5 p. / an easy to use framework to help develop a contingency plan for drought

Quality protein maize (QPM) has enhanced levels of two essential amino acids, lysine and tryptophan compared to normal maize. This makes QPM an important cereal crop in communities where maize is a staple crop. The main abiotic factor to QPM production is drought stress. Little information is available on the effect of drought stress on QPM. Therefore, the objectives of this study were to: (i) conduct diversity analysis of QPM inbred lines using morpho-agronomic and simple sequence repeat markers, (ii) screen available QPM inbred lines and F1 progeny for tolerance to seedling drought stress, (iii) determine the combining ability and type of gene action of QPM inbred lines for tolerance to seedling drought stress, grain yield and endosperm modification. The study was conducted in South Africa, at the University of Fort Hare. Morphological characterisation of 21 inbred lines was done using quantitative and qualitative traits. A randomised complete block design with three replicates was used for characterizing the inbred lines in the field. Genstat statistical software, version 12 (Genstat ®, 2009) was used for analysis of variance (ANOVA) and descriptive statistics. Analysis of variance was performed on all quantitative data for morphological traits. Data for qualitative traits was tabulated in their nominal classes. Traits that contributed most to the variation were days to anthesis, days to silking, anthesis-silking interval, plant height, number of kernel rows, ear length and grain yield. Cluster analysis grouped the inbred lines into three main clusters. The first cluster was characterised by tall and average yielding lines, while the second cluster showed the least anthesis-silking interval, and had the highest yield. Cluster three consisted of lines that were early maturing, but were the least yielding. Genetic distances between maize inbred lines were quantified by using 27 simple sequence repeat markers. The genetic distances between genotypes was computed using Roger’s (1972) genetic distances. Cluster analysis was then carried out using the neighbour-joining tree method using Power Marker software version 3.25. A dendrogram generated from the genetic study of the inbred lines revealed three groups that concurred with expectations based upon pedigree data. These groups were not identical to the groups generated using morpho-agronomic characterisation. Twenty one QPM inbred lines were crossed using a North Carolina design II mating scheme. These were divided into seven sets, each with three inbred lines. The three inbred lines in one set were used as females and crossed with three inbred lines in another set consisting of males. Each inbred line was used as a female in one set, and as a male in a second set. Sixty three hybrids (7 sets x 9 hybrids) were formed and evaluated in October 2011, using a 6x8 alpha-lattice incomplete block design with three replicates under glasshouse and optimum field conditions. A randomised complete block design with three replicates was used for the 21 parental inbred lines. Traits recorded for the glasshouse study were, canopy temperature, chlorophyll content, leaf roll, stem diameter, plant height, leaf number, leaf area, fresh and dry root and shoot weights. Data for the various traits for each environment, 25 percent (stress treatment) and 75 percent (non-stress) of field capacity, were subjected to analysis of variance using the unbalanced treatment design in Genstat statistical package Edition 12. Where varietal differences were found, means were separated using Tukey’s test. Genetic analyses for grain yield and agronomic traits were performed using a fixed effects model in JMP 10 following Residual Maximum Likelihood procedure (REML). From the results, inbred lines that were not previously classified into heterotic groups and drought tolerance categories were classified based on their total dry weight performance and drought susceptibility index. Inbred lines L18, L9, L8, L6 and L3, in order of their drought tolerance index were the best performers under greenhouse conditions and could be recommended for breeding new varieties that are tolerant to seedling drought stress. Evaluation of maize seedlings tolerant to drought stress under glasshouse conditions revealed that cross combination L18 x L11 was drought tolerant, while cross L20 x L7 was susceptible. Total dry weight was used as the major criteria for classifying F1 maize seedlings as being resistant or susceptible. General combining ability effects accounted for 67.43 percent of the genetic variation for total dry weight, while specific combining ability effects contributed 37.57 percent. This indicated that additive gene effects were more important than non-additive gene action in controlling this trait. In the field study (non-drought), the experimental design was a 6x8 alpha lattice incomplete block design with three replicates. On an adjacent field a randomised complete block design with three replicates was used to evaluate the parental inbred lines. The following variables were recorded: plant height, ear height, ears per plant, endosperm modification, days to silking and days to anthesis, anthesis-silking interval, number of kernels per row, number of rows per ear and grain yield. General analyses for the incomplete lattice block design and randomised complete block design for hybrid and inbred data respectively were performed using JMP 10 statistical software. Means were separated using the Tukey's test. Genetic analyses of data for grain yield and agronomic traits were conducted using a fixed effects model using REML in JMP 10. The importance of both GCA (51 percent) and SCA (49 percent) was observed for grain yield. A preponderance of GCA existed for ear height, days to anthesis, anthesis-silking interval, ears per plant and number of kernels per row, indicating that predominantly, additive gene effects controlled hybrid performance under optimum field conditions. The highest heritability was observed for days to silking (48.27 percent) suggesting that yield could be improved through selection for this trait. Under field conditions, variation in time to maturity was observed. This implies that these inbred lines can be recommended for utilisation in different agro-ecologies. Early maturing lines such as L18 can be used to introduce earliness in local cultivars, while early maturing single crosses such as L18 x L2, L5 x L9, L3 x L4 and L2 x L21 could be recommended for maize growers in drought prone areas such as the former Ciskei. Single crosses L18xL11, L16xL18, L8xL21 and L9xL6 had good tolerance to seedling drought stress. On the other hand, single crosses L18xL11 and L11xL13 had high grain yield and good endosperm modification. All these single crosses could be recommended for commercial production after evaluation across locations in the Eastern Cape Province. Alternatively they can be crossed with other superior inbreds to generate three or four way hybrids, which could then be evaluated for potential use by farmers in the Eastern Cape.

Species inhabiting intermittent streams must have life-history traits that confer resistance or resilience to flow cessation or drying. However, we lack basic life-history information for most aquatic invertebrate species, especially those from intermittent streams. I documented the life cycle and distribution of an unusual winter stonefly species, Mesocapnia arizonensis (Capniidae). The species was first described from 6 localities in 1969, but its natural history remained enigmatic. I surveyed >90 streams across the southwestern USA, documented the life cycle of M. arizonensis at 1 locality, and experimentally rehydrated dry streambed sediment in search of dormant stoneflies at another locality. Field surveys expanded the number of localities from 22 to 98, most of which were intermittent with flow durations as brief as 3 mo/y, and extended the known range of the species by 800 km. Nymphs were abundant within days of flow resumption, grew rapidly as a single cohort, and started emerging as adults 42 d after flow resumed. The brief appearance of a 2(nd) cohort of tiny nymphs 1 mo before the stream dried indicates direct hatching of at least some eggs. I failed to find dormant stoneflies in the top 30 cm of dry stream sediment, suggesting that M. arizonensis undergoes dormancy deep in the substrate, putting it safely out of reach of scouring summer floods that occur between favorable winter seasons. The remarkable ability of M. arizonensis to survive in short-flow duration streams and to endure multiple consecutive dry years, suggests that the species is well prepared for the drier climatic conditions predicted to occur across its range.

Drought (soil water deficit) as a major adverse environmental condition can result in serious reduction in plant growth and crop production. Plants respond and adapt to drought stresses by triggering various signalling pathways leading to physiological, metabolic and developmental changes that may ultimately contribute to enhanced tolerance to the stress. Here, a novel non-coding RNA (ncRNA) involved in plant drought stress tolerance was identified. We showed that increasing the expression of this ncRNA led to enhanced sensitivity during seed germination and seedling growth to the phytohormone abscisic acid. The mutant seedlings are also more sensitive to osmotic stress inhibition of lateral root growth. Consistently, seedlings with enhanced expression of this ncRNA exhibited reduced transiprational water loss and were more drought-tolerant than the wild type. Future analyses of the mechanism for its role in drought tolerance may help us to understand how plant drought tolerance could be further regulated by this novel ncRNA.

Includes bibliographical references / Drought is one of the natural hazards that threaten the economy of many nations, especially in Southern Africa, where many socio-economic activities depend on rain-fed agriculture. This study evaluates the capability of Regional Climate Models (RCMs) in simulating the Southern African droughts. It uses the Standardized Precipitation-Evapotranspiration Index (SPEI, computed using rainfall and temperature data) to identify 3-month droughts over Southern Africa, and compares the observed and simulated drought patterns. The observation data are from the Climate Research Unit (CRU), while the simulation data are from 10 RCMs (ARPEGE, CCLM, HIRHAM, RACMO, REMO, PRECIS, RegCM3, RCA, WRF, and CRCM) that participated in the Regional Climate Downscaling Experiment (CORDEX) project. The study also categorizes drought patterns over Southern Africa, examines the persistence and transition of these patterns, and investigates the roles of atmospheric teleconnections on the drought patterns. The results show that the drought patterns can occur in any season, but they have preference for seasons. Some droughts patterns may persist up to three seasons, while others are transient. Only about 20% of the droughts patterns are induced solely by El Niño Southern Oscillation (ENSO), other drought patterns are caused by complex interactions among the atmospheric teleconnections. The study also reveals that the Southern Africa drought pattern is generally shifting from a wet condition to a dry condition, and that the shifting can only be captured with a drought monitoring index that accounts for temperature influence on drought. Only few CORDEX RCMs simulate the Southern African droughts as observed. In this regard, the ARPEGE model shows the best simulation. The best performance may be because the stretching capability of ARPEGE helps the model to eliminate boundary condition problems, which are present in other RCMs. In ARPEGE simulations, the stretching capability would allow a better interaction between large and small scale features, and may lead to a better representation of the rain producing systems in Southern Africa. The results of the study may be applied to improve monitoring and prediction of regionally-extensive drought over Southern Africa, and to reduce the socio-economic impacts of drought in the region.

In the South African context, a geographical region prone to the occurrence of frequent and intense periods of drought, the emergence of climate conditions reaching new extremes raises concerns of adaptability to sustain living and work well-being in such circumstances. The realisation of economic, social, environmental and psychological impacts resultant from drought conditions is particularly relevant to farmers, an occupation group who are often characterised by socio-economic vulnerability in South Africa. Consequently, this research seeks to explore the yet undocumented experiences of farmers living and working in the current drought conditions, located in the Karoo region of South Africa. A further aim of this research is to explore how these experiences have affected farmers' psychological well-being, as well as understanding the coping mechanisms they have used to deal with this long-standing crisis situation. The present study adopted an exploratory case study design using an interpretivist paradigmatic stance. Based on research conducted and reviewed within the climate change domain, it was understood that farmers' experiences of working in drought conditions were complex, context specific and differed amongst individuals. Therefore, knowledge was viewed as subjective as there was no particular, correct path to knowledge as it emerged through various contexts. The case under study was Karoo farmers in the Western Cape province. Their living and working experiences, and coping mechanisms were specific to their surrounding landscapes and chosen type of farming. Furthermore, this case study was particularly concerned with farmers who retained close living, working and cultural relationships to their natural environments. Consequently, the unit of analysis in this study was the individual. A purposive sampling strategy was adopted and a total of eight participants were interviewed. An inductive approach to analysing the data was undertaken, using Braun and Clarke's (2006) Thematic Analysis. Three major themes emerged during the analysis with a number of associated sub-themes. The results describe the sample's shared ecological grief experiences due to both implicit and explicit impacts resultant from sustained drought conditions. The negative psychological outcomes the sample endured as a result of these experiences, demonstrates the implication of living and working in such conditions for work and psychological well-being. The common coping mechanisms employed over this time are also extracted from the themes. The discussion presents the findings of this study through the lens of the Sustainable Livelihoods Approach framework, to understand how drought conditions presents barriers to these farmers sustaining their well-being.

Regional assessments of droughts are limited and meticulous assessment of droughts over larger spatial scales are often not substantial. Understanding drought variability on a regional scale is crucial for enhancing resiliency and adaptive ability of water supply and distribution systems. Moreover, it can be essential for appraising the dynamics and predictability of droughts based on regional climate across various spatial and temporal scales. The drought analysis of the past was carried out with the development of a high-resolution dataset (1km×1km) for three drought-prone regions of India between 1950 and 2016. In the study the monthly values of self-calibrating Palmer Drought Severity Index (scPDSI), incorporating Penman–Monteith (PM) approximation, which is physically based on potential evapotranspiration. Climate data were statistically downscaled using the delta downscaling method and was formulated to form a timeline for characterizing major drought events that occurred in the past. The downscaled climate data were validated with the station observations. Major severe drought events that occurred between 1950 and 2016 were identified and studied with greater emphasis to the drought situation in smaller spatial extent such as districts, villages or localities. A timeline of drought events within the period of study was also prepared to have an understanding of the severity of drought in all three regions.Likewise, the future drought durations are projected for droughts of different levels of severity and assessed in the same regions of India. Coupled Model Intercomparison Project Phase 6 (CMIP6) simulated precipitation and climate data were used for near‐future (2015–2044) for different shared socio-economic pathways (SSPs). scPDSI, was used again based on its fairness in identifying drought conditions which accounts for the temperature as well. Gridded rainfall and temperature data of spatial resolution of 1km were used to bias correct the multi-model ensemble (MME) mean of 7 Global Climatic Models (GCMs) from CMIP6 project. Equidistant quantile-based mapping was adopted to remove the bias in the rainfall and temperature data and were corrected at the monthly scale. The downscaled climate data exhibited good statistical agreement with station data with correlation coefficient (R) ranging from 0.83 to 0.93 for both precipitation and temperature. Drought analysis indicated several major incidences over the analysis time period considered in this work, which truly adheres to the droughts recorded in qualitative reports of meteorological institutions in those regions. The drought study of the past helped to understand the situation in local levels and understand the necessities that can be opted for the future by proper management of water resources. While the outcome of the future prediction of drought duration suggests multiple severe to extreme drought events in all three study areas of appreciable durations mostly during the mid-2030s under the SSP2-4.5 scenario. The severe drought durations under the SSP2-4.5 scenario were found to be ranging around 25 to 30 months in 30 years period of the near future. The high-resolution drought index proved to be key to assess the drought situation for both the past and the future in three different drought-prone regions of India.

In most parts of the world, drought is an inevitable and natural occurrence. However, as the climate continues to warm, and populations grow and expand, the negative impacts of this extreme weather event are predicted to become more pronounced. This leads many communities and stakeholders to question what is being done to prepare society for widespread drought? The following research determines different social and atmospheric characteristics that affect a city’s likelihood of having a drought policy in place.To do this, a thorough search was conducted at the city level to determine where drought policies are currently located in theU.S. The search included all U.S. cities with a population greater than 100,000. Policies and city plans were identified using a list of search terms ranging from “drought” and “water conservation” to “climate mitigation”. By identifying locations where these policies are currently in place this study explores commonalities between cities that have and have not implemented drought management plans.

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