Occasional Droughts Research Articles

Potential Impact of Climate Change on Salmonid Smolt Ecology

The migratory life history of anadromous salmonids requires successful migration between nursery, feeding, and spawning habitats. Smolting is the major transformation anadromous salmonids undergo before migration to feeding areas. It prepares juvenile fish for downstream migration and their entry to seawater. We reviewed the effects of climate change on smolt ecology from the growth of juveniles in fresh water to early post-smolts in the sea to identify the potential effects of climate change on migratory salmonid populations during this period in their life history. The focus was especially on Atlantic salmon. The shift in suitable thermal conditions caused by climate change results in Atlantic salmon expanding their range northward, while at the southern edge of their distribution, populations struggle with high temperatures and occasional droughts. Climatic conditions, particularly warmer temperatures, affect growth during the freshwater river phase. Better growth in northern latitudes leads to earlier smolting. Thermal refuges, the areas of cooler water in the river, are important for salmonids impacted by climate change. Restoring and maintaining connectivity and a suitably diverse mosaic habitat in rivers are important for survival and growth throughout the range. The start of the smolt migration has shifted earlier as a response to rising water temperatures, which has led to concerns about a mismatch with optimal conditions for post-smolts in the sea, decreasing their survival. A wide smolt window allowing all migrating phenotypes from early to late migrants’ safe access to the sea is important in changing environmental conditions. This is also true for regulated rivers, where flow regulation practices cause selection pressures on migrating salmonid phenotypes. The freshwater life history also affects marine survival, and better collaboration across life stages and habitats is necessary among researchers and managers to boost smolt production in rivers. Proactive measures are recommended against population declines, including sustainable land use in the catchment, maintaining a diverse mosaic of habitats for salmonids, restoring flow and connectivity, and conserving key habitats.

Genome-wide association study presents insights into the genetic architecture of drought tolerance in maize seedlings under field water-deficit conditions.

Drought stress is one of the most serious abiotic stresses leading to crop yield reduction. Due to the wide range of planting areas, the production of maize is particularly affected by global drought stress. The cultivation of drought-resistant maize varieties can achieve relatively high, stable yield in arid and semi-arid zones and in the erratic rainfall or occasional drought areas. Therefore, to a great degree, the adverse impact of drought on maize yield can be mitigated by developing drought-resistant or -tolerant varieties. However, the efficacy of traditional breeding solely relying on phenotypic selection is not adequate for the need of maize drought-resistant varieties. Revealing the genetic basis enables to guide the genetic improvement of maize drought tolerance. We utilized a maize association panel of 379 inbred lines with tropical, subtropical and temperate backgrounds to analyze the genetic structure of maize drought tolerance at seedling stage. We obtained the high quality 7837 SNPs from DArT's and 91,003 SNPs from GBS, and a resultant combination of 97,862 SNPs of GBS with DArT's. The maize population presented the lower her-itabilities of the seedling emergence rate (ER), seedling plant height (SPH) and grain yield (GY) under field drought conditions. GWAS analysis by MLM and BLINK models with the phenotypic data and 97862 SNPs revealed 15 variants that were significantly independent related to drought-resistant traits at the seedling stage above the threshold of P < 1.02 × 10-5. We found 15 candidate genes for drought resistance at the seedling stage that may involve in (1) metabolism (Zm00001d012176, Zm00001d012101, Zm00001d009488); (2) programmed cell death (Zm00001d053952); (3) transcriptional regulation (Zm00001d037771, Zm00001d053859, Zm00001d031861, Zm00001d038930, Zm00001d049400, Zm00001d045128 and Zm00001d043036); (4) autophagy (Zm00001d028417); and (5) cell growth and development (Zm00001d017495). The most of them in B73 maize line were shown to change the expression pattern in response to drought stress. These results provide useful information for understanding the genetic basis of drought stress tolerance of maize at seedling stage.

Climate change impacts on socio-hydrological spaces of the Brahmaputra floodplain in Assam, Northeast India: A review

Intensification of the water cycle mediated by global warming increases the risk of hydrological disasters by modifying precipitation patterns across the globe which leads to adverse socio-economic impacts, especially in developing countries. Socio-hydrological spaces in the vicinity of major river systems are prone to the devastating effects of hydrological disasters yet attract human settlements due to the availability of fertile lands that support agriculture. The Brahmaputra floodplain (BFP) of Assam in Northeast India (NEI) is one such region that supports a high population in spite of being ravaged by annual floods and occasional droughts. The current study attempts to critically review the climate change impacts on socio-hydrological spaces of the BFP exploring climate change-hazard-lives and livelihood linkages of floodplain dwellers. This work utilizes peer reviewed articles along with reports of government and international/national organizations to critically appraise the following-(i) existing climate and fluvial hazard scenario in the BFP, (ii) impacts of climate change on the fluvial hazard and agriculture in the BFP, and (iii) the adaptation and mitigation measures that exist in the BFP. Shifts in the long-term trends of temperature and rainfall have occurred over this region leading to speculations on future scenarios of hydrological hazards and their impacts. Studies project an alteration in the hydrology and flow regime of the Brahmaputra River under climate warming scenarios which will influence the hazard characteristics with implications for agriculture and food security. Integrating disaster risk reduction with agricultural management can provide better climate resilience to the farming communities in the BFP.

Assessing the Opportunities Available to Banks in Financing Horticulture Sub-Sector in Ethiopia

This assessment is aimed at conducting exploring the opportunities that Banks in Ethiopia have in working in with horticultural industry players. This export sales trend of horticulture has shown an immense fluctuation from the selected more latest year 2009/10 to 2018/2019 by using qualitative and quantitative data analysis. This, the variation was shows alarming increase had shown significant to the total export sales gain of the country for the sector where it was become cover about 10% whole export commodity of 2009/10 to 2018/19. From this assessment it was found that horticulture export commodity of Ethiopia plays significant role in foreign exchange gains earning and competency in the international arena which makes the banks to working with makes difference. Despite, several challenges and opportunities namely tumultuous weather, seasonal cyclones, occasional drought, demographic pressure, industrialization, urbanization and unprecedented use of insecticide &amp; pesticide and compulsion for migration of rural masses to urban areas, especially for their livelihood. Ethiopia is the second largest supplier and exporter of horticulture produce in Africa after Kenya, due to is currently the fifth foreign revenue earner to the Ethiopian economy and it is one of the commodity a boost to the export sector of the country, so it is better for banking working in horticulture and the sector key players. In general, over the past few years, horticulture has made remarkable progress in terms of expansion in area and production under different crops, increase in productivity, crop diversification, technological interventions for production and post-harvest and forward linkages through value addition and marketing which makes benefit the banks involving in the sector. Keywords: Horticulture, Horticulture production, Value chain, Key player DOI: 10.7176/RJFA/13-9-03 Publication date: May 31 st 2022

Capturing Genetic Variability and Identification of Promising Drought-Tolerant Lines in Exotic Landrace Derived Population Under Reproductive Drought Stress in Rice.

Drought is one of the most predominant abiotic stresses in this century, leading to a drastic reduction in the yield of rainfed rice ecosystems. Breeding of drought-resilient rice varieties is very much in demand for sustainable rice production in drought-prone rainfed ecology. An experiment was designed under irrigated non-stress and drought-stress situations involving an exotic drought-tolerant landrace (Chao Khaw) and a high-yielding aromatic rice cultivar (Kasturi), and an F2:4 derived population of 156 breeding lines was developed at IRRI South Asia Hub, Hyderabad. The objective of the study was to assess the genetic variability, drought tolerance behavior, and identify promising breeding lines for different rice ecologies and drought breeding programs. Restricted maximum likelihood (REML) analysis using the mixed model approach revealed a considerable genetic variation in the population for yield and yield contributing traits in non-stress and drought-stress conditions. We observed very high heritability for all the selected traits under stress 2015 WS (73.8% to 85.3%) and 2016 WS (72.4% to 93.5%) and non-stress 2015 WS (68.2% To 92.9%) and 2016 WS (61.4% to 92.6%) environments, indicating possible selection for grain yield under drought stress and non-stress with the same precision level. None of the secondary traits except harvest index and biomass included in our study showed a positive association with grain yield, indicating indirect selection’s ineffectiveness in improving yield under drought. A total of 48 promising breeding lines were found to have a better yield than donor Chao Khaw (up to 38% advantage) and popular drought-tolerant cultivars Shabhagidhan (up to 48% advantage) in stress conditions and recommended for rainfed upland ecology, 34 breeding lines under the well-watered condition suited for rainfed lowland ecology. Overall, the study found 21 common breeding lines that showed their superiority in non-stress and under drought stress situations, fitting best in rainfed lowland ecology with occasional drought occurrence. The large genetic variation found in this population can be exploited further to develop a few forward breeding high-yielding lines with better drought tolerance ability and used as drought donors in drought breeding programs.

The cumulative drought exert disruptive effects on tropical rainforests in the northern edge of Asia - Based on decadal dendrometric measurements and eddy covariance method

Studies on the effects of drought on tropical rainforests have revealed their sensitivity on multiple levels, for example, decreased photosynthetic capacity and increased mortality. However, studies on the impact of occasional drought on the rainforests are not enough as they tend to recover from such droughts within a few years. In the present study, the Xishuangbanna rainforest, located at the northern edge of Asia, witnessed extensive damage after six years of a field drought treatment (30 m × 30 m plot; ∼35% through-fall reduction): the plant carbon pool decreased at the rate of 13.71 T ha−1 yr−1 (amount to 23% loss of plant carbon in the 10th year compared to the 7th), although soil carbon accumulated at the rate of 2.68 T ha−1 yr−1. The radial growth rate of the surviving tagged trees was not constrained by drought. Additionally, drought reduced the number of seedlings per unit area by 61% compared to the control plot. The residual analysis indicates that the net ecosystem carbon exchange (NEE) of eddy covariance (EC) flux site was insensitive to soil drought on annual scale, while regression analyses showed that photosynthetic light response parameters were inhibited by drought on decalal scale. The results of both drought experiment and flux data analysis showed that the impact of drought on the rainforest will be highly apparent on long-term scale. In order to predict the fate of forests more accurately in response to prolonged drought, it is worth reassessing the long-term drought sensitivity of forest ecosystems.

Conditional inference trees in the assessment of tree mortality rates in the transitional mixed forests of Atlantic Canada.

Long-term predictions of forest dynamics, including forecasts of tree growth and mortality, are central to sustainable forest-management planning. Although often difficult to evaluate, tree mortality rates under different abiotic and biotic conditions are vital in defining the long-term dynamics of forest ecosystems. In this study, we have modeled tree mortality rates using conditional inference trees (CTREE) and multi-year permanent sample plot data sourced from an inventory with coverage of New Brunswick (NB), Canada. The final CTREE mortality model was based on four tree- and three stand-level terms together with two climatic terms. The correlation coefficient (R2) between observed and predicted mortality rates was 0.67. High cumulative annual growing degree-days (GDD) was found to lead to increased mortality in 18 tree species, including Betula papyrifera, Picea mariana, Acer saccharum, and Larix laricina. In another ten species, including Abies balsamea, Tsuga canadensis, Fraxinus americana, and Fagus grandifolia, mortality rates tended to be higher in areas with high incident solar radiation. High amounts of precipitation in NB’s humid maritime climate were also found to contribute to heightened tree mortality. The relationship between high GDD, solar radiation, and high mortality rates was particularly strong when precipitation was also low. This would suggest that although excessive soil water can contribute to heightened tree mortality by reducing the supply of air to the roots, occasional drought in NB can also contribute to increased mortality events. These results would have significant implications when considered alongside regional climate projections which generally entail both components of warming and increased precipitation.

MONITORING DROUGHT VULNERABILITY AT DIFFERENT TIME SCALES: A CASE STUDY FROM RAJSHAHI DISTRICT, BANGLADESH

Drought is a slow onset natural disaster which creates a threat to social and agro-ecological balance. The failure of rain and the occurrence of drought during any particular growing season may lead to severe food shortage and increase vulnerability. The purpose of this study is to estimate the Drought Index (DI) in multiple time scales for Rajshahi district of Bangladesh.The 52 years daily rainfall data during the period 1964-2015 used for analysis. There were some missing data over that range. We separated this time interval in 5, 7 and 10 days series format then we estimate missing value by using imputtation method. Finally, we used R code to analyze Markov Chain Model by considering threshold value 3mm. At first, we find out the Drought Index from the first transition probability matrix and then estimate with higher transition probability matrix. When the higher transition probability matrix became stable, then we estimate the DI. The empirical study showed that for 5, 7 and 10 days Drought Index (DI) followed extreme to moderate, mild to occasional, and extreme to occasionally drought respectively. But in first transition probability matrix it showed chronic drought and due to climate change after different stages chronic drought turned into severe, moderate, mild and occasional drought. In overall interpretation, we found mild for 5 days and occasional drought for 7 and 10 days respectively. By extracting information about drought characteristics that include its spatial extent, severity, and frequency are important for policy maker to take necessary steps in advance to mitigate the effect of drought for producing crops which will reduce the food insecurity and vulnerability for developing sustainable development.

The impact of occasional drought periods on vegetation spread and greenhouse gas exchange in rewetted fens.

Peatland rewetting aims at stopping the emissions of carbon dioxide (CO2) and establishing net carbon sinks. However, in times of global warming, restoration projects must increasingly deal with extreme events such as drought periods. Here, we evaluate the effect of the European summer drought 2018 on vegetation development and the exchange of methane (CH4) and CO2 in two rewetted minerotrophic fens (Hütelmoor—Hte and Zarnekow—Zrk) including potential carry-over effects in the post-drought year. Drought was a major stress factor for the established vegetation but also promoted the rapid spread of new vegetation, which will likely gain a lasting foothold in Zrk. Accordingly, drought increased not only respiratory CO2 losses but also photosynthetic CO2 uptake. Altogether, the drought reduced the net CO2 sink in Hte, while it stopped the persistent net CO2 emissions of Zrk. In addition, the drought reduced CH4 emissions in both fens, though this became most apparent in the post-drought year and suggests a lasting shift towards non-methanogenic organic matter decomposition. Occasional droughts can be beneficial for the restoration of the peatland carbon sink function if the newly grown vegetation increases CO2 sequestration in the long term. Nonetheless, care must be taken to prevent extensive peat decay.This article is part of the theme issue ‘Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.

Salt stress induces endoplasmic reticulum stress-responsive genes in a grapevine rootstock.

Grapevines, although adapted to occasional drought or salt stress, are relatively sensitive to growth- and yield-limiting salinity stress. To understand the molecular mechanisms of salt tolerance and endoplasmic reticulum (ER) stress and identify genes commonly regulated by both stresses in grapevine, we investigated transcript profiles in leaves of the salt-tolerant grapevine rootstock 1616C under salt- and ER-stress. Among 1643 differentially expressed transcripts at 6 h post-treatment in leaves, 29 were unique to ER stress, 378 were unique to salt stress, and 16 were common to both stresses. At 24 h post-treatment, 243 transcripts were unique to ER stress, 1150 were unique to salt stress, and 168 were common to both stresses. GO term analysis identified genes in categories including 'oxidative stress', 'protein folding', 'transmembrane transport', 'protein phosphorylation', 'lipid transport', 'proteolysis', 'photosynthesis', and 'regulation of transcription'. The expression of genes encoding transporters, transcription factors, and proteins involved in hormone biosynthesis increased in response to both ER and salt stresses. KEGG pathway analysis of differentially expressed genes for both ER and salt stress were divided into four main categories including; carbohydrate metabolism, amino acid metabolism, signal transduction and lipid metabolism. Differential expression of several genes was confirmed by qRT-PCR analysis, which validated our microarray results. We identified transcripts for genes that might be involved in salt tolerance and also many genes differentially expressed under both ER and salt stresses. Our results could provide new insights into the mechanisms of salt tolerance and ER stress in plants and should be useful for genetic improvement of salt tolerance in grapevine.

COMPARATIVE VESSEL TRAITS OF MACARANGA GIGANTEA AND VATICA DULITENSIS FROM MALAYSIAN BORNEO

Trade-offs in wood anatomical characteristics reflect different strategies used by trees to deal with water transport in response to variation in environmental conditions. To study vascular strategies for Bornean rainforest trees, we compared water transport-related anatomical characteristics in branch wood between the common tree species Vatica dulitensis (Dipterocarpaceae) from old-growth forest and the common pioneer tree species Macaranga gigantea (Euphorbiaceae) from selectively logged forest. We hypothesised that the vessel traits of the pioneer species would reflect the need to capture and transport resources to support its fast growth rate (resource-acquisitive strategy), while the species of the old-growth forest would display more conservative vessel traits (resource-conservative strategy). We found that M. gigantea had significantly greater vessel area, hydraulically weighted diameter, vessel area to number ratio, and potential hydraulic conductivity than V. dulitensis. These results suggest that vessel traits of the common old-growth species would ensure high hydraulic safety during occasional drought when soil moisture is limited, while the common species of selectively logged forest possesses an efficient water transport system but its vessels would confer lower hydraulic safety during drought conditions. These contrasting vascular strategies highlight the potential for divergent responses of species of Bornean forest trees to future climatic extremes.

Palynological assemblage from the lower Cenomanian plant-bearing Lagerstätte of Jaunay-Clan-Ormeau-Saint-Denis (Vienne, western France): Stratigraphic and paleoenvironmental implications

We describe here the palynological content from the lower Cenomanian plant-rich site of Jaunay-Clan (Vienne, western France), a site that previously yielded exceptional leaf impressions. Altogether, 184 species of palynomorphs have been identified, and two palynological intervals were recognized in the sedimentary sequence. The lower interval is characterized by the taxonomical and numerical dominance of spores of Gleicheniaceae, Cyatheales, and Anemiaceae, while the upper interval is characterized by an abrupt increase in the abundance of Classopollis and the appearance of dinocysts. This shift in the palynological composition, coupled with paleobotanical observations, is interpreted as reflecting a transition from a calm freshwater environment, with occasional droughts to an environment more open to very occasional marine inputs, such as an inner lagoon.The association of Tehamadinium coummia, Trichodinium spinosum, Tricolpites nemejcii, Retitricolporites decorosus, and Microreticulatiporites sacalii, coupled with the absence of Normapolles pollen grains, suggests that the Jaunay-Clan assemblage is early Cenomanian in age, corroborating the previous determination based on lithological and paleontological proxies. However, the Jaunay-Clan palynoflora is considered to be slightly younger than the numerous earliest Cenomanian assemblages described from Charente-Maritime, owing to its resemblance with mid-lower Cenomanian palynofloras from western France. The paleoflora and palynoflora from Jaunay-Clan are similar to other assemblages found in the upper Albian of Spain (Teruel Province), and in the Cenomanian of France and Czech Republic (Peruc-Korycany Formation, La Buzinie, Archingeay). The combined Jaunay-Clan palynoflora and paleoflora is considered to be the most diversified Cenomanian paleobotanical-palynological assemblage described so far in Western Europe.

Effects of tillage practice on soil structure, N2O emissions and economics in cereal production under current socio-economic conditions in central Bosnia and Herzegovina.

Conservation tillage is expected to have a positive effect on soil physical properties, soil Carbon (C) storage, while reducing fuel, labour and machinery costs. However, reduced tillage could increase soil nitrous oxide (N2O) emissions and offset the expected gains from increased C sequestration. To date, conservation tillage is barely practiced or studied in Bosnia and Herzegovina (BH). Here, we report a field study on the short-term effects of reduced (RT) and no tillage (NT) on N2O emission dynamics, yield-scaled N2O emissions, soil structure and the economics of cereal production, as compared with conventional tillage (CT). The field experiment was conducted in the Sarajevo region on a clayey loam under typical climatic conditions for humid, continental BH. N2O emissions were monitored in a Maize-Barley rotation over two cropping seasons. Soil structure was studied at the end of the second season. In the much wetter 2014, N2O emission were in the order of CT > RT > NT, while in the drier 2015, the order was RT > CT > NT. The emission factors were within or slightly above the uncertainty range of the IPCC Tier 1 factor, if taking account for the N input from the cover crop (alfalfa) preceding the first experimental year. Saturated soils in spring, formation of soil crusts and occasional droughts adversely affected yields, particularly in the second year (barley). In 2014, yield-scaled N2O emissions ranged from 83.2 to 161.7 g N Mg-1 grain (corn) but were much greater in the second year due to crop failure (barley). RT had the smallest yield-scaled N2O emission in both years. NT resulted in economically inacceptable returns, due to the increased costs of weed control and low yields in both years. The reduced number of operations in RT reduced production costs and generated positive net returns. Therefore, RT could potentially provide agronomic and environmental benefits in crop production in BH.

Subtropical native grasslands may not require fire, mowing or grazing to maintain native-plant diversity

The rarity of native grasslands in agricultural districts heightens the requirement for optimal management to maintain diversity. Previous studies have suggested that disturbance is required to maintain species diversity in temperate Australian grasslands, but grasslands in semiarid environments do not have the same disturbance requirement. The current study examines the short-term responses to disturbance of subtropical grassland of the Darling Downs, south-eastern Queensland. We also compare temperate and subtropical grasslands in terms of biomass and rainfall. A field experiment was established with treatments, including burning in 2013, burning in 2014, burning in both years, mowing in both years, mowing and raking in both years, and an undisturbed control. Treatments were replicated at each of seven sampling stations in similar environments. The initial sampling after 2013 followed a wet summer and the final sampling was in 2015 after a dry summer. Non-metric multi-dimensional scaling showed that environmental differences, including silt content, soil pH, waterlogging and rainfall history, had more effect on the variation in species composition than did the treatments. The treatments engendered no significant response in species diversity. Of 51 widespread species, only four had a significant change in abundance in response to treatment. Herbaceous biomass was higher in temperate than subtropical grassland after a dry period. The grassland sward may be more open in the subtropics than in temperate grassland because of higher decomposition rates. A comparison of rainfall distribution between subtropical grassland and temperate grassland indicated that droughts are much more frequent in the former environments. These occasional droughts may provide a stress that reduces perennial grass cover, supplanting the requirement for grazing or fire to maintain plant diversity in grasslands. The management of grassland remnants in the subtropics, therefore, seems straightforward because there is little response in species richness or composition to disturbance. However, soil disturbance should be avoided to ensure that exotic species do not proliferate.

Ensuring A Better Water Future for Malaysia

Human overuse of water resources and diffuse contamination of freshwater are stressing the water resources in the terrestrial water cycle. As a consequence, the ecological functions of water bodies, soils and groundwater in the water cycle are hampered and being further exacerbated by threats from impending climate change. Though Malaysia is blessed with fairly abundant rainfall it still has its fair share of water woes, such as occasional droughts, looding and pollution of its rivers and water bodies. Only recently, the country was faced with water related hazards of fairly disastrous proportions. Recurring potable water shortages that occurred in 2014 and 2015 in several states had led to water rationing. Malaysia has since the early 1990s set its vision to become a fully developed country by the year 2020 (Vision 2020). The transformation of the water sector must also evolve in tandem to meet sustainable development goals beitting a developed nation status by 2020. The National Water Resources Policy (NWRP), launched in March 2012, is based on the 3 essential principles i.e. water resources security, water resources sustainability and collaborative governance. This paper will review the various water-related issues and challenges whilst proposing the implementation of the Integrated Water Resources Management (IWRM) Road Map including the measures to be undertaken to effect the transformation of the water sector in pursuit of Vision 2020 and to achieve the post 2015 Sustainable Development Goals (SDGs). The indings and recommendations are largely based on several in-depth studies undertaken by the Academy of Sciences, Malaysia (ASM) pertaining to the water sector and the IWRM agenda.

Ensuring A Better Water Future for Malaysia

Human overuse of water resources and diffuse contamination of freshwater are stressing the water resources in the terrestrial water cycle. As a consequence, the ecological functions of water bodies, soils and groundwater in the water cycle are hampered and being further exacerbated by threats from impending climate change. Though Malaysia is blessed with fairly abundant rainfall it still has its fair share of water woes, such as occasional droughts, looding and pollution of its rivers and water bodies. Only recently, the country was faced with water related hazards of fairly disastrous proportions. Recurring potable water shortages that occurred in 2014 and 2015 in several states had led to water rationing. Malaysia has since the early 1990s set its vision to become a fully developed country by the year 2020 (Vision 2020). The transformation of the water sector must also evolve in tandem to meet sustainable development goals beitting a developed nation status by 2020. The National Water Resources Policy (NWRP), launched in March 2012, is based on the 3 essential principles i.e. water resources security,water resources sustainability and collaborative governance. This paper will review the various water-related issues and challenges whilst proposing the implementation of the Integrated Water Resources Management (IWRM) Road Map including the measures to be undertaken to effect the transformation of the water sector in pursuit of Vision 2020 and to achieve the post 2015 Sustainable Development Goals (SDGs). The indings and recommendations are largely based on several in-depth studies undertaken by the Academy of Sciences, Malaysia (ASM) pertaining to the water sector and the IWRM agenda.

Brez namakanja v Egiptu ne gre

In Egypt agriculture holds above-average importance, both from the aspect of employment and of GDP. The fact is that there would be no agriculture if it were not for irrigation, which in turn would not be possible without the Nile, which is the only larger surface water source. Irrigation dates back far, yet throughout history there was the problem of floods and occasional droughts if the floods were late. The Aswan Dam built in the beginning of 1970s enabled the storage of large quantities of water (Lake Nasser), which can be exploited in a controlled manner for irrigation and generation of electricity. The project itself was often discussed one-sidedly. Because Egyptians had finished it with help from the Russians, the West above all others pointed out the negative consequences that Egyptians would have to take into consideration more seriously in the future. Historically speaking, this is one of the most important Egyptian economic projects, which has enabled improved farming and consequently greater food production; realistic possibilities do exist for the irrigation of brand new surfaces in the drought areas of the Western or Libyan Desert.

Implications of rural irrigation schemes on household economy. A case of Lower Gweru Irrigation Scheme, Zimbabwe

Rural poverty is a major challenge in most developing countries especially in Africa where the majority of people are still living below the poverty datum line. In Zimbabwe, poverty is made more severe by occasional droughts associated with climate change, climate variability and failed socio-economic-political governance. One of the ways to mitigate the impact of drought and prevent deepening poverty is the introduction of small irrigation schemes. However, there is a raging debate on the social and economic viability of these schemes on household livelihood security and income. This paper aims at investigating the socio-economic impacts of Lower Gweru Irrigation project in Zimbabwe. A case study approach was used in this study. Primary data was gathered using self-administered questionnaire and complemented by secondary data. Results demonstrated that rural irrigation has a critical role in ensuring sustainable household and community income. Irrigators fared well regarding wealth accumulation, household food security and quality of life as measured through the use of standardised HDI. In light of the above, there is a need to fund and develop more rural irrigation schemes so as to ensure livelihood security and rural development in Zimbabwe. Keywords : Rural livelihood, Poverty, Climate change, Irrigation, Lower Gweru, Extension.

Small Vernal Home Ranges in the Namaqualand Speckled Tortoise,Homopus signatus

Abstract In some herbivores, home range size is correlated negatively with the primary productivity of their environments. Although the South African Succulent Karoo is arid, it receives relatively predictable winter rainfall and therefore relatively predictable primary production toward the following spring. Lush springs may alternate with occasional drought years. Over five spring seasons with variable rainfall patterns, I studied home range size in 21 male and 31 female Namaqualand Speckled Tortoises (Homopus signatus) in the Succulent Karoo using opportunistic sightings, thread-trailing, and radio telemetry. In addition, daily movement distances were determined for 8 males and 28 females with the use of thread-trailing over three spring seasons. The average home range size for H. signatus was 3,470 m2, much smaller than home ranges for tortoises in other arid regions. Home range size did not differ between the sexes, but was negatively correlated with rainfall. Daily movement distances were also simil...

Drought tolerant maize for farmer adaptation to drought in sub-Saharan Africa: Determinants of adoption in eastern and southern Africa

In sub-Saharan Africa (SSA), “maize is life,” due to its importance to food security and economic wellbeing. Around 40 % of Africa’s maize-growing area faces occasional drought stress, resulting in yield losses of 10–25 %. Around 25 % of the maize crop suffers frequent drought, with losses of up to half the harvest. To reduce vulnerability and improve food security, the Drought Tolerant Maize for Africa (DTMA) project has made releases of 160 drought tolerant (DT) maize varieties between 2007 and 2013. These have been tested in experimental and farmers’ fields, and disseminated to farmers in 13 African countries through national agricultural research systems and private seed companies. Yields of the new varieties are superior to those of currently available commercial maize varieties under both stress and optimum growing conditions. Although the benefits of DT maize for African farmers have been repeatedly predicted, realization of those benefits depends on farmer uptake, which has received limited empirical study. We use new plot-level data from surveys of 3,700 farm households in six countries (Ethiopia, Tanzania, Uganda, Malawi, Zambia, and Zimbabwe) to measure DT maize adoption rates and their determinants. The data reveal considerable inter-country variation in farmer uptake of DT maize, from 9 % of maize plots in Zimbabwe to 61 % in Malawi. The major barriers to adoption include unavailability of improved seed, inadequate information, lack of resources, high seed price, and perceived attributes of different varieties. Based on the results, we recommend that seed companies and agro-dealers ensure adequate supply of DT maize seed in local markets and sell seed in affordable micro-packs (1 or 2 kg). Furthermore, the DTMA project and partners should ramp up promotional efforts to ensure widespread awareness and understanding of the benefits of the new DT maize varieties.