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Speleothem deposits in nowadays arid environments are important climate archives, as they indicate phases of enhanced precipitation and can precisely be dated by uranium-series dating. So far only very few of such archives have been found in the today hyper-arid Saharo-Arabian Desert (SAD). Therefore, the study at hand fills a gap that exists for speleothem climate archives in Northeast Africa. A new record from Saqia Cave (Central Eastern Desert, Egypt) documents for the first-time speleothem growth in Egypt for all sub-stages of MIS 5 and singular phases during MIS 6. Most important growth phases occur during periods of strong increase and maximum orbitally-forced northern hemisphere insolation, but also during phases of low insolation, which are in general attributed to aridity in North Africa. Here, at least semi-arid climate conditions are proposed for periods of low insolation during stadials of MIS 5. This suggests an impact of different possible sources of precipitation, apart from large scale shifts of the African monsoon, such as Red Sea Troughs, tropical plums and a larger spatial extent of the Mediterranean winter-rainfall zone. Concerning the spatial rainfall pattern in Egypt, we propose a considerable east to west rainfall gradient in Egypt for the Last Interglacial and suggest a stronger impact of variable moisture sources in the Eastern Desert near the Mediterranean and Red Sea in comparison to the more continental Western Desert of Egypt. This reveals more favorable pre-conditions for an enhanced land use potential in the past. Therefore, the more sustaining wetter climate in the Eastern Desert point to a recurring feasible dispersal corridor for Homo sapiens from the tropical climate into the temperate climate regime throughout MIS 5. Such a more humid climate provided an ideal basis for long-term, favorable environmental conditions east of the Nile Valley, creating a kind of contiguous landscape corridor that may have been attractive to humans and wildlife alike, linking the East African tropical climate regime with that of the temperate zone in Northeast Africa and Eurasia.

Roselle (Hibiscus sabdariffa L.) is recognized as a valuable food crop due to its nutraceutical potential, rich pigment content, and medicinal properties. However, there is limited information on planting dates and suitable genotypes for roselle cultivation in arid and semi-arid regions. The objective of this field study was to investigate the influence of five planting dates (March, April, May, June, and July) on morphological and phytochemical characteristics of different roselle genotypes. Among genotypes, eight (Jiroft, Dalgan, Bampoor, Iranshahr, Nikshahr, Roodbar, Saravan, and Qaleganj) were Iranian landraces, and HA and HS-24 were originated from Ghana and Bangladesh, respectively. Planting date significantly influenced the number of branches, bolls and seeds per plant, sepal fresh weight, calyx and biomass yields, and harvest index in tested roselle landraces. The greatest morphological growth, fresh sepal weight (50.6 g plant−1) and calyx yield (1519 kg ha−1) were observed with the roselle planted in early May. Moreover, amounts of chlorophyll, flavonoids and antioxidant remained higher in roselle when planted between April–May. The number of branches/plant was found to be an important determinant of calyx yield (r = 0.707) in roselle. Dalgan resulted in the greatest growth and yields within a comparatively shorter period of time compared to other tested landraces. Both principal component analysis (PCA) and cluster analysis also indicated that Dalgan landrace possessed most suitable morphological and phytochemical traits among tested landraces, and therefore, it could be planted adopted for extensive cultivation settings in the arid and semi-arid regions.

The Azraq oasis in the Eastern Desert of Jordan has produced considerable stone artefacts attributed to the early Palaeolithic, yet relatively few data are available regarding the chronology and palaeoenvironmental contexts of the remains. In this study, we present stratigraphic, sedimentological, and micropalaeontological analyses of the Late Acheulean site SM1 located within the former Shishan Marsh, which we combine with geochronological and sedimentological data from 13 neighbouring geological exposures to reconstruct landscape evolution at the western margin of the Shishan Marsh. We then discuss the Late Quaternary palaeolandscapes of the Greater Azraq Oasis Area over the past c. 350 ka. Our work demonstrates that the central Azraq Basin experienced three local wetting-drying cycles since the late Middle Pleistocene that would have dramatically shifted the quantity and distribution of freshwater resources, ranging from expansive wetland landscapes to desert refugia characterised by isolated spring pools—changes that would have significantly impacted the mobility decisions and settlement patterns of Palaeolithic inhabitants. Our study highlights that developing long-term records of human-environment dynamics in arid environments requires a mosaic approach to palaeoenvironmental reconstruction that is nested within a well-developed understanding of landscape evolution.

We present a multiproxy record of grain size and stable carbon isotope from the Lilaur lake, Ganga Basin, India to understand the history of lake formation linked to changes in Indian monsoon precipitation during ~13714 to 3073 calibrated year before Present (cal yr BP). A comparison is made between Lilaur lake proxy record with those from other parts of South Asia as well as North Atlantic to understand extent and causes of monsoon variability and its influence on the fauna and flora of the region. Chronology of lake core was constrained using AMS 14C and optically stimulated luminescence (OSL) dates. This study suggests a transition from river to lake during ~5800 to 5189 cal yr BP which is supported by reduced precipitation with weakening of the Indian summer monsoon (ISM). This river to lake transition culminated in a severe arid phase during 4250 to 4050 cal yr BP (4.2 ka event), corresponding to enhanced El Nino activity, southward shift of the Inter-Tropical Convergence Zone, and aridification of India when the ISM was weak.

Rates of soil development provide critical information about the types and rates of geomorphic and landscape evolutionary processes. Soil development in arid and semiarid regions of the southwestern United States is predominantly controlled by influx of eolian dust, yet our ability to quantify the rates of morphologic development and of dust and carbonate incorporation is limited by available age control. We describe 10 pedons in the Socorro area of central New Mexico and analyze their silt, clay, and carbonate contents. These soils have well-established direct or indirect age control that we used to estimate average rates of dust and carbonate accumulation over the past ~0.5–800 ka. We also computed the profile development index (PDI) for these soils using 10 common morphologic properties and compare our resulting PDI chronofunction to those from northern and southern New Mexico. We find that the net silt-and-clay content increases in progressively older soils at rates similar to the profile-mass carbonate contents, presumably sourced primarily from eolian dust. Our chronofunction comparison indicates that soil development occurs more rapidly in higher latitude regions of New Mexico than in the drier warmer climates of the Socorro area and southern New Mexico. We interpret the N–S regional trend of soil development considering a regional climate gradient. We conclude that greater mean annual precipitation and cooler mean annual temperatures and/or slower rates of eolian dust accumulation into the soil profile at higher latitude northern sites cause the observed differences in regional soil development. This would promote greater mobility of available silt and clay, and also increase rates of soil formation, as indicated by the presence of argillans in late-Pleistocene soils of northern New Mexico.

This paper presents the first insight into the interpretation of the wood charcoal from the Holocene layers of Wonderwerk Cave. Situated in the Northern Cape Province in the arid interior of South Africa, the site provides a unique and valuable chronological record of past environmental fluctuations and responding human behavioural adaptations spanning the last two million years. The Holocene strata have been dated to cover the last 12.5 ka cal BP years, but exclude the last 100 years because of contamination. A sizeable amount of charcoal was recovered from these strata and remnants have been identified, described and the species composition amongst the strata compared. Most identified species are those that tolerate hot, dry conditions, signalling an arid trend during the Holocene. Comparison with present day species distributions suggests an eastwards shift in modern vegetation. The charcoal data also indicate that during the mid Holocene there was a wetter period from 6.2 to 4.5 ka cal BP, coinciding with stratum 4a.

We have reassessed the palynological record of Equus Cave in the Savanna Biome of the southern Kalahari, one of the longest Late Quaternary pollen records for the semi-arid central interior of South Africa. We combined published pollen results from the cave, derived from hyena coprolites and the rubified deposits in which they occur, into a single sequence. By re-considering the chronology of this sequence, we critically evaluated the palaeoenvironmental record for the site. We compared the pollen evidence from Equus Cave to that from the longer Wonderwerk Cave records (stalagmite, sediments and dung), also located in the Savanna Biome. Then, we contrasted Equus and Wonderwerk records with other previously published pollen sequences derived from a range of sources from several sites in central South Africa. These sites follow a broad northwest to southeast transect of c. 500 km through the Grassland and Nama Karoo Biomes of the Free State and Eastern Cape. Applying Principal Components Analysis to the pollen data, we derived climatic signals at a regional scale to refine reconstructions of Late Quaternary changes for central South Africa., LS was supported by the National Research foundation (South Africa) (NRF Grant no. 85903). The Leakey Foundation (USA) and the National Science Foundation (USA) respectively supported CBB’s work at Baden-Baden and Blydefontein. LS appreciates Juan Ochando Tomas’ collaboration relating to hyena coprolites in Project CGL-PID2019-1049449GB-I00 (FEDER/Ministry of Science and Innovation, Spain).

In this study we investigate the timing and nature of moisture availability in the Late Holocene by examining a multiproxy paleoenvironmental record from Kathu Pan at the southern edge of the Kalahari. In a region where organic proxy records are scarce, Kathu Pan provides a unique record of changes in past environmental conditions. Pollen, spore, charcoal, and stable isotope records were obtained from organic deposits at Kathu Pan and examined within a radiocarbon-constrained chronological framework. The Kathu Pan record registers a relatively moist phase occurring between 4.8 ka and 2.5 ka cal BP. Local environmental conditions at Kathu Pan shift gradually beginning around the terminal Northgrippian ~4.8 ka cal BP. Kathu Pan reaches maximum moisture availability with marsh-like conditions signaled by increased organic content, dominance of Cyperaceae pollen, presence of freshwater fungi, and δ13C values consistent with local C3 vegetation, around the inception of the Meghalayan Stage, although due to uncertainties in the age-depth model these changes may have taken place 1–2 centuries on either side of the formal date for the onset of the Meghalayan at 4.2 ka cal BP. This interval also corresponds with the highest charcoal concentrations, indicating the importance of adequate moisture conditions to support the growth of biomass which eventually becomes a fuel source. The moist phase lasts ca. 2000 years until a hypothesized shift to arid conditions occurs c. 2.5 ka cal BP leading to a change in local hydroclimate that may have terminated the accumulation of organic-bearing sediments.

Little attention has been paid to climate change in the marginal regions of the Asian summer monsoon (ASM) domain since Marine Isotope Stage (MIS) 3 (60-27 cal kyr BP). Here, based on the mineralogy and grain size of a 24-m-long sediment core retrieved from Jilantai Salt Lake, we provide a paleolake evolution record from a marginal region of the ASM domain over the past 47 kyr. Our results indicate that the lake was a brackish or saline lake and that the region was relatively humid during 47–43 cal kyr BP. From 43 to 27.5 cal kyr BP, the lake salinity increased and the climate began to deteriorate. From 27.5 to 11.8 cal kyr BP, aeolian activity intensified and the climate was arid. From 11.8 to 5.6 cal kyr BP, the lake salinity continuously increased, and the climate was persistently arid. After 5.6 cal kyr BP, the lake salinity dramatically increased, the lake became a salt lake, and the climate was extremely arid. In general, the climate was semihumid in mid-late MIS 3, arid in MIS 2 (27–11.7 cal kyr BP), and hyperarid in the Holocene. This climate change pattern is apparently different from that in the regions influenced by the Asian monsoon and westerlies, indicating that the enhanced Asian monsoon or westerlies were not the main forcing mechanism driving climate change in the marginal regions of the ASM domain. Enhanced ice-albedo feedback caused by the expanded Northern Hemisphere ice volume during MIS 3 would have resulted in less net incoming solar radiation and relatively low temperatures in the mid-high-latitudes. The relatively low temperatures might have weakened the evaporation capacity of Jilantai Basin and increased south-north temperature gradients, resulting in an increase in local precipitation. Therefore, the climate was semihumid in mid-late MIS 3. The lowest Northern Hemisphere summer insolation (NHSI) combined with significantly increased ice-albedo feedback associated with the largest Northern Hemisphere ice volume would have led to a remarkable reduction in temperature, resulting in the reorganization of major atmospheric and hydrological systems in the Northern Hemisphere and an arid climate in MIS 2. Subsequently, the Northern Hemisphere ice volume nearly vanished, and the rising NHSI enhanced evaporation, thereby generating a hyperarid climate in the Holocene.

Temporal and spatial changes of green water (GW) security due to climate and land-use/land-cover (LULC) changes can be used to make the best decisions for sustainable GW management. In this study, simultaneous effects of climate and LULC changes on water resources in Kashafrood Basin were evaluated using the Soil and Water Assessment Tool (SWAT). A land change modeler was set up to monitor LULC, assess changes and make predictions. The MIROC-ESM model derived from Coupled Model Intercomparison Project Phase 5 under two representative concentration pathway (RCP) emission scenarios RCP2.6 and RCP8.5 was applied to evaluate the effects of climate change. Two indices of GW-Scarcity and GW-Vulnerability, representing GW-Security, were quantified using the GW-Footprint concept in Kashafrood Basin. The results show that the annual average of blue water was predicted to increase by 142–350%, and GW storage and the annual averages of GW flow were predicted to decrease by 12–65 and 8–20%, respectively, depending on emission scenarios and time. The GW-Security estimates in the entire basin suggest a better condition in the future by indicating 24–45 and 16–52% decreases in GW-Scarcity and GW-Vulnerability, respectively, depending on emission scenarios and time. HIGHLIGHTS Land change modeler predicts a decline in agricultural area and a growth in urban and pasture areas.; Blue water rises by 142–350% under the effect of climate and land-use changes.; Green water (GW) storage and GW flow decrease by 12–65 and 8–20%, respectively.; The condition of the basin in terms of GW-Security would improve in the future.; GW-Scarcity and GW-Vulnerability escalate in southern and some western subbasins.

Brazil’s leadership in soybean and maize production depends on predictable rainfall in the Amazon-Cerrado agricultural frontier. Here we assess whether agricultural expansion and intensification in the region are approaching a climatic limit to rainfed production. We show that yields decline in years with unusually low rainfall or high aridity during the early stages of crop development—a pattern observed in rainfed and irrigated areas alike. Although agricultural expansion and intensification have increased over time, dry–hot weather during drought events has slowed their rate of growth. Recent regional warming and drying already have pushed 28% of current agricultural lands out of their optimum climate space. We project that 51% of the region’s agriculture will move out of that climate space by 2030 and 74% by 2060. Although agronomic adaptation strategies may relieve some of these impacts, maintaining native vegetation is a critical part of the solution for stabilizing the regional climate. Soybean and maize yields in the Amazon-Cerrado region of Brazil are dependent on water from rain. Warming and drying will make the climate less suitable for agricultural production; changes have already moved 28% of croplands out of their optimum climate space.

The presence of Xylocopa valga is reported for the first time from the high altitudes of Union Territory of Ladakh (more than 3,000 m above sea level), India. Several bees were observed in the area from May 2019 to September 2020, where it is considered to be a pest because of its aptness for making nests in residential and commercial buildings. The species has likely expanded its geographical area due to environmental changes. It is important to disseminate knowledge among Ladakh people about this bee to ensure the preservation of its populations. Premier signalement de Xylocopa valga Gerstaecker, 1972 dans les conditions froides et arides du Ladakh en Inde (Hymenoptera : Apidae : Xylocopini) La présence de Xylocopa valga est reportée pour la première fois dans les territoires du Ladakh en Inde (plus de 3000 m d’altitude). Plusieurs individus ont été observés sur ce territoire entre mai 2019 et septembre 2020. L’espèce y est considérée comme nuisible par la population à cause de sa capacité à faire des nids dans les bâtiments commerciaux et résidentiels. Cette espèce a probablement étendu son aire de répartition à cause des changements environnementaux. Il apparaît important de communiquer autour de cette espèce auprès de la population de Ladakh pour préserver ses populations.

International audience; Life history traits are adaptations to specific environmental conditions, but are also phylogenetically constrained. We studied life history traits of free-living bush Karoo rats (Otomys unisulcatus) that are endemic to the semi-arid regions of South Africa. They show behavioural, rather than physiological, adaptations to arid environments, which might affect life history traits compared to their mesophyllic otomyine relatives. We studied the reproduction and lifespan of bush Karoo rats over two and a half years. Mean litter size was 1.7, and was not dependent on the month of birth. Males were larger and had higher disappearance rates than females. Age and mass at reproductive maturity did not differ between the sexes. Individuals born earlier (May-July) in the breeding season reached reproductive maturity in the year of their birth whereas those born later (August-November) reached maturity in the following year. Mass at maturity was dependent on timing of birth; individuals born earlier were lighter than those born later. Growth rate of all males was double that of all females, and male post-weaning growth rates were greater than that of females, but not affected by the timing of birth. Lifespan, which was shorter in males than females, was not dependent on timing of birth. Compared to other members of the tribe Otomyini, bush Karoo rats had a slow pace of life, possibly because of the energy constraints in their arid habitat. Litter size, mass at maturity and lifespan are assumed to be phylogenetically constrained in the tribe Otomyini.

The Kettara abandoned mine, Morocco, is a highly acid drainage-generating site with negative impacts. In order to impede the water–oxygen migration within tailings of Kettara mine, a store-and-release (SR) cover made with phosphate mine wastes (PMW) layers was implemented on the tailings of Kettara mine in five experimental cells. The characterization of vegetation is an important aspect of the monitoring strategy for the SR cover. In this optic, the objective of this study was to follow the local flora dynamic on the SR cover. Furthermore, this research highlighted the potential of this flora for the development of other appropriate phytomanagement plans of mining wastes. The monitoring surveys were carried out over five years (March 2015–April 2019). Six permanent transects were placed on five-constructed cells. The method of Line Intercept Transect was used to evaluate the vegetation cover and to determinate the floristic composition and relative frequency of the species. Plant diversity was quantified by Shannon diversity (H′) and Pielou evenness (J') indices. Four functional groups of plants were identified; therophytes and chamaephytes were the most abundant. Among 19 recorded families on SR cover, the most widely represented were Compositae (26.83%), Leguminosae and Poaceae with 9.76%, Apiaceae and Brassicaceae with 7.32% of the total taxa for each one of them. Of the 39 identified vascular species on SR cover, the most abundant were Anacyclus valentinus L., Calendula arvensis M.Bieb., Emex spinosa (L.) Campd., Hirschfeldia incana (L.) Lagr.-Foss., Spergularia rubra (L.) J.Presl & C.Presl, Stipa capensisthunb, and Herniaria cinerea L. Significant differences in Shannon diversity index (H′) were observed between the sampling areas (p > 0.05), it ranged from 0.739 to 3.857 bits/ind. on SR cover. The Pielou evenness index was not significantly different through transects; it varied from 0.578 to 0.978. These values indicated an equitable distribution of individuals within species on the investigated transects. The study revealed 29 vascular plant species that represent a great potential to be promoted for the phytomanagement of mine wastes in the context of arid and semi-arid environments.

The Ladakh Range in the Trans Himalaya houses sub-routes of the Silk route through its passes (La in local language) which may have been the main commercial and cultural passage to connect the central Asia and Tibetan region with the rest of India. A ca 6400-220 cal yr B.P. hydroclimatic record of two lakes viz Tsoltak lake and Yaya Tso near the Chang La and Hor La passes of Ladakh Range is presented here. The overall record (mineral magnetic analysis and microbiota) from the Ladakh range shows wetter conditions ca 6400 cal yr BP consistently declining till ~5000 cal yr BP and moderately wet and stable till ~4300 cal yr BP, followed by an arid cold phase (~4300-4000 cal yr BP). This precedes two moderately wet phases (ca 4300-3500 cal yr BP and ca 1260-220 cal yr BP) and the peak arid conditions between 3500 and 2860 cal yr B P and 2230-855 cal yr BP, which may have affected the trade activities and had an adverse affect of cultural transitions during these periods across the Ladakh Range on the to and fro movements from this northern sub-route branch. The biotic assemblage is rich in Non Pollen Palynomorphs (76%) with minor amounts of pollens (24%). An improvement in the conditions since 855 cal yr BP and thereafter from 340 to 220 cal yr BP records the onset of the cold arid conditions again in the Ladakh Range. Presently due to contemporary deglaciation the Ladakh Range is becoming ice free and a number of lakes surrounded by herbaceous meadows are seen in the area due to glacial melt, likely to encourage the human settlements to soon occupy the higher reaches that will negatively affect the natural lake productivity.

In the coming three decades, world waste will be expected to increase by 70%. Coupled with the absence of waste management technologies, unregulated dumping remained a threat to sustainable development in developing countries. To this end, this study emphasized to trace socially acceptable and environmentally friendly solid waste dumpsite for the northeastern arid cities of Ethiopia. The tuneful integration of GIS and MCDA was used for the end-to-end processing of 17 variables. At the earlier, to increase alternative dumpsites and seeking for safe zone outside the cities, 20 km buffer at Semera-logia city was used as a spatial scope of the study. Fifteen key informants (KIs) from related departments of the city and Samara University were selected to validate the model result. In the end, Ordinal Regression (OR) analysis was used to test the significance of the criteria's on suitable dumpsite selection. The pair-wise comparison matrix shows that variables such as distance from surface water (11.32%), distance from the settlement (9.88%), distance from boreholes (8.87%), and aquifer productivity (8.51%) were the top weighed criteria for the study area. The weighted overlay result shows that 10.75% and 38.64% of the study area are found to be convenient and prohibited for dumping, respectively. Indeed, the KIs were agreed on 77% of the validation points and the agreement decreases from points of not-suitable to highly suitable. Except for aquifer productivity, all the 16 variables are significantly and negatively affect dumpsites suitability. This result can be further used as a preliminary database for experts to design landfill structures and also management operations for decision-makers.Implications: The identification of potential dumpsite is an important step towards maximizing efficiency and building sustainability in the arid areas. The decision-making process shall be based on the empirical investigation. The decision-making process on dumpsite selection were well thought out both the socio-economic and environmental factors. In owing process, the empirical investigation that was conducted focusing on socio-economic dimension jeopardized other components of the environments. The approach that considers both socio-economic and spatial factors was all-inclusive. Overall, decision-makers could have a good insight to work on prioritizing dumpsite alternatives and implement feasible waste management actions.

Biological soil crusts (BSCs), or biocrusts, are composed of fungi, bacteria, algae, and bryophytes (mosses, etc.) that occupy bare soil, entwining soil particles with filaments or rootlike structures and/or gluing them together with polysaccharide exudates to form a consolidated surface crust that stabilizes the soil against erosion. BSCs are common in arid and semiarid regions where vascular plant cover is naturally sparse, maximizing the exposure of surface-dwelling organisms to direct sunlight. Although less prominent and less studied there, BSC organisms are also present in more mesic areas such as the Great Plains where they can be found in shortgrass and mixed-grass prairie, in the badlands of several states, where burrowing animals have created patches of bare soil, on damaged road-cuts, strip-mines, gas and oil drill pads, military training areas, heavily grazed areas, and burn scars. Even where BSCs are not readily visible to the naked eye, many of the organisms are still present. BSC organisms are passively dispersed to the Great Plains as airborne organismal fragments, asexual diaspores, or sexual spores that accompany wind-blown dust from as far away as northern China and Mongolia. BSCs can best be studied and managed by 1) acknowledging their presence; 2) documenting their diversity, abundance, and functional roles; and 3) minimizing unnecessary disturbance, particularly when the soils are dry. This paper describes the current knowledge of Great Plains BSCs in an effort to heighten awareness of these cryptic but crucial ecosystem components and to encourage new research initiatives to better understand and manage them in this biome. Some specific actions may include refined taxonomic and ecologic studies of BSC organisms in underexplored areas, particularly those previously less or not recognized as BSC habitat, and incorporation of techniques to sample airborne organisms.

Long-term carbon cycle models are critical for understanding the levels and underlying controls of atmospheric CO2 over geological time-scales. We have refined the implementation of two important boundary conditions in carbon cycle models, namely consumption by silicate weathering and carbon degassing. Through the construction of continental flooding maps for the past 520 million years (Myrs), we have estimated exposed land area relative to the present-day (fA), and the fraction of exposed land area undergoing silicate weathering (fAW-fA). The latter is based on the amount of exposed land within the tropics (±10°) plus the northern/southern wet belts (±40-50°) relative to today, which are the prime regions for silicate weathering. We also evaluated climate gradients and potential weatherability by examining the distribution of climate-sensitive indicators. This is particularly important during and after Pangea formation, when we reduce fAW-fA during times when arid equatorial regions were present. We also estimated carbon degassing for the past 410 Myrs using the subduction flux from full-plate models as a proxy. We further used the subduction flux to scale and normalize the arc-related zircon age distribution (arc-activity), allowing us to estimate carbon degassing in much deeper time. The effect of these refined modelling parameters for weathering and degassing was then tested in the GEOCARBSULFvolc model, and the results are compared to other carbon cycle models and CO2 proxies. The use of arc-activity as a proxy for carbon degassing brings Mesozoic model estimates closer to CO2 proxy values but our models are highly sensitive to the definition of fAW-fA. Considering only variations in the land availability to weathering that occur in tropical latitudes (corrected for arid regions) and the use of our new degassing estimates leads to notably higher CO2 levels in the Mesozoic, and a better fit with the CO2 proxies.

Rice is one of the most culturally valued and widely grown crops in the world today, and extensive research over the past decade has clarified much of the narrative of its domestication and early spread across East and South Asia. However, the timing and routes of its dispersal into West Asia and Europe, through which rice eventually became an important ingredient in global cuisines, has remained less clear. In this article, we discuss the piecemeal, but growing, archaeobotanical data for rice in West Asia. We also integrate written sources, linguistic data, and ethnohistoric analogies, in order to better understand the adoption of rice outside its regions of origin. The human-mediated westward spread of rice proceeded gradually, while its social standing and culinary uses repeatedly changing over time and place. Rice was present in West Asia and Europe by the tail end of the first millennium BC, but did not become a significant crop in West Asia until the past few centuries. Complementary historical, linguistic, and archaeobotanical data illustrate two separate and roughly contemporaneous routes of westward dispersal, one along the South Asian coast and the other through Silk Road trade. By better understanding the adoption of this water-demanding crop in the arid regions of West Asia, we explore an important chapter in human adaptation and agricultural decision making. Introduction Domestication - East Asia - South Asia Himalayan Plateau West and Central Asia - Historical Sources - Archaeobotanical Data South Asian Coastal Routes - Historical Sources - Archaeobotanical Data Intensification of Rice Cultivation Culinary Shift Conclusions

Water scarcity is a real challenge in the Mediterranean countries such as Tunisia. Currently, in Tunisia, about 80% of the resources are allocated to the agricultural sector. The irrigated areas are estimated at 420000 ha, consist of 220000 ha of public perimeters and 200000 ha of private perimeters. In arid and semi-arid regions of central and southern Tunisia, the cultivation of the olive tree (Olea europaea L.) is an important widespread activity, mainly due to its great adaptability to the conditions of water deficit and its nutritional value. Olive oil is a susceptible product, its quality and organoleptic characteristics can be influenced by several factors from harvest to storage, such as irrigation. The results obtained in the present study allowed classifying the monovarietal oils samples in the extra virgin category. In general, the impact of irrigation is very remarkable, mainly in the reduction of the pigments, alpha tocopherols, oleic acid, and total phenol compound contents. This decrease recorded in these various parameters is found in olive oil produced from trees grown under daily irrigation in Ksar Ouled Debbab. The data registered in this present work revealed that oil composition and quality could be directly affected by irrigation. Our results can give useful indications for explaining more the relation between irrigation strategies and olive oil quality: Qualitative and quantitative compositional analysis showed that several oil parameters significantly decreased in the freshwater irrigated plot more than the rainfall plot.

In a scenario of world population increase and climate change, an efficient use of water is key for agricultural production. Onion is one of the most profitable crops and can adapt to particular conditions of water stress. The objective of this research was to determine growing degree-days and accumulated radiation under non-stress conditions and yield of an F1 2000 hybrid of onion (Allium cepa L.) under water deficit (WD) and biofertilization in a semi-arid environment. An established nutrient requirement of 247 kg N, 240 kg P2O5(105 kg P), 240 kg K2O (199 kg K), and two irrigation factors were applied: normal irrigation with a daily and WD with a 3 d interval irrigation frequencies. The effect of biofertilization was evaluated through the inoculation of a microbial consortium (MC) in combination with four NPK fertilizer treatments. The crop accumulated 1334 degree-days and 1188 MJ m−2·d−1at the time of harvest at 71 d after transplanting. The yield was 36 t·ha−1, similar under both irrigation conditions; and the WD treatment resulted in a 35% water savings, a 47% and 65% increase in water use efficiency and modulus of elasticity, respectively. The MC resulted in a 50% NPK savings under non-limiting water conditions and produced a similar yield compared with the 100% NPK non-inoculated control. The lower irrigation frequency together with the 100% NPK fertilization dose without the MC and the use of the microorganisms and the 50% NPK treatment without water stress are recommended as agrosustainable practices for onion production.

Crops in the northwest arid region of China frequently suffer from low emergence and poor yield due to high water deficit. Mulching is an important approach to reduce irrigation amount while increasing productivity but faces the challenge of ecological adaptability in this region. A field experiment was carried out in the three growing seasons from 2011 to 2013 to study the effects of mulching with crushed wheat straw padding and plastic film on sunflower seed emergence and yield under different irrigation intensities. A two-factor (mulching and irrigation intensity) completely randomized block design was applied, resulting in a total of 12 treatments repeated three times. Mulching treatments include zero mulch (N), straw mulching at the beginning of the experiment (S), plastic film mulching when sowing (F; a commonly used mulching by local farmers), and double mulching with plastic film on the crushed wheat straw layer (SF). Irrigation intensity includes high (H = 900 m3·ha−1), medium (M = 750 m3·ha−1), and low (L = 600 m3·ha−1). Results showed that all mulching treatments promoted the early emergence of seedlings compared with N, with SF and F performing better than the rest. SF was the best-performing mulching approach in this study, and it had significantly improved sunflower yield and yield components compared with other treatments. In SF, medium irrigation level had significantly increased sunflower 100-seed weight. Therefore, SF with M irrigation level showed the most positive effect on sunflower production, and it is now the recommended agronomic solution for sunflower production in the northwest arid regions and, potentially, other irrigated areas with similar ecological conditions.

• Savin juniper is an excellent species for desertification control in arid and semi-arid areas, where it typically establishes under the protection of nurse plants. Ultimately, established plants emerge into full sunlight as they grow, and this transition is accompanied by an increase in the preponderance of scale-like vs. needle-like leaf forms. • To test how age and variable sunlight environments affect shade tolerance in savin juniper, we established a pot study under field conditions with two age cohorts (1- and 4-year-old rooted scions) and three sunlight regimes (10%, 50% and 100% light transmittance). We measured growth, leaf parameters, photosynthesis, chlorophyll fluorescence and foliar pigments on a monthly basis (seven growing months per year, from 2015 to 2017). • Overall, there was little interaction for all variables, and both cohort and light regime had significant effects. Leaf form and spacing varied continuously, tending towards shorter, more closely spaced and more appressed scale leaves with higher dry leaf mass per area in older plants or under higher sunlight. There were no clear age-related patterns in carotenoids but both cohort and light had significant effects on gas exchange and chlorophyll fluorescence variables. • Savin juniper shows an intermediate tolerance to shade that changes with growth in that younger plants were less tolerant of full sun than older plants, consistent with its reliance on nurse plants for ultimate establishment in the open.

Numerous paleoclimatic records from lake sediment cores in arid central Asia (ACA) suggest a more humid climate in the Little Ice Age (LIA) cold period than that of the contemporary warm period (the last century). Our high-resolution study of a sediment core from Yileimu Lake presents end members (EMs) of grain-size distributions (~5-year resolution), and major and trace elements (~10-year resolution), including the Chemical Index of Alteration (CIA) and Rb/Sr ratio. In contrast to records from these other lakes in ACA, our study indicates a warming and wetting trend in the southern Altay regional climate over the last five centuries. We suggest that continuously increasing snow/ice meltwater from the surrounding high mountains related to an increasing trend in atmospheric temperature, and increasing winter snowfall triggered by a decreasing trend in winter North Atlantic Oscillation (NAO) index, have dominated the regional climate in the southern Altay Mountains during 1620–1835 AD. We also suggest that temperature dependent evaporative losses greatly exceeding the water input to the lake, and reduced summer precipitation, caused the drought events during 1586–1620 and 1835–1870 AD. Heavy summer precipitation associated with significant increases in the local moisture supply induced by intense evaporation of snow/ice meltwater in the alpine and gorge terrain of the Altay Mountains played a critical role in the summer floods around the 1900s AD.

This paper focuses on the effects of chemical precipitation on the permeability of geotextile envelopes for a subsurface drainage system in arid areas by conducting precipitation experiments of the geotextile in static or flowing solution. The results show that the precipitation process is not significantly promoted or inhibited by the network structure of geotextile. The precipitates in the form of rhombus wrap around the fiber surface. The number of geotextile pores with the smaller diameters decreases significantly after precipitation experiments. As the increase of the area density of precipitates (ΔR), the variation of the pore area (ΔS) and the variation of permeability coefficient (ΔK) of the geotextile decrease rapidly at first and then slowly. The ΔK and ΔS VS ΔR data were best fitted with logarithmic trend line. This study provides a preliminary reference for quantifying the chemical clogging process of geotextile envelopes in arid areas.

Water scarcity constrains global cotton production. However, partial root-zone drying (PRD) and mulching can be used as good techniques to save water and enhance crop production, especially in arid regions. This study aimed to evaluate the effects of mulching for water conservation in an arid environment under PRD and to further assess the osmotic adjustment and enzymatic activities for sustainable cotton production. The study was carried out for 2 years in field conditions using mulches (NM = no mulch, BPM = black plastic mulch at 32 kg ha-1, WSM = wheat straw mulch at 3 tons ha-1, CSM = cotton sticks mulch at 10 tons ha-1) and two irrigation levels (FI = full irrigation and PRD (50% less water than FI). High seed cotton yield (SCY) achieved in FI+WSM (4457 and 4248 kg ha-1 in 2017 and 2018, respectively) and even in PRD+WSM followed by BPM>CSM>NM under FI and PRD for both years. The higher SCY and traits observed in FI+WSM and PRD+WSM compared with the others were attributed to the improved water use efficiency and gaseous exchange traits, increased hormone production (ABA), osmolyte accumulation, and enhanced antioxidants to scavenge the excess reactive oxygen. Furthermore, better cotton quality traits were also observed under WSM either with FI or PRD irrigation regimes. Mulches applications found effective to control the weeds in the order as BPM>WSM>CSM. In general, PRD can be used as an effective stratagem to save moisture along with WSM, which ultimately can improve cotton yield in the water-scarce regions under arid climatic regions. It may prove as a good adaptation strategy under current and future water shortage scenarios of climate change.

Considering three sites under different climate conditions (arid, semiarid, and subhumid), this study aims to use the vadose-zone water stable isotope profiles to estimate the groundwater recharge rate. High-resolution vertical subsurface soil sampling along the vadose zone of the investigated sites was conducted. The collected samples were analysed to determine their stable isotopes ratios (δ2H and δ18O) that were used in the piston displacement method for estimating recharge. Annual recharge rates of 0.2% (±0.1%), 2.5 %, and 18% of the total annual precipitation were obtained for the arid, semiarid, and subhumid sites, respectively. Recharge rates at the semiarid and subhumid sites are comparable to those previously estimated using water balance-based methods. The recharge rate at the arid site is lower than that previously estimated for that site using the water budget-based method, revealing difficulties in applying the piston displacement method under an arid regime.

Grouping characteristics and population growth dynamics of Sambar were studied in Bir Jhunjhunu Conservation Reserve (BJCR) and Bairasar Johad (BJ) in Rajasthan, India from July 2018 to June 2019. Following the scan sampling method, a total of 117 sightings of Sambar (N= 488 individuals) were recorded in BJCR, and 106 in BJ (N= 389 individuals), during 24 fortnightly visits. The data revealed that besides solitary sightings of Sambar, groups ranging from 2–11 and 2–12 individuals were observed in BJCR and BJ, respectively. The overall mean group size and mean crowding of Sambar were 4.2±0.2 S.E. and 5.3 respectively in BJCR, and 3.7±0.2 S.E. and 5.0 respectively in BJ. The sex ratio was skewed towards females. The overall adult male: adult female: fawn ratio was 74.4: 100: 47.1 (N= 488 individuals) in BJCR while the ratio was 92.6: 100: 41.1 (N= 389 individuals) in BJ. As far as the social organization of Sambar is concerned, six types of herds were recorded in the present study. It is urged that sambar populations outside protected area also need simultaneous strategies for conservation attention.

Purpose. The research is aimed at developing methods for creating highly productive and highly nutritious pasture agrophytocenoses, adapted to the extreme conditions of the arid zone of the Northern Caspian region. Methods. The paper provides an assessment of the productivity of perennial one-species (Agropyron) and poly-species (Agropyron, Eutoria, Kochia) agrophytocenoses for a five-year period of their vegetation, depending on the timing (autumn, spring) and sowing methods (ordinary, scattered). Results. These phytocenoses, created in the harsh climatic conditions of the semi-desert on light chestnut soils with a low level of fertility (humus – 0.68 %), starting from the first year, formed the yield 2–7 times higher than the natural pasture. According to the results of the study, it was revealed that a significant role in the creation of arid forage phytocenosis was played by the sowing method and species composition, including the scattered sowing method turned out to be more productive (in monospecific – by 57–70 %, in poly-species – by 63–82 %), the yield of the poly-species composition of the phytocenosis, starting from the second year, increased by 1–2 t/ha for all years of the study in comparison with the monospecific composition both on the row and on the spread method of sowing. Scientific novelty. All created agrophytocenoses for all variants had a fodder value 3–10 times higher than the natural pasture, including the presence of different plant species on the pasture increased the collection of fodder units in comparison with a single-species pasture by 1.5–2 times, and the spread method of sowing also increased the provision of pasture fodder with protein by 0.18–0.2 t/ha. Already by the second year of plant development, it was noted that the presence of shrubs and semi-shrubs on the forage lands creates better conditions than the aftermath of the corn crop for snow retention, and, accordingly, contributes to a greater accumulation of moisture in the soil.

This paper studies the effects of drought shocks in a vulnerable environment – the Brazilian Semi-Arid. We analyze the impact of drought shocks, measured as deviations from long-run historical averages, on agricultural outcomes in a region that suffers recurrently from drought. After controlling for municipality and year fixed effects, we use weather shocks to exactly identify outcomes. Our benchmark results show substantial effects on the loss of crop area and on the value of agricultural output, as well as on crop yields. As we investigate distributional effects, our results show that crops related to familiar agriculture suffer more from drought shocks. We follow our investigation by testing heterogeneity effects and show that adequate water provision and maintenance of forest cover help in reducing the impact of drought shocks.

Flash floods have led to disruptions of human activities and the destruction of properties particularly in the Nuweiba region of southeast Sinai. Despite the arid nature of Sinai, flash floods still pose a great hazard to the region. Using remote sensing characterization, geohazard models were developed to identify flash flood areas; delineate and discriminate morphological features, active channels areas, and soil physiography with a view to categorize risk areas exposed to flash floods hazards in a hazard map; and proffer measures for mitigation. The characterization was achieved using a workflow model developed from spatial data sets of the Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) and the red-green-blue (RGB) composites from Landsat bands 7 Enhanced Thematic Mapper (ETM+). The data were used to investigate and assess flash flood areas for morphological attributes, watershed basin characterization, and generation of false color composite from the Landsat 7 ETM+ 7, 4, and 2 RGB bands, and the principal component analysis band from a composite of 742 RGB. Multivariate analysis of generated raster layer attributes provided enhancements and attribute discrimination for delineating areas of active flood channels, upslope zones, and soil physiography discrimination from their spectral reflectance. The results are presented in an integrated approach of remote sensing with geographic information systems (GIS) and indicate that the soil types and geologic units contribute greatly toward activation of these flash floods, which is triggered by intense rainstorms. Components of the generated map attributes of SRTM DEM, gradient of DEM, and Landsat 7 ETM+ composite of 742 bands in GIS were used to generate a hazard map using spatial analysis to depict the nature and scale of the issues identified. Due to the flash flood vulnerabilities, the study area was classified into stable/low-, moderate-, and high-risk areas. Mitigation measures to control flash floods were proposed to enable adequate preparations to mitigate impending flash flood disasters.

Development in Sub-Saharan Africa (SSA) is adversely affected by climate variability and change due to the dependence of its economies and livelihoods primarily on rain-fed agriculture. Agro-advisories boost informed decision-making as well as planning of farm activities. The purpose of this study was to characterize the pathways through which farmers receive usable location-specific agro-advisories as well as to evaluate the effect of the socio-economic environment in the access to such information. Data was collected from 400 randomly selected households in lower eastern Kenya in a cross-sectional survey. Multivariate probit regression was used to determine the factors influencing the choice of pathways used in accessing climate change adaptation information. Household socio-economic characteristics that were found to be significant in explaining access to disseminated agro-advisories include phone and radio ownership, level of education, marital status, and farm size among others. Based on these findings a conclusion is made that the socio-economic environment within which information is disseminated is vital in determining those who access information and probably act on it. Additionally, pathways found to be complementary or substitutable give information providers new insights on the channels to use in information dissemination. The study recommends that these factors be considered in efforts geared towards promoting agro-advisory preparation and dissemination to improve adaptation to climate variability and change in dryland areas.

Salinity is a major environmental restraint in arid and semi-arid regions. Excessive amounts of salt in natural soils and in saline irrigation reduce seed germination and plant growth of most plants in the agricultural lands of these regions. The purpose of this research was to investigate the effect of salinity on seed germination, growth performance, and physiological processes; such as chlorophyll content, chlorophyll fluorescence (Fv/Fm), and gas exchange of two Moringa species, Moringa oleifera and Moringa peregrina. Salinity treatments comprised 5 NaCl concentrations; (0, 50, 100, 150 and 200 mM). The germination test took place in petri dishes, while plants were grown in pots under controlled environments inside plant growth chambers. Results showed that seed germination was significantly affected by salinity. The effect of salinity on germination performance differed between the two species. For example, none of the two Moringa seeds germinated at the high level of salinity (200 mM), while M. oleifera seeds germinated at 150 mM and those of M. peregrina showed no signs of germination. Results demonstrated that salinity significantly reduced all growth parameters of the two Moringa species. However, low salinity (50 mM) enhanced all growth parameters and the photosynthetic performance of the two Moringa species compared to the control plants. The chlorophyll content was not affected by salinity for both species, but the saturation rate of photosynthesis was inhibited, and in particular under high NaCl concentration. The effect of salinity on quantum yield followed the same effect pattern as for the saturation rate of photosynthesis, while the (Fv/Fm) was not significantly affected. The two species of Moringa, M. oleifera and M. peregrina differed in the mechanisms of salt tolerance; for example, M. oleifera expressed high salt tolerance at germination phase, whereas M. peregrina demonstrated high photosynthesis rates at low and medium levels of salinity. The physiological responses of M. peregrina to withstand medium levels of salinity makes it a more successful species in harsh environments such as that of Saudi Arabia.

Pollen evidence from a 25.3-m-long section (~2.2–0.41 Ma) in the Jinyuan Cave, Liaodong Peninsula, indicates that from the Early–Middle Pleistocene, the climate showed a trend of gradual cooling and drying, with obvious fluctuations. The vegetation was represented by temperate broad-leaved forest from ca. 2.2 to 1.87 Ma, suggesting a relatively warm and humid climate. The period from 1.87 to 1.82 Ma witnessed an obviously cold and dry event, and coniferous and broadleaved mixed forests developed from 1.82 to 1.76 Ma. From 1.52 Ma to the Mid-Pleistocene Transition (MPT), the vegetation was dominated by forest steppe, and the climate became cold in the later stage. During the 0.59–0.41 Ma period, steppes developed, and the climate was cold and arid. At the same time, with climate variation, the faunal communities also changed obviously and co-evolved with vegetation types. In the early stage of the Early Pleistocene, the warm and humid climate was related to the presence of a wide range of thermophilous animals. From 1.7 to 1.5 Ma, the transition from forest to forest steppe might have promoted the emergence of certain grassland-adapted animals. During the MPT, grassland-adapted animals became dominant due to the flourishing forest steppe vegetation. The Middle Pleistocene witnessed the expansion of steppe and animals adapted to the arid grassland environment at that time.

In India the demand of sustainable energy is growing at a fragmented level. The demand of rural electrification and economic growth requires high production of energy. Hence, the use of renewable energy may help to mitigate air pollution, and allow specific regenerative agriculture, waste, and forest biomass for producing the energy and achieving sustainable development goals. In the current work, we have selected a district of Maharashtra state of India as a case study and mapped the different land cover categories, and their estimated biomass. Based on this we have prepared the biomass thematic maps for the study area. These biomass maps have been prepared in the GIS environment and they displayed the biomass of crops, forests, and wastelands. The studied district has huge potential for agricultural biomass and can act as biofuel and biomass economies. These maps may play a crucial role in upgrading biomass sites focused on generating power from plants in the district Akola of Maharashtra, India.

In the breeding process of agricultural crops, including sorghum, the use of multivariate statistics methods makes it possible to determine the correlation between morphometric traits, yield elements and biochemical parameters of grain in the model population, as well as to identify the load of hypothetical factors. The purpose of the current study was to identify the correlations between morphometric traits, yield elements and biochemical parameters of grain, which characterize the load of hypothetical factors in the model grain sorghum population. For practical breeding process, there have been analyzed 13 economically valuable traits in 27 grain sorghum varieties, developed by the FSBSI Russian Research and Project-technological Institute of sorghum and maize “Rossorgo”. There has been established a different variation degree of the traits of grain sorghum; a strong variation degree was established for such traits as ‘flag leaf area’, ‘the largest leaf area’, ‘panicle stem’, ‘productive tilling capacity’, ‘weight and number of grains per panicle’ (27.3–35.2%); a weak variation degree was established for such traits as ‘protein percentage’ and ‘starch content’ in grain (2.8–8.6%). The group with an average degree of variation includes the traits ‘plant height’ after 30 days of growing and at ripening period, ‘panicle length’, ‘1000-grain weight’, and ‘grain yield’ (10.1–15.6%). When analyzing the matrix of correlation coefficients, there were calculated the hypothetical factors with a contribution of more than 5% to the accumulated variance. There has been built a correlation pleiad, which made it possible to demonstrate mean (r = 0.51–0.68) and strong (r = 0.76–0.94) correlations. There have been considered six hypothetical factors reflecting the total contribution to the accumulated variance, Z-1 – 40.86%, Z-2 – 13.76%, Z-3 – 11.85%, Z-4 – 8.74%, Z- 5 – 6.69%, Z-6 – 5.99%. The first hypothetical factor is determined by such traits as ‘the largest leaf area’ and ‘flag leaf area’ (0.78–0.80), ‘weight and number of grains per panicle’ (0.84–0.91), ‘grain productivity’ (0.77) and ‘productive tillering capacity’ (- 0.78). The results obtained are used in breeding programs to develop grain sorghum varieties and hybrids adapted to the arid conditions of the Lower Volga region.

Water is an important nutrient, and its continuous provision is a critical welfare issue for cattle grazing arid and semiarid rangelands. Time and labor are needed to monitor water availability, and automated monitoring systems are a costly input on expansive rangeland pastures. The objective of this study was to evaluate the potential of detecting water system failures using Global Positioning System (GPS) tracking and accelerometers, assuming the data could be monitored in real or near-real time. Water system failure was simulated in a 1 096-ha pasture in Arizona by placing metal panels around the only drinker for 4 h (0800−1200) on three occasions in 2018 and two occasions in 2019. Randomly selected cows (10 in 2018 and 23 in 2019) of the 120 cows in the pasture were tracked with GPS collars, and 7 (2018) and 10 (2019) of the tracked cows were fitted with triaxial accelerometers. Movement intensity measured by accelerometers was greater (P = 0.03) on the day of simulated water failure than on control days with available water. During simulated water failure, cows remained closer to water (P = 0.01) after approaching the drinker (

Geodiversity refers to the variety of geological and physical elements as well as to geomorphological processes of the earth surface. Heterogeneity of the physical environment has an impact on plant diversity. In recent years, the relations between geodiversity and biodiversity has gained attention in conservation biology, especially in the context of climate change. In this study, we assessed the spatial and temporal change in plant’s community structure in a semi-arid region, Sayeret Shaked Long Term Ecosystem Research (LTER) station, Israel. Vegetation surveys were conducted on different hillslopes, either with or without rock covers in order to study the spatial trends of hillslope geodiversity. The surveys were conducted for two consecutive years (2016 and 2017), of which the second year was drier and hotter and therefore permitted to investigate the temporal change of plant’s community structure. The results of the spatial trends show that (1) geodiversity increases vegetation biodiversity and promotes perennial plants and those of the temporal change show that (2) the positive effect of geodiversity on plants’ community structure and species richness is greater in the drier year than that in a wetter year. The main insight is that in these drylands, hillslopes with higher geodiversity appear to buffer the effect of drier years, and supported a more diverse plant community than lower geodiversity hillslopes.

Climate change will cause Sub-Saharan tropical countries to experience a disproportionate increase in the number of extremely hot days when compared to Western countries with more temperate climates. We use the High Occupational Temperature Health and Productivity Suppression (HOTHAPS) model to estimate the potential impact of rising temperatures on worker productivity in different climate regions within Ethiopia, Uganda, Rwanda, and Kenya under varying future climate change scenarios. Using population data obtained from the International Labor Organization, we also estimate productivity losses at a country-wide level. We project large inter-country and intra-country disparities in productivity losses due to varying climatic conditions and local geography. Populations living in lower elevations or in more tropical and arid zones will experience higher productivity losses than those at higher elevations with more temperate climates. We estimate that some areas could lose over 12% productivity by 2099. Comparing climate change impacts across cities, Mombasa, Kenya, is projected to suffer most, losing 13% of its labor productivity. Cities above 1500 m in elevation showed almost no productivity loss by the end of the century. Increased heat stress projected from climate change will pose added risk to workers and labor production in lower elevation settings across East Africa. Key words: Climate change, occupational health, Sub-Saharan Africa, health impacts, heat stress, WBGT.

Kajiado County is mainly Arid and Semi-Arid Lands (ASALs) and as such it is faced with harsh climatic conditions. The county is dominantly inhabited by the Maasai pastoralists who depend on climate-sensitive natural resources for their provisions and production needs. As such, they are faced with low productivity. Therefore, the study investigated historical temperature characteristics combined with surveys on the Maasai pastoralists’ experiences. The study used a mixed-method approach using temperature data along with semi-structured questionnaires. Temperature analysis utilised a mix of ground-based meteorological and satellite data. These temperature data were retrieved from Kenya Meteorological Department (KMD) and Climate Hazards Infra-Red Temperature with Stations (CHIRTS) respectively. The climatology analysis from the T-test showed that both the maximum and minimum temperature increased significantly at p < 0.05. A similar temperature rise was noted for spatial analysis where an overall warming trend was observed across the entire county. The Chi-square analysis affirmed the adverse effects of the temperature rise on the Maasai pastoralists as indicated in the growing numbers of heat-related illnesses and deaths in livestock. The resultant social-economic impacts translated to a decline in livestock population pointing up to the need for enhanced preparedness for the warming trends and better prediction models to enhance both societal and ecosystem resilience. Key words: Temperature, natural resources, pastoral livelihood system, society, ecosystem, resilience, climate risks.

This research aims at assessing the impact of drought (in the form of original and modified reconnaissance drought indices (ORDI and MRDI)) on water productivity of rainfed winter wheat in some arid and semi-arid regions of Iran. It focuses on different timescales of drought to determine which period of the year had the greatest significant impact. RDI was modified using the Food and Agriculture Organization of the United Nation method (FAO) (MRDI-1), US Bureau of Reclamation (USBR) (MRDI-2), the Simplified version of Soil Conservation Service of the US Department of Agriculture method (USDA-SCS-simplified) (MRDI-3), and the CROPWAT version of USDA-SCS method (USDA-SCS CROPWAT) (MRDI-4). Results showed that in Tabriz and Zanjan stations, 3-month scale of MRDI-2; in Ghazvin, Arak, and Kerman stations, 6-month scale of MRDI-4; in Sanandaj station, 12-month timescale of MRDI-3; and in Shiraz stations, 1-month timescale of MRDI-1 resulted in the highest values of correlation coefficients. According to the goodness-of-fit parameters, in Tabriz and Zanjan stations, MRDI-1; in Ghazvin, Arak and Kerman stations, MRDI-2; in Shiraz station, MRDI-3; and in Sanandaj station, ORDI resulted in the best generalized estimating equation model. These results can be useful to plann for the management of cultivation in impressive timescales. HIGHLIGHTS Investigate the impacts of drought on wheat water productivity.; Considering different timescales of drought.; Modified reconnaissance drought index was used, which considers the effective precipitation.; Water productivity of winter wheat was simulated using the AquaCrop model.; Generalized estimating equation models were used to address the impact of drought on water productivity.

In order to meet the dietary requirements of the rising human population with diminishing water resources, there is the need to adopt techniques that optimize crop yield under reduced water conditi...

This research proposes an integrated methodology for incorporating RS, GIS and AHP techniques for the assessment of agricultural land suitability. In Kadapa district, Andhra Pradesh, India, study is being done on how to best promote agriculture as a source of income to boost the economy of the region. A combined RS, GIS and AHP techniques has been utilized that incorporates organizing AHP hierarchy, criteria specification, pairwise comparison, and criterion map preparation. Land suitability comparison showed that an area of 4.42 km2 (2.62%) is appropriate for irrigation, while an area of 54.39 km2 (32.33%) is appropriate moderately suitable for rainfed agriculture and 95.76 km2 (56.93%) is marginally suitable for agricultural productions. About 13.64 km2 (8.11%) land is currently not suitable for agricultural production. Additionally, the analysis clearly shows the necessity of a decrease in irrigated agricultural land and an increase in dry farm agricultural land. This application of RS, GIS and AHP based agricultural land suitability analysis is helpful in referring agricultural activities to the areas with good physical and environmental conditions, allowing maximum agricultural efficiency in the countryside, increasing non-agricultural uses in areas with low efficiency, and avoiding the construction and environmental pressures on suitable farmland.

This study uses choice experiments to assess fresh produce and hay/forage grower preferred drought management strategies, the level of drought at which growers adopt specific management strategies and the level of drought at which they choose to exit farming in the arid west. Results show preferred strategies differ by drought level and across grower groups. Using logit models, we find that fresh produce growers prefer adopting a water-saving technology (cover crops, manure/mulch application, etc.) and hay/forage growers prefer switching to a more efficient irrigation system. Growers would only exit farming in extreme circumstances such as loss of all water resources. Policies aimed at assisting growers with drought adaptation should focus on preferred strategies to ensure effectiveness. Incentives to offset adoption costs are also recommended. Additionally, growers may benefit from information related to productivity changes under various drought management strategies and drought scenarios.

Our study is the first to demonstrate a high-temporal-resolution record of mineral composition in a Greenland ice core over the past 100 years. To reconstruct past variations in the sources and transportation processes of mineral dust in northwestern Greenland, we analysed the morphology and mineralogical composition of dust in the SIGMA-D ice core from 1915 to 2013 using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The results revealed that the ice core dust consisted mainly of silicate minerals and that the composition varied substantially on multi-decadal and inter-decadal scales, suggesting that the ice core minerals originated from different geological sources in different periods during the past 100 years. The multi-decadal variation trend differed among mineral types. Kaolinite, which generally formed in warm and humid climatic zones, was abundant in colder periods (1950–2004), whereas mica, chlorite, feldspars, mafic minerals, and quartz, which formed in arid, high-latitude, and local areas, were abundant in warmer periods (1915–1949 and 2005–2013). Comparison to Greenland surface temperature records indicates that multi-decadal variation in the relative abundance of these minerals was likely affected by local temperature changes in Greenland. Trajectory analysis shows that the minerals were transported mainly from the western coast of Greenland in the two warming periods, which was likely due to an increase in dust sourced from local ice-free areas as a result of shorter snow/ice cover duration in the Greenland coastal region during the melt season caused by recent warming. Meanwhile, ancient deposits in northern Canada, which were formed in past warmer climates, seem to be the best candidate during the colder period (1950–2004). Our results suggest that SEM–EDS analysis can detect variations in ice core dust sources during recent periods of low dust concentration.

Purpose This study aimed to evaluate the role of seed bank during ecosystem transitions from arid grassland to shrubland. Methods We explored the aboveground vegetation, seed bank and soil environmental factors at 29 sites along a moisture gradient that served as a space-for-time substitution in the Qaidam Basin on the Tibetan Plateau to test whether changes seed bank composition or changes in the ability of the seed bank to restore aboveground vegetation could lead to ecosystem transition. Results We found that the composition of the aboveground vegetation presented nonlinear changes with decreased soil moisture and showed an inflection point in the threshold zone on the spatial scale of ecosystem transition from arid grassland to shrubland; however, an inflection point was not observed for the seed bank. Surprisingly, an inflection point of the similarity between the aboveground vegetation and seed bank also emerged at this threshold zone (ecosystem transition from arid grassland and shrubland). Conclusions Our results suggest that the transition from arid grassland to shrub ecosystem is not caused by changes of the seed bank composition but by the inhibition of the seed bank's restorability to aboveground vegetation. Future work on changes in vegetation composition and species diversity with ecosystem transitions should consider the belowground seed bank.

Previous studies have successfully applied variance decomposition frameworks based on the Budyko equations to determine the relative contribution of variability in precipitation, potential evapotranspiration (E0), and total water storage changes (ΔS) to evapotranspiration variance (σET2) on different timescales; however, the effects of snowmelt (Qm) and vegetation (M) changes have not been incorporated into this framework in snow-dependent basins. Taking the arid alpine basins in the Qilian Mountains in northwest China as the study area, we extended the Budyko framework to decompose the growing season σET2 into the temporal variance and covariance of rainfall (R), E0, ΔS,Qm, and M. The results indicate that the incorporation of Qm could improve the performance of the Budyko framework on a monthly scale; σET2 was primarily controlled by the R variance with a mean contribution of 63 %, followed by the coupled R and M (24.3 %) and then the coupled R and E0 (14.1 %). The effects of M variance or Qm variance cannot be ignored because they contribute 4.3 % and 1.8 % of σET2, respectively. By contrast, the interaction of some coupled factors adversely affected σET2, and the out-of-phase seasonality between R and Qm had the largest effect (−7.6 %). Our methodology and these findings are helpful for quantitatively assessing and understanding hydrological responses to climate and vegetation changes in snow-dependent regions on a finer timescale.

Elevation in atmospheric carbon dioxide concentration (eCO 2 ) affects vegetation water use, with consequent impacts on terrestrial runoff ( Q ). However, the sign and magnitude of the eCO 2 effect on Q are still contentious. This is partly due to eCO 2 -induced changes in vegetation water use having opposing responses at the leaf scale (i.e., water-saving effect caused by partially stomatal closure) and the canopy scale (i.e., water-consuming induced by foliage cover increase), leading to highly debated conclusions among existing studies. In addition, none of the existing studies explicitly account for eCO 2 -induced changes to plant rooting depth that is overwhelmingly found in experimental observations. Here we develop an analytical ecohydrological framework that includes the effects of eCO 2 on plant leaf, canopy density, and rooting characteristics to attribute changes in Q and to detect the eCO 2 signal on Q via vegetation feedbacks over 1982–2010. Globally, we detect a very small decrease of Q induced by eCO 2 during 1982–2010 ( − 1.7 %). Locally, we find a small positive trend ( p 0.01) in the Q –eCO 2 response along a resource availability ( β ) gradient. Specifically, the Q –eCO 2 response is found to be negative (i.e., eCO 2 reduces Q ) in low- β regions (typically dry and/or cold) and gradually changes to a small positive response (i.e., eCO 2 increases Q ) in high- β areas (typically warm and humid). Our findings suggest a minor role of eCO 2 on changes in global Q over 1982–2010, yet we highlight that a negative Q –eCO 2 response in semiarid and arid regions may further reduce the limited water resource there.