land. Currently, 50% of all irrigation schemes are affected by salinity. Nutrient disturbances under both drought and salinity reduce plant growth by affecting the availability, transport, and partitioning of nutrients. However, drought and salinity can differentially affect the mineral nutrition of plants. Salinity may cause nutrient deficiencies or imbalances, due to the competition of Na+ and Cl, with nutrients such as K+, Ca2+, and NO. Drought, on the other hand, can affect nutrient uptake and impair acropetal translocation of some nutrients. Despite contradictory reports on the effects of nutrient supply on plant growth under saline or drought conditions, it is generally accepted that an increased nutrient supply will not improve plant growth when the nutrient is already present in sufficient amounts in the soil and when the drought or salt stress is severe. A better understanding of the role of mineral nutrients in plant resistance to drought and salinity will contribute to an improved fertilizer management in arid and semi-arid areas and in regions suffering from temporary drought. This paper reviews the current state of knowledge on plant nutrition under drought and salinity conditions. Specific topics include: (1) the effects of drought and salt stress on nutrient availability, uptake, transport, and accumulation in plants, (2) the interactions between nutrient supply and drought- or salt-stress response, and (3) means to increase nutrient availability under drought and salinity by breeding and molecular approaches. Trockenstress und Salzstress , Vergleich der Auswirkungen auf die mineralische Ernährung von Pflanzen Eine Zunahme von Trockenperioden in vielen Ländern der Welt und assoziierte Probleme der Versalzung in bewässerten Gebieten führen häufig zu gleichzeitigem Auftreten von Trockenheit und Salinität. Gegenwärtig sind weltweit ungefähr 50 % aller Bewässerungsflächen durch Salinität beeinträchtigt. Nährstoffstörungen bei Trocken- und Salzstress beeinträchtigen die Verfügbarkeit, den Transport und die Verteilung von Nährelementen in der Pflanze und reduzieren somit das Pflanzenwachstum. Trocken- und Salzstress können sich jedoch unterschiedlich auf die Nährstoffversorgung der Pflanzen auswirken. Salinität kann aufgrund der Konkurrenz zwischen Na+ bzw. Cl, und Nährelementen wie K+, Ca2+ und NO Nährstoffmängel oder -ungleichgewichte in den Pflanzen verursachen. Trockenstress kann sowohl die Nährstoffaufnahme als auch den akropetalen Transport einiger Elemente beeinträchtigen. Trotz kontroverser Schlussfolgerungen in der Literatur hinsichtlich der Wechselbeziehungen von Nährstoffangebot und Trocken- bzw. Salzstress auf das Pflanzenwachstum ist allgemein akzeptiert, dass Nährstoffzufuhr das Pflanzenwachstum nicht verbessert, wenn ausreichend Nährstoffe im Boden verfügbar sind oder bei stark ausgeprägter Trockenheit oder Salinität. Ein besseres Verständnis der Rolle von Mineralstoffen in der Toleranz von Pflanzen gegenüber Trocken- oder Salzstress dürfte gerade in ariden und semi-ariden Gebieten sowie in Regionen, die unter periodischer Trockenheit leiden, zu verbesserten Düngestrategien beitragen. In der vorliegenden Arbeit wird der gegenwärtige Kenntnisstand der mineralischen Ernährung bei Trockenheit und Salinität diskutiert. Schwerpunkte der Betrachtungen sind (1) die Auswirkungen von Trockenheit und Salzstress auf die Verfügbarkeit, die Aufnahme, den Transport und die Anreicherung von Nährelementen in der Pflanze, (2) Wechselbeziehungen zwischen dem Nährstoffangebot und Trockenheit oder Salinität sowie (3) Maßnahmen zur Verbesserung der Nährstoffverfügbarkeit bei Trockenheit und Salzstress mittels züchterischer und molekularbiologischer Ansätze. [source] The influence of phosphorus nutrition on the physiological response of moth bean genotypes to droughtJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 4 2004Balvinder K. Garg Abstract Four genotypes of moth bean (Vigna aconitifolia Jacq. Marechal), including two early (RMO-257 and CZM-18) and two late flowering types (CAZRI moth-1 and Jawala) were grown at two levels of phosphorus (0 and 40 kg ha,1) and subjected to drought by withholding of water until wilting at the pre-flowering stage in a pot trial. Drought significantly decreased plant water potential, relative water content, rate of net photosynthesis, contents of chlorophyll, starch, soluble protein, and nitrate reductase activity in all genotypes. The adverse effects of drought were less pronounced in early than in late flowering genotypes. Phosphorus application significantly ameliorated the negative effects of drought on above parameters, particularly in the late genotypes. We conclude that P addition to moth bean may be justified even in low-rainfall years because of its ability to improve yield under water-limited conditions. [source] Praying for Drought: Persistent Vulnerability and the Politics of Patronage in Ceará, Northeast BrazilAMERICAN ANTHROPOLOGIST, Issue 3 2009Donald R. Nelson First page of article [source] Call for Papers for a Special Series on Africa, Agriculture, Desertification, Drought, Land and Rural DevelopmentNATURAL RESOURCES FORUM, Issue 1 2008Article first published online: 4 APR 200 No abstract is available for this article. [source] Combating drought through preparednessNATURAL RESOURCES FORUM, Issue 4 2002Donald A. Wilhite Drought is a complex, slow,onset phenomenon that affects more people than any other natural hazard and results in serious economic, social, and environmental impacts. Although drought affects virtually all climatic regimes and has significant consequences in both developed and developing countries, its impacts are especially serious in developing countries where dryland agriculture predominates. The impacts of drought are often an indicator of unsustainable land and water management practices, and drought assistance or relief provided by governments and donors encourages land managers and others to continue these practices. This often results in a greater dependence on government and a decline in self,reliance. Moving from crisis to risk management will require the adoption of a new paradigm for land managers, governments, international and regional development organizations, and non,governmental organizations. This approach emphasizes preparedness, mitigation, and improved early warning systems (EWS) over emergency response and assistance measures. Article 10 of the Convention to Combat Desertification states that national action programmes should be established to identify the factors contributing to desertification and practical measures necessary to combat desertification and mitigate the effects of drought. In the past 10 years, there has been considerable recognition by governments of the need to develop drought preparedness plans and policies to reduce the impacts of drought. Unfortunately, progress in drought preparedness during the last decade has been slow because most nations lack the institutional capacity and human and financial resources necessary to develop comprehensive drought plans and policies. Recent commitments by governments and international organizations and new drought monitoring technologies and planning and mitigation methodologies are cause for optimism. The challenge is the implementation of these new technologies and methodologies. It is critical for governments that possess this experience to share it with others through regional and global networks. One way to accomplish this goal is to create a network of regional networks on drought preparedness to expedite the adoption of drought preparedness tools to lessen the hardships associated with severe and extended drought episodes. [source] Drought and symbiosis , why is abscisic acid necessary for arbuscular mycorrhiza?NEW PHYTOLOGIST, Issue 3 2007Thomas Fester First page of article [source] Child Growth in the Time of DroughtOXFORD BULLETIN OF ECONOMICS & STATISTICS, Issue 4 2001John Hoddinott This paper examines the impact of rainfall shocks on a measure of child health, growth in height, drawing on a unique household panel data set from rural Zimbabwe. We find that children aged 12 to 24 months lose 1.5-2 cm of growth in the aftermath of a drought. Catch-up growth in these children is limited so that this growth faltering has a permanent effect. By contrast, there is no evidence that older children experience a slowdown in growth. There is some evidence that the loss in growth is unequally distributed with children residing in poorer households and offspring of women who are daughters of the household head appearing to be especially vulnerable. [source] Physiological Responses of Forest Trees to Heat and DroughtPLANT BIOLOGY, Issue 5 2006H. Rennenberg Abstract: The heat wave of summer 2003 was the largest and the most persistent ever experienced in Central Europe and has fuelled concern about the effects of climate change on European ecosystems. Since forests constitute the most important European ecosystems, in this review article we assess current knowledge on the effects of heat and drought on key metabolic processes for growth and productivity of forest trees. In particular, the general consequences of heat and drought on (1) photosynthesis and respiration at the cellular and community level, and (2) on nutrient uptake, partitioning and competition for nutrients are summarized. The latter are a major sink for photosynthetic energy and, therefore, are indirectly but strongly connected to the performance of photosynthesis. In addition, the interaction of heat and drought with stress compensation mechanisms and emission of biogenic volatile organic compounds (BVOC) are discussed, since these processes are directly connected to carbon metabolism. Effects on the emission of BVOC are also included because they constitute an important feedback mechanism on ozone formation and, thus, on atmospheric pollution. As far as available, data collected during the 2003 heat wave are included and discussed. [source] | ||||||||||||||||||||||||||||||||||||||||||||||