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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.

This article will explore some of the Qing Empire's primary adaptations, mainly pastoral and agricultural, to the arid environments of southern, eastern and northern Xinjiang - that is, the Tarim, Hami-Turfan and Zünghar basins respectively. It first examines the region's arid climate and its constraining implications for, first, agriculture as the empire's standard form of territorial incorporation in the south and east; and, second, pastoralism and agro-pastoralism in the north. These relations were not purely social, but were conditioned within both human and natural parameters. Xinjiang's general aridity informed Qing interactions with the territory's diverse peoples, which presented both cultural and ecological - that is, environmental - obstacles and opportunities.

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.

Dioecy, the separation of sexes into different male and female plants, can enable sexes to independently develop optimal strategies for the sex-linked allocation of reproductive resources. Understanding how dioecious species vary as conditions become more or less favourable may affect conservation and revegetation efforts in arid environments. Our study investigated sex-related resource allocation in the Australian native shrub, Pimelea microcephala subsp. microcephala (Thymelaeaceae) at four sites across an annual rainfall gradient of 250-390 mm in semi-arid South Australia. The study measured 25 male and 25 female individuals for plant height, plant diameter, the number of inflorescences per plant, number of flowers per inflorescence and the ratio of reproductive to vegetative biomass. Significant differences in the ratio of biomass allocated to reproduction between sexes (p < 0.05) were detected at three of the four sites, with sex-related differences increasing with decreased annual rainfall. Female reproductive allocation was two to five times greater, and was less variable than males at all sites except the highest rainfall site (p < 0.05), while male reproductive allocation decreased with average annual rainfall (p < 0.05). Growth outcomes of males and females were equal and female reproductive traits were mostly consistent between sites and were not associated with rainfall, therefore population structure may remain stable for P. microcephala subsp. microcephala as habitats become drier, so long as pollen limitation does not occur. Refereed/Peer-reviewed

Quillaja saponaria is a sclerophyllus evergreen tree species distributed from 30° to 38° S in Central Chile. In this wide distribution it is expected that the species exhibits phenotypic plasticity in the morphology of leaves associated to climate variation; however, the information on this topic is still scarce. We studied leaf phenotypic variation and its relationship with temperature, precipitation, and aridity in 85 stands of Q. saponaria throughout the natural distribution of the species. The results show that the basal diameter of petiole, the number of secondary veins, and the basal diameter of the principal vein increased with precipitation and decreased with aridity, while the length, basal diameter and the relative length of the petiole decreased with temperature. This confirms that phenotypic variation for foliar characters in Q. saponaria is related to climatic variables indicating an adapting capability of the species to the wide range of environmental conditions in which grows.

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.

Mycobionts make up most of the genetic diversity of underground life. Despite their abundance, their impact on terrestrial ecosystem processes is still poorly understood. Estimates suggest that 95% of plant species rely entirely on microbial symbiotes for growth and survival, underlining their importance in soil as a regulator of plant species richness and diversity. In this study, we explore an inventory of the fungal rhizobiome of two populations of Atlas pistachio in Laghouat (Algeria), a typical hot and arid region. Six healthy trees of different age classes were randomly sampled from each site during April 2016. In spite of the arid climate in our study area, microscopic identification revealed important fungal richness belonging to four phyla: Ascomycota, Glomeromycota and Basidiomycota with the exclusive presence of Mucoromycota in dayate Saadi. The fungal strains recorded indicate a high abundance of the Acaulospora sp. and Glomus sp. genera for the Glomeromycota phylum and Fusarium sp. genus for the other phyla. Shannon-Wiener diversity and evenness indices proved to be the highest at dayate Saadi. Dayate El Gouffa, however, is the least disturbed. Most of the strains recorded correspond to genera with a strong affinity for environments rich in organic matter, with high levels of total limestone, basic pH, and high levels of clay and fine silts as shown in the dayate Saadi soils. As for the dayate El Gouffa soils, they show a low organic matter content. They are less calcareous, with a very basic pH and predominance of coarse silts and coarse sands. The high rate of these granulometric fractions could explain the presence of Gigaspora sp. only in this daya. Our results indicated the strong impact of soils proprities on the rhizobiome community composition and might be explained by differences in the degree of fungi selectivity for each sampled site.

A Late Cretaceous fossil flora composed of five fossil seed genera and two charophyte genera was discovered and reported here from the siltstone and green marl band of the Lameta Formation at the Chui Hill section and the Chhota Simla Hill section in the Jabalpur area. On the basis of comparative studies, including thin-section and XRD analysis, the palaeoenvironment is deduced to be arid to semi-arid fluvial-lacustrine. The recovered flora suggests Laurasian palaeobiogeographic affinity and shows the dispersal route from Europe to India via Africa.

Relationships between genome size and environmental variables suggest that DNA content might be adaptive and of evolutionary importance in plants. The genus Larrea provides an interesting system to test this hypothesis, since it shows both intra- and interspecific variation in genome size. Larrea has an amphitropical distribution in North and South American deserts, where it is most speciose. Larrea tridentata in North America shows a gradient of increasing auto polyploidy; while three of the four studied South American species are diploids, L. divaricata, L. nitida, L. ameghinoi, and the fourth is an allopolyploid, L. cuneifolia. We downloaded available focal species’ georeferenced records from seven data reservoirs. We used these records to extract biologically relevant environmental variables from WorldClim at 30 arcseconds scale, to have a broad characterization of the variable climatic conditions of both regions, and a climatic envelope for each species. We estimated relative DNA content index and relative monoploid genome values, by flow cytometry, of four most abundant Larrea species throughout their respective ranges. Then we winnow the bioclimatic dataset down to uncorrelated variables and sampled locales, to analyse the degree of association between both intra- and interspecific relative DNA content and climatic variables that are functionally relevant in arid environments using Pearson correlations, general linear and mixed effects models. Within the genus Larrea, relative DNA content increases with rising temperature and decreases with rising precipitation. At the intraspecific level, all four species show relative DNA content variation across climatic conditions. Larrea is a genus that shows genome size variation correlated with climate. Our results are also consistent with the hypothesis that extreme environmental pressures may have facilitated repeated whole genome duplication events in North America, while in South America, reticulate evolution, as allopolyploidization, and speciation might have been climate-dependent since the Oligocene.

Harvesting water from the atmosphere is an important process to solve the extreme lack of water resources in arid regions. Adsorption-based atmospheric water harvesting (AWH) takes advantage of solar thermal energy to harvest water from air. This technique is particularly suitable for arid regions characterized by low humidity and an abundance of sunshine. Nonetheless, under low humidity conditions, AWH is highly dependent on water-adsorbing materials exhibiting excellent performance. In this work, a metal–organic framework (MOF), namely [Zn2(bpy) (btec)(H2O)2]·2H2O, also denoted as MWH-1, was investigated for application in water harvesting under low humidity conditions ( 200 cm3∙cm−3; RH = 10%, uptake: >250 cm3∙cm−3). This ensured effective water harvesting at high temperatures during the day. In situ powder X-ray diffraction and Fourier-transform infrared analyses confirmed the sensitive water adsorption process of MWH-1a. The X-ray single-crystal study further demonstrated that single-crystal structures could be completely restored following water harvesting. MWH-1 showed good structural stability and enabled water harvesting under low humidity and high temperature conditions. Thus, it has the potential for application in round-the-clock water harvesting in extremely arid regions.

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.

A study was undertaken to identify differences in the performance of low-impact development (LID) measures in arid and humid cities. Yinchuan and Guangzhou in China were selected as a representative of each type. A stormwater management model was constructed with the aid of a geographic information system and LID measures of permeable pavements (PP), rain gardens (RG), green roofs (GR) and combinations of these were then designed. The results showed that a combination of PP, RG and GR provided the largest reduction in total runoff, peak runoff and runoff coefficient in both cities. Paired measures also delivered a significantly higher performance than single measures, with PP plus GR better than other paired combinations. The results of this work could guide the construction of sponge cities in both arid and humid areas.

Hydrologic response in a watershed is driven by precipitation. Multi-site rainfall generators can be used to model watersheds using spatially varied rainfall inputs to better analyze how the rainfall variability affects runoff generation. This study adopted both a single-site rainfall generator (CLIGEN) and a multi-site rainfall generator to generate two rainfall data sequences, which were then used to drive the Soil and Water Assessment Tool (SWAT) for runoff simulation. The 148-km2 Walnut Gulch Experimental Watershed and its two sub-watersheds were selected to evaluate the hydrologic response. Runoff calibration was done against measured runoff in the watershed. Statistics showed that the single-site and multi-site rainfall generators gave similar results regarding annual precipitation. However, the multi-site generator performed much better than the single-site generator in both mean summer flow and for the different return period flows. The runoff derived from the single-site generator was significantly over-estimated in all three watersheds. As for the multi-site generator, the derived runoff was satisfactorily predicted in the smaller watersheds but only overestimated in the largest watershed. This indicated that in small to medium sized watersheds, the spatial variability of rainfall could play an important role for hydrologic response because of the heterogeneity of convective rainfall in this semi-arid region, which makes the application of multi-site rainfall generator a better option than the single-site generator.

Fat-tailed Barbary sheep are well-adapted to Tunisian arid areas and extensive management. Multivariate morphometric characteristics of this important breed have not been investigated. Morphometric data, collected during February-April 2014, of 249 purebred redhead Barbary ewes, ranged into young (1–2 years) and adults (2–9 years), and reared in Sfax, southern Tunisia, were used to explore the breed morphostructural characteristics under harsh arid conditions (

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.

MDFRC item.Freshwater rivers have been substantially altered by development and flow regulation. Altered hydrological regimes have affected a range of biota, but impacts are often most obvious on freshwater fish. Flow largely influences the range of physical habitat available to fish at various life history stages. Biological rhythms are therefore often linked to flow and optimized so that opportunities for spawning, growth and dispersal are synchronized. Assuming that flow therefore becomes the main factor which structures freshwater fish communities, the use of species specific biological information should be able to inform adaptive flow delivery strategies from the river reach to catchment scale. A test of this assertion was performed as a case study of native fish within the Edward-Wakool River system (New South Wales, Australia). Fish within the system were assigned to one of four groups based on biological similarity. Aspects of reproductive and movement ecology were then reviewed to generate optimal flow release strategies for each group. Life expectancy and hydrological constraints were then investigated and used to develop a possible 10-year flow delivery program that could generate ecological outcomes within a strategic adaptive management framework that considered potential impacts on third parties. The approach could be used to develop flow characteristics to benefit biota in any watercourse provided enough data are available to link potential outcomes with flow delivery.

The Upper Indus Basin (UIB) supplies water resources for the downstream areas of the Indus Basin, and the associated climate changes have attracted considerable attention. Here, we project the aridity changes in the UIB during the 21st century relative to 1995-2014 based on 12 Coupled Model Intercomparison Project Phase 6 (CMIP6) models under the 3 Shared Socioeconomic Pathway (SSP) scenarios. The aridity index (AI), defined as the ratio of annual precipitation to potential evapotranspiration (PET), is applied to quantify the dry conditions. According to the median of the preferred models, the annual mean temperature is projected to increase continually in the UIB across the 21st century under SSP2-45 and SSP5-85, and it increases before the 2050s and then stabilizes afterwards under SSP1-26. Generally, PET will increase and AI will decrease (a drying trend) in the UIB during the 21st century. The regionally averaged AI over the UIB linearly decreases as global warming intensifies at a slope of 0.1 °C-1 under both SSP2-45 and SSP5-85. Remarkable increases in aridity occur in the northern and northwest parts of the UIB. Seasonally, the largest decrease in AI is seen in December-January-February, and the smallest occurs in June-�July-August. Furthermore, PET plays a key role in AI changes, excluding the southeast part of UIB, and the percent contribution of PET to AI changes tends to increase over time in the 21st century. Overall, AI and PET changes are primarily determined by thermodynamic factors in the UIB.

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).

The Yangtze River is a major component of the ‘Asian Water Tower’ and it provides freshwater resources for hundreds of millions of people in East Asia. Hence, climatic and environmental changes in the source region of the Yangtze River (SRYR) are of major significance for understanding changes in the status of its freshwater resources. However, due to the contradictory results shown by the available paleoclimatic records from the SRYR and neighboring regions, it remains unclear how the regional climate and hydrology have evolved since the middle Holocene. Here, we present records of hydrological variations based on multiple proxies (grain size, scanned micro-scale X-ray fluorescence (XRF) element composition, and loss on ignition (LOI)) of the sediments of alpine lake Saiyong Co, with the aim of reconstructing hydrological changes in the SRYR since 5.8 ka. The first principal component (PC1) of the XRF scanned element record is dominated by Ti, Fe and K, representing terrigenous inputs from the catchment. The LOI profile shows an inverse pattern of variation to that of PC1, suggesting that the sedimentary organic matter is primarily derived from aquatic plants. Since 5.8 ka the overall decrease in sample scores on PC1 and the increasing LOI, together with the grain-size based lake-level record, indicate an overall drying trend in SRYR. Furthermore, several major droughts are recorded, at ∼4.0 ka, ∼2.8 ka and ∼1.8 ka. The hydrological variations at Saiyong Co are supported by multiple records from the SRYR, suggesting that millennial-scale environmental variations were regionally synchronous and were influenced by Northern Hemisphere summer insolation and movement of the intertropical convergence zone.

Lake ecosystems in arid Central Asia are in crisis due to water abstraction and eutrophication, and it is important to understand their response to combined climate and human impacts. In this study, based on the relationship between modern chironomids and salinity, we studied subfossil chironomid remains in a ~4550-year sedimentary record from Lake Ulungur in northwest China, with the aim of reconstructing past ecosystem dynamics, especially in response to climate change and human impacts. The results show that from 4550–580 cal yr BP the hydrological status of Lake Ulungur was transformed from close to open and the salinity decreased causing an increase in freshwater chironomid species. Comparison with regional paleoclimatic records makes us to infer that the lake ecosystem evolution has been primarily controlled by changes in the westerly driven by the Northern Hemisphere insolation. Since 580 cal yr BP, the lake returned to be closed and the structure of the aquatic community reorganized. In recent centuries, human activities have made a more significant effect on lake ecosystems in northwest China than natural climate changes, which largely was induced by a surge in the human population related to national policies. Furthermore, due to the combined effects of global warming and intensifying human activities, lake ecosystems in Central Asia are subject to unprecedented anthropogenic pressures and urgent action is needed to protect them.

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.

Tremendous benefits of biochar (BC) amendment to soil have been reported, including their role in alleviating the impact of salinity stress in plants. The aim of this study was to evaluate the effects of BC produced at 300 °C (BC300) and 700 °C (BC700) on the germination rate (GR) and selected growth characteristics of corn plants irrigated with salinized water over a growth period of 6 weeks. The experimental treatments included three biochar treatments: BC0 (control, without biochar addition), BC300, and BC700. The treatments also included three salinity levels of irrigation water: 0, 3, and 6 dS·m−1. The biochar was applied at a rate of 3%. The GR decreased with increasing salinity level, which was more evident in the first week. This stress impact was reduced when treated with the BC700 relative to the saline treatments without BC. Both BC treatments demonstrated contrasting effects on corn growth, nutrient uptake, and Na+ and K+ content in plant tissue. The effect of BC700 treatment on plant height and root length was limited, but the impact of salinity stress on chlorophyll meter readings, chlorophyll fluorescence parameter (Fv/Fm), dry matter yield, and N and P uptake were largely mitigated. It also increased K+ and decreased Na+ content in plant tissue. However, the BC300 treatment adversely affected plant growth parameters at each salinity level. Overall, the BC produced at a higher temperature significantly alleviated the impact of salinity stress on plant growth characteristics, which is probably attributed to their higher surface area and porosity, enhancing their salt ion sorption capacity.

PREMISE OF THE STUDY Continental-scale disjunctions and associated drivers is a core research interest in biogeographic studies. Here, we selected a species-rich Australian plant genus (Calytrix; Myrtaceae) as a case study to investigate these patterns. The endemic Australian starflower genus has a disjunct distribution across the mesic fringes of the continent and is largely absent from the arid centre. METHODS We used high-throughput sequencing to generate unprecedented resolution and near complete species-level nuclear and plastid phylogenies for Calytrix. BioGeoBEARS and biogeographic stochastic mapping were used to infer ancestral areas, the relative contributions of vicariance and dispersal events, and directionality of dispersal. KEY RESULTS Present-day disjunctions in Calytrix are explained by a combination of scenarios: (1) retreat of multiple lineages from the continental centre to the more mesic fringes as Australia became progressively more arid, with subsequent extinction in the centre, and also (2) origination of ancestral lineages in southwestern Australia (SWA) for species-rich clades. The SWA biodiversity hotspot is a major diversification centre and the most common source area of dispersals, with multiple lineages originating in SWA and subsequently spreading to the adjacent arid Eremaean region. CONCLUSIONS Our results suggest major extinction, as a result of cooling and drying of the Australian continent in the Eocene-Miocene, shaped the present-day biogeography of Calytrix. We hypothesise that this peripheral vicariance pattern, which is similar to the African Rand flora, may explain the disjunctions of many other Australian plant groups. Further studies with densely sampled phylogenies are required to test this hypothesis. This article is protected by copyright. All rights reserved.

This work analyze the technological management of raw materials and the mobility strategy of the human groups that occupied during the mid-Holocene (ca. 8000-3000 BP) the eastern Tandilia mountain range, and discuss them inside of settlement systems context for the southeastern Pampean region. The lithic study results of 13 occupations excavated in caves and rockshelters shows that mobility strategies in Tandilia mountain ranges were closer to collector models, where logistical groups moved into mountain range valleys in search of natural resources. We can recognize different strategies for raw material procurement: the immediately available rocks were obtained through direct access on daily foraging trips; the regional rocks were obtained through logistical displacements, residential movements and embedded strategies; and the access to the long distance rocks was through exchange between neighboring populations. Besides, during ca. 7000 to 5000 cal BP an increased use of immediately available raw materials and a high archaeological signal was detected. This scenario can be linked with an increased environmental aridity episode where human groups occupied with most intensity the Tandilia mountain valleys due to the greater availability of the water resources. Finally, this work provides new data suggesting that during this period in the southeastern Pampean region context, the hunter-gatherer groups combined forager and collector strategies to take advantage of the natural resources of the landscape with diverse environments (coastline, grassland plains, dunes field and mountain ranges).

Climate change effects on host–parasite interactions have been poorly studied in arid or semi-arid habitats. Here, we conducted an experiment aimed to increase the temperature inside European roller Coracias garrulus nest boxes located in a semi-arid habitat on different nest-site types to look for effects on different ectoparasite abundances and nestling growth. Average nest temperature was slightly higher in heated nests than in control nests, although differences were not statistically significant. However, relative humidity was significantly lower at night in heated nests as compared to control nests. The abundance of sand flies, mites and carnid flies was significantly higher in heated, less humid, nests while biting midge abundance was significantly lower in heated nests. Other ectoparasites were not significantly affected by treatment. Relative humidity was high even in heated nests, reaching more than 60%. Sand fly abundance was higher in nests located in sandstone walls, while mite abundance was higher in isolated farmhouses. In addition, sand fly prevalence was higher in nests located in isolated farmhouses and sandstone walls. Heat treatment, nest-site type or ectoparasite abundances did not affect the nestling body mass, wing length or their growth at different nestling ages., This study was funded by the project CGL2015-67789-C2-1-P (MINECO/FEDER). Also, this project is part of the project PGC2018-097426-B-C21 and PGC2018-097426-B-C22 funded by MCIU/AEI/10.13039/501100011033/ and by ‘ERDF A way of making Europe’.

Knowing the tolerance of plants grown in the Brazilian semi-arid region to salt stress is of paramount importance for the sustainability of regional agriculture. This study was developed to examine the growth and yield of prickly pear cactus ‘Orelha de Elefante Mexicana’ (Opuntia stricta Haw) irrigated with increasing water salinity levels (0.75, 3.0, 5.25 and 7.50 dS m-1 to 25 ºC) and grown on soils representative of the Brazilian semi-arid region (chromic Luvisol, Solonetz and Fluvisol). Total fresh weight decreased linearly, with a 21.42% reduction when we compare the average fresh weight per plant in the lowest and highest saline level treatments. The chromic Luvisol and Solonetz soils showed the best fresh weight and dry matter yields under the present experimental conditions. Conhecer a tolerância das plantas cultivadas na região semiárida brasileira ao estresse salino, é de fundamental importância para a sustentabilidade da agricultura regional. Este trabalho objetivou avaliar o crescimento e produtividade de palma forrageira ‘Orelha de Elefante Mexicana’ (Opuntia stricta Haw), irrigada com níveis crescentes de salinidade da água (0,75; 3,0; 5,25; e 7,50 dS m-1 a 25 ºC) e cultivada sobre solos representativos da região semiárida brasileira (Luvissolo crômico, Planossolo nátrico e Neossolo flúvico). A massa verde total apresentou efeito linear decrescente havendo uma redução de 21,42 % ao comparar a massa verde média por planta do tratamento de menor nível com o tratamento de maior nível salino. Os solos Luvissolo crômico e Planossolo nátrico apresentaram as melhores produtividades de massa verde e massa seca nas condições deste experimento.

This study presents a paleolimnological and paleoclimatological reconstruction based on diatoms and phytoliths of four Pampean shallow lakes (from south to north, La Salada, Sauce Grande, Los Chilenos, and Puan) strategically located along a climatic gradient from arid (south) to semiarid conditions (north). This research aims to identify the main drivers and mechanisms of long-term ecological change, and the main climatic mechanisms behind the regional hydroclimatic variability. It was found that these lakes were initially temporary, with clear waters, and eventually, became permanent with turbid waters. We propose that this change is due to an increase in precipitation in the last ca 1000 years, which resulted in higher lake levels and an increase in surface area, leading to an increased fetch and subsequent resuspension of sediment. This climatic amelioration occurred after ∼910 cal yr BP, first in what is today the arid Pampean region, then in the semiarid region, and finally in the modern humid region at ∼ -9 cal yr BP (1959 CE). Variations in lake's water level were the main driver of ecological change, followed by salinity (in Puan and La Salada) and nutrient load (in Los Chilenos and Sauce Grande). In general, those lakes on the southwest, located closer to the limit of moisture influence originating in the Pacific and Atlantic oceans (Arid Diagonal) were more sensitive to hydroclimatic changes than those located in the central Pampean region.

As a common measure for grassland restoration, the fence for prohibition of grazing is usually applied to the steppe in northern China. A study in Hulunbuir grassland showed the average litter mass in the steppes that enclosed for ten years can reach 70-550g/m2. The excessive accumulation of litter caused by long-term grazing prohibition can intercept more precipitation, which will reduce the water available to grassland plants and hinder the further recovery of plant communities. Therefore, the establishment of a reasonable litter interception model can help estimating the interception of steppes with different litter accumulation and provide some theoretical support for the formulation of fencing policies. Based on the model of litter interception rate change, we established a dynamic interception model of litter: I = I m ( 1 − e − k t ) ( t : time; I : dynamic interception; I m : maximum interception; k : exponential coefficient of litter interception). After testing by an indoor simulated rainfall experiment, we found that this model has high accuracy ( R 2 : 0.908 – 0.992). The litter mass (LM) determines the maximum interception, and the rainfall intensity (RI) determines the speed of interception which reaches its maximum value. After the conversion of coefficients, we established a prediction model of litter interception based on LM and RI: I = ( 0.003 L M + 0.44 ) [ 1 − e − ( 0.33 R I + 3.76 ) t ] , R 2 = 0.86 , P 0.001 . The easily obtainable characteristics of LM and RI data make this model easy to apply.

Urban parks play an essential role in urban settings; significantly contribute to the health of every age group person. Parks provide opportunities for families to connect with nature and breathe in the fresh air. Due to global climate change and increased urbanisation in the past few decades, extreme heat can be experienced in urban areas. Mental and physical health issues arise primarily due to a sedentary lifestyle in cities. Staying at parks for a longer duration could promote stress reduction and perceived physical health. The present study aims to assess the thermal comfort conditions at an urban park in the hot semi-arid climate(BSh) of Haryana, India. The present study investigated the outdoor thermal comfort range and thermal sensations of visitors at a park during the summer season using the onsite monitoring of the microclimate parameters and questionnaire survey in the hot-semi arid region of India. Thermal comfort indices, Physiological equivalent temperature (PET) and Universal Thermal Climate Index (UTCI) and Wet bulb globe temperature(WBGT) have been applied to investigate the outdoor thermal comfort conditions. The seven-point sensation scale has been used to record the visitors' thermal sensations. The results indicated that:1) WBGT was found to be the most suitable index to investigate the OTC conditions. The neutral UTCI, PET, and WBGT ranged within 28.03 °C to 35.6 °C, 24.04 °C to 37.5 °C, and 23.5 °C to 26.1 °C, respectively. 2) The neutral PET ,UTCI, and WBGT were found to be 30.8 °C, 31.8 °C, and 24.8 °C, respectively.3) Dry bulb temperature is the most significant thermal comfort parameter affecting visitors' thermal sensations, followed by mean radiant temperature.4) Thermal comfort indices were found to be most significantly affected by globe temperature. The study's outcome could provide theoretical design reference to urban designers to develop new parks and existing parks, ultimately promoting public health.

Rapid global warming during the Paleocene-Eocene Thermal Maximum (PETM) profoundly affected the marine and terrestrial environments. However, details of the climate and vegetation of subtropical and arid regions of central China during the hyperthermal event are poorly understood. Here, we report a palynological record from the black shale of the lowermost Yangxi Formation exposed in Songzi city, western Jianghan Basin, central China. Biostratigraphy, magnetostratigraphy and isotope stratigraphy indicate a PETM age for the sedimentary succession. The palynological assemblage was characterized by high abundances of diverse tropical and subtropical broadleaved tree pollen, providing strong evidence of a dense south subtropical forest ecosystem that once existed in the arid belt of central China during the PETM. The reconstructed climatic parameters indicate an extremely warm and humid south subtropical climate, with mean annual temperatures (MAT) ranging from 21 to 24 °C and mean annual precipitation (MAP) ranging from 1396 to 1997 mm. The reconstructed precipitation was surprisingly high for such an arid setting that widespread arid climate prevailed in central China at that time. These findings demonstrate that rapid global warming during the PETM significantly increased precipitation, leading to the growth of dense forest ecosystems as well as increasing lake eutrophication in central China. The changes to precipitation and terrestrial ecosystems during this warming event are considerably more significant than previously reported in other mid-latitude regions, and highlighting the need to consider regional geographic characteristics to fully understand how the environment responds to rapid global warming.

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.

The absence of large archaeological settlements in the Eastern Arabian Peninsula suggests that most of the recent wet periods occurring during climate oscillations in these areas were short-lived. However, a ∼ 2-by-3-km buried rectangular feature was discovered opportunistically in the southeast of the Qatar Peninsula while performing radar subsurface mapping of structural conduits for groundwater characterization. The feature is characterized by its unique contrasting patterns of surface and subsurface roughness as well as its organic-rich mixture of soils, as assessed from high-resolution radar and multispectral observations, respectively, and validated with GPR and EM subsurface probing. The above characteristics could be the only remaining evidence for a large primitive settlement due to the harsh erosive setting. To explore the natural or anthropogenic origin of this anomalous feature, we compare its dimensions, structural setting, roughness, and composition to similar formations in the Qatar Peninsula and other arid karst environments. Findings suggest that the feature is texturally and compositionally unique within the Qatar Peninsula, and is not reproduced in other arid karst terrains nor reproduced by the fracture patterns associated with the Qatar-South Fars Arch. We hypothesize that the feature is a karst depression modified by semi-stationary primitive human settlements ∼ 3640 BP or earlier based on radiocarbon dating of in-situ charcoal samples. Moreover, the organic-rich mixture of soil and the occurrence of several symmetrical features observed inside the perimeter suggest that landscaping, farming and irrigation activities could have occurred within the site, further suggesting that long-lasting wet conditions—with sufficient fresh water resources or reliance on karst aquifers—were able to sustain a relatively large primitive settlement not previously witnessed in the region’s archaeological record. Future improvements in the resolution and coverage of orbital L-band radar observations, as used above, can provide new insights into understanding prehistoric human occupation under fluctuating climatic conditions and groundwater dynamics in these hyper-arid regions.

The major tributary of the lower Colorado River, the Gila River, is a critical source of water for human and natural environments in the southwestern United States. Warmer and drier than the upper Colorado River basin, with less snow and a bimodal precipitation regime, the Gila River is controlled by a set of climatic conditions that is different from the controls on upper Colorado River flow. Unlike the Colorado River at Lees Ferry in Arizona, the upper Gila River and major Gila River tributaries, the Salt and Verde Rivers, do not yet reflect significant declines in annual streamflow, despite warming trends. Annual streamflow is dominated by cool-season precipitation, but the monsoon influence is discernable as well, variable across the basin and complicated by an inverse relationship with cool-season precipitation in the Salt and Verde River basins. Major multiyear streamflow droughts in these two basins have frequently been accompanied by wet monsoons, suggesting that monsoon precipitation may partially offset the impacts of a dry cool season. While statistically significant trends in annual streamflow are not evident, decreases in autumn and spring streamflow reflect warming temperatures and some decreases in spring precipitation. Because climatic controls vary with topography and the influence of the monsoon, the impact of warming on streamflow in the three subbasins is somewhat variable. However, given relationships between climate and streamflow, current trends in hydroclimate, and projections for the future, it would be prudent to expect declines in Gila River water supplies in the coming decades. Significance Statement This research investigates the climatic controls on the Gila River and its major tributaries, the Verde and Salt Rivers, to gain insights on how trends in climate may impact future water supply. The Gila River is the major tributary of the lower Colorado River, but, unlike the situation for the upper Colorado River, no significant decreasing trends in annual streamflow are evident despite warming temperatures. Climate–streamflow relationships are more complex in this part of the Colorado River basin, and several factors may be buffering streamflow to the impact of warming. However, given the key climatic controls on streamflow, current and emerging trends in climate, and projections for the future, declines in streamflow should be expected in the future.

This paper presents a new index to determine meteorological drought conditions, the Drought Exceedance Probability Index (DEPI), derived from monthly precipitation time series. Its formulation is simple and undemanding in terms of baseline information requirements. This makes the DEPI suitable for routine application to any climate, similar to the well-known Standardized Precipitation Index (SPI). The index is based on the calculation of cumulative rainfall anomalies and their subsequent standardization, similarly to other indices. The hallmarks of the DEPI, and its main comparative advantages, are the process of accumulating anomalies and their standardization process. The paper compares the DEPI with the SPI in several different climates across the world and in all cases the results show the complementarity of both indices. The DEPI shows an excellent ability to reflect the actual severity and duration of droughts, without requiring application on different time scales, unlike the SPI. It is also valid for all types of climates, including arid and semiarid or Mediterranean, for which the literature has shown that using the SPI is problematic.

Soil salinization caused by natural and anthropogenic factors is an important environmental hazard especially in arid and semi-arid regions of the world. Accumulation of salts in the soil is a major threat to crop production and global agriculture; therefore, rapid and precise detection of salt-affected lands is highly critical for preserving soil sustainability and supporting food production. Advancement in remote sensing techniques and machine-learning algorithms has started to contribute to fast and large-scale monitoring and mapping of soil salinization throughout the world. This paper aims to analyze the performance of three different machine-learning algorithms to map soil salinity using Landsat-8 OLI, Sentinel-2A satellite images, and ground-based electrical conductivity (EC) measurements with the aid of Google Earth Engine (GEE) platform. Classification and regression trees (CART), random forest (RF), and support vector regression (SVR) methods are implemented to create a correlation between ground measurements and satellite-derived environmental variables or spectral indices. After selecting the optimum five variables including wetness band, three soil salinity indices, and one vegetation index, soil salinity maps are generated in three machine-learning algorithms. The output soil salinity map in RF algorithm demonstrated the most reliable spatial distribution of various soil salinity classes in the selected study area. Despite CART provided slightly better prediction of soil salinity with R-squared (R2) of 0.98 for Sentinel-2A data, and 0.96 for Landsat-8 OLI data in comparison with accuracy results of RF technique with R2 of 0.96 for Sentinel-2A data and 0.94 for Landsat-8 OLI data, the output map of RF model estimated more reliable salinity levels in salt crusts, agricultural lands, drainage areas, and swamps. The corresponding result highly matched with visual interpretation. Soil salinity maps derived from SVR algorithms by using various combinations of input variables displayed relatively poor estimation of soil EC values compared to the other two methods.

An unprecedented demand for Food, Energy, and Water (FEW) resources over coming decades and the rising climate concerns require integrated FEW innovations with least environmental footprint. Collocating photovoltaic (PV) technology with agriculture is a promising approach towards dual land productivity that could locally fulfill growing food and energy demands particularly in rural areas. This ‘agrivoltaic’ (AV) solution can be highly suitable for hot and arid climates where an optimized solar panel coverage could prevent excessive thermal stress during harsh weather thereby increasing the crop yield and lowering the water budget. One of the concerns with using standard fixed tilt solar array structure that faces North/South ( N / S ) direction for AV farming is the spatial heterogeneity in the daily sunlight distribution for crops and soil water contents, both of which could affect crop yield. Dynamic tilt control through a tracking system can eliminate this problem but could increase the system cost and complexity. Here we present the investigation of vertically tilted bifacial AV farms which can be especially attractive for climates where PV losses due to dust are high. The relative food-energy performance for the vertical East/West faced bifacial panel ( bi- E / W ) scheme is compared with the standard monofacial tilted panels facing North/South ( mono- N / S ) through integrated models for energy conversion, spatial/temporal shade patterns, and the crop yield that is benchmarked against the reported field experiments for lettuce. We show that both schemes have similar food-energy yields for shade-sensitive crops which require a relatively low array density (i.e. ⩽ 1 / 2 of that for the standard ground mounted PV systems). On the other hand, the two PV schemes have remarkably different food-energy yields for denser PV array configuration for which bi- E / W provides higher crop yield and mono- N / S exhibits higher energy yield. To preserve ⩾ 80% of lettuce yield, the maximum array density is limited from half to twice of the standard PV systems corresponding to the varying shade response for the crop. Similarly, to preserve 80% of the energy yield, the lettuce yield is predicted to vary from 65% (shade-sensitive) to 100% (shade-tolerant). The vertical bi- E / W scheme is although not superior in terms of the combined food-energy performance, it could be attractive for its distinct advantages such as spatial homogeneity for shades and rainfall under panels, convenient architecture for farm machinery mobility, and an inherent resilience to soiling.

A field experiment conducted at research farm of College of Agriculture Jabalpur J.N.K.V.V (M.P) on 2017–18. First year of experiment on based on Agri-Horticulture practices of agroforestry. It have two system of Sole-Horticulture (Mango) plantation and another Agri-Horticulture practices (Mustard crops + Mango). Agri-Horticulture practices have five mustard varietal treatment (Pusa Bold, Arpan, JM-3, NRCDR-2, and Urvashi) in six replication. Computation of data by RBD design applied to analysis of yield performance of mustard variety. After analysis of parameters, we have recorded following data. First fall plant population of mustard varieties were recorded highest to lowest NRCDR-2(37.67) > Arpan (35.44) > Urvashi (34.67) > JM-3(27.22) > Pusa Bold (26.67) continually. In aspect number, silique braches−1 and number of silique plant−1 were significantly superior 23.73 and 120.90 found in Arpan and minimum recorded in Urvashi 21.83 & 111.63 variety of mustard respectively. The maximum production grain yield were found in Arpan 955.28 kg ha−1 and lowest in Urvashi 680.89 kg ha−1 also in respect of harvesting index Arpan (13.61) highest and NRCDR-2 (9.80) minimum recorded. This analysis conclude that the highest yielding variety was Arpan among mustard varieties. Economic evaluation we find it the cost of cultivation of Agri-Horticulture practise is higher than Sole-Horticulture practice, the gross monitoring return & net monitoring return were highest found in Arpan (Rs 62,153.85 ha−1 & Rs 36,916.45 ha−1 respectively) variety. The B/C ratio was not significantly difference but highest found in Arpan 0.966 in 1st year of plantation.

Under global warming, according to results obtained from offline drought indices driven by projections of general circulation models (GCMs), future droughts in China will worsen but the results are not consistent. We analyzed changes in droughts covering the entire hydrologic cycle using outputs of GCMs of the 6th Coupled Model Intercomparison Project (CMIP6) for SSP2-4.5 and SSP5-8.5 climate scenarios, and compared the results with that of popular, offline drought indices [the self-calibrating Palmer Drought Severity Index (scPDSI), Standardized Precipitation Evapotranspiration Index (SPEI) and Standardized Precipitation Actual Evapotranspiration Index (SPAEI)]. Among meteorological, agricultural, and hydrological drought indices tested under both SSP scenarios, the results obtained from SPAEI and scPDSI agree better with univariate drought indices than SPEI. scPDSI generally agrees well with agricultural droughts (Standardized Soil Moisture Index with the surface soil moisture content; SSIS). Future droughts estimated using soil moisture analysis are more widespread than that from precipitation and runoff analysis in humid regions of South China by the end of the twenty-first century. In arid northwestern China and Inner Mongolia, drought areas and severity based on scPDSI and SSIS forced with the SSP scenarios show obvious decreasing trends, in contrast to increasing trends projected in South China. Trends projected using SPEI contradict those projected by other drought indices in non-humid regions. Therefore, selecting appropriate drought indices is crucial in project representative future droughts and provides meaningful information needed to achieve effective regional drought mitigation strategies under climate warming impact.

Two global experiments were carried out to investigate the effects of dynamic vegetation processes on numerical climate simulations from 1948 to 2008. The National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) was coupled with a biophysical model, the Simplified Simple Biosphere model (SSiB) version 2 (GFS/SSiB2), and the same model coupled with a biophysical and dynamic vegetation model, SSiB version 4/Top-down Representation of Interactive Foliage and Flora Including Dynamics (TRIFFID) (GFS/SSiB4/TRIFFID). The effects of dynamic vegetation processes on the simulation of precipitation, near-surface temperature and the surface energy budget were identified on monthly and annual scales by assessing the GFS/SSiB4T/TRIFFID and GFS/SSiB2 results against the satellite-derived leaf area index and albedo and the observed land surface temperature and precipitation. The results show that, compared with the GFS/SSiB2 model, the temporal correlation coefficients between the globally averaged monthly simulated leaf area index and the Global Inventory Monitoring and Modeling System (GIMMS)/Global Land Surface Satellite (GLASS) leaf area index in the GFS/SSiB4/TRIFFID simulation increased from 0.31/0.29 (SSiB2) to 0.47/0.46 (SSiB4). The correlation coefficients between the simulated and observed monthly mean near-surface air temperature increased from 0.50 (Africa), 0.35 (Southeast Asia) and 0.39 (South America) to 0.56, 0.41, and 0.44, respectively. The correlation coefficients between the model-simulated and observed monthly mean precipitation increased from 0.19 (Africa), 0.22 (South Asia), and 0.22 (East Asia) to 0.25, 0.27, and 0.28, respectively. The greatest improvement occurred over arid and semiarid areas. The spatiotemporal variability and changes in vegetation and ground surface albedo modeled by the GFS with a dynamic vegetation model were more consistent with the observations. The dynamic vegetation processes contributed to the surface energy and water balance and, in turn, improved the annual variations in the simulated regional temperature and precipitation. The dynamic vegetation processes had the greatest influence on the spatiotemporal changes in the latent heat flux. This study shows that dynamic vegetation processes in Earth system models significantly improve simulations of the climate mean status.

Soil inorganic carbon (SIC) is an important reservoir of carbon (C) in arid, semi-arid, and semi-humid regions. However, knowledge is incomplete on the dynamics of SIC and its relationship with soil organic C (SOC) under different land use types in the semi-humid region, particularly in coastal zones impacted by soil salinization. We collected 170 soil samples from 34 profiles across various land use types (maize-wheat, cotton, paddy, and reed) in the middle-lower Yellow River Delta (YRD), China. We measured soil pH, electrical conductivity (EC), water-soluble salts, and SOC and SIC contents. Our results showed significant differences in both SOC and SIC among land use types. The dry cropland (maize-wheat and cotton) soils had significantly higher SOC and SIC densities (4.71 and 15.46 kg C m–2, respectively) than the paddy soils (3.28 and 14.09 kg C m–2, respectively) in the 0–100 cm layer. Compared with paddy soils, reed soils contained significantly higher SOC (4.68 kg C m–2) and similar SIC (15.02 kg C m–2) densities. There was a significant positive correlation between SOC and SIC densities over a 0–100 cm soil depth in dry cropland soils, but a negative relationship in the paddy soils. On average, SOC and SIC densities under maize-wheat cropping were 15% and 4% lower, respectively, in the salt-affected soils in the middle-lower YRD than the upper YRD. This study indicated that land use types had great influences on both SOC and SIC and their relationship, and salinization had adverse effect on soil C storage in the YRD.

Water crises in arid and semi-arid regions, particularly in desert areas, are considered a challenge owing to the fact that no functioning solutions have been introduced throughout history to change the whole map from yellow to green. Current desert regions are still deserts from millions of years ago, and all scenarios that have been introduced to occupy desert regions accounts for 1%–2% of the total area. Middle East and North Africa (MENA) countries that are located in such arid and semi-arid zones are disadvantaged by limited water supply because of high temperature, low precipitation, and limited water resources. We have found that, there is no consortium between different fields of interest in the hopes of eventually overcoming the global water crisis. This is practically the case when it comes to using desalination and wastewater treatment technologies and their application for agriculture. Water crises should not only be solved using desalination and wastewater treatment, but other items should be also taken into consideration such as soil, plant, and organic matter use, among others. In the present perspective, we are developing novel solutions to overcome the global water crisis via nonconventional water reuse with minimum constrains to ecosystems using the principles of the Sophisticated Desert Development Project (SDDP) or “Electro-agric technology”. Electro-agric is technique that uses electrical fields throughout agricultural practices. Electro-agric technology comprises five main sections, including water, soil, organic matter, and plants, among others, that may be achieved via the establishment of a consortium between different major establishments like the Faculties of Engineering, Agriculture, and Science. Traditional approaches for cultivating land in arid and semi-arid regions are inappropriate and electro-agric technologies may be considered as the only alternative solution for regions that are located between the latitudes 35°N to 35°S in which the arid and semi-arid weather prevails and in which in seven of the world's major deserts are located. We believe that the map of MENA countries produced will transform from yellow to green, indicating reclamation of this resource; however this can only be accomplished if we comply with electro-agric technologies. Moreover, national incomes will be increased, and new communities will be stabilized.