Journal of Arid Environments最新文献

Inland Australia supports by far the world's most diverse arid-adapted ant fauna, but there are no published studies of regional ant faunas from the central arid zone. Here we describe the ants collected by pitfall trapping at 22 sites in World Heritage-listed Uluru-Kata Tjuta National Park (300 mm mean annual rainfall), representing all major vegetation types from spinifex grasslands to eucalypt woodlands. A total of 154 (mostly undescribed) ant species from 26 genera were recorded, with the richest genera being Melophorus (30 species), Monomorium (26), Iridomyrmex (18) and Camponotus (12). The pattern of species accumulation suggests that many more species remain to be collected from the Park, and we estimate that the total fauna consists of around 300 species. The most abundant ants were species of Iridomyrmex (collectively contributing 76% of all ants collected), as is the case throughout arid Australia. Species of Monomorium and Melophorus were also highly abundant. No exotic species were recorded. Ant species composition was strongly related to vegetation type, with a particular distinction between the various grasslands on one hand, and woodlands on the other. Unexpectedly, species richness was higher in structurally simple spinifex grasslands than in eucalypt woodlands. The woodland fauna lacks many taxa characteristic of such habitats in similarly arid regions of southern Australia, which we attribute to remoteness and small patch size. Uluru-Kata Tjuta National Park supports an extremely diverse ant fauna, but surveys of other areas are required for an improved understanding of patterns of ant biodiversity in Australia's central arid zone.

Hyperarid habitats comprise the most dominant and harsh portion of the Sahara Desert, yet how local biotas have responded to paleoclimatic shifts and landscape heterogeneity remains unclear. Here, we assess the historical biogeography of Cerastes cerastes, a conspicuous but poorly known vertebrate inhabiting the hyperarid Sahara, to understand the links between intermittent and stable climatic suitability and patterns of genetic diversity and differentiation in these extreme environments. We combine phylogeographic and ecological modelling tools using a comprehensive species dataset, which includes DNA samples (n = 62) and occurrence records (n = 557) covering most of its range. We show that paleoclimatic oscillations were major evolutionary and biogeographic drivers in C. cerastes, which exhibits different levels of intra-specific diversity and allopatric lineage structuration across the desert. High lineage richness in the north-western Sahara contrasts with an overall lack of genetic diversity throughout the central and eastern Sahara. Climatic refugia along the desert's periphery and around mountain patches harbour single endemic lineages, stressing the links between stable climatic conditions and population isolation and divergence. Increasing climatic suitability during historical arid phases prompted widespread connectivity across the desert. This study lays the groundwork for better understanding the historical dynamics of the hyperarid Sahara.

Moringa stenopetala, an important vegetable tree locally called “Haleko” in Derashe and “Shelagda” in Konso area, is cultivated and managed mainly for its edible leaves and for various other purposes in the southern part of Ethiopia. The study explored Ethnobotanical knowledge of the local communities in Konso and Derashe districts. Data were collected using household survey, focus group discussion and key informant interview. A total of 180 households were interviewed using a semi-structured questionnaire. Focus group discussions were also conducted involving both men and women. The result showed that M. stenopetala (Haleko) is an important component of the daily dish of the study ethnic groups and used for medicinal purposes. Farmers in both ethnic groups propagate M. stenopetala using its seeds and cuttings. The studied ethnic groups plant the species in home gardens and their crop fields. Farmers produce and use succulent leaves for preparation of local dish. They also practice pollarding of M. stenopetala tree at about 2.30 m to avoid bird resting on the trees and damage their crops. The study also recommends further promotion of the species to other areas with similar agroecology, and propagation techniques research to investigate the optimum cutting height, age and season.

Understanding the dynamics of metacommunity structure and temporal beta diversity is vital for comprehending ecological dynamics at local and regional scales; it is essential to evaluate impacts of factors such as climate change, dispersal, and biotic interactions. We examined changes in the composition and abundance of 199 perennial plant species in the semiarid Zapotitlán Valley, Mexico, over a 43-year period. We studied three local community types, scrubland, cardonal, and tetechera, with surveys conducted in 1980, 2003, 2018, and 2023. Shifts in species composition and abundance over time were analysed using the Temporal Beta Diversity Index distinguishing between species gains or losses. We investigated the metacommunity structure elements—coherence, turnover, and boundary clumping—in each survey. We observed pronounced temporal changes in species’ composition and abundance across all community types. These temporal changes stem from the losses and gains in species and individuals. Notably, 2023 showed significant losses in species occurrence and abundance, potentially attributable to an extended drought likely exacerbated by climate change. Surprisingly, the metacommunity structure remained Clementsian throughout our study, emphasising the stability of the cardonal in maintaining distinctions between local community types. This suggests that the metacommunity spatial structure is resistant to changes in local community compositions.

The objective of this study was to evaluate the effect of two spineless cactus (Nopalea cochenillifera) levels (250 g/kg or 550 g/kg) as an exclusive source of water on the performance, serum biochemistry, blood count, ingestive behaviour, carcass characteristics and non-carcass components of confined goats. Forty Anglo-Nubian castrated male goats were used, housed in individual pens and distributed in a 2 × 2 + 1 factorial design of spineless cactus factor (250 g/kg or 550 g/kg of spineless cactus in the dry matter of the diet) and water factor (with or without access to drinking water) and control diet (without spineless cactus and with access to drinking water). The restriction on drinking water did not influence (P > 0.05) the average daily gain, carcass weight or serum biochemistry of the goats. The inclusion of spineless cactus increased (P < 0.05) the average daily gain, body weight at slaughter and carcass weight of the goats and reduced (P < 0.05) animal drinking water intake. Goats fed 250 g/kg of spineless cactus in their diet chewed more (P < 0.05), drank more water (P < 0.05) and had greater gastrointestinal tract contents (P < 0.05) than goats fed 550 g/kg of spineless cactus in the diet. Spineless cactus from 250 g/kg can be used as an exclusive source of water in the diets of confined goats.

Banqueting is a simple and cheap soil conservation practice in natural rangelands under dry climates. Little research exists about its impacts compared to other land uses, where agriculture and land abandonment may be important reasons for degradation. This study has evaluated water infiltration and key physico-chemical properties of soil in natural rangelands with banquets in West Azerbaijan (North-Western Iran) compared to: (i) undisturbed sites (assumed as reference condition) and (ii) cultivated or abandoned dry farmlands. Under these soil conditions, the texture, bulk density, porosity, water content, pH, electrical conductivity, organic carbon and carbonate contents of soil (using common physical-chemical methods) as well as the hydraulic conductivity (using a single-cylinder infiltrometer) were measured in the topsoil (0–20 cm). This data was further processed by applying the Principal Component Analysis and the Agglomerative Hierarchical Cluster Analysis. In areas with banquets, soil hydraulic conductivity was higher by 84% compared to dry farmlands (abandoned or not), where water infiltration was noticeably reduced (−44%) compared to the reference soil condition. Moreover, a noticeable increase in organic carbon content (+80%) and a lower salinity (−36%) of soil compared to cultivated areas was measured. These effects are important to enhance soil fertility on one side, and resistance to erosion on the other side. Therefore, in the experimental areas, banqueting may counteract the degradation of soil due to the agricultural activity as well as its abandonment, and restore the properties of the undisturbed soils that are typical of natural rangelands. The results of this study may be of help for landscape managers and agronomists for the pressing needs for soil conservation and productivity in semi-arid areas that are prone to degradation and abandonment.

Ongoing climate change and anthropogenic impacts will continue to worsen the problem of water crisis. In order to explore practical solutions for drought and climate change adaptation, this work uses a set of different methodologies to evaluate an operational fog collection project and discuss solutions for some emerging challenges. This study uses fog collection rate, Water Quality Index (WQI) and interviews with the community as indicators for the assessment. Results indicate that the project continues to deliver improved drinking water access to the community. Fog harvesting rate yielded an annual average from 1.6 to 6 L/m²/d. Interviews confirm the social commitment of the local community. However, challenging points emerge: (1) ongoing groundwater pollution due to the lack of sanitation; (2) if fog water is the only source, inconsistent fog yields may negatively impact water availability; (3) poor solid waste management. The findings represent a baseline for assessing and benchmarking other similar projects or project proposals in the Atlantic coast of North Africa. Therefore, the proposed methodology can also be used in other fog collection projects around the world.

Where they occur at high densities, herbivores are likely to impact ecosystems by functioning as nutrient vectors that shift nutrients from areas where they graze to other locations. Such lateral shifts in nutrients are important to understand as they can alter the balance of species interactions and composition of ecological communities. In arid Australia, kangaroo (Macropus spp.) populations have irrupted due to suppression of their chief predator and their presence can have marked impacts on vegetation and soils in areas where they graze. Kangaroos are hypothesised to facilitate the transport of nutrients by ingesting organic material and depositing it in the form of faecal matter and urine under the shade of trees where they rest during the day. Here, we investigate the role that kangaroos and shade play as nutrient vectors and nutrient sinks, respectively. We compared kangaroo visitation and soil nutrients under experimental shades with unshaded areas in an arid landscape with little natural shade. Kangaroo visitation was greatest at shaded plots. Dung accumulation was greater at shaded plots than unshaded plots. Total carbon (TC) was greater in soils within shaded plots than control plots; however, there was no difference in TC between shaded plots and procedural control plots. There was no difference in total nitrogen and plant available phosphorus between shaded, control and procedural control plots. Our findings demonstrate that the presence of shade in an arid landscape influences the microhabitat choice of kangaroos, but only partially supports the hypothesis that nutrients concentrate within the soil under shade.

The microbial communities in saline lakes play important roles in maintaining their unique ecosystems. However, little is known about the vertical distribution of the sediment microbial communities in saline lakes. We therefore studied the vertical distribution of the sediment microbial communities and their relationships with environmental factors in Ebinur Lake, China. Our sediment cores, collected in 2018, were analyzed using Illumina MiSeq sequencing. The results indicated that microbial diversity significantly increased in the sediment core with increasing salinity. At the phylum level, the six most abundant microbes were Proteobacteria, Chloroflexi, Bacteroidetes, Firmicutes, Gemmatimonadetes and Deinococcus-Thermus, accounting for 42.9%, 10.7%, 9.6%, 5.2%, 4.6% and 3.6% of the total reads, respectively; At the genus level, the six most abundant genera were Halothiobacillus, Desulfotignum, Truepera, Salipaludibacillus, Marinobacter and Halomonas, accounting for 15.4%, 4.8%, 3.6%, 2.7%, 2.6% and 2.3% of the total reads respectively. There were significant vertical variations in microbial community composition (MCC) between upper layers and lower layers. Canonical correspondence analysis demonstrated that salinity was the dominant environmental factor affecting the vertical variation of sediment MCC. Thus, this study could greatly improve our understanding of the MCC of saline lakes in the arid and semi-arid ecosystems.

Serious concerns have arisen regarding the depletion of groundwater aquifers and water shortage, particularly in the Middle East. The utilization of qanat, subterranean tunnel-wells, may serve as a solution to addressing water scarcity and present targeted strategies toward sustainable groundwater management. This research presents an analysis of the spatial distribution of active qanats in Afghanistan, Iran, Iraq, and Syria, considering the annual rainfall rate, the elevation from sea level, water stress risks, and groundwater table decline. It aims to identify the qanat sites that may be maintained and utilized. The findings reveal distinct geographical clusters of qanats, with a concentration in mountainous regions characterized by consistently high elevations ranging from 1500 to 2500 m above sea level and annual rainfall rates between 200 and 300 mm. In contrast, a more sporadic presence is observed in low-lying plains with elevations ranging from sea level to 1000 m, where the annual rainfall ranges between 300 and 600 mm. Participation in the restoration, maintenance, and utilization of qanats in regions facing high water stress and the risk of groundwater table decline, such as the central plateau of Iran, may offer a sustainable solution to water risk challenges.