Journal of Arid Environments最新文献

Niche complementarity (i.e., complementarity effect) or differences in competitive ability (i.e., selection effect) are the two main mechanisms underlying the biodiversity and ecosystem functioning relationships within a single trophic level. However, few studies have explored such operating mechanisms across multitrophic levels and ecosystem functions, such as pollination. In this large grassland biodiversity study in Inner Mongolia, we partitioned the net biodiversity effect on seed production into the complementarity and selection effects and related these effects to functional diversity and the composition of flowering plant traits, and a range of plant–pollinator network parameters. The positive effect of plant species richness on the complementarity effects overwhelmed the negative effect on the selection effects. Hence, plant diversity positively impacted the net biodiversity effects. In addition, the net biodiversity and complementarity effects were increased in plant communities dominated by species with long inflorescences, suggesting that the facilitative effects of these dominant species attract more pollinators for other species. Furthermore, the complementarity effect increased with decreasing niche overlap of pollinator species, indicating complementary resource use among plant–pollinator interactions. Collectively, our findings highlight the importance of multitrophic interactions in maintaining multitrophic ecosystem functions.

Determining shoot and root biomass and carbon (C) and nitrogen (N) stocks in different ecosystems is crucial to propose adaptative measures to reduce greenhouse gas emission. Data on systems of semiarid areas are scarce, especially irrigated ones. We compared biomasses of four irrigated (bean, maize, grapevine, and mango) and four rainfed livestock systems (buffel grass, prickly pear, gliricidia and leucaena) with those of a preserved and an open tropical dry forest (Caatinga) used as pasture. Caatinga biomass was estimated by allometry and biomasses of the other systems by the destructive method. Root biomasses were determined in layers down to 100 cm. Mango had the highest aboveground and root biomasses: 34.2 and 91.3 Mg ha⁻¹. Preserved Caatinga was the second in aboveground biomass: 25.1 Mg ha⁻¹, compared 9–14.1 Mg ha⁻¹ of the open Caatinga and permanent crops and 3.0–11.8 Mg ha⁻¹ of the grass and annual crops. Preserved Caatinga, gliricidia and buffel grass formed the second group in root biomass (23.7–25.1 Mg ha⁻¹), while all other systems had less than 13.5 Mg ha⁻¹. Preserved and open Caatinga, annual crops and prickly pear had root:shoot ratios below 1, while the other systems had ratios >1, especially mango (2.7). Most systems had roots concentrated in the 0–15 cm layer, but the permanent crops, except prickly pear, concentrated about half of their roots in deeper layers. C (34.2–46.6%) and N (0.6–3.4%) concentrations varied less than biomasses. Root biomass was the plant factor mostly correlated with soil C and N stocks. Therefore, irrigated crops can accumulate more biomass than the native forest, but substitution by mango led to a severe depletion in soil C and N stocks, and all other systems also lost soil C and N. Management strategies such as green manure and crop diversification should be adopted to maintain plant and soil C and N stocks similar to those of the original vegetation.

This study investigates the diet of copper miners at Naḥal ‘Amram (southern Negev Desert), through the examination of the well-preserved remains of plants, mammal and fish bones, dating to the Roman-Byzantine periods (1st–5th centuries CE), recovered during excavations undertaken in three different localities at this mining complex.

Our analyses revealed that the miners enjoyed a varied and nutritious diet, comprising nine species of fruits and vegetables, alongside meat from two domestic animal taxa and representatives of eight different families of fish. While the fish and animal foods were brought to the mines from the Red Sea and neighboring regions, the vegetal food originated from a variety of different sources, some nearby, others quite distant.

We suggest that since copper was traded from Naḥal ‘Amram, the foods arrived at the mines via the same trade routes, from settlements along the ‘Arabah, and these foodstuffs were likely bartered in exchange for copper. The results imply that the people engaged in copper mining were likely a local desert population, Nabataeans, supplementing their food needs from external sources and so enjoying improved nutritional status.

Beyond its findings, the importance of this study lies in the combination of several disciplines, a methodology which can be useful for future research and provide a more reliable understanding of reconstructing the ancient diet.

Nutrient dynamics directly influence forest productivity, yet their exploration in tropical dry forests, particularly in human-modified landscapes, is limited. We examine aboveground and soil carbon, nitrogen, and phosphorus concentrations and stocks in 19 stands across gradients of rainfall, chronic anthropogenic disturbances (CAD), aboveground biomass (AGB), and soil fertility in a Caatinga dry forest. Leaves exhibit three times higher N and P concentrations than twigs but a 20% lower C concentration. Conversely, the soil compartment presented the lowest concentration scores across all nutrients. Stoichiometric N ratios exceed 20 in all compartments. Soil C, N, and P stocks are approximately two, seventeen, and twelve times greater than aboveground biomass. Rainfall, CAD, and AGB exert both positive and negative effects on C and N concentrations and stoichiometric ratios in twigs and soil. Our results suggest that the Caatinga dry forest in human-modified landscapes supports woody plant assemblages with high nutrient concentration but reduced stocks across all compartments. Both environmental and human-related disturbances play specific roles by affecting nutrient availability. In this P-limited system, reduced nutrient stocks and the prevalence of disturbance-adapted plant species apparently dependent on biotic associations for nutrient uptake render Caatinga forest productivity and resilience highly susceptible to human disturbances.

Comparative studies of basic physiological performance are needed to give insight of how grass species survive and grow under current and more severe drought predicted in the framework of climate change in arid steppe grasslands. In this study, photosynthetic performance and stomatal conductance (gs) were measured in leaves of six main grass species of southern Patagonian steppe, after exposing plants to different conditions of water availability. There was a negative linear relationship between photosynthesis at light saturation (Pmax) and plant water stress, expressed as pre-dawn leaf water potential (ψ_pd), mainly explained by the reduction in gs. A negative linear relationship was also observed between the photosynthetic efficiency (α) and the ψ_pd of plants, but only under moderate to severe water stress conditions. Grass species had different response to water stress graded in the following order: Pappostipa chrysophylla > Festuca gracillima > Rytidosperma virescens > Poa dusenii > Bromus setifolius. These results can assist to understand the natural spatial distribution of these species under arid conditions, to predict their performance under changing climate, and to select proper species for restoration plans in steppe grasslands.

Cultivated for millennia, the grapevine held a special status as one of the most important fruits in the historical Levant and the Mediterranean world. However, since past farmers typically did not leave written accounts of their activities, viticulture history is often shrouded in ambiguity, especially concerning the classification of grapevine landrace varieties. Hence, the study of archaic viticulture relies heavily on methodological fusion to unravel its more readily discernible biological and oral traditions. We therefore merged archaeological fieldwork, historical archival analysis, field geography and ethnographic interviews to collect multifarious data on the Dabouki grapevine. Our analytical synthesis enabled us to depict how, over the course of history, diverse communities variously grew this cultivar in dryland vineyards. The cultural history of the Dabouki stretches from at least the Ottoman era, when it was widely planted throughout the region under various names, to its current revival by enterprising Israeli and Palestinian winemakers. The majority of our research was conducted within a unique environmental corridor in the western Negev of Israel where dense concentrations of relic Dabouki grapevine survive. Our paper surveys the cultural history of the Dabouki grape as a flagship cultivar in the intergenerational horticultural regimes of arid land farmers in the western Negev of the southern Levant. Remarkably, archaic Negev viticulturalists used the same cultivars across successive historical periods and varying socioeconomic contexts. As such, the paper illustrates that arid regions with longstanding winegrowing traditions are ideal for locating endemic grapevines that apparently can withstand challenging growing conditions. Focusing on the enduring legacy of the Dabouki, we suggest how historical knowledge of ancient dryland farming systems and landrace cultivars can bolster the sustainability of contemporary viticulture.

Gypsum soils, despite physico-chemical constraints, harbor a unique biota composed of specialist (gypsophiles) and stress-tolerant non-specialist species (gypsovags). Gypsophily has been addressed in plants, although is important to ask whether lichen communities also contain gypsophile species. Therefore, our main aim is the analysis of the affinity of lichens for the gypsum substrate in Spain. Affinity was estimated using two methods: a “geological method”, overlapping lichen occurrence data on a geological map of Spain; and a “biological method”, overlapping the occurrences on a map constructed with the distribution of plant gypsophiles. To assess the accuracy of both methods, we compared them with a literature review. Lichen occurrence data was obtained from GBIF. The biological method was the most accurate as it showed similar percentages to the literature review. The affinity for gypsum substrate has been effectively demonstrated by the employment of these methods, probing the existence of a group of lichens considered gypsophiles. Twenty lichen species are considered gypsophiles, 7 strict and 13 preferential (ca. 40% of 50 taxa analyzed), and 30 gypsovags. This approximation can apply to the study of the affinity for the substrate for other organisms/substrates, and for characterizing geological units when detailed geological maps are not available.

Surveys in arid regions worldwide reveal the widespread presence of naturally found Terrestrial Snails (TSs) in extreme arid and semi-arid regions and poor soil conditions such as eroded loess plains. A significant beneficial connection between TS and their impact on ecosystem functioning is suggested including their use as bio-fertilizers. The study was conducted from 2017 to 2023 in Northern Negev, Israel, at the PWA farm and Sayeret-Shaked LTER. The study aimed to determine the influence of TSs on soil fertility and explore its potential contribution to sustainable and profitable agriculture. The findings indicate that the local TSs contributed to a 2% increase in organic matter content, a significant 60% increase in Calcite-Magnetite, and up to six times higher levels of soluble Calcium and Magnesium compared to unaffected soil. An increase with a potential for CO₂ inorganic sequestration. It is also indicated that successful agricultural utilization of TS relies on unmanaged rocky slopes for reproduction, designated migration paths for farmland access, and a unique cultivation approach to enhance decomposition. The finding may enable policymakers, and regional or government agencies to further invest in local ecosystems, and effective management tools for enhancing the reproduction of bio-fertilizers such as TS are also raised.

This study focuses on the traditional methods used by the Janabib Bedouin tribe in the Negev Highlands to cultivate wheat and barley during the British Mandate period from 1917 to 1948. Despite the fact that this region receives only 90 mm of precipitation per year on average, and was located at a great distance from settlements and markets, the local Bedouin cultivated cereals by exploiting the ancient agricultural terraces from the Byzantine period which prevented runoff and distributed water over the agricultural plots. This research also found that the choice of which cereals to grow in different years, were determined by local climatic conditions. Thus, the Bedouin who lived in the Negev Highlands before 1948, developed specific adaptations in order to survive in these arid conditions.