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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.

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.

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.

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.

In the present study, we explored how the combination of site soil qualities and invasion by Prosopis juliflora affects the species specific (Leptadenia pyrotechnica) morphological (canopy volume) and population traits (density and Relative Importance Value) in an arid region of the India. For this, we surveyed 9 sites, categorized under two scenarios sites (n = 5) invaded by P. juliflora (Scenario 1), and sites (n = 4) un-invaded with P. juliflora (Scenario 2). With respect to sites, density of both these species exhibited reverse trends to each other. Similar trends were also recorded for canopy volume and cover of L. pyrotechnica and P. juliflora, respectively. We found log-normal distribution types at all the studied sites. In our empirical study, fifteen Relative Importance Value (RIV) of P. juliflora was identified as threshold level beyond which it can drastically reduced the community diversity and niche space of various associates. Further, Relative Severity of Competition (RSC for density, canopy volume and cover) suggested that density (RSC 0.24) and canopy volume (RSC 0.20) of L. pyrotechnica suffered most due to invasion of P. juliflora. Partial Least Square (PLS), regression suggested that density of L. pyrotechnica and P. juliflora are orthogonal to each other indicated significant negative relationships between both of them (r2 = − 0.95). Soil potassium and organic carbon are located close to density of L. pyrotechnica that is both these two variables have positive impacts with density (r2 = 0.95). Similar positive relationships also observed between canopy volume and clay content (r2 = 0.95), while, sand content was orthogonal to this parameter (r2 = − 0.95). Present study suggested how the invasive P. juliflora along with certain soil factors controls the population, morphological and community position attributes of L. pyrotechnica.

To evaluate food preferences and group activity patterns, a fragmented population of Blackbuck Antilope cervicapra was selected for observation in a semi-arid ecosystem of western Haryana. A field survey was conducted fortnightly, from dawn to dusk, between September 2019 and August 2020, covering every season. Scan sampling and quadrat methods were used to record data on group size and vegetation. Group sizes ranged from 3 to 72 individuals. Based on visual observation, blackbuck seasonally consumed 26 species belonging to 25 families with varied preferences, out of a total of 53 plant species documented from the study site. Some plant species with high medicinal and therapeutic values were preferred, including Artemisia scoparia, Cucumis callous, Ziziphus jujuba, and Ziziphus nummularia. Unlike most herbivores, Blackbuck also consumed the toxic and medicinally rich Calotropis procera. We suggest that zoos which house blackbuck include these preferred wild plant species in their diet. Observations on group activity were analyzed on hourly, monthly and seasonal bases, and converted into time percentages. Group foraging activity was at a maximum in the monsoon (62%) and minimum in winter (50%), followed by resting: maximum in winter (21%) and minimum (12%) in monsoon, largely influenced by food availability. Foraging/walking ratio was at a maximum (5.2) in monsoon and minimum (3.1) in winter, and was correlated with the number of group sightings (maximum in winter and minimum in monsoon) in nearby farmland, when the animals faced food scarcity in their natural habitat and fed on crops.

Chronic anthropogenic disturbance (CAD) and climate change represent two of the major threats to biodiversity globally, but their combined effects are not well understood. Here we investigate the individual and interactive effects of increasing CAD and decreasing rainfall on the composition and taxonomic (TD), functional (FD) and phylogenetic diversity (PD) of plants possessing extrafloral nectaries (EFNs) in semi-arid Brazilian Caatinga. EFNs attract ants that protect plants against insect herbivore attack and are extremely prevalent in the Caatinga flora. EFN-bearing plants were censused along gradients of disturbance and rainfall in Catimbau National Park in north-eastern Brazil. We recorded a total of 2243 individuals belonging to 21 species. Taxonomic and functional composition varied along the rainfall gradient, but not along the disturbance gradient. There was a significant interaction between increasing disturbance and decreasing rainfall, with CAD leading to decreased TD, FD and PD in the most arid areas, and to increased TD, FD and PD in the wettest areas. We found a strong phylogenetic signal in the EFN traits we analysed, which explains the strong matching between patterns of FD and PD along the environmental gradients. The interactive effects of disturbance and rainfall revealed by our study indicate that the decreased rainfall forecast for Caatinga under climate change will increase the sensitivity of EFN-bearing plants to anthropogenic disturbance. This has important implications for the availability of a key food resource, which would likely have cascading effects on higher trophic levels.

The confident identification to species rank of fragmentary and sterile plant material is often challenged by the absence of diagnostic characters, which are present in intact specimens, reproductive parts, and plants in habitat. Here, we consider leaf surface micromorphology for the identification of the genus Aloe in the Horn of Africa region. Primary and secondary sculpturing of the leaf epidermis and stomata were characterised from SEM micrographs of 35 taxa representing 31 species of Aloe (Asphodelaceae subfam. Alooideae). Detailed comparison revealed that leaf surface characters are conserved between species and within-species variation is modest. Closely related taxa in the Aloe adigratana—A. camperi—A. sinana species complex could be distinguished using leaf surface micromorphology alone. These characters also guide species delimitation; in the species complex including A. schoelleri and A. steudneri, a narrow circumscription is supported, whereas with A. ankoberensis and A. pulcherrima, a wider circumscription merits consideration. The observed trait combinations are characteristic of plants in xeric environments, with the most notable feature being stomata that are most deeply sunken in species in more arid habitats. Our findings support the use of comparative study of micromorphological leaf surface characters for species identification and taxonomy in the genus Aloe.

1. Carbon (C) loss due to soil erosion is a major issue in semi-arid grasslands. The extent of soil erosion is determined by soil properties and vegetation structure, especially during the non-growing season. In many Inner Mongolian grasslands, intensive land-use, such as overgrazing and mowing, has severely reduced plant cover and damaged soil structure, which has exacerbated soil C loss by erosion. At the same time, increasing winter snowfall due to climate change is stimulating plant growth and altering plant composition. However, we do not know how changes in winter snow cover interact with land-use practices to regulate soil C loss due to erosion. 2. Here, we conducted a 6-year snow manipulation experiment under different land-use practices (control; moderately mowed, MM; heavily mowed, HM) to measure net changes in soil depth, soil C, plant biomass and vegetation structure. 3. After 6 years, soil C loss under ambient snow was three times greater in the MM and four times greater in the HM treatment compared with controls during non-growing season. However, deepened winter snow alleviated erosion-induced soil C loss by 14%, 47%, 16% in the controls, MM and HM treatments respectively. 4. The severity of soil C loss declined with increasing above-ground biomass (AGB), surface root biomass and vegetation structure. Vegetation structure and AGB explained more of the variation in soil C loss than surface root biomass, possibly because a complex canopy and plant cover increases overall surface roughness, thereby reducing soil C loss. Intensified land-use reduced AGB, surface root biomass and vegetation structure, but deepened snow increased overall surface roughness by promoting AGB. Hence, our study demonstrates that deepened snow can alleviate soil C loss due to land-use practices by promoting AGB. A free Plain Language Summary can be found within the Supporting Information of this article.

The Mio-plio-quaternary aquifer of the Djelfa Syncline is part of a region in Algeria which is characterized by the lack of surface water resources and located in a semi-arid climate. Since alluvial aquifers, and among them our aquifer, are the most vulnerable because of thier direct exposure to the pollution caused by the infiltrated pollutants, this work focused on the assessemnt of groundwater pollution vulnerability, hazard and risk. Thus, several methods were used, for this purpose, such as the DRASTIC and WQI methods mapped using a GIS. The results obtained clearly show a low to moderate vulnerability. The DRASTIC model and its validation based on the correlation with WQI revealed a low correlation (WQI vs DI : 0.221). Since the vulnerability model does not match with the groundwater quality, pollution risk was assessed by combining vulnerabilty and hazard (i.e, water quality). The risk map illustrated three levels ranging from low to high risk. This map should be helpful in decision making and groundwater management through avoiding high risk areas.

Made available in DSpace on 2022-04-29T08:31:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-01 Savanna tree communities occurring in confluence zones with other biomes likely experience different environmental pressures, resulting in shifts in the selection of individual traits, the combinations of such traits, and species composition. In seasonally dry fire-prone environments, plant survival is presumably associated with adaptive changes in bark properties related to fire protection and water storage. Here, we integrated the multiple functions of the bark to investigate whether different selective pressures could influence patterns of variation in bark structure and allocation across species in a broad geographical range. We measured thickness, density, and water content of the inner and outer bark in branches and the main stem of the 51 most abundant species in three savanna communities differing in climatic aridity, one located at the core region of Cerrado in Central Brazil and the other two at its periphery, in the transition zones with Amazonia and Atlantic forest biomes. We found no difference in outer bark thickness but markedly difference in inner bark thickness between the three plant communities. In the central region, where dry season is long and fire is frequent, branches and main stem showed thicker inner bark. Contrastingly, in the south periphery region, where dry season is short, species showed thinner inner bark in both branches and main stem. Species from the north periphery region, where mean annual precipitation is higher, but fire is frequent and the dry season is also long, showed similar main stem inner bark thickness, but thinner branch inner bark compared to core region species. Our findings support the idea that investing in inner bark thickness and bark moisture may be the most advantageous strategy in plant communities that suffer from high evaporative demand during a long period and are at a high risk of fire. Programa de Pós-Graduação em Ecologia e Conservação Universidade Federal do Paraná Departamento de Biologia Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista Environmental Change Institute School of Geography and the Environment University of Oxford Departamento de Botânica Universidade Federal de São Carlos Department of Biological Sciences Macquarie University Departamento de Zoologia Universidade Federal do Paraná Laboratório de Ecologia Funcional de Comunidades (LABEF) Departamento de Botânica Universidade Federal do Paraná Department of Plant & Microbial Biology North Carolina State University Programa de Pós-graduação em Ecologia e Conservação Universidade do Estado de Mato Grosso – UNEMAT Laboratório de Ecofisiologia Vegetal Departamento de Botânica Instituto de Ciências Biológicas Universidade de Brasília Select Carbon Pty Ltd Departamento de Biologia Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista

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.

Global warming has exacerbated desertification in arid regions. Exploring the environmental variables and microbial communities that drive the dynamics of geographic patterns of desert crops is important for large-scale standardization of crops that can control desertification. Here, predictions based on future climate data from CMIP6 show that a steady expand in the suitable production areas for three desert plants (Cistanche deserticola, Cynomorium songaricum and Cistanche salsa) under global warming, demonstrating their high adaptability to future climate change. We examined the biogeography of three desert plant soil bacteria communities and assessed the environmental factors affecting the community assembly process. The α-diversity significantly decreased along elevated latitudes, indicating that the soil bacterial communities of the three species have latitude diversity patterns. The neutral community model evaluated 66.6% of the explained variance of the bacterial community in the soil of desert plants and Modified Stochasticity Ratio

Trade-offs exist for xerophytic shrubs between functional traits, involving in water loss and assimilate accumulation, can contribute to its survival and growth rate regulation in arid environments. However, growth analysis based on plant functional traits has been focused on the study of herbs and woody species. It is still unclear how the functional traits of xerophytic shrubs regulate their growth rate. In this study, we selectedeight xerophytic shrubs as samples to analyze the regulation process of the functional traits of shrubs on growth rate. Plants were cultivated for three years, and three harvests (every one year) were carried out. Factors explaining between-species differences in relative growth rate (RGR) varied, depending on whether different ages were considered. The results showed that RGR was positively correlated with net assimilation rate, but there was a significant negative correlation with leaf area ration (LAR), specific leaf area (SLA), and leaf biomass ratio in the age 1. However, in the age 2, RGR showed a significant positive correlation with the morphological traits (i.e., leaf area ration and specific leaf area), but not with physiological traits (i.e., net assimilation rate) and leaf biomass allocation. Our results suggested that the fluctuation of environmental factors affects the regulation path of the plant functional traits on RGR of xerophytic shrubs. However, the analysis of causality model showed that no matter in which age, net assimilation rate and leaf area ration principally drive the variation in RGR among xerophytic shrubs.

The composition, function, and assembly mechanism of the bacterial community are the focus of microbial ecology. Unsupervised machine learning may be a better way to understand the characteristics of bacterial metacommunities compared to the empirical habitat types. In this study, the composition, potential function, and assembly mechanism of the bacterial community in the arid river were analysed. The Dirichlet multinomial mixture method recognised four ecotypes across the three habitats (biofilm, water, and sediment). The bacterial communities in water are more sensitive to human activities. Bacterial diversity and richness in water decreased as the intensity of human activities increased from the region of water II to water I. Significant differences in the composition and potential function profile of bacterial communities between water ecotypes were also observed, such as higher relative abundance in the taxonomic composition of Firmicutes and potential function of plastic degradation in water I than those in water II. Habitat filtering may play a more critical role in the assembly of bacterial communities in the river biofilm, while stochastic processes dominate the assembly process of bacterial communities in water and sediment. In water I, salinity and mean annual precipitation were the main drivers shaping the biogeography of taxonomic structure, while mean annual temperature, total organic carbon, and ammonium nitrogen were the main environmental factors influencing the taxonomic structure in water II. These results would provide conceptual frameworks about choosing habitat types or ecotypes for the research of microbial communities among different niches in the aquatic environment.

This editorial introduces the Australian Journal of Botany special issue ‘Vegetation science for decision-making’. Vegetation science and classification are crucial to understanding Australian landscapes. From the mulga shrublands of the arid interior to the monsoon rain forests of northern Australia, we have culturally and scientifically built upon the delineation of vegetation into recognisable and repeatable patterns. As remote sensing and database capacities increase, this improved capability to measure vegetation and share data also prompts collaboration and synthesis of complex, specialised datasets. Although the task faces significant challenges, the growing body of literature demonstrates a strong discipline. In Australia, purpose-driven products describe vegetation at broad scales (e.g. the National Vegetation Information System, the Terrestrial Ecosystem Research Network). At fine scales however (i.e. that of the vegetation community), no uniform framework or agreed protocols exist. Climate and landform dictate vegetation patterns at broad scales, but microtopography, microclimate and biotic processes act as filters at finer scales. This is the scale where climate-change impacts are most likely to be detected and effected; this is the scale at which a deeper understanding of evolutionary ecology will be achieved, and it is the scale at which species need to be protected. A common language and system for understanding Australian communities and impetus for collecting data at this scale is needed. In the face of ongoing climate and development pressures and an increasingly complex set of tools to manage these threats (e.g. offset policies, cumulative impact assessments), a nationally collaborative approach is needed. It is our hope that this special issue will help to achieve this.

Waterbodies with a naturally high level of mineralization are geographically widespread. They are found not only in hot and arid regions but also in some regions with temperate and cold climates, in particular, Eastern Siberia. Usually, these are groups of closed lakes that share common features: their location in a semiarid climate zone, the absence of surface runoff, a shallow depth, and a limited catchment area. They have significant variations in size and mineralization. The article presents the results of studies of the structure of plankton communities and the relationship between environmental factors and the main characteristics of plankton in littoral biotopes of different types (overgrown and open littoral) of soda lakes of the Onon–Borzin system.

Trends in the changes in air temperature, precipitation, and hydrothermal conditions, as expressed by the Selyaninov hydrothermal coefficient, were analyzed based on data from six meteorological stations in the Rostov region in the period 1960–2019. A significant trend was determined for all meteorological stations: an increase in the average annual air temperature and the sums of temperatures above 10°C. The annual amount of precipitation had a significant upward trend only at the Chertkovo meteorological station, while there was an upward trend at the other five meteorological stations. Against the background of an intense increase in temperatures, the values of the Selyaninov hydrothermal coefficient tended to decrease for the Gigant, Rostov-on-Don, Taganrog, and Tsimlyansk meteorological stations. At the meteorological stations Chertkovo and Remontnoye, an increase in the amount of precipitation compensated for the temperature increase; as a result, the values of the Selyaninov hydrothermal coefficient tended to increase. The hydrothermal conditions at six meteorological stations in 1960–2019 were characterized as dry, and the mean long-term value of the coefficient varies within 0.64–0.82. The driest conditions are typical of meteorological stations located in the east and northeast of the Rostov region. Based on the calculated trends, it can be concluded that the Gigant, Rostov-on-Don, Taganrog, and Tsimlyansk meteorological stations were characterized in 1960–2019 by arid warming, while the Remontnoye and Chertkovo meteorological stations were characterized by humid warming.

Human communities living in and around the forest are highly dependent on the forest for subsistence and livelihood. Kailadevi Wildlife Sanctuary (KWLS), is an important landscape for securing tiger population in semi arid western India. Human population and their livestock residing in KWLS are exerting anthropogenic pressure on the habitat. Understanding the nature of the anthropogenic pressure is essential to mitigate anthropogenic pressure, reduce negative human-wildlife interactions and improve habitat for wildlife. Anthropogenic disturbance caused by 12 enclave villages inside KWLS was measured using cumulative disturbance index (CDI). Livestock grazing and extraction of wood was found to be the most pressing anthropogenic pressures in the KWLS. Outcome of the study will help the forest managers to devise strategies to improve the habitat quality for the wildlife.

The ecological state of inland waterbodies, including hyperhaline lakes, is determined by the combined influence of natural and anthropogenic factors. For the purpose of holding interannual and seasonal monitoring of the hypersaline lake Adzhi-Baichi, located on the western coast of the Crimean peninsula in the arid climate zone, we studied the change in air and water temperatures, as well as the hydrochemical parameters of brine and the dynamics of the Artemia population Artemia salina in 2017–2020. The established general trends are expressed in an increase in air and water temperature in the summer period with maximum values in July–September (above +30°С), which was accompanied by an increase in reservoir salinity and a decrease in the oxygen content. Fluctuations in the pH and values of the redox potential Eh were less pronounced. The maximum brine salinity (more than 350‰) was noted in 2017, the minimum oxygen content (0.7–1.0 mg/L) occurred in 2020, and the lowest Eh values (–78.5 mV) were found in 2019. Crustacean cysts were found in all of the studied periods during the year. Nauplii appeared in March–April at a water temperature of +3…+7°C; adults were found in the summer months and at the beginning of autumn. In summer, at high water temperature and salinity but a low oxygen content, a crustacean die-off occurred. The results reflect the characteristics of the influence of climatic and anthropogenic factors on the ecosystem of the hypersaline lake and can serve as a model for the prediction of possible scenarios of the impact of climate change on inland waterbodies and can be useful for an understanding of the processes of transformation of aquatic ecosystems in arid zones located in a region of intense anthropogenic influence, as well as the development of measures for their protection and the rational use of resources.

The study assesses the reliability of the description of hydrothermal conditions in the territory of Kalmykia with the use of quantitative climate indicators based on air-temperature and precipitation data that are available in databases and are widely used in climate models. The present study considers the use of the Selyaninov hydrothermal coefficient, the precipitation-evaporation coefficient, the Thornthwaite aridity index, the Koppen method, and the Holdridge scheme. Quantitative climate indicators were estimated for 1966–2017 based on data on the average monthly air temperature and total monthly precipitation at Yashkul’ weather station located in the Chernye Zemli strict nature reserve, which is the most arid part of the Republic. The estimated values of Selyaninov hydrothermal coefficient for the considered period corresponded to natural zones of deserts in two cases, semideserts in 19, and steppes in 31. With the precipitation-evaporation coefficient, the climate conditions corresponded to semidesert in 45 cases and steppe in seven. The values obtained with Thornthwaite aridity index were inherent for deserts and hyperarid regions. According to the Holdridge scheme, the hydrothermal conditions matched steppe zones in 25 cases and deserts in 27. The reliability is highest for climate assessments produced with the involvement of Selyaninov hydrothermal coefficient, which indicate humid warming in Kalmykia and are supported by material collected via the observation of plant communities that form on the ameliorated lands of Priergeninskaya Plain. The presence of humid warming is also supported by estimates based on the Koppen method, the Holdridge scheme, and, to a lesser degree, the precipitation-evaporation coefficient. The assessment involving the Thornthwaite aridity index points to an intensified climate aridization, which is not in line with the modern dynamics of climate conditions in Kalmykia and is thus not reliable.

Anthropogenic impacts on dryland ecosystems result in environmental pollution. Assessment of the state of nature in arid regions is the most important task for scientific and technological progress. Various research methods have been used to study the current state of the Turali lakes as representatives of reservoirs of arid conditions. This made it possible to draw a conclusion about the pollution level of objects and to assess the ecological state of waterbodies inherent in natural complexes of arid conditions.

This paper presents the results of an analysis of trends in variation in the mean monthly air temperature in arid lands in the European part of Russia and adjacent areas in summer; the direction of these trends and the rate of temperature changes in the second half of the 20th and early 21st centuries are estimated. The regional features of the thermal regime in the European part of Russia (EPR) have been studied against the background of global climate change. The latitudinal and longitudinal quantitative indicators of changes in the thermal regime, including their spatial distribution in the study area, are estimated. A significant increase in the air temperature has been recorded in the arid lands of Russia, where the trend in the temperature increase (0.066°C over the 10 years) is much higher than the values obtained from assessment reports.

The results are presented for a study of the biotechnological properties of the introduced Moldova variety, which grows in different soil and climatic conditions of the arid territories of Dagestan. Features of the synthesis of the components of carbohydrate, acid, nitrogen, phenolic, amino acid and vitamin complexes have been determined with respect to the cultivation location. It is noted that the Moldova variety can synthesize a large amount of valuable nutrients at a low moisture supply and high indicators of the sum of active temperatures. This variety has demonstrated ecological plasticity and technological versatility, and it has been experimentally proven that high-quality wine materials can be obtained from it for the production of sparkling and original special wines. Thus, the expansion of areas of grape planting in arid conditions is expedient.

The study is mainly focused on the Orthopteran fauna of Ladakh. In the current field survey and literature survey, 29 species, 24 genera, 11 subfamilies, and five families belonging to four super families of Tettigonioidea (Krauss, 1902), Acridoidea (MacLeay, 1821), Eumastacoidea (Burr, 1899), and Pyrgomorphoidea (Burnner von Wattenwyl, 1847) are reported. The subfamily Gomphocerinae, and the following species Leva indica, Stenohippus mundus, Calliptamus italicus, Phaneroptera gracilis, Conocephalus longipennis, and C. maculatus are recorded for the first time from the region.

Mediterranean countries are still characterized by a great variety of historical cultural landscapes, as a result of the millenary human presence that has shaped the territory through agro-silvo-pastoral practices. In the arid regions of south eastern Tunisia, the land use is predominantly olive trees cropping and, because of the difficulties related to water scarcity, local population have developed a peculiar water harvesting technique ensuring the cultivation activities and minimising the risk from droughts. Jessour consist of small dams built across gullies and wadi thalwegs, creating a succession of terraces that partially retain the surface water and sediments required for crop growth. These structures are commonly built inside the watercourses to intercept runoff and sediments or at the foot of slopes. Considering that the biodiversity associated to traditional agricultural practices is important, especially in difficult environments, for ensuring food and nutrition to local communities, it results fundamental to preserve these peculiar practices. Moreover, taking into account that the presence of these water harvesting techniques allows the existence of a wide variety of flora and fauna species it result to be even more important to identify and maintain them from an ecological point of view. The research focused on the jessour identification and mapping in order to define their distribution nearby Douiret, in south of Tunisia, and describe the wide variety of species cultivated thanks to this traditional water harvesting solution. Moreover, using QGis software it was possible to analyse both jessour structure and peculiarities as well as their distribution according to the local morphological structure.

Rainfall prediction using Artificial Intelligence technique is gaining attention nowadays. Semi-arid region receives rainfall below potential evapotranspiration but more than arid region. However, in mountainous semi-arid region high rainfall intensity makes it highly variable. This renders rainfall prediction difficult by applying normal techniques and calls for data pre-processing. This study presents rainfall prediction in semi-arid mountainous region of Abha, KSA. The study adopted Moving Average (Method) for data pre-processing based on 2 years, 3 years, 4 years, 5 years and 10 years. The Artificial Neural Network (ANN) was trained for a period of 1978-2016 rainfall data. The neural network was validated against the existing data of period 1997-2006. The trained neural network was used to predict for period of 2017-2025. The performance of the model was evaluated against AAE, MAE, RMSE, MASE and PP. The mean absolute error was observed least in 2 years moving average model. However, the most accurate prediction models were obtained from 2 years moving average and 5 year moving average. The study concludes that ANN coupled with MA have potential of predicting rainfall in Semi-Arid mountainous region.

Megaherbivores (adult body mass > 1000 kg) are suggested to disproportionately shape ecosystem and Earth system functioning. We systematically reviewed the empirical basis for this general thesis and for the more specific hypotheses that 1) megaherbivores have disproportionately larger effects on Earth system functioning than their smaller counterparts, 2) this is true for all extant megaherbivore species and 3) their effects vary along environmental gradients. We furthermore explored possible biases in our understanding of megaherbivore impacts. We found that there are too few studies to quantitatively evaluate the general thesis or any of the hypotheses for all but the African savanna elephant. Following this finding, we performed a qualitative vote counting analysis. Our synthesis of this analysis suggests that megaherbivores can elicit strong impacts on, for example, vegetation structure and biodiversity, and all the elephant species promote seed dispersal. We were, however, unable to evaluate whether these effects are disproportionate to smaller large herbivores. Although environmental conditions can mediate megaherbivore impact, few studies quantified the effect of rainfall or soil fertility on megaherbivore impacts, precluding prediction of megaherbivore effects on the Earth system, particularly under future climates. Moreover, our review highlights major taxonomic, thematic and geographic biases in our understanding of megaherbivore effects. Most of the studies focused on African savanna elephant impacts on vegetation structure and biodiversity, with other megaherbivores and Earth system functions comparatively neglected. Studies were also biased towards semi-arid and relatively fertile systems, with the arid, high-rainfall and/or nutrient-poor parts of the megaherbivores' distribution ranges largely unrepresented. Our findings highlight that the empirical basis of our understanding of the ecological effects of extant megaherbivores is still limited for all species, except the African savanna elephant, and that our current understanding is biased towards certain environmental and geographic areas. We further outline a detailed, urgently needed avenue for future research.

Green roofs are expected to contribute to higher biodiversity in urban surroundings. Typically, green roofs have been designed with low plant diversity. However, plant diversity can be enhanced by controlling resource availability and creating distinct niches. Here we hypothesize that by using different drainage heights during the short plant-growing season in a semi-arid green roof system we can create distinct niches and plant communities. Our experiment took place at the University of Haifa, north Israel. We tested three different heights of drainage outlet: 10 cm under the surface of the substrate (Low), 1 cm under the surface of the substrate (Medium) and 3 cm above the surface of the substrate (High) on plant species-composition in green-roof gardens. Grasses cover was higher in High and Medium drainages while forbs cover was higher in Low drainage. Species richness was the highest in Low drainage while diversity indices showed the opposite trend. We conclude that by changing the height of the drainage we can create different niches and change species composition in a short time period of one growing season. This way we can create more diverse green roof communities and enhance biodiversity in urban areas, particularly in semi-arid regions.

In the present study, we tested the chronological and geographic origins of the mostly arid Australian Ptilotus (Amaranthaceae) and its close relatives (i.e. the ‘aervoids’) by reconstructing a dated phylogeny with near-comprehensive sampling for Ptilotus and estimating ancestral geographic ranges. We investigated climatic niche evolution within Ptilotus and identified likely climatic origins and subsequent niche shifts by reconstructing ancestral states of climatic variables on the phylogeny, which was visualised using a phyloecospace approach. Geospatial analyses were employed to identify probable diversification hotspots within Australia. We inferred that the aervoids originated in Oligocene Africa–Asia and that Ptilotus arrived in northern Australia by dispersal in the Early Miocene. Subsequent diversification of Ptilotus was rapid, giving rise to all major clades in the western Eremaean by the time of an aridification pulse in the Middle Miocene. Climatic niche shifts from the arid Eremaean into monsoonal northern and temperate southern Australia are apparent for multiple independent species groups. Our analyses support the hypothesis that a pre-adaptation to aridity and early arrival in an aridifying Australia were integral to the success of Ptilotus, and that the Eremaean has been a source of biodiversity in the genus and for independent radiations into neighbouring climatic zones.

Global climate change has led to significant shifts in local climatic conditions of Ukraine with the trend to aridity aggravation. Sustainable crop production is at risk due to the aridity level increase. The study is aimed to evaluate aridity index in Ukraine (on the whole country and individual regions’ scales) and the needs in irrigation using hydro-meteorological data of the key regional stations for the periods of 1961-1990 and 2010-2020. The results of hydro-meteorological evaluation were supported by the data on the soil moisture regimes provided by Soil Explorer service. The general trend to aridity aggravation in Ukraine was proved. It was found out that modern climate in most territory of Ukraine is semi-arid, dry subhumid and humid zones are observed in the western regions only. Humid soil moisture regimes (ustic and udic) are observed in the West and the North of the country. As a result of combined analysis of both aridity index and soil moisture regimes the conclusion was drawn that 46.05% of Ukrainian croplands cannot provide sustainable crop production without irrigation, 42.65% need irrigation for the cultivation of crops with high water use, and just 11.30% of the arable land require little or no irrigation.

The standard method for the estimation of reference evapotranspiration (ETo) is FAO-Penman-Monteith (FAO56-PM). However, it requires various climatic parameters which are often hard to achieve due to various reason. In order to bridge this gap an alternative equation has to be find out. The main aim of this research work was to assess the performance of the various mass transfer-based method with respect to standard FAO56-PM. Daily meteorological data from 1980 to 2018 has been used to compute reference evapotranspiration. Daily ETo values were computed. Among the computed values 70% of them were used to calibrate the mass transfer equations under study and remaining 30 % data were used to validate the calibrated equation against the standard method. The calibrated models were analysed and compared using statistical tools and ranked using Global Performance Indicator where a higher value represented a model’s better performance. The models were then arranged using GPI and it was found that Albrecht model resulted in best estimation capability. The results of this study could be used by the water management system, crop cultivators, crop advisors, researchers and students from universities and research centres. Moreover, it is beneficial for the decision maker in the vast field of agriculture, hydrology and environment.

Long-term studies are required to reveal responses by long-lived, top-order predator populations to ongoing seasonal fluctuations. However, such investigations are rare in the Australian context. Between 2009 and 2019, the breeding density and productivity of an arid and a mesic wedge-tailed eagle Aquila audax population, each occupying an area of 2800 km2, were compared (11–98 pairs monitored annually). Breeding pairs spaced themselves evenly in both study areas, with no significant difference between the average arid zone nearest-neighbour distance of 5.32 ± 1.98 km (n = 44) and that determined for the mesic zone (4.88 ± 2.32 km, n = 54). This similarity in spacing suggests a maximum average density is tolerated by these territorial raptors. By contrast, annual breeding success (proportion of pairs fledging young) and productivity (fledged young per pair) differed significantly between the two populations, with rainfall (but not temperature) influencing reproduction. In the arid zone, the proportion of successful pairs per occupied breeding home range was consistently low each year (mean = 12 ± 7% fledged broods per pair, range 0–26%) and positively correlated with annual rainfall. In the mesic zone, it was consistently high each year (mean = 69 ± 9%, range 57–91%) and not significantly correlated with annual rainfall. Overall productivity figures showed similar differences, with 0.13 and 0.77 fledglings per pair per year for arid (n = 9 years) and mesic (n = 11 years) eagles, respectively. Such low arid zone productivity, the lowest ever recorded for the species, could have long-term implications in the face of the increased frequency of extreme weather events. That breeding density can be independent of climatic factors provides new insight into the way a large Aquila species integrates with Australia’s predominantly arid environment. This study provides an important baseline data set for continued research on long-term occupancy and productivity trends.

Prickly pear cactus (Opuntia ficus‐indica) is a medicinal plant that plays important economic and ecological roles in arid and semi-arid regions. This study aims to assess the effectiveness of arbu...

Continuous landscape components along the lateral riverside are affected by both hydrologic connectivity and disconnectivity. In recent years, anthropogenic activities and climate changes have caused wetland shrinkage and land degradation along the lateral riverside of many arid and semiarid regions. Since microorganisms are major drivers of soil biochemical cycling, it is essential to examine soil microbial communities along the lateral landscape continuum to understand their ecosystem functioning and predict future land changes. Here, we collected samples along a lateral riverbed center-riverbed edge-oxbow lake-floodplain-terrace continuum (i.e., landward distribution) in the Xilin River Basin, Inner Mongolia, China. The floodplain had the highest microbial diversity and heterogeneity, with Bacteroidetes, β- and γ-Proteobacteria being the most abundant taxa. In contrast, the terrace had the lowest microbial diversity and heterogeneity, with Acidobacteria, Actinobacteria, Verrucomicrobia, Gemmatimonadetes, and α-Proteobacteria as the most abundant taxa. Silt particle, salinity, and moisture were the most influential factors for landward variation of bacterial communities along the riverside continuum. Altogether, we demonstrate that dominant bacterial lineages, soil particles, and moisture-related factors are valuable indicators of this continuum, which can be leveraged for the early prediction of drought-induced wetland shrinkage and grassland desertification.

Calcium (Ca) is an essential nutrient for plant growth and Ca concentrations in forage have important implications for ruminant diet and health. It remains an open question whether forage Ca concentration would be decreased by increasing nitrogen (N) deposition. We manipulated the increasing rates of N addition (2008–2015) in a semiarid grassland, northern China. Plant Ca concentrations for all species were examined in each plot under N treatment. The Ca concentrations at functional group and community levels were calculated based on the concentration of each species presented and their relative biomass in each plot. We found that community-level Ca concentration remained stable across a gradient of wide-ranged N addition rates, although Ca concentration at both species and functional group levels showed negative responses to N enrichment. Given that forbs had higher Ca concentration than grasses, the increasing relative biomass of forbs canceled out the negative responses of species-level and functional group-level Ca concentration. Our results further showed that community Ca pool showed a positive but saturating response to N addition, with a threshold at the rate of 10 g N m−2 yr−1. Our findings highlight the role of changes in plant relative biomass in controlling the responses of forage Ca concentration and stock to N enrichment.

• 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.