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Mule deer (Odocoileus hemionus) are important economically, culturally, and recreationally to the Pueblo of Santa Ana in central New Mexico, USA. Studies of habitat selection improve our understanding of mule deer ecology in central New Mexico and provide the Tribe with valuable information for management of mule deer. We used global positioning system telemetry‐collar data collected on mule deer around the Pueblo of Santa Ana to create resource selection functions from proximity‐based habitat predictors using a generalized linear mixed model. We created separate resource selection functions for females and males during summer and winter at different times of the day. Season generally had a greater effect on mule deer habitat use than the time of day. Female and male mule deer selected for similar habitats but were sexually segregated in their summer distributions. These findings are consistent with results from other locations where mule deer partitioned habitat similarly between seasons and sexes. Supported models reaffirm accepted patterns of habitat selection for mule deer to the Pueblo of Santa Ana where local results were lacking. Our results can help managers identify locations in and around the Pueblo of Santa Ana where future development such as highway expansion are likely to conflict with mule deer activity and locations where habitat enhancement projects such as adding water sources can have the greatest effect for the deer population. [ABSTRACT FROM AUTHOR]

The European rabbit Oryctolagus cuniculus is an exotic herbivorous mammal undergoing an active phase of geographical expansion in the arid ecosystems of Argentina. The Adaptive Flexibility Hypothesis states that populations at the range edge (new populations) will exhibit greater flexibility in the use of resources compared with populations located in the range core (older populations). The objective of this work was to compare the rabbit's use of spatial and trophic resources in relation to the establishment time of their populations. The sampling was carried out for 2 years (2017 and 2018) in sites with different establishment times for rabbit populations. Random sampling stratified by type of habitat was applied using 115 fixed strip transects of 1,000 m2 laid out across the study areas. Fresh rabbit signs were recorded in each transect, and environmental and anthropic variables were measured. Our results show that the individuals from the range edge are more selective in the use of habitat than those from the range core. At the microhabitat level, we observed a pattern in the particular components of habitat use by rabbits mainly linked to food availability and proximity to water. From a trophic perspective, rabbits could show flexible adjustment to novel conditions and environments in the range edge. The variability in resource use by the European rabbit confirms its ecological flexibility, pivotal for their advance toward new environments in Argentina. [ABSTRACT FROM AUTHOR]

Context: Dynamic feedbacks between physical structure and ecological function drive ecosystem productivity, resilience, and biodiversity maintenance. Detailed maps of canopy structure enable comprehensive evaluations of structure–function relationships. However, these relationships are scale-dependent, and identifying relevant spatial scales to link structure to function remains challenging. Objectives: We identified optimal scales to relate structure heterogeneity to ecological resistance, measured as the impacts of wildfire on canopy structure, and ecological resilience, measured as native shrub recruitment. We further investigated whether structural heterogeneity can aid spatial predictions of shrub recruitment. Methods: Using high-resolution imagery from unoccupied aerial systems (UAS), we mapped structural heterogeneity across ten semi-arid landscapes, undergoing a disturbance-mediated regime shift from native shrubland to dominance by invasive annual grasses. We then applied wavelet analysis to decompose structural heterogeneity into discrete scales and related these scales to ecological metrics of resilience and resistance. Results: We found strong indicators of scale dependence in the tested relationships. Wildfire effects were most prominent at a single scale of structural heterogeneity (2.34 m), while the abundance of shrub recruits was sensitive to structural heterogeneity at a range of scales, from 0.07 – 2.34 m. Structural heterogeneity enabled out-of-site predictions of shrub recruitment (R2 = 0.55). The best-performing predictive model included structural heterogeneity metrics across multiple scales. Conclusions: Our results demonstrate that identifying structure–function relationships requires analyses that explicitly account for spatial scale. As high-resolution imagery enables spatially extensive maps of canopy heterogeneity, models for scale dependence will aid our understanding of resilience mechanisms in imperiled arid ecosystems. [ABSTRACT FROM AUTHOR]

Summary: Deserts represent key carbon reservoirs, yet as these systems are threatened this has implications for biodiversity and climate change. This review focuses on how these changes affect desert ecosystems, particularly plant root systems and their impact on carbon and mineral nutrient stocks. Desert plants have diverse root architectures shaped by water acquisition strategies, affecting plant biomass and overall carbon and nutrient stocks. Climate change can disrupt desert plant communities, with droughts impacting both shallow and deep‐rooted plants as groundwater levels fluctuate. Vegetation management practices, like grazing, significantly influence plant communities, soil composition, root microorganisms, biomass, and nutrient stocks. Shallow‐rooted plants are particularly susceptible to climate change and human interference. To safeguard desert ecosystems, understanding root architecture and deep soil layers is crucial. Implementing strategic management practices such as reducing grazing pressure, maintaining moderate harvesting levels, and adopting moderate fertilization can help preserve plant–soil systems. Employing socio‐ecological approaches for community restoration enhances carbon and nutrient retention, limits desert expansion, and reduces CO2 emissions. This review underscores the importance of investigating belowground plant processes and their role in shaping desert landscapes, emphasizing the urgent need for a comprehensive understanding of desert ecosystems. [ABSTRACT FROM AUTHOR]

Anthropogenic habitat modification can indirectly effect reproduction and survival in social species by changing the group structure and social interactions. We assessed the impact of habitat modification on the fitness and life history traits of a cooperative breeder, the Arabian babbler (Argya squamiceps). We collected spatial, reproductive and social data on 572 individuals belonging to 21 social groups over 6 years and combined it with remote sensing to characterize group territories in an arid landscape. In modified resource‐rich habitats, groups bred more and had greater productivity, but individuals lived shorter lives than in natural habitats. Habitat modification favoured a faster pace‐of‐life with lower dispersal and dominance acquisition ages, which might be driven by higher mortality providing opportunities for the dominant breeding positions. Thus, habitat modification might indirectly impact fitness through changes in social structures. This study shows that trade‐offs in novel anthropogenic opportunities might offset survival costs by increased productivity. [ABSTRACT FROM AUTHOR]

Fire-adapted dry forests and nearby communities both need to be sustained as climate changes. Wildfires have increased in the ~25.5 million ha of dry forests in the western US, but are wildfires already more severe than historical (preindustrial) wildfires, warranting suppression, or is more fire needed? Recent research suggests that a higher percentage are more severe, but is this from more high-severity fire (≥70% mortality) or simply less lower-severity fire? To resolve this question, I compared government fire-severity data from 2000–2020 with corresponding government Landfire historical data, representing the last few centuries. The fire rotation (expected time to burn across an area of interest) for high-severity fire was 477 years recently versus 255 years historically, a deficit, not a surplus. High-severity fire would need to increase 1.9 times to equal historical rates. Thus, reducing high-severity fire through fuel reductions is fire suppression, which has significant well-known adverse ecological impacts. These include reductions in (1) natural burn patches, snags, and non-forest openings, that favor diverse fire-adapted species, and (2) landscape heterogeneity that can limit future disturbances and enhance landscape ecological processes. Even larger deficits were in moderate (4.4 times) and low (5.8 times) fire severities. However, if only these lower severities were restored, the high-severity percentage would correspondingly be reduced to low levels. All fire severities are needed to provide a variety of post-fire settings that favor a broad suite of selection pressures and adaptations to emerging climate. This paper shows that to sustain and adapt dry forests and nearby communities to fire and climate change, the billions spent on fuel reductions to reduce high-severity fire can be redirected to protecting the built environment, fostering both safe and sustainable dry forests and human communities. [ABSTRACT FROM AUTHOR]

Dryland ecosystems are among the most widespread biomes on Earth and sustain nearly 40% of the global human population. Knowledge on drylands throughout the world has come from diverse disciplinary fields including natural and social sciences. The use of quantitative tools, such as science mapping or bibliometric analysis, may help to explore the structure of knowledge and to identify emerging issues. Here, we analyzed the dynamics of scientific production on dryland ecosystems throughout fifty years since the creation of the Argentine Institute for Dryland Research (IADIZA). We focused on IADIZA as a case study because it is one of the oldest dryland research institutions in South America whose contributions may exemplify research trajectories in drylands. We conducted a systematic search in Scopus for the 1972-2022 period, complemented with the institute's records, which resulted in 1828 publications. We identified 48 research themes studied at IADIZA. The diversity of themes has increased through time, moving from the early descriptive studies of species and communities to the current focus on paerns and processes. From 2000 to the present, we detected a remarkable incorporation of new concepts, indicating that the conservation and management of natural resources, the systematics and taxonomy of species and ecological interactions constitute the central research themes, along with emerging themes such as genetics, evolution and urban ecology. In conclusion, our synthesis offers a clear description of the dynamics of research themes in the study of drylands and indicates a growing international interest in IADIZA's contributions to dryland functioning. [ABSTRACT FROM AUTHOR]

Given the current environmental crisis, biodiversity protection is one of the most urgent socio‐environmental priorities. However, the effectiveness of protected areas (PAs), the primary strategy for safeguarding ecosystems, is challenged by global climate change (GCC), with evidence showing that species are shifting their distributions into new areas, causing novel species assemblages. Therefore, there is a need to evaluate PAs' present and future effectiveness for biodiversity under the GCC. Here, we analyzed changes in the spatiotemporal patterns of taxonomic and phylogenetic diversity (PD) of plants associated with the Neotropical seasonally dry forest (NSDF) under GCC scenarios. We modeled the climatic niche of over 1000 plant species in five representative families (in terms of abundance, dominance, and endemism) of the NSDF. We predicted their potential distributions in the present and future years (2040, 2060, and 2080) based on an intermediate scenario of shared socio‐economic pathways (SSP 3.70), allowing species to disperse to new sites or constrained to the current distribution. Then, we tested if the current PAs network represents the taxonomic and phylogenetic diversities. Our results suggest that GCC could promote novel species assemblages with local responses (communities' modifications) across the biome. In general, models predicted losses in the taxonomic and phylogenetic diversities of all the five plant families analyzed across the distribution of the NSDF. However, in the northern floristic groups (i.e., Antilles and Mesoamerica) of the NSDF, taxonomic and PD will be stable in GCC projections. In contrast, across the NSDF in South America, some cores will lose diversity while others will gain diversity under GCC scenarios. PAs in some NSDF regions appeared insufficient to protect the NSDF diversity. Thus, there is an urgent need to assess how the PA system could be better reconfigured to warrant the protection of the NSDF. [ABSTRACT FROM AUTHOR]

In its most recent concept, the genus Cheilanthes encompasses three clades distributed across South America, Africa, and Australasia. Previous studies in Peru recorded 23 species; however, advancements in molecular systematic have led to the segregation of eight of them into at least three genera. In this study, 15 species are recognized in the Peruvian flora based on the examination of 459 herbarium and field specimens, and the evaluation of morphological characters using 131 specimens. The affinities among the lineages proposed in this study are consistent with recent phylogenetic hypotheses, wherein Cheilanthes species in Peru are members of two clades, the South American and the Australasian-South American, with taxonomically important characters being the shape of rhizomatous scales and types of frond indumentum (scales, microscales, scuamules, and hairs). We found that the genus Cheilanthes is present in 20 departments of Peru, with most species having wide distribution in the central-southern Andean regions, four species having endemic status. Meanwhile, C. cantangensis, C. lonchophylla, and C. obducta are poorly represented in the northern region. The first two species are considered endemic and categorized as Endangered (EN), while the other two are classified as Least Concern (LC). Additionally, a taxonomic key is provided. [ABSTRACT FROM AUTHOR]

Understanding the rate and direction of pyrogenic succession in arid ecosystems, which depends on many factors, including the intensity of grazing and the frequency of pyrogenic expo-sure, will allow for more accurate predictions of the consequences of fire onplant communities, and will assist with better fire management. We studied the vegetation on 55 sites in and near the "Chernye Zemli" Natural Biosphere Reserve that burned at different times or were not affected by fires over the past 35 years and characterized the changes in vegetation cover associated with the impact of wildfire and grazing. The descriptions were grouped into chronological stages according to the time elapsed since the last fire, or into groups according to the frequency of fires. In pairwise comparison of the projective cover of plant species between chronological stages, it correlated most strongly between successive initial stages (for stages 1 and 2, p = 0.003, r = 0.73; for stages 2 and 3, p < 0.001, r = 0.78). Species with an initially higher projective cover were more likely to grow on plots in the first year after the fire: p < 0.03. Plots with rare and frequent fires had similar projective cover of individual species (r = 0.64, p < 0.001). We conclude that in the course of pyrogenic succession, communities are gradually replaced over at least ten years. At the same time, the composition of a plant community at the initial point of succession depends on the prevalence of species in the community before the fire. No fundamental effect of the frequency of fires on the composition of plant communities has been revealed. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare two methods for assessing damage from the degradation of soils and agricultural lands located in the Kalachevsky district of the Volgograd Region. The amount of damage from soil and land degradation was calculated by the "Methodology for determining the amount of damage from soil and land degradation" (1994) and the cost of restoration (reclamation) of degraded soils was determined using the SmetaWizard estimate program (version 4.1.3). It was established that the most significant contribution to the total amount of damage from soil and land degradation (175 573 000 rubles or 64 955 rubles/ha) was made by the increase in the share of exchangeable sodium in soils (147 424 528 rubles or 54 541 rubles/ha), which is due to the development of the process of alkalinization in the soils of the studied agricultural sector in the region. This degradation process, which is harmful to the agricultural use of soils and lands, was found in areas that comprise 52% of the total farm area. This indicator's significant damage is also associated with extended periods of restoration (reclamation) work, 4 years. The cost of reclamation work amounted to 11 647 353 rubles or 4309 rub./ha. The maximum contribution (78%) to this was made by damage from soil organic matter losses (the amount of damage was 9 131 525 rubles or 3378 rubles/ha). The significant difference in the total values of the environmental and economic assessment of soil degradation and the land of the Donskoye agricultural enterprise in the Kalachevsky district, calculated in various ways, is associated with the methodological features of this assessment: the assessment of damage from degradation by the "Methodology ..." (1994) is a stricter approach than estimating the cost of reclamation (restoration) measures. Thus, soils may be degraded compared with a standard (considered when assessing damage), but this degradation is "insufficient" to justify reclamation. [ABSTRACT FROM AUTHOR]

Questions: The classification of plant communities is a well‐established practice in ecology. However, the factors that determine the distribution of common species and the extent of their dominance and overlap are still being debated. Large‐scale studies based on field data are of great interest in the face of biodiversity changes and climate change impacts. This research was designed to answer the following two questions: What are the dominant plant communities in the Patagonian steppes and how do they relate to environmental features, as measured by latitude, longitude, altitude, mean annual precipitation and mean temperature? What have been the recent changes in plant communities in terms of expansion and contraction of different types of communities? Location: Patagonian steppes (South America). Methods: We used a large database of species‐by‐species vegetation cover from 426 monitoring plots in the South American Patagonian steppes, surveyed between 2007 and 2019, with two different assessment dates at least 5 years apart. We applied archetypal analysis to identify different vegetation compositions at a regional scale (called floristic archetypes) and to track their changes over time. In addition, we analyzed the relationship between floristic archetypes and spatial and meteorological variables to assess the association between floristic composition and the environmental context. Results: Seven floristic archetypes were identified in the Patagonian steppes. The dominant and most widespread floristic archetype showed an expanding pattern in floristic trajectories and was positively associated with mean annual temperature. This floristic archetype was characterized by both drought‐ and grazing‐tolerant species. Two floristic archetypes located at the longitudinal extremes showed decreasing relative participation in the vegetation configurations, and the archetype located towards the west showed a positive relationship with annual precipitation, suggesting a threatened scenario in the face of drier conditions. Southern floristic archetypes either showed a slight decrease or remained stable. Conclusions: Patagonian steppes are dominated by both drought‐ and grazing‐tolerant species communities and their spatial distribution is expanding across different biomes, whereas the more forage‐preferred species were associated with a decreasing floristic archetype. A projected drier and hotter climate scenario may potentiate this pattern. The floristic archetypes framework has potential as a monitoring tool for tracking changes in vegetation composition at a mesoscale and for identifying hotspots of vulnerable vegetation in the face of environmental changes. [ABSTRACT FROM AUTHOR]

In the southern Kalahari Desert, cooperatively breeding Southern Pied Babblers Turdoides bicolor frequently build their nests and forage in camelthorn trees Vachellia erioloba, a keystone species in the region, and blackthorn trees Senegalia mellifera, a widespread early successional shrub. Using Ivlev's electivity indices (Ei), we show that Southern Pied Babblers preferentially nest in camelthorn trees and preferentially forage in or under camelthorn and blackthorn trees. Southern Pied Babblers primarily forage on the ground; however, they will make use of arboreal resources when these are available. We observed the birds spending the highest proportion of foraging time off the ground during October, when breeding is also most common, compared with all other months within the austral summer breeding season. They are most likely to be observed foraging in camelthorn trees earlier in the breeding season and blackthorn trees later in the breeding season. We demonstrate that Southern Pied Babblers have a strong relationship with camelthorn trees, in which they prefer to both nest and forage. We highlight the importance of protecting camelthorn trees, a keystone species in the region, as part of the conservation and management of endemic Kalahari fauna such as the Southern Pied Babbler. In addition to contributing to the literature on keystone species, our observations raise questions about the ways in which avian reproduction in the arid zone could be decoupled from rainfall via the phenology of deep‐rooted tree species. [ABSTRACT FROM AUTHOR]

In the last few decades, revegetation strategies for ecosystem restoration have received great attention in dryland studies, especially those related to the restoration and revegetation of native desert plants to combat land degradation. Long-term monitoring and assessment are critical for the restoration programs to track the progress of the restoration program goals. The effectiveness and success of monitoring depend on the selected methods with respect to spatial and temporal scales. Traditional methods for vegetation monitoring are time-consuming, expensive, and require considerable labor efforts (manpower) in terms of field measurements, collecting samples, lab analysis, and the difficulty of accessing some study areas. Thus, satellite remote sensing images have been widely used to monitor land degradation and restoration programs using multispectral and hyperspectral sensors and indices such as NDVI, which is the most popular index for vegetation monitoring. However, such techniques showed many limitations when used in arid ecosystems, especially for seasonal vegetation assessments, which could mislead the monitoring and assessment of the restoration projects. This paper discusses lessons learned from previous research work, including the limitations of using satellite remote sensing in arid ecosystems and the use of UAV methods to overcome these issues and challenges to provide more accurate outcomes for seasonal assessment of vegetation in arid landscapes.

AbstractArthropods play an essential role in steppe ecosystems. However, studies testing the overall response of terrestrial arthropods to overgrazing are scarce. The problem is particularly worrisome in Central Asia, while, to date, only a very few broader studies have been conducted in this region. We investigated how epigeic terrestrial arthropod assemblages respond to different livestock grazing pressure in two ecozones in SE Mongolia by examining their structure using pitfall traps. We also assessed which groups can be utilised as the most efficient indicators of grazing intensity. Our analyses demonstrated that the habitat type, grazing intensity, and the interaction of these variables had a significant effect on the overall species composition and abundance. However, the grazing intensity caused different changes in the composition of arthropod communities in both studied ecozones. Contrary to the semi-desert, in the steppe habitat, the grazing had the strongest impact in the moderately grazed site. It is most likely because steppe-dwelling species are more sensitive to loss of plant biomass and changes in habitat structure. We also found that the most representative species within and from different groups can react differently to changing grazing intensities, indicating with their presence the characteristics of the respective habitat. Such differences should also be considered when elaborating the management plan of conserved species but also when applying grazing management in different habitat types. Our survey is one of the most comprehensive in Central Asia and should help implement further, more targeted studies in the corresponding habitats.

Dryland ecosystems are among the most widespread biomes on Earth and sustain nearly 40% of the global human population. Knowledge on drylands throughout the world has come from diverse disciplinary fields including natural and social sciences. The use of quantitative tools, such as science mapping or bibliometric analysis, may help to explore the structure of knowledge and to identify emerging issues. Here, we analyzed the dynamics of scientific production on dryland ecosystems throughout fifty years since the creation of the Argentine Institute for Dryland Research (IADIZA). We focused on IADIZA as a case study because it is one of the oldest dryland research institutions in South America whose contributions may exemplify research trajectories in drylands. We conducted a systematic search in Scopus for the 1972-2022 period, complemented with the institute’s records, which resulted in 1828 publications. We identified 48 research themes studied at IADIZA. The diversity of themes has increased through time, moving from the early descriptive studies of species and communities to the current focus on pa�erns and processes. From 2000 to the present, we detected a remarkable incorporation of new concepts, indicating that the conservation and management of natural resources, the systematics and taxonomy of species and ecological interactions constitute the central research themes, along with emerging themes such as genetics, evolution and urban ecology. In conclusion, our synthesis offers a clear description of the dynamics of research themes in the study of drylands and indicates a growing international interest in IADIZA’s contributions to dryland functioning.

Arid and semi-arid ecosystems dominate the RS variability due to the multiple changing factors that control it. Consequently, any variation, in addition to climate change and land use change, impacts the concentration of CO2 in the atmosphere. Here, the effect of the interannual variation and the controlling factors of RS in native xeric shrublands and agricultural systems is investigated. This study was conducted in four sites per condition for two years (2019 to 2020), where RS and the soil properties were measured. The RS presented a higher variation in the xeric shrubland. The agricultural plots showed the highest RS (0.33 g CO2 m−2 hr−1) compared to the xeric shrubland (0.12 g CO2 m−2 hr−1). The soil water content was the main controlling variable for RS in both land uses. However, soil temperature affected RS only in agricultural plots. The variation in the RS under different land uses confirms that changes in the soil and environmental conditions (i.e., season) control the RS. In addition, if current management practices are maintained in agricultural sites and under a temperature increase scenario, a significant increase in the RS rate is expected. [ABSTRACT FROM AUTHOR]

Restoring the hundreds of millions of hectares of degraded ecosystems worldwide will require new approaches to raise the required funds and new systems to implement at the required scales. Two decades of large-scale restoration in the subtropical thicket biome in the Eastern Cape, South Africa, have generated valuable information for developing such approaches and systems. The successful upscaling of restoration in this biome can be attributed to four main actions. First, from the outset in 2003, peer-reviewed science was foundational to the entire restoration initiative. Second, also from the outset, there was a commitment to large-scale, long-term ecological research by the public sector (the then Department of Water Affairs and Forestry in South Africa), which resulted in what is to our knowledge the world’s largest ecosystem restoration experiment, comprising 330 quarter-hectare plots distributed over ∼75,000 km2. Third, retrospective scientific description of previous restoration work — done by farmers in the 1960s and 1970s — provided valuable information on restoration’s multiple benefits, without having to wait for the large-scale restoration experiment to yield results. Lastly, diverse and short-term scoping studies were undertaken to address questions that emerged during the large-scale implementation of restoration. These studies were vital for rapid adaptive management and planning new scientific experiments, filling a gap between long-term ecological research and retrospective science.

Desertification processes in Central Asia are largely dependent on soil degradation induced by excessive livestock grazing, besides climate changes. Desertification represents a threat to wildlife species living in arid environments, since reduced accessibility to water strongly affects their distribution and behavior. Moreover, livestock presence exacerbates competition with wildlife for scarce water resources. Given their crucial importance to wildlife persistence, water sources in arid environments are critical to the study of wildlife behavior and interspecific competition. The Small Gobi A is one such environment of Mongolia, characterized by high grazing pressure despite low human presence. Between September and October 2017, we conducted camera trapping surveys at two waterholes identified as potential drinking sources for wildlife. We aimed to explore the spatio-temporal interactions among large domestic ungulates (e.g., Bactrian camel Camelus bactrianus), and wild ungulates (e.g., Asian wild ass Equus hemionus, and goitered gazelle Gazella subgutturosa), which are among the most iconic and threatened ungulates of Mongolia. The results showed a complete spatial segregation between domestic and wild ungulates, and a high temporal segregation among wild ungulates. This study confirms spatial and temporal niche partitioning as a strategy adopted by wild species to reduce competition and allow species coexistence. We recommend enhanced management measures of free-roaming livestock to reduce the pressure on wild species at drinking sites. [ABSTRACT FROM AUTHOR]

Keywords: arid ecosystems; deserts; drylands; functional traits; limiting resources; local adaptation; plant traits EN arid ecosystems deserts drylands functional traits limiting resources local adaptation plant traits 1 4 4 08/31/23 20230801 NES 230801 Population success is an elusive term that integrates assumptions regarding traits that enable individuals to respond to local conditions with assumptions regarding the effects of these traits on characteristics of the population in which the individuals grow. Arid ecosystems, deserts, drylands, functional traits, limiting resources, local adaptation, plant traits Dryland mechanisms could widely control ecosystem functioning in a drier and warmer world. In such a case, while part of the trait variation may result from non-adaptive responses, it is highly unlikely that the major driver of plant responses, as reflected by their trait composition and variability, is an inadequate ability of individuals to respond to local habitat conditions. [Extracted from the article]

Arthropods play an essential role in steppe ecosystems. However, studies testing the overall response of terrestrial arthropods to overgrazing are scarce. The problem is particularly worrisome in Central Asia, while, to date, only a very few broader studies have been conducted in this region. We investigated how epigeic terrestrial arthropod assemblages respond to different livestock grazing pressure in two ecozones in SE Mongolia by examining their structure using pitfall traps. We also assessed which groups can be utilised as the most efficient indicators of grazing intensity. Our analyses demonstrated that the habitat type, grazing intensity, and the interaction of these variables had a significant effect on the overall species composition and abundance. However, the grazing intensity caused different changes in the composition of arthropod communities in both studied ecozones. Contrary to the semi-desert, in the steppe habitat, the grazing had the strongest impact in the moderately grazed site. It is most likely because steppe-dwelling species are more sensitive to loss of plant biomass and changes in habitat structure. We also found that the most representative species within and from different groups can react differently to changing grazing intensities, indicating with their presence the characteristics of the respective habitat. Such differences should also be considered when elaborating the management plan of conserved species but also when applying grazing management in different habitat types. Our survey is one of the most comprehensive in Central Asia and should help implement further, more targeted studies in the corresponding habitats. In meadow steppes and other arid habitats, livestock grazing is one of the most severe causes of desertification and leads to an overall decline in vegetation cover, plant species richness and aboveground biomass, and, consequently, most often negatively affects arthropod diversity. Although the impact of grazing on arthropod diversity has already been the subject of numerous studies, most of them were focused only on a single or small number of arthropods and were conducted outside Central Asia (e.g., there is only one paper dealing with analyses of several arthropod groups conducted in Mongolia, where over 40% of the human population depends on pastoral livestock production and up to 90% of its territory belongs to various arid areas). We hypothesise that the overall diversity of different arthropod groups will change according to the grazing intensities, and these changes will depend on the habitat type and will differ between arthropod groups. Our analyses demonstrated that the habitat type, grazing intensity, and the interaction of these two variables significantly impacted the overall species composition and abundance. Our results highlight that the different terrestrial arthropod groups and representative species of the most abundant groups can react differently to changes in grazing intensity, and such differences should be considered when elaborating the management plan of conserved species and when applying grazing management in different habitat types. Our results also highlight that the species diversity alone cannot indicate the changes in species composition along the grazing intensity, and one should also consider the individual needs of specific species while investigating the impact of grazing on arid habitats. [ABSTRACT FROM AUTHOR]

Understanding the rate and direction of pyrogenic succession in arid ecosystems, which depends on many factors, including the intensity of grazing and the frequency of pyrogenic expo-sure, will allow for more accurate predictions of the consequences of fire onplant communities, and will assist with better fire management. We studied the vegetation on 55 sites in and near the “Chernye Zemli” Natural Biosphere Reserve that burned at different times or were not affected by fires over the past 35 years and characterized the changes in vegetation cover associated with the impact of wildfire and grazing. The descriptions were grouped into chronological stages according to the time elapsed since the last fire, or into groups according to the frequency of fires. In pairwise comparison of the projective cover of plant species between chronological stages, it correlated most strongly between successive initial stages (for stages 1 and 2, p = 0.003, r = 0.73; for stages 2 and 3, p < 0.001, r = 0.78). Species with an initially higher projective cover were more likely to grow on plots in the first year after the fire: p < 0.03. Plots with rare and frequent fires had similar projective cover of individual species (r = 0.64, p < 0.001). We conclude that in the course of pyrogenic succession, communities are gradually replaced over at least ten years. At the same time, the composition of a plant community at the initial point of succession depends on the prevalence of species in the community before the fire. No fundamental effect of the frequency of fires on the composition of plant communities has been revealed.

Active restoration is frequently implemented to restore degraded drylands globally, yet predicting the overall success of these restoration projects remains challenging. Here, we aim to explore if vegetation spatial patterns can be used to monitor ecosystem recovery and anticipate the success of restoration practices. We combined field surveys and high‐resolution drone images to analyze how vegetation spatial patterns change after the large‐scale straw checkerboards restoration projects in the sand dune systems of the Tengger Desert in northern China. We found that vegetation cover, plant species richness, and diversity increased rapidly, approaching the level of the naturally vegetated sand dunes, after 5 years of restoration. Soil fertility remained low despite the positive vegetation change. Along with the recovery process, we found a larger diversity of patch sizes (i.e. spatial variance) with an increasing proportion of large‐size patches. These patterns, combined with a constant positive recovery rate in vegetation cover, are consistent with theoretical predictions used to anticipate transitions to alternative ecosystem states. Although some indicators may be masked by the artificial planting scheme and community succession process during recovery, our results show that vegetation spatial patterns can be used to forecast and monitor the possible recovery of drylands. [ABSTRACT FROM AUTHOR]

• Fire and precipitation affect the population dynamics of Senecio bracteolatus. • A stochastic matrix model was parameterized with experimental and field data. • High fire frequencies decrease population whereas high spring rain increase it. In arid and semi-arid environments, demographic processes of shrubs are affected by fire and precipitation. Understanding the impact on the demographic processes of the population is crucial for ecosystem conservation and management. Our aim was to assess the population dynamics of the native shrub Senecio bracteolatus and its relation to fire frequency and precipitation in northwestern Patagonia. We constructed a stochastic matrix model and we conducted numerical simulations to evaluate scenarios varying fire frequency and precipitation. To parameterize the model, we conducted greenhouse and common garden experiments and collected previous field and precipitation data. We divided the S. bracteolatus life cycle into four classes (current year seedlings, previous year seedlings, juvenile, and adult plants) and two recruitment microsites (under tussock canopy and gaps between tussocks). The climate was included in the model as accumulated spring and summer precipitation. The former affects seedling germination, while the latter affects fire regimes. The model predicts that frequent fires (every four years) increase the population of S. bracteolatus , but if fires are infrequent (more than 16 years), the population increase with an annual rate of growth of around 8.5 %. However, for annual and biannual fire frequencies, the population experiences a decline, and with a three-year fire return interval, it stabilizes. High fire frequencies lead to population decrease, attributed to the reduction of the protective canopy of tussock grasses, essential for the recruitment of the shrub. The population growth rate of S. bracteolatus increases significantly more when spring precipitation is above historical averages, and fire frequency increases when summers are dry. Our study contributes to understanding the influence of fire and precipitation on shrub demographic processes in the context of climate change, providing useful information for fire management to improve the sustainable use of grasslands. [ABSTRACT FROM AUTHOR]

Arid and semi-arid ecosystems dominate the RS variability due to the multiple changing factors that control it. Consequently, any variation, in addition to climate change and land use change, impacts the concentration of CO2 in the atmosphere. Here, the effect of the interannual variation and the controlling factors of RS in native xeric shrublands and agricultural systems is investigated. This study was conducted in four sites per condition for two years (2019 to 2020), where RS and the soil properties were measured. The RS presented a higher variation in the xeric shrubland. The agricultural plots showed the highest RS (0.33 g CO2 m−2 hr−1) compared to the xeric shrubland (0.12 g CO2 m−2 hr−1). The soil water content was the main controlling variable for RS in both land uses. However, soil temperature affected RS only in agricultural plots. The variation in the RS under different land uses confirms that changes in the soil and environmental conditions (i.e., season) control the RS. In addition, if current management practices are maintained in agricultural sites and under a temperature increase scenario, a significant increase in the RS rate is expected.

Summary: The least‐cost economic theory of photosynthesis shows that water and nitrogen are mutually substitutable resources to achieve a given carbon gain. However, vegetation in the Sahel has to cope with the dual challenge imposed by drought and nutrient‐poor soils.We addressed how variation in leaf nitrogen per area (Narea) modulates leaf oxygen and carbon isotopic composition (δ18O, δ13C), as proxies of stomatal conductance and water‐use efficiency, across 34 Sahelian woody species.Dryland species exhibited diverging leaf δ18O and δ13C values, indicating large interspecific variation in time‐integrated stomatal conductance and water‐use efficiency. Structural equation modeling revealed that leaf Narea is a pivotal trait linked to multiple water‐use traits. Leaf Narea was positively linked to both δ18O and δ13C, suggesting higher carboxylation capacity and tighter stomatal regulation of transpiration in N‐rich species, which allows them to achieve higher water‐use efficiency and more conservative water use.These adaptations represent a key physiological advantage of N‐rich species, such as legumes, that could contribute to their dominance across many dryland regions. This is the first report of a robust mechanistic link between leaf Narea and δ18O in dryland vegetation that is consistent with core principles of plant physiology. [ABSTRACT FROM AUTHOR]

Fertile islands are an important determinant of ecosystem functioning in drylands. These resource‐rich patches are maintained by complex interactions among biotic and abiotic factors. Soil microorganisms are responsible for essential ecosystem processes and could affect the ability of fertile islands to capture and cycle nutrients, both directly and indirectly enhancing the fertile island effect. In this context, we aimed to evaluate the attributes of soil microbial communities (abundance and activity), elucidate key drivers of the fertile island effect and analyze relationships with a range of soil parameters (physicochemical). The soils under shrub canopies had higher values of microbial biomass carbon (MBC) and soil basal respiration (SBR) rates than soils from intercanopy spaces. However, no differences were observed in Soil Organic Carbon (SOC) or in fungal and bacterial abundances between the microhabitats. Soil nutrient stocks (NPK) and pH values had a positive correlation with MBC and SBR. Also, a positive correlation was observed for fungi abundance and the K content of the soil. We also observed a positive correlation between the bacterial abundance and soil N content. This study suggests that M. tridens can be considered a keystone species that generates fertility islands, critical for biodiversity and ecosystem functioning. The keystone role that M. tridens plays in this system underscores the importance of improving our understanding of these interactions (plant–soil‐microorganisms), especially important as drylands expand and aridity increases due to climate change in the second half of this century. [ABSTRACT FROM AUTHOR]

Urbanization usually reduces bat richness; however, the presence of green areas within cities and peripheral rural areas in arid ecosystems may provide microhabitats for some species. Light pollution is a major feature of urbanization, but its impact on bat behavior appears to be species-specific and previous studies have documented contrasting responses. Moreover, the effect of urbanization on bat species has been poorly studied in arid regions. We assessed the effect of artificial night light intensity (as a proxy of urbanization) on both bat occupancy and the acoustic space used (ASU) in an urbanization gradient in Peruvian central coast, based on passive acoustic recorders. We collected 26,169 recordings from 19 sites which resulted in 579 independent detections of 15 bat species. Variation in both ASU and species richness was best explained by artificial night light intensity. Species-specific effects of the artificial night light intensity based on a multi-species occupancy modeling showed that this covariate had a negative effect on occupancy for most of the bat species (12 species). ASU and both observed and posterior bat species richness were positively correlated, suggesting that ASU can be used as a proxy of bat richness. This study provides evidence that both bat richness and occupancy decrease with artificial light intensity; nevertheless, eight species used urban areas, similar to results found in other cities around the world. [ABSTRACT FROM AUTHOR]

Because many plants ensure their reproductive success using some level of self‐fertilization, it is predicted that the balance between pollinator‐mediated pollen transfer and autonomous selfing will be correlated with habitat harshness and pollinator activity. To study these correlations, we used three annual species that differ in their self‐incompatibility and compared their reproductive success in the form of fruit production and seed viability, with and without pollinators, along a rainfall gradient and in relation to pollinator activity. We found that pollinator activity decreased with increasing aridity. Although the reproductive success in the absence of pollinators fitted the species' level of self‐incompatibility, no clear trend was detected between pollinator visits or site harshness and relative reproductive success. Only one of the species, Sinapis alba, showed a consistent increase in autonomous selfing with both increased aridity and decreased pollinator visits, a finding that was supported by an increase in the viability of seeds produced in the absence of pollinators. Nevertheless, unlike our prediction, the absolute number of seeds produced per S. alba flower increased with aridity. Our overall findings suggest that despite decreasing pollinator abundance and diversity with increasing aridity, the reproductive success of annual species, even of those with high self‐incompatibility, remains relatively high. Although there may be several mechanisms governing these results, the overall constant seed production despite environmental uncertainties may be part of the mechanism by which plants in arid ecosystems buffer environmental variations. [ABSTRACT FROM AUTHOR]

Abstract In recent years, passive acoustic monitoring has emerged as a reliable method for monitoring soniferous fauna, with numerous studies finding estimates of species richness and community composition are comparable with estimates derived from conventional field surveys. Most of these studies compare point counts of forest bird communities with contemporaneous short‐duration acoustic recordings, but several questions remain. How do these two methods compare in more open, arid ecosystems, how does applying methods optimally influence comparisons, and how do patterns in acoustically detectable species compare with overall patterns? Here we demonstrate techniques for improving sampling of acoustic data and conduct acoustic surveys to estimate species richness from ephemeral creek‐lines in the Australian arid zone using a long‐term passively derived acoustic dataset. We examine these results in the context of long‐term observer‐based transect surveys conducted along the same creek‐lines to define species within the avian assemblage that are acoustically detectable or acoustically undetectable/cryptic. Our data suggest that some species were consistently missed by acoustic surveys, but most belonged to groups that are typically excluded from inventories prior to analysis including rare species, raptors, waterbirds, swallows and nocturnal birds. Further, the relative diversities of sites were well estimated by acoustic surveys, with variations between sites reflecting those estimated by observer‐based field surveys. This suggests that in our study system, acoustically detectable species are reliable indicators of overall species richness. Field‐based surveys will remain an important component of sampling in arid ecosystems and we highlight the value of applying acoustic and conventional field‐based surveys in a complementary manner. This approach allows large, publishable datasets to be generated by exploiting the temporal reach of acoustic sensors, while also maximizing detections of acoustically cryptic species via field‐based surveys. We argue that acoustic monitoring has the potential to facilitate greater research effort in largely research‐deficient arid ecosystems.

Abstract Revealing the roles of biotic factors in driving community assembly, which is crucial for the understanding of biodiversity and ecosystem functions, is a fundamental but infrequently investigated subject in microbial ecology. Here, combining a cross‐biome observational study with an experimental microcosm study, we provided evidence to reveal the major roles of biotic factors (i.e., soil fungi and cross‐kingdom species associations) in determining soil bacterial biogeography and community assembly in complex terrestrial ecosystems of the arid regions of northwest China. The results showed that the soil fungal richness mediates the balance of assembly processes of bacterial communities, and stochastic assembly processes decreased with increasing fungal richness. Our results further suggest that the predicted increase in aridity conditions due to climate change will reduce bacterial α‐diversity, particularly in desert soils and subsurface layer, and induce more negative species associations. Together, our study represents a significant advance in linking soil fungi to the mechanisms underlying bacterial biogeographic patterns and community assembly in arid ecosystems under climate aridity and land‐use change scenarios.

Uncovering the linkages between community assembly and species diversity is a fundamental issue in microbial ecology. In this study, a large‐scale (transect intervals of 1257.6 km) cross‐biome soil survey was conducted, which ranged over agricultural fields, forests, wetlands, grasslands and desert, in the arid regions of northwest China. The aim was to investigate the biogeographic distribution, community assembly and species co‐occurrence of soil fungi. The fungal communities in agricultural soils exhibited a steeper distance–decay slope and wider niche breadths, and were more strongly affected by stochastic assembly processes, than fungi in other natural habitats. A strong relationship was revealed between soil fungal richness and community assembly in arid ecosystems, with the influence of stochastic assembly processes decreasing with increasing fungal richness. Moreover, aridity was the most important environmental factor influencing fungal richness, β‐diversity and species co‐occurrence patterns. Specifically, the predicted increase in arid conditions will probably reduce fungal richness and network complexity. These findings represent a considerable advance in linking fungal richness to mechanisms underlying the biogeographic patterns and assembly processes of fungal communities in arid ecosystems. These results can thus be used to forecast species co‐occurrence and diversities pattern of soil fungi under climate aridity and land‐use change scenarios. [ABSTRACT FROM AUTHOR]

Local ecological knowledge (LEK) of forage resources available in the forest is crucial in the sustainability of extensive grazing systems in the arid Chaco region. Here, we document goat farming management strategies of local peasants, assess their LEK about forage plants and evaluate the local perception related to pollination of native tree species. We used semi-structured interviews to obtain ethnoecological information and a cognitive approach to inquire about the plant species considered as fodder and their relative importance. Peasants listed a total of 48 ethnospecies (60 species from 23 botanical families) used as fodder. The most important forage plants in our study were Neltuma spp., Sarcomphalus mistol and Castela coccinea , which provide high quality fruits and also leaves as forage at different moments of the year. Local producers did not identify pollination as a key factor for the production of forage fruits, but they did emphasize the importance of climatic factors for fruit production. This ethnoecological information related to forage plants and factors that determine fruit production is important to understand peasant management systems that sustain local communities and play an important role in forest persistence. • Local ecological knowledge plays an important role in peasant goat farming systems. • The most important forage plants provide high quality fruits and leaves as forage. • Peasants did not identify pollination as a key factor for forage fruit production. • Climatic factors were considered by peasants as determinant for fruit production. • Local and scientific knowledge integration could improve goat farming sustainability. [ABSTRACT FROM AUTHOR]

Abstract Pasturelands are globally extensive, sensitive to climate, and support livestock production systems that provide an essential source of food in many parts of the world. In this paper, we integrate information from remote sensing, global climate, and land use databases to improve understanding of the resilience and resistance of this ecologically vulnerable and societally critical land use. To characterize the effect of climate on pastureland productivity at global scale, we analyze the relationship between satellite‐derived enhanced vegetation index data from MODIS and gridded precipitation data from CHIRPS at 3‐ and 6‐month time lags. To account for the effects of different production systems, we stratify our analysis by agroecological zones and by rangeland versus mixed crop‐livestock systems. Results show that 14.5% of global pasturelands experienced statistically significant greening or browning trends over the 15‐year study period, with the majority of these locations showing greening. In arid ecosystems, precipitation and lagged vegetation index anomalies explain up to 69% of variation in vegetation productivity in both crop‐livestock and rangeland‐based production systems. Livestock production systems in Australia are least resistant to contemporaneous and short‐term precipitation anomalies, while arid livestock production systems in Latin America are least resilient to short‐term vegetation greenness anomalies. Because many arid regions of the world are projected to experience decreased total precipitation and increased precipitation variability in the coming decades, improved understanding regarding the sensitivity of pasturelands to the joint effects of climate change and livestock production systems is required to support sustainable land management in global pasturelands.

Soil moisture plays a key role in the ecological capability of arid and semi-arid woodland. Reducing soil moisture due to frequent droughts causes pest prevalence and disease outbreak and the consequence of forest dieback. On the other hand, soil moisture is strongly correlated with the amount of radiation received on the Earth’s surface. The sun’s radiation is traditionally described often by aspect and sometimes by toposhape. The use of the hillshade map for estimating solar radiation is possible through developing GIS. The present study aimed to compare the relationship and the ability of these indices to describe the phenomenon of arid and semi-arid woodland decline better and more accurately in a case study in the west of Iran. To this aim, the aspect and toposhape layers were generated in 5 and 12 classes, respectively. Then, the hillshade map in range of 0-255 was made during the peak of summer heat. The comparison of the dieback ratio in the three characteristic histograms showed that the shade index, unlike the other two indicators, had a significant effect on forest drought (R2=0.91 for linear equation and R2=0.94 for quadratic equation). The results indicated that the application of hillshade in describing and analysing ecological processes by relying on soil moisture such as woodland dieback is superior to the other two indicators. It is suggested that this index be used to obtain a risk model to predict woodlands dieback which are under the pressure of frequent droughts due to climate change or other mortal factors.

Disturbance by small mammals and shrub canopies are ecological factors typical of arid ecosystems that may influence plant invasion through environmental and community changes. Whereas disturbance beneath shrub canopies may promote invasion by removing dominant species, disturbance in open areas may hinder plant invasion by increasing environmental harshness. However, we are unaware of studies explicitly addressing the interactive effects of disturbance by mammals and shading by shrubs on community assembly processes to understand plant invasion. In an arid shrubland, disturbance and shading were caused by the fossorial rodent Spalacopus cyanus and the shrub Flourensia thurifera, respectively. We used functional dispersion data (trait convergence vs. divergence) and Grime´s theory (competitive, stress‐tolerant and ruderal strategies, CSR) to gain insights into the underlying assembly processes.We compared environmental conditions, richness and abundance of native and exotic species, as well as functional dispersion and prevalence of CSR‐strategies across four microsites (60 × 60 cm plots): undisturbed/open, undisturbed/shaded, disturbed/open and disturbed/shaded. We tested for functional differences between native and exotic species.Species richness was similar among microsites for both native and exotic species. Shading ameliorated environmental conditions, promoted trait divergence and increased prevalence of C‐ and R‐strategies. Disturbance increased the abundance of exotic species and removed dominant species in shaded microsites. Exotic and native species were functionally different: exotics showed shorter life span, lower height, thinner stems and smaller leaves than natives.Synthesis. Disturbance, by removing plant biomass, favoured exotic species in shaded microsites, where shrub canopy ameliorated environmental conditions and—by relaxing habitat filtering—promoted niche partitioning processes as well as C‐ and R‐strategies. We illustrate the value of linking trait‐based ecology approaches to micro‐environmental conditions, as it may provide insights into the underlying community processes when studying plant invasions at the local and microsite scales. Disturbed microsites beneath shrub canopies could be 'hotspots' where to concentrate efforts to manage plant invasions in arid ecosystems. [ABSTRACT FROM AUTHOR]

Riparian trees play a critical role in the ecological function of rivers, yet are threatened by anthropogenic change to the hydrological cycle. Identifying the sources of water used by riparian trees can inform sustainable water policy. We used isotopic analysis complemented by measurements of plant water relations to assess water sources for riparian trees at two sites with contrasting hydrogeological processes; one with an alluvial aquifer overlaying an aquitard, and one where fault‐induced preferential pathways in the aquitard allowed the flow of deeper, older groundwater from a regional aquifer to the alluvium. At both sites, plant water potential, stomatal conductance, and plant water isotope composition in the xylem sap of riparian trees were collected from two landscape positions, the riverbank and floodplain. We used a Bayesian mixing model (MixSIAR) to assess differences in the proportion of water sources for sites and landscape positions. We found that xylem water isotope values differed between the two sites in line with their hydrogeological characteristics, with trees at the regional aquifer site using water sourced from the regional groundwater and trees at the site with only an alluvial aquifer present using a mixture of water sources, with no dominant source identified. Higher plant predawn water potential values at the regional site indicated greater water availability and support the inference that plants were using more groundwater at the regional site compared to the alluvial site. Trees closer to the river had higher isotope values, indicative of surficial water sources i.e. shallow soil water and river water. Our findings show that the water sources used by riparian trees reflect local hydrogeology and resource availability. Water managers should identify and protect plant water sources to ensure maintenance of riparian trees. [ABSTRACT FROM AUTHOR]

Summary: Asian Houbara Chlamydotis macqueenii is a vulnerable flagship species specific to steppe, desert and semi-desert habitats of the Middle East and Central Asia. Iran provides a critical corridor in the middle of Asian Houbara's migratory route and also hosts a relatively large proportion of wintering and breeding populations. The aim of this study was to assess the distribution and habitat suitability of both wintering and breeding populations of Asian Houbara in Iran and evaluate the effectiveness of the existing protected area network for long-term protection of the species. For this purpose, 644 occurrence points for wintering and 216 points for breeding birds were collected from 17 Iranian provinces during 2015 to 2017. We then used a consensus species distribution modelling (SDM) approach using 11 uncorrelated environmental variables to explore the distribution of Asian Houbara habitats. Results showed that climatic and topographic variations have the most significant influence on the regional-scale distribution of Asian Houbara. Of the suitable habitats recognised for the wintering and breeding populations, 40.6% and 29.6% respectively overlapped with the extent of the protected network. A high level of spatial niche similarity (78%) was observed between wintering and breeding populations. The central, eastern and south-central Iranian semi-arid regions and desert landscapes hosted the majority of both wintering and breeding houbara occurrences. Results of this study could be used for adopting direct management planning and raising the protection level of important no-hunting areas. [ABSTRACT FROM AUTHOR]

Ecohydrological phenomena are o ften multiscale in nature, with behavioTur that emerges from the interaction of tightly coupled systems having characteristic timescales that differ by orders of magnitude. Models address these differences using timescale separation methods, where each system is held in psuedo‐steady state while the other evolves. When the computational demands of solving the 'fast' system are large, this strategy can become numerically intractable. Here, we use emulation modelling to accelerate the simulation of a computationally intensive 'fast' system: overland flow. We focus on dryland ecosystems in which storms generate overland flow, on timescales of 101 − 2 s. In these ecosystems, overland flow delivers crucial water inputs to vegetation, which grows and disperses 'slowly', on timescales of 107 − 9 s. Emulation allows for a physically realistic treatment of flow, advancing on phenomenological descriptions used in previous studies. Resolving the within‐storm processes reveals novel dynamics, including new transition pathways from patchy vegetation to desertification, that are specifically controlled by storm processes. [ABSTRACT FROM AUTHOR]

Human–wildlife conflict arising from livestock-losses to large carnivores is an important challenge faced by conservation. Theory of prey–predator interactions suggests that revival of wild prey populations can reduce predator's dependence on livestock in multiple-use landscapes. We explore whether 10-years of conservation efforts to revive wild prey could reduce snow leopard's Panthera uncia consumption of livestock in the coupled human-and-natural Trans-Himalayan ecosystem of northern India. Starting in 2001, concerted conservation efforts at one site (intervention) attempted recovery of wild-prey populations by creating livestock-free reserves, accompanied with other incentives (e.g. insurance, vigilant herding). Another site, 50km away, was monitored as status quo without any interventions. Prey remains in snow leopard scats were examined periodically at five-year intervals between 2002 and 2012 to determine any temporal shift in diet at both sites to evaluate the effectiveness of conservation interventions. Consumption of livestock increased at the status quo site, while it decreased at the intervention-site. At the intervention-site, livestock-consumption reduced during 2002–2007 (by 17%, p=0.06); this effect was sustained during the next five-year interval, and it was accompanied by a persistent increase in wild prey populations. Here we also noted increased predator populations, likely due to immigration into the study area. Despite the increase in the predator population, there was no increase in livestock-consumption. In contrast, under status quo, dependence on livestock increased during both five-year intervals (by 7%, p=0.08, and by 16%, p=0.01, respectively). These contrasts between the trajectories of the two sites suggest that livestock-loss can potentially be reduced through the revival of wild prey. Further, accommodating counter-factual scenarios may be an important step to infer whether conservation efforts achieve their targets, or not. [ABSTRACT FROM AUTHOR]

Analysis of the taxonomic structure of prokaryotic microbial complexes of the saline soils in the Lake Elton area and their comparative characteristics were carried out for a soil catena along the Khara River flowing into the hypersaline Lake Elton. High-throughput pyrosequencing detected 11 bacterial and 2 archaeal phyla. Comparative analysis of community structure revealed the differences between Solonchaks located at the river flood land and Kastanozems at the slope and top of the river terrace. The patterns of occurrence were described for six predominant phyla (Euryarchaeota, Thaumarchaeota, Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria). For the floodplain soils, the relations between the distribution of Euryarchaeota, Thaumarchaeota, Firmicutes, Actinobacteria, Proteobacteria and soil salinity as well as soil pH were described. Occurrence of members of the phyla Euryarchaeota, Thaumarchaeota, Firmicutes, Actinobacteria, and Proteobacteria in flood land soils was shown to depend on the soil salinity and pH. Members of the phyla Actinobacteria and Firmicutes were shown to predominate in Gleyic Kastanozems. Cloning of the 16S rRNA gene revealed high diversity within the genus Streptomyces (Actinobacteria). A number of the isolated streptomycete clones were homologous to the known antibiotic producers, which indicates that soils of this area are promising for further biotechnological screening. [ABSTRACT FROM AUTHOR]

In recent years, passive acoustic monitoring has emerged as a reliable method for monitoring soniferous fauna, with numerous studies finding estimates of species richness and community composition are comparable with estimates derived from conventional field surveys. Most of these studies compare point counts of forest bird communities with contemporaneous short‐duration acoustic recordings, but several questions remain. How do these two methods compare in more open, arid ecosystems, how does applying methods optimally influence comparisons, and how do patterns in acoustically detectable species compare with overall patterns? Here we demonstrate techniques for improving sampling of acoustic data and conduct acoustic surveys to estimate species richness from ephemeral creek‐lines in the Australian arid zone using a long‐term passively derived acoustic dataset. We examine these results in the context of long‐term observer‐based transect surveys conducted along the same creek‐lines to define species within the avian assemblage that are acoustically detectable or acoustically undetectable/cryptic. Our data suggest that some species were consistently missed by acoustic surveys, but most belonged to groups that are typically excluded from inventories prior to analysis including rare species, raptors, waterbirds, swallows and nocturnal birds. Further, the relative diversities of sites were well estimated by acoustic surveys, with variations between sites reflecting those estimated by observer‐based field surveys. This suggests that in our study system, acoustically detectable species are reliable indicators of overall species richness. Field‐based surveys will remain an important component of sampling in arid ecosystems and we highlight the value of applying acoustic and conventional field‐based surveys in a complementary manner. This approach allows large, publishable datasets to be generated by exploiting the temporal reach of acoustic sensors, while also maximizing detections of acoustically cryptic species via field‐based surveys. We argue that acoustic monitoring has the potential to facilitate greater research effort in largely research‐deficient arid ecosystems. [ABSTRACT FROM AUTHOR]

Questions: How do fire frequency and fire size affect the long-term population dynamics of Mulinum spinosum? Which demographic parameters contribute most to the overall effect of fire on population growth? What is the relative importance of resprouting in sustaining population increase? Location: Grass-shrub northwestern Patagonian steppe, Argentina. Methods: We monitored five permanent plots excluded from grazing for 6 years. We measured shrub abundance, dimensions, reproductive status, seedling emergence, and the size structure of M. spinosum, a resprouting native shrub inhabiting the northwest Patagonian steppe. Data were used to parametrize a stochastic matrix model developed to explore the influence of fire frequency and fire size on long-term population dynamics. We analyzed hypothetical scenarios that included fire frequencies ranging from one per year up to exclusion. Results: Except for annual fires, projections show growing populations regardless of fire frequency. For fire return intervals greater than 50 years, the population becomes independent of fires, with an annual population growth rate of 5.6%. The results suggest two relevant aspects of the population dynamics of this species: M. spinosum is well adapted to the current fire frequency and its resprouting capability will allow M. spinosum to survive and persist in the community, even under frequent fires. Conclusions: Climate change models forecast an increase in summer temperature in NW Patagonia and, consequently, an enhanced fire frequency. Fire is a driver of M. spinosum encroachment that gets worse in overgrazed grasslands. Mulinum spinosum encroachment derivate in a relative replacement of palatable grasses by shrubs changes the ecosystem functionality and reduces productivity. Controlling this process is highly difficult and we suggest a change in the land use for the areas already deteriorated. [ABSTRACT FROM AUTHOR]

Precipitation alteration and nitrogen (N) deposition caused by anthropogenic activities could profoundly affect the structure and functioning of plant communities in arid ecosystems. However, the plant community impacts conferred by large temporal changes in precipitation, especially with a concurrent increase in N deposition, remain unclear.To address this uncertainty, from 2016 to 2017, an in situ field experiment was conducted to examine the effects of five precipitation levels, two N levels and their interaction on the plant community function and composition in a desert steppe in northern China.Above‐ground net primary production (ANPP) and plant community‐weighted mean (CWM) height significantly increased with increasing precipitation, and both were well fitted with a positive linear model, but with a higher slope under N addition. The ANPP increase was primarily driven by the increase in Artemisia capillaris, a companion forb sensitive to precipitation variation. The plant community composition shifted with precipitation enhancement—from a community dominated by Stipa tianschanica, a perennial grass, to a community dominated by Artemisia capillaris.Synthesis. The findings imply that the ecosystem sensitivity to future changes in precipitation variability will be mediated by two potential mechanisms: concurrent N deposition and plant community‐level change. It is suggested that we should consider the vegetation compositional shift and multiple resource colimitation in assessing the sensitivity of terrestrial ecosystems to climate change. [ABSTRACT FROM AUTHOR]

Urban development is one of the leading causes of biodiversity change. Understanding how soil microorganisms respond to urbanization is particularly important because they are crucial for the provisioning of ecosystem functions and services. Here, we collected monthly soil samples over one year across three locations representing an urbanization gradient (low-moderate-high) in the arid Southwestern USA, and we characterized their microbial communities using marker gene sequencing. Our results showed that microbial richness and community composition exhibited nonsignificant changes over time regardless of the location. Soil fungal richness was lower in moderately and highly urbanized locations, but soil bacterial/archaeal richness was not significantly different among locations. Both bacteria/archaea and fungi exhibited significant differences in community composition across locations. After inferring potential functional groups, soils in the highly urbanized location had lower proportions of arbuscular mycorrhizal fungi and soil saprotrophic fungi but had higher proportions of bacterial taxa involved in aromatic compound degradation, human pathogens, and intracellular parasites. Furthermore, ammonia-oxidizing bacteria were more abundant in the highly urbanized location, but ammonia-oxidizing archaea were more abundant in lowly and moderately urbanized locations. Together, these results highlight the significant changes in belowground microbial communities across an urbanization gradient, and these changes might have important implications for aboveground–belowground interactions, nutrient cycling, and human health.