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Abstract: The effluent from a Chinese paper mill (pH 7.1) was concentrated, and the solid residue was dried and ground. Crude lignosulfonate was obtained as a brown powder, and a novel sand-fixation agent was synthesized by means of graft copolymerization of the lignosulfonate with acrylic acid and formaldehyde. The newly synthesized product had good water solubility, potentially good biodegradation, and produced no additional pollution. The crusts formed on shifting sands using this agent had higher crushing strength and better resistance to wind erosion than those produced with two other recently patented fixatives. [Copyright &y& Elsevier]

The semi-arid central Karoo of South Africa is an important livestock farming region, oftentimes characterized by water scarcity and limited grazing resources. This paper builds on previous research that has predominantly focused on post 19th century Karoo rainfall characteristics. The paper aims to: 1) establish the long-term frequency and longevity of droughts or dry periods; 2) explore spatial hydroclimatic variability across the Karoo during given dry/drought periods; 3) compare the timing and duration of 19th century Karoo droughts with those of neighboring regions to the east (Lesotho) and north (southern Kalahari); 4) establish the possible role of the El Niño Southern Oscillation (ENSO) in drought occurrence across the Karoo-Kalahari-Lesotho region; 5) determine whether the so called 'global drought' of 1877-78 is evident in the central Karoo; and 6) place 19th century droughts in a 20th– 21st century context (or visa versa) for the Karoo. Documentary sources were accessed, photographed and digitized from a variety of repositories (Libraries, Museums, and online sites such as READEX). Multi-station instrumental rainfall records (1861–2022) were made available by the Rubidge family at Wellwood farm. Historical droughts (1861–2022) in the Karoo were spatially highly variable in severity. However, severe droughts in the Karoo have decreased in frequency and amplitude (rainfall deficit) between 1861 and the present. • Historical droughts in the Karoo were at times highly variable in space and time. • Long and severe droughts have decreased in frequency and amplitude. • The 1877-78 drought was the most hydrologically severe 2-year drought. [ABSTRACT FROM AUTHOR]

The qualitative component of the effectiveness of seed dispersal by endozoochory encompasses seed deposition. Neltuma flexuosa , a keystone tree of the Monte biome, is dispersed by several animals and in this paper we aimed to study the qualitative aspect of its dispersal. We studied the effect of the dung of Bos taurus (cow), Equus ferus caballus (horse) and Dolichotis patagonum (mara) on seed germination and growth of N. flexuosa seedlings. We conducted greenhouse experiments using dung or field soil as substrate, under two water regimes: pot capacity and pulsed irrigation; testing manually scarified seeds collected from trees. We observed that the effect of dung on the two key processes of plant regeneration was different and depended on the animal species: it either reduced or did not affect maximum germination, and promoted or did not affect seedling growth, compared to the soil. Horse and mara manure reduced germination, while manure from both domestic animals promoted seedling growth. The water storage capacity, drying rate and nutrient level of the substrates did not directly explain the results obtained. Overall, cow dung appeared as the best microsite for early regeneration of N. flexuosa , while mara manure was the most restrictive for this process. • Dung impacts the quality component of Prosopis flexuosa seed dispersal. • Manure from distinct animals differentially affects early seedling establishment. • Cow dung provides the most favourable microenvironment for plant regeneration. • Mara faeces provides the least favourable microenvironment for germination and growth. [ABSTRACT FROM AUTHOR]

Abstract Archaeological studies typically describe arid areas as extremely unpleasant areas for human occupation and use. Without suggesting that arid areas are pleasant places, however, this paper provides a reassessment of the meaning of aridity for an area showing a vast amount of evidence of (past) human activities. Several climatic proxy data suggest that at the transition between the late Bronze Age and the Early Iron Age (around c. 1300-1100 BC) the southern Levant witnessed more arid conditions, while after 1100 BC relatively moist conditions would have prevailed. In drylands, small changes in temperature and water availability can have large effects on subsistence options. Building on cooperation between an archaeologist and a water scholar, this paper offers an approach to study how people in the past were able to craft a livelihood in the arid environments in the southern Levant and elsewhere. Focusing on the Zerqa area, the paper explores the potential of this cooperation by studying effects of climatic changes at the transition from the Late Bronze Age to the Iron Age through a modelling approach. Changes in temperature and moisture availability were simulated, showing that increased aridity could have been met by either naturally available water (especially groundwater) or artificially added water (although the timing appears to be crucial). While the model approach under discussion offers an approximation of the past, it shows the potential impact of climatic changes on the subsistence of past communities. It shows that details can mean the difference between survival or collapse. Highlights • Modelling provides boundaries for thinking about ancient resilience. • Rainfed crop yields could be sustained with irrigation, even in the frequent dry years. • Increasing aridity might have been a trigger for expanding the irrigation system. • The Zerqa Triangle was affected by the LBA crisis, yet continuity is visible as well. • Aridity did not necessarily bring crisis, even in arid areas like the Zerqa Triangle. [ABSTRACT FROM AUTHOR]

Dust storms are a major cause of central Sonoran Desert weather fatalities. Through back-trajectory analysis of North American Monsoon dust storms in central Sonoran Desert of the United States. This study is specific to central Arizona (USA) from 2009 to 2022 using the HYSPLIT model. Our findings have shown that dust storms originate from southerly or near-southerly regions. The dust storms displaying the highest concentrations of particulates show a preference to originate from the southwest. This coincides with the development of a 500 hPa ridge to the east of the study area. The highest concentration storms' back-trajectories display the lowest heights above the ground. Given their southwestern origin, these storms travel upslope along the seasonally dry river beds of the Gila River and its tributaries. Weaker dust storms originate over a wider area with a shift to a southerly direction. Such origination indicates that weaker dust storms are traveling downslope through the washes and channels of the dry Santa Cruz River. As dust concentrations drop, storm direction drifts east and dust height is suspended higher. This paper highlights the spatial variations in central Arizona dust storms, showing the likeliest paths of the strongest events and assists in identifying aeolian dust origins. • Identification of source regions of dust storms impacting the central Sonoran Desert located in the Arizona region of the Southwestern United States. • Use of the HYSPLIT back trajectory model. • Most large dust storms impacting central Arizona have a southwestern origin, having traveled upslope along the normally-dry Gila River and its tributaries. [ABSTRACT FROM AUTHOR]

There is growing global consensus that assessments of land degradation be conducted at regional or smaller scales. Working at this scale allows for locally relevant environmental and land use conditions to be incorporated into the assessment methodology. In this paper, a recently developed regional approach to assessing land degradation in the Hardeveld bioregion of the Succulent Karoo is applied to the Little Karoo region of this biome. The methodology uses fuzzy classification statistical techniques to combine field data with multiple Sentinel-2A and Landsat vegetation indices, as well as regionally modelled soil variables. The resultant habitat condition archetype map values show strong correlation with field observations of perennial plant and bare soil cover in 96 ground-truthed plots. The archetype map indicates that heavily degraded hotspots of high bare ground cover occur throughout the project region, although there is an overall lower average habitat condition in the western half of the Little Karoo. The mean habitat condition archetype value for the entire project area is 0.54 (standard deviation = 0.13), on a continuous scale where 0 and 1 represent the most degraded and pristine extremes, respectively. Random forest regression analysis of various environmental covariates of degradation indicates a strong relationship between habitat condition and topographic as well as rainfall variables, although the limited accuracy of modelled livestock data may obscure the negative impacts of overgrazing. The 30 m resolution habitat condition archetype map builds upon previous degradation research in the Little Karoo and has the potential to inform future conservation, restoration, and rangeland management decisions. The methodology was successfully transferred to a new region and provides an opportunity to improve reporting on the extent of land degradation across South Africa. • Effective transfer of methodology for regional scale assessment of degradation. • Western Little Karoo has lower habitat condition score than the eastern part. • Topography, rainfall, and land use history influence habitat condition score. • 30 × 30 m habitat condition map can inform sustainable land management decisions. [ABSTRACT FROM AUTHOR]

In the Sahel region, drought is of serious concern due to its consequences on the livelihoods of the populations. In this paper, opportunities for proactive drought policies are analyzed with qualitative techniques using a series of semi-structured qualitative interviews with key experts from the public, private, and other relevant societal sectors. The results show that adaptation options such as sustainable agricultural practices, migration, diversification of income sources, and social networks are most frequently used as a drought response by rural households in the region. To build resilience to drought in the Sahel, there is a need to disseminate climate-friendly agricultural practices accompanied by strong monitoring and evaluation system. It is also important to provide information on early drought warning and preparedness and mobilize more financial resources in implementing policies for building drought resilience. Finally, a drought policy should be participatory and results-based, and be based on long-term forecasting to ensure sustainability and resilience. • Proactive measures are advised in building resilience to drought. • The involvement of all stakeholders is necessary for building resilience to drought. • Failure of early warning and preparedness are constraints for any drought policy. • Lack of financial support negatively affects drought policy implementation. [ABSTRACT FROM AUTHOR]

Trees in agroforestry parklands influence crops both through competitive and facilitative mechanism, but the effects are challenging to disentangle due to the complexity of the system with high variability in tree cover structure and species diversity and crop combinations. Focusing on a landscape in central Burkina Faso dominated by Vitellaria paradoxa and Parkia biglobosa , this paper examines how tree cover influences crop yield at landscape scale using satellite data and spatial statistics. Our analysis is based on data from 2017 to 2018 with differences in rainfall to assess the stability in identified relationships. Our findings showed that tree canopy cover and tree density inside the fields tended to decrease crop yield because of competition, but also that these variables when considering the surrounding landscape exerted an opposite effect because of their buffering effects. The explanatory variables representing soil properties did have limited effects on crop yield in this study. These patterns were consistent during the two years of monitoring. Overall, our results suggest that farmers in this area might manage the tree cover in a way that optimizes sustainable yields as canopy cover and tree density in most parklands is below the limits identified here where competition outweight the facilitative effects. • We studied causes of crop yield variability in parklands at landscape scale. • Satellite remote sensing and field data was used in spatial statistics. • Trees in agricultural fields tend to reduce crop yield through resource competition. • Surrounding trees had positive influence on crop yield via buffering effects. • Fewer large trees have more positive influence on crop yield than many small ones. [ABSTRACT FROM AUTHOR]

In this longitudinal and qualitative study of rural life in western Turkey, I argue that ecological conditions, state policies, and villagers’ agency play a significant role in the suburbanization of villages. This paper traces the history of how villagers in the Yuntdağ north of Manisa, an arid and rocky region, used nomadic heritage and Islamic culture as economic resources. I argue that villagers have gone from being cultural heritage entrepreneurs to wage laborers, incorporating and identifying with the ethno-national identity of the nation while adjusting their lives to the state. In so doing and with the bureaucratic redefinition of the villages in the region as urban neighborhoods, the meaning and definition of rural life gradually is erased. Based on over fifteen years of ethnographic fieldwork, 2000–2015, this paper considers the suburbanization of rural life and the highly gendered economic decisions villagers make. [ABSTRACT FROM AUTHOR]

With increasing global population, the production of more food and fiber has led to an expansion of the areas under cultivation, of which low-lying flat areas (including marginal graben bottoms) are of particular interest. Marginal grabens have been the center of agricultural development around the world. This paper examines the opportunities and challenges related to natural resources in rural development and highlights the knowledge gaps and priorities for the research and development of marginal grabens with specific reference to Ethiopia's Rift Valley marginal grabens, which have sufficient land banks to accommodate irrigated agriculture. Repeated transect walks, focus group discussions and interviews carried out in Northern Ethiopia, have been employed to address these research questions, while content analyses and descriptive statistics have been used to analyze the data. This paper shows that marginal grabens are rich in blue and green waters due to their topographical and geological characteristics, and are fertile plains suitable for irrigated agriculture. However, marginal grabens can reach closing and closed basin status in arid and semi-arid environments. Salinization, waterlogging, incisions and sedimentation also threaten the livelihoods of smallholder farmers in the grabens. Thus, appropriate river basin governance, integrated land management, and wise water allocation is needed to optimize land and water resources during rural development in the (semi)closed marginal grabens of northern Ethiopia and elsewhere in the world with similar geographical settings. [ABSTRACT FROM AUTHOR]

This paper documents the various dipinti in a cave dwelling on the southern slope of the Byzantine town of 'Avdat, located in the central Negev highlands of Israel. The dipinti are viewed in their architectural and spatial contexts and discussed in light of previous dipinti finds in another cave dwelling at the site. This helps to build an evidentiary base for associating the cave with monks present in the town. Thus, the paper expands our currently limited knowledge of Byzantine monastic communities and activities in the Negev Desert region. [ABSTRACT FROM AUTHOR]

More than 50 years after the first comprehensively designed projects, the significance of research on past societies and their interactions with landscapes has even increased: Studying arid landscapes opens many areas of general interest about adapted lifestyles and livelihoods, since aridity touches upon problems of desertification and climate change, decentral water and food security. This synoptical paper sheds light onto the premises, functionalities and questions of water harvesting systems in antiquity and asks about the implications of runoff-based economies and societies in the Old World Dry Belt. By comparing results and considerations of the individual contributions to this special issue on ancient water management in general, and water and soil harvesting in particular and other relevant studies, it aims at extracting commonalities and differences between the interlinkages of environmental conditions and human intervention. Moreover, it embeds the various approaches, methods and results of the special issue's authors into overarching considerations oriented towards achieved results, application-oriented aspects and towards focal open questions. Differential analysis of the studied cases, i.e. systematic evaluation of the differences and similarities increases the understanding of the complex issues of runoff agriculture under various environmental and socio-economic conditions. The relevance of the models of ancient water-harvesting based systems evolved during the last decades for modern challenges is given special regard. • Interdisciplinary research in drylands models ancient resource management and livelihoods on a local and regional scale. • Potentials and dynamics of agro-ecosystems are outlined on basis of ancient water harvesting systems. • Studies of ancient resource management are relevant for actual development, sustainability and resilience objectives. • Comparative and complementary analysis of different studies and regions enhances understanding of issues at question. [ABSTRACT FROM AUTHOR]

In the hyperarid Atacama Desert (Northern Chile), the economic and social development is supported using fossil groundwater. The groundwater extraction (GWE) has significantly increased over the last 30 years, reaching ∼4.2 m3.s−1 in 2018 (+1890%) at the Pampa del Tamarugal Aquifer (PTA). But opposite assumptions lead to uncertainties concerning the role of the increasing anthropogenic pressures and the ephemeral recharge events in the water table (WT) variations. This paper analyzes: (i) the long-term groundwater levels changes between the late 1950s (post Saltpeter Work) and the early 2010s, and (ii) the short-term response of groundwater levels, based on the analysis of the 1998–2018 WT time series at 10 observation boreholes. Results indicate that the WT variations in space and time are strongly related to the anthropogenic pressure changes. Since the late 1950s, the WT is declining in the major part of the PTA. Nevertheless, local reduction of GWE together with ephemeral recharge events in alluvial fans allowed local WT rises. But after a large GWE increase (+114%) between 2004 and 2006, all observation boreholes highlight a general WT decline (−9.8 ± 5.8 cm.yr−1). Over the years, anthropogenic pressures became the dominant factor of the WT variations and led to overuse the aquifer. • Groundwater use has increased 1890% over the last 30 years. • Water table variation in space and time depends on anthropogenic pressure changes. • Water table decline averages ∼10 cm.yr-1 over the 2008–2018 decade. • Recharge events from floods do not outweigh groundwater use increase. • Pampa del Tamarugal Aquifer is overexploited. [ABSTRACT FROM AUTHOR]

The Nubian Flapshell Turtle, Cyclanorbis elegans , is classified as one of the most threatened chelonian species globally (Critically Endangered according to the IUCN Red List). The species is presumed extinct in most of its historical distribution range, but still survives along the White Nile between South Sudan and northern Uganda. In this paper, we utilised the maximum entropy model (MaxEnt) to evaluate the habitat suitability of the species to explore its distribution decline by comparing historical and current presence data, as well as correlate the predicted past and present distribution with human population density. Our assumption is that overexploitation of the turtle occurs (and has occurred in the past) in sites with high human density. We show that: (1) a large number of historical sites where the turtle was present had high human population densities, whereas (2) the current distribution model showed low overlap between areas with high probability of turtle presence and high human population density. We suggest that Nubian flapshells are likely to have become extinct because of high human density (and therefore high overexploitation) and remnant populations have only survived along waterbodies with low numbers of people. However, the presence sites of this species in northern Uganda are under pressure by rapidly growing refugees'settlements. We also hypothesize that the range of the Nubian Flapshell may be shifting to the south (where the general environment is wetter and cooler) due to climate change affecting the distribution of this freshwater species. The conservation implications of these evidence are also presented. • The Nubian flapshell turtle is one of the most threatened reptile species in the world. • A spatial modelling approach revealed intriguing extinction patterns across Africa. • There was an association between historical sites of presence and high density of humans (hence fishers). • There i san association between current remnant presence sites and low human density. • Refugees' settlements represent a serious torea for turtles in northern Uganda. [ABSTRACT FROM AUTHOR]

This paper presents empirical evidence of historical vegetation and climate change in the arid Pro-Namib and hyper-arid Namib Desert spanning the late 19th century to the present based on one hundred archival landscape photographs that have been re-photographed or 'matched'. Each photo site was evaluated for changes in woody cover and taken together serve as a proxy for how climate has changed in the region. Vegetation change was related to values for precipitation and temperature derived from the Global Land Data Assimilation System for the period 1948–2017 as well as the number of fog days expected at a site. The resulting analysis reveals a trend of increased vegetation cover associated with increased precipitation (fog and rain) in the coastal Fogbelt and the inland Savanna transition with a shrinking of the hyper-arid Minimum zone between the two. These findings accord with projected effects of global warming on the Benguela upwelling system but are at variance with regional climate model forecasts that project widespread aridification. In the absence of long-term climate data, the results of this research are an important contribution of evidence-based knowledge of past climate trends and their relationship to future climate change scenarios for the region. • Global change models predict Namibia becoming hotter leading to aridification. • We used historical photos of the Pro-Namib and Namib Desert to test this forecast. • Correlations between historical climate values and vegetation change were analysed. • Contrary to expectations, woody plant cover has increased at most locations. • Past trends of increased rainfall and fog predict environmental futures. [ABSTRACT FROM AUTHOR]

Abstract Over the last 30 years, geoarchaeological surveys undertaken in the Near East have offered a powerful way of studying, inter alia, water supply systems at a microregional to regional scale. However, efforts to synthesize the results of surveys at a sub-continental scale in order to understand local differences and similarities, and compare local strategies through time, require specific tools. In this paper, we develop a methodology designed to characterize and facilitate comparison of strategies employed across the arid areas of Western Syria. This requires microregional field studies undertaken at the level of specific landscapes to be integrated within a wider GIS framework, based upon thematic layers (soils, rainfalls, hydrology) at a uniform spatial scale of assessment (in this case the pixel of a Landsat image), and a common description of the agronomic potential in those areas in which specific hydraulic installations were employed. In contrast to the usual practice of modelling, which depends upon the downscaling of environmental data (land cover, rainfall maps) generated at a continental scale, we stress here the need to generalize upwards, from observations made at the microregional level, by using common descriptors and qualitative indicators. The GIS analysis of these data provides a weighted average model derived from field evidence for the different technical choices made (i.e. the decision to utilize specific water management devices) in relation to the various agronomic landscapes. Highlights • Long term history of Syrian arid steppic landscapes enlighted by water mastering techniques • Modelling spatial location of past water management devices in arid areas • Modelling the regional agronomic potential in Near East arid areas [ABSTRACT FROM AUTHOR]

Abstract This paper presents the estimates of nitrogen and phosphorus loads associated with different land uses in a semi-arid watershed in the Brazilian northeast (NE). To calculate the annual loads and calibrate de estimates, we used emission factors related to natural processes and human activities from land uses and monitored the nutrient concentrations in surficial waters. The concentrations of TN were above the 2.18 mg N L−1 limit for lotic environments while the TP exceeded the limit value of 0.15 mg P L−1 established in the Brazilian legislation. The total loads L e N , P corresponded to 16,621 t N yr−1 and 3,211 t P yr−1 or 1,292 t N km−2 yr−1 and 250 t P km−2 yr−1. The anthropogenic emissions accounted for 82.1% of the N and 91.3% of the P emitted. The results for the Salgado river basin are lower than those estimated globally, but exceed the values obtained for the South American continent in an order of magnitude. The use of nutrient loads instead of concentrations, particularly in areas where detailed studies on nutrient concentrations are unavailable, such as in the semi-arid NE Brazil, may become a satisfactory approach to evaluate the sensitivity of aquatic systems to a further introduction of anthropogenic effluents. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Abstract This paper explores an original approach in which greenhouse gas (GHG) emissions and carbon (C) accumulation are assessed monthly and at landscape scale to account for the highly seasonal monsoon climate and the mobility of pastoral herds that characterize West African pastoral ecosystems. The study was conducted in northern Senegal, in the service area of the Widou Thiengoly borehole, a circular zone of 706 km2 centered on the borehole. The C balance was calculated using an ecosystem approach, i.e. taking all main sources of GHG emissions and C sinks of the ecosystem, not only anthropogenic sources, into account. The annual C balance of the pastoral ecosystem was −0.04 ± 0.01 tC-eq.ha−1.year−1, showing that total GHG emissions were mitigated by C accumulation in trees, soil and livestock. The C balance varied considerably with the seasons, with a positive monthly balance in the wet season, from July to October (+0.58 tC-eq.ha−1.month−1) and a negative monthly balance in the cold dry season from November to February and the hot dry season from March to June (−0.57 and −0.05 tC-eq.ha−1.month−1 respectively). Care should be taken when generalizing these results, which were obtained in a dry year, because of strong inter-annual variations in rainfall. Highlights • Sahelian rangeland ecosystems have a neutral carbon balance. • Accumulation of carbon and greenhouse gas emissions vary strongly between seasons. • The main source of greenhouse gas emissions is livestock. • The main carbon sinks are trees and soils. • Seasonality is explained by both rainfall patterns and pastoral practices. [ABSTRACT FROM AUTHOR]

Abstract MARAS (Monitoring of Arid and Semiarid Regions) consists of 379 ground monitors in Patagonia, a 624.500 km2 semiarid area of southern Argentina and Chile. The objective of this paper was to describe the system and analyze four variables of the initial data base. Floristic composition, diversity and cover were analyzed with intercept lines (500 points). Patches (resource-sinks areas) and Interpatches (areas that loose resources) were described using Gap intercept lines (50 m). Eleven Landscape Functional Analysis indicators were recorded in 10 interpatches: Soil stability, Infiltration and Nutrient cycling. Vegetation Cover was 43 ± 2%, Richness 15 ± 7 species/monitor, Interpatch Size 154 ± 134 cm and LFA Stability Index 46 ± 1%. Cover, Richness and Stability maps had bimodal distribution and maximum in S and NE areas, following rainfall gradients. Variability analysis shows that cover estimations are within 5% error at site and regional scales. Graphical analysis of single monitors shows observational biases in interpatch size and LFA Stability index. Richness estimations correlate significantly with α diversity (R2 = 0.80). Analysis of 5-year change in 115 monitors shows significant reductions in cover and interpatch length, especially N of the region. These base line evaluations enable analysis of future changes that were not possible with multiple techniques and isolated data bases. Highlights • 379 ground monitors of vegetation and soil were installed in Patagonia. • Six teams in two countries shared a single protocol and data base. • Errors of estimations at site and regional scales are acceptable. • Contour maps of main variables show gradients associated to aridity. • This baseline enables future change evaluation. [ABSTRACT FROM AUTHOR]

Abstract Past water resource developments in dryland regions rarely estimated the full suite of environmental and social impacts arising from damming and diverting water for food production. Nowadays there is a greater focus on sustainable resource development which considers the economic, social and environmental costs and benefits. A challenge is to apply tools and methods which can capture the often disparate knowledge and data describing many costs and benefits. This paper describes a proof of concept application of a large Bayesian Decision Net to estimate the total utility of water resource development according to criteria of social, economic and environmental sustainability. We focus on two water-scarce catchments in remote northern Australia which are under investigation for development. The study catchments contain a diverse set of ecosystem services and socio-cultural values, including important Indigenous values and high value freshwater ecosystems. The Bayesian Decision Net was shown to have many properties that made it useful for performing a social, economic and environmental sustainability assessment, in particular its ease of construction; its ability to handle quantitative and qualitative data types; its preservation of system knowledge and; its ease of use in aiding decision making. From the perspective of the sustainability assessment in our case study, the total utility of water resource development for new irrigation is negative in both the studied catchments. The overall utility of water resource development could be positive if irrigation development is highly sensitive to the environment and there are very low environmental impacts, and much higher net economic returns to irrigators eventuate, possibly through higher commodity prices, lower capital costs of irrigation development or some combination of both. Highlights • Development of water resources involves trade-offs between economy and environment. • Integrated social-environment-economy sustainability (SEES) assessments support trade-offs analyses. • Bayesian Decision Networks (BDNs) support SEES assessments with diverse data types. • BDN applied to irrigation development scenarios of two remote catchments in north Australia. • The economic and ecosystem service benefits of the case study irrigation developments are questionable. [ABSTRACT FROM AUTHOR]

Abstract The large and widespread decline of European migratory birds spending the northern winter in the Sahel suggests – on top of adverse changes in the breeding quarters ‒ pivotal changes in African overwintering areas. This paper attempts to answer three questions related to the sub-Saharan region: (1) can a change in the woody vegetation explain the decline of migratory birds feeding in trees, (2) ditto for the ground vegetation and bird species searching for food on the ground, and (3) are African bird species also in decline? The analysis is confined to the western Sahel (annual rainfall 100–400 mm, 15.5–18°N and 14.7–16°W), a region intensively used as rangeland but too dry for agriculture. The woody cover, largely stable before 1970, declined in the driest zone by 90% between the 1960s and 2000s, and by 40% in the more humid zone where the woody cover was already low in the 1960s. The woody vegetation changed in many places from an Acacia savanna into an open savanna with scattered bushes and few trees, concomitant with a shift in species composition. These changes took place during a prolonged drought (1969–1992), and were aggravated by increased grazing pressure after the construction of boreholes as evident from the loss of woody cover close to boreholes. A comparison of bird composition and densities in grazed and ungrazed areas and in three study sites intermittently surveyed between 1960 and 1994, with our surveys in the same sites in 2014–2015, revealed about 80% losses for birds feeding on the ground. The increased grazing pressure of livestock must have caused a large reduction of the soil seed bank and most likely also of insects. Between 15 and 16°W an estimated 8 million arboreal birds, mainly migrants, and 30 million ground-feeding birds, mainly granivorous residents, lost their habitat. Assuming that this zone is representative for the Sahelian rangelands as a whole, 1.5–2.0 billion birds have lost their habitat in half a century. Highlights • Sahelian savanna has changed due to the increased grazing pressure by livestock. • Woody cover declined by > 80% during the dry 1980s and 1990s. • Loss of woody cover affected migratory birds, especially those from S. Europe. • Granivorous birds, mostly residents, declined by c. 80%. [ABSTRACT FROM AUTHOR]

Abstract This paper calls attention to the presence of countless ancient paths on the basalt-covered surfaces characteristic of harra landscapes in north-eastern Jordan. These paths have developed over the course of at least the last two millennia, and potentially prior to that, by trafficking of nomadic peoples and animals. These paths facilitated movements through terrains that were otherwise difficult to traverse. Paths can be recognised on high-resolution satellite imagery, which allows for systematic documentation and the reconstruction of potential routes through the landscape. The identification and mapping of these paths is important for better understanding mobility patterns of nomadic peoples who inhabited these desert landscapes in antiquity. Highlights • Ancient paths were identified on harra surfaces in northeastern Jordan. • Paths can be systematically mapped using high resolution satellite imagery. • Paths developed as a result of trafficking of people and animals. • Paths were used to traverse the landscape at least for the last 2000 years. • Routes relate to nomadic exploitation of the environment on a local scale. [ABSTRACT FROM AUTHOR]

Desert tourism has grown steadily in several regions of the world, due to a post-modern fascination with remoteness, barrenness, silence and solitude. This paper evaluates the trend towards tourism development in South Africa's arid Karoo region. It utilises several methodologies – analysis of discourse, demand and supply – to track the changing profile of tourism in the Great Karoo. The paper concludes that the reputation of the Karoo has shifted profoundly from being hostile, dangerous and boring to being attractive, enticing and spiritual. At the same time, tourists are increasingly expressing favourable opinions of the Karoo as a destination, while accommodation facilities are growing apace. The overview also finds that tourism services in some Karoo towns are developing at a much faster rate than others, so the tourism performance is uneven. A survey of tourists in the Karoo found that the arid environment and small-town ambience offer significant attractions, and Karoo guest houses have a positive outlook for the future. These findings suggest that the Great Karoo is indeed in the process of becoming a tourism destination. [ABSTRACT FROM AUTHOR]

Scarcity of in situ vegetation data inhibits research and natural resource management in the Sudano-Sahelian zone (SSZ). Satellite and aerial remote sensing (RS) constitute key technologies for improving the availability of vegetation data, and consequently the preconditions for scientific analysis and monitoring. The aim of this paper was to investigate how the hands-on application of RS for vegetation analysis has developed in the SSZ by reviewing the scientific literature published between 1975 and 2014. The paper assesses the usages and the users of RS by focusing on four aspects of the material (268 peer-reviewed articles), including publication details (time of publication, scientific discipline of journals and author nationality), geographic information (location of study areas and spatial scale of research), data usage (application of RS systems and procedures for accuracy assessments), and research topic (scientific objective of the research). Three key results were obtained: i) the application of RS to analyze vegetation in the SSZ has increased consistently since 1977 and it seems to become adopted by a growing number of scientific disciplines; ii) the contribution of African authors is low, potentially signalling a need for an increased transfer of knowledge and technology from developed countries; iii) RS has primarily been used to analyze changes in vegetation productivity and broad vegetation types, whereas its use for studying interactions between vegetation and environmental factors has been relatively low. This calls for stronger collaborative RS research that enables the mapping of additional vegetation variables of high relevance for the environmental problems facing the SSZ. Remotely sensed vegetation data are needed at spatial scales that suits the requirements of both research and natural resource management in order to further enhance the usefulness of this technology. [ABSTRACT FROM AUTHOR]

Climate change has an adverse impact on rural livelihoods by increasing vulnerability and reducing crop yields. Climate-smart agricultural (CSA) practices have been advanced as a possible solution to adopt and mitigate climate change issues. Administering a structured questionnaire survey among the 494 rural farming households of an eastern Indian state, namely Odisha, the study explores the key determinants of CSA adoption. Three districts, one from the state's coastal and two from the inland regions, are chosen for the study. The majority of the respondents (85%) perceive an increase in temperature and (76%) perceive a decrease in rainfall due to climate change in the region. The respondents have adopted a range of CSA practices such as rescheduling planting (74.5%), crop rotation (59.3%), crop diversification (31.2%), soil conservation (62.1%), drought-resistant seeds (36%) and agroforestry (10.3%) to adapt to these weather anomalies. The current paper employs a multivariate probit model in which the findings of econometric modelling have been triangulated to explore the key determinants of the adoption of CSA practices. The result shows that the key determinants are – perception of climate change, agricultural extension services, and access to energy for irrigation. • Climate change has adversely affected yields and the livelihood of rural farmers in Odisha. • Climate-smart agricultural practices have been advanced as a possible solution. • A multivariate method has been used to analyze the factors affecting the adaption. • Perception, access to extension and energy sources are the major determinants. • The information gap and lack of financial and market access are the barriers to adoption. [ABSTRACT FROM AUTHOR]

The aspirational goal of a land degradation neutral world, to be realized by reducing the rate of land degradation and increasing the rate of restoration of degraded land, was agreed at the Rio+20 Conference in 2012. This paper evaluates the feasibility of introducing a Land Degradation Neutral (LDN) scheme as an activity of the United Nations Convention to Combat Desertification (UNCCD). It concludes that national and international implementation would involve political, organizational and technological challenges. Monitoring restoration of desertified land by revegetation would be feasible immediately, but monitoring cuts in national rates of desertification would not, because no baseline rates are currently available; national and international scientific capacities to measure desertification are limited; and further scientific knowledge is required to supplement existing knowledge of desertification processes and of land use and land cover change processes generally. This paper therefore suggests introducing an LDN scheme in phases. Phase 1 would focus on restoring degraded lands, improving national land use planning systems, and establishing international and national monitoring capacities. Phase 2 would reduce desertification rates with the help of fully integrated land use planning and monitoring systems. Phase 3 would set a target year for realizing an LDN goal, based on experiences in Phases 1 and 2. All three phases would be informed by accessing existing scientific knowledge, and gaining new knowledge by launching a scientific LDN process that can evolve in parallel with the political process. [ABSTRACT FROM AUTHOR]

Water is a scarce resource in arid regions, and hence water harvesting is critically important in these regions for which many different means are adopted including groundwater and rainwater harvesting. This paper examines the feasibility of rainwater harvesting from roof catchments in arid regions of Australia. For this, ten representative locations in the arid regions of Australia are selected. Also, ten different sizes of rainwater tanks ranging from 5 kL to 50 kL and three different combinations of water uses are considered. A model is developed to simulate the performance of a rainwater harvesting (RWH) system. It is found that the reliability of a RWH system is highly dependent on mean annual rainfall at the location of interest. It is found that a 20 kL tank can provide a reliability of 61%–97% for toilet and laundry use depending on the location within the Australian arid regions. At the current water price, RWH system is not financially viable in the Australian arid regions. The methodology adopted in this paper can be adapted to other similar arid regions of the world. [ABSTRACT FROM AUTHOR]

Mobility appears to be in decline in modern pastoralism, but measurement of mobility has been ambiguous. This paper develops a metrics system to evaluate multi-scale pastoral mobility, and uses continuous, frequent, cross-season GPS-tracking data to investigate movement patterns in five pastoral communities in southern Ethiopia. The metrics system includes both broad-scale indicators such as home range and number of camps, and fine-scale indicators such as herding loop length, daily maximum distance from camp, and angular distribution of observed cow locations. The findings suggest pastoral mobility patterns are highly heterogeneous, and there are clear trade-offs among different mobility indicators in pastoralists’ herding strategies. In contrast to conventional understanding that mobility declines when pastoralists settle down, I find evidence of sedentarized pastoralists engaging in more rigorous fine-scale movement than those who keep practicing camp relocation. Thus, pastoral mobility cannot be generalized according to any single indicator, and comprehensive evaluation is necessary to advance our understanding of pastoral mobility as a complex strategy to manage herds in the arid and semi-arid environments. [ABSTRACT FROM AUTHOR]

We study in this paper land degradation processes in arid environments that are leading to a major environmental change. These processes, which are mostly the outcome of gully development, have direct impact on agriculture potential, biomass degradation, and escalating desertification. Three representative sites within the Negev Highland, Israel, are studied by utilizing terrestrial laser scans to gain detailed spatial information, accurate estimations, and concisely document overarching trends. The resulting information allows us to thoroughly characterize and quantify the geomorphic and vegetative changes and to calibrate rates and trends that have only been roughly estimated thus far. The scans, which were taken over a four-year span (2009–2013), cover three different types of hydrological seasons and provide unique insights on development rates and subsequent ramifications. The characteristic progression of natural land degradation in the Negev Highlands and the techniques used to document and analyze it can be extended globally to regions undergoing similar transitions. [ABSTRACT FROM AUTHOR]

Previous research shows little haplotype diversity in small geographic areas, such as islands and areas where physical barriers interrupt gene flow. The general pattern is the presence of a small number of haplotypes spread across sampling sites. Instead, this paper reports the presence of a large number of haplotypes ( Cytb and COI) in the extremely small distribution area (Los Planes basin, Baja California Sur, Mexico) of the Cerralvo pocket mouse, Chaetodipus siccus . Haplotype zoning revealed that haplotypes considered as ancestral are located to the periphery of the distribution area, whereas derived haplotypes are located to the center of the distribution range. Most derivatives are unique haplotypes and many of them exhibit a remarkable characteristic: a separation of not more than 1.7 km between them, which prompts a genetic microstructured population. All these features suggest the presence of a strong philopatric behavior among females. [ABSTRACT FROM AUTHOR]

The responsiveness of net photosynthetic rate (A a ) to mean monthly air temperature (T M ) of eight Mediterranean evergreen species was investigated by analyzing the inter-annual changes in leaf mass area (LMA), leaf tissue density (LTD) and leaf thickness (LT). We wanted to test if species leaf habitus affected this response. To hit the goal, a multi-year dataset from our previously published papers was used. The inter-annual variability in LMA, LTD and LT was assessed by their coefficients of variation (CVs). A a sensitivity to T M (SA a ) was quantified by the slope of the species-specific relationships A a -T M . A Principal Component Analysis (PC) was carried to identify the leaf morphological variation patterns across species. SA a was affected by the coordination of LTD and LT across species and this coordination depended on leaf habitus. The relationship between CVs and SA a revealed that only evergreen sclerophyllous with a longer leaf life-span rely on the inter-annual changes in LTD and LT to modulate their SA a . Overall, the results showed that the inter-annual LTD and LT variability affected the responsiveness of net photosynthetic rate of the selected species according to their leaf habitus. [ABSTRACT FROM AUTHOR]

Pastoralist women are perceived as doubly disadvantaged, due to gender inequality and their low status as pastoralists. Thus, development organizations are adopting gender-specific approaches to improve the specific position of female pastoralists. This paper examines this issue with respect to the Raika (Rabari), the largest nomadic pastoral community of Western India, using an ecofeminist theoretical framework. Because Raika women observe purdah, there is an outward impression that men play the dominant role in sheep production, but in reality nomadic shepherding is a family operation and dependent in equal parts on the contribution of women and men. A series of interviews and group discussions revealed that women often prefer being on migration to staying in the villages because of lower workloads, nevertheless, they are concerned about security issues and the dangers of nomadism. Raika women increasingly express their resistance to traditional customs by refusing to consummate marriages with husbands to whom they have been betrothed in childhood. Very often the reason for the refusal is that they do not want a husband following the traditional pastoralist livelihood, preferring an urban way of life. The gradual decline of Rajasthan's sheep population over the last fifteen years may be due in part to women's refusal to engage in shepherding. It is suggested that this issue needs to be addressed by instating pro-pastoralist policies that benefit pastoralist families at large rather than gender-specific measures. [ABSTRACT FROM AUTHOR]

This article is a collation and synthesis of the literature review with the focus on the vulnerability of rural women in developing countries to climate change on the one hand and being pro-active in adapting to climate change on the other. The geographic coverage of the literature is global but with specific examples from India. The information presented in this paper is derived from diverse sources including journal articles and thematic books, and indicates severe adverse impacts not only on women's livelihood opportunities but also on exacerbating the workload and fatigue while decreasing their self esteem and forcing them to undertake some high risks and hazardous activities. The literature indicates that poverty, gender inequality, insecure land rights, heavy reliance on agriculture, less access to education and information are among the principal reasons for their vulnerability to climate change. The vulnerability is also confounded by the meager asset base, social marginalization, lack of mobility and exclusion from the decision-making processes in response to a disaster. However, the literature also shows that women are not only the passive victims of climate change but are also pro-active and agents of hope for adaptation to and mitigation of abrupt climate change. They utilize their experience and expertise to reduce the adverse impacts by adopting prudent strategies. They are also concerned about environmental issues, and are highly supportive of policies regarding environmental restoration. Large knowledge gaps exist regarding the vulnerability of women to changing and uncertain climate especially in arid regions. Authors of this article suggest some action plans and strategies to minimize vulnerability to climate change such as empowering women economically and educationally, organizing training and outreach programmes, and involving them in formal climate change mitigation and adaptation policies and programmes. Authors also outline research needed in order to identify and implement strategies regarding climate change. Collective and continuous efforts are critical to finding the sustainable solutions for this global phenomenon which is adversely impacting the most vulnerable but critically important members of the society. [ABSTRACT FROM AUTHOR]

This paper problematizes the binary division between substantivist vs formalist approaches, and suggests instead that in the case at Bedouin women living in unrecognized villages, within a settler context, deprived from the equal rights for developing an appropriate “rational” economic systems, people turn to their limited local economic systems aiming to produce economic safety net for their economic survival. However, lacking the conditions for their maintenance, these sociocultural institutions do not provide a sufficient base to maintain their economic systems, thus they recreate their “economy of survival” systems. [ABSTRACT FROM AUTHOR]

This paper provides an in-depth review of evidence for the presence of twelve waterbodies spanning the Late Pliocene through Late Pleistocene in southern Israel and southern Jordan. A comprehensive description of these waterbodies is presented, combined with new field, paleontological and numerical age data, along with a discussion of their implications for paleohydrology and paleoclimate. The region is currently hyper-arid and there are no permanent rivers, wetlands or lakes in the area. Nevertheless, during the time-frame examined, continuous layers of limestones and mudstones were deposited in wetlands and shallow lakes. According to their location, the waterbodies were classified into either resulting from local tectonic depressions or in wide natural depressions at base levels. Following the types of sediments and fauna associated with these waterbodies, it is suggested that four wetter periods occurred: Late Pliocene/Early Pleistocene, Middle Pleistocene, Middle Late Pleistocene and terminal Late Pleistocene. This resulted in the deposition of limestone, chalk, travertine, calcrete, mudstone, marl, clay, silt and sandstone. For several waterbodies, vertical and lateral transitions between white limestone and fine clastic sediments rich in carbonate, indicate changes in depositional conditions from a shallow lake to a wetland, both associated with wetter hydrological settings compared to current climatic conditions. [ABSTRACT FROM AUTHOR]

The interactive relationships between ecological and hydrological processes drive plant performance, community structure, and community succession in arid areas. Yet the nature of potential hydrologic thresholds for responses of vegetation remains poorly understood. In this paper, we report on hydrologic thresholds associated with aboveground net primary production (ANPP) of Haloxylon ammodendron (HA) and sand-fixation region (SFR) between 1987 and 2012 in the ecotone of desert and oasis in the northwest China. In particular, we focused on precipitation and soil moisture dynamics. Our results showed that 1) ANPP and soil moisture of both HA and SFR decreased from 1987 to 2005, and then reached a stable state; 2) nonlinear models provided a much better fit to the data than linear models, highlighting the presence of a discontinuity in vegetation ANPP changes along precipitation and soil moisture gradients; 3) precipitation, accumulated between preceding-year June to current-year August, of <160 mm, or soil moisture at < 1.4–1.5% may decrease ANPP. Our results provide insights into the thresholds of precipitation and soil moisture in a long-term sand-fixing ecosystem, and highlight the importance of legacy precipitation for the recovery of the sand-fixing ecosystem. Consequently, the findings provide useful references for further understanding of the mechanisms of ANPP changes in a sand-fixing ecosystem with changes in precipitation and soil moisture. [ABSTRACT FROM AUTHOR]

Many scholars of rangeland institutions have found fertile theoretical and empirical ground in early efforts by the Kenyan government and international development agencies to socially engineer a shift from open range to discrete territories held under collective freehold title. A rich literature on the dynamics of subsequent subdivision of these “Group Ranches” elucidates a complex interplay of exogenous and endogenous drivers. This paper, on the contrary, explores the dynamic tensions between individualization and collectivization of land and related benefit flows in a group ranch that has thus far not undergone formal subdivision. Research was conducted in Koija Group Ranch, one of 13 group ranches located in Mukogodo Division, on the Laikipia plateau. Drawing on key informant interviews and focus group discussions with those differentially positioned relative to the benefits of de facto processes of rangeland exclosure, and household surveys to document trends in participation and perception, we explore how these processes are perceived and governed. Cross-case comparison highlights the suite of factors shaping which forms of enclosure are contested; the diversity of legitimizing tactics that ensue from such contestation; and the balancing act these tactics represent between retention of privilege and restoration of peaceful relations among group ranch members. [ABSTRACT FROM AUTHOR]

Soil microbes, as an important biological component of soils, have a function in the formation of soils and soil-remediation processes. This paper aims to analyze effects of biocrusts on soil microbial activities in desert ecosystems. Two sets of samples were collected under biocrusts in April, July, October, 2013, and January, 2014, in natural and revegetated areas of the Tengger Desert. The results showed that biocrusts significantly improved soil physicochemical properties, basal respiration and the quantity of soil alkaline phosphatase, protease, and cellulose, and decreased q CO 2 in vegetated areas. Impact of biocrusts on soil microbial activities also varied, depending on the successional stage of crusts and the restoration age. Soil basal respiration and enzyme activity were obviously higher, but q CO 2 were significantly lower in moss-dominated crusts than those dominated by cyanobacteria-lichen. Soil basal respiration and enzyme activity positively correlated with the restoration age, but q CO 2 negatively correlated with the restoration age. Soil basal respiration and enzyme activity were the highest in summer, followed by autumn, and the lowest in spring and winter; whereas, q CO 2 displayed an opposite trend. The study suggests that biocrusts have the ability to improve soil quality and promote soil recovery in vegetated areas of the Tengger Desert. [ABSTRACT FROM AUTHOR]

Past cultures in all the major continents have, for millennia, developed symbolic systems and iconographies whose depictions spanned a multiplicity of media, including rock art as well as ceramic decoration and other physical forms. This is an area which has long been recognised, but requires further investigation and research for any meaningful conclusions to be drawn - particularly regarding its potential to assist in the meaning and chronology of rock art. Taken together with other data such as the contrasting distribution of archaeological sites and rock art locations, we may form independent lines of evidence, not conclusive in their own right, but when combined can provide convincing arguments toward specific chronology and attribution. Indeed, each rock art site needs to have its own tailored interpretive framework, devised to maximally exploit the available archaeological and other data to assist in the understanding of the rock art. This paper will describe a multidimensional methodology to rock art chronological and cultural attribution using an approach applied at the site of Hierakonpolis, Upper Egypt which is known for its late Predynastic and Early Dynastic settlement and funerary localities, occurring adjacent to rock beds and hills incorporating rock art and inscriptions from a span of ages. [ABSTRACT FROM AUTHOR]

All the main Central Saharan mountainous massifs present rock art from various periods, stretching from prehistory until the recent historical era. The paintings and engravings have been documented, described, and classified into the chronological-stylistic groups. However, a special group of carvings called kettles and cupules have been given little or no attention in the rock art studies. Since these artificial formations are abundantly present in the Central Sahara their systematic study is needed. After a short presentation of the Saharan rock art groups, this paper examines kettles and cupules situated in the territory dominated by the earliest paintings called Round Heads, in the mountains of the Algerian Tassili, Algerian Tadrart and the Libyan Acacus. The results of the author's prolonged fieldwork are presented here, namely the quantity and distribution of kettles/cupules in the study area, their presumed relationship to the Round Head paintings, and their possible function. [ABSTRACT FROM AUTHOR]

The Limarí Valley stands within Central Northern Chile and forms part of the foothills of the western Southern Andean region. In terms of altitude, much of the upper reaches of the valley stands over 1000 m above sea level. The natural environment comprises mainly semi-arid scrubland. During later prehistoric times, the Limarí Valley would have provided an important access route between the Pacific Ocean and communities occupying the valley (and its tributary valleys to the north and south). It is within the upper reaches of the valley that prehistoric rock art is located in a variety of locates including rock shelters and open-air sites. Many sites show that both painting and engraving techniques have been applied. This diverse media, along with changes in style, composition and subject matter reflects at two different chronological phases: hunter-gatherers and agrarian communities. In this short paper we compare the socio-ritual organisation of landscape among these two communities that at different times occupied this semi-arid area. Despite the aridity of this landscape, water appears to be the main focus for ritual activity among hunter-gatherers, especially within the secluded upland side valleys. Whilst hunter-gatherer rock art is associated with settlement, agrarian rock art relates to route-ways and the movement of people; here panels appear to act as markers within a transitional landscape. Fieldwork has revealed that hunter-gatherer rock art was usually placed close to flowing water, whilst agrarian rock art sites were located in isolated places, and with no apparent relationship with water. Both hunter-gatherer and agrarian communities are paradoxically contradicting each other in that hunter-gatherer rock art is metaphorically sedentary and agrarian rock art is fluid. Both regimes show how two different ways to engaged with arid places in the Southern Andean region; one related with water and the other with the movement of people and commodities. Both are key aspects to how communities utilised the same landscape, but in different ways and at different times. [ABSTRACT FROM AUTHOR]

A rock engraving site at Kalabasput in the Upper Karoo, South Africa, includes an unusual set of engravings featuring vultures. In relation to the ‘frequently depicted’ subject matter of South African rock art – such as eland and ostrich – images of vultures are rare. The site provides an opportunity for considering these unusual images relative to a background of “shared, transcending beliefs and values”, showing how they may have acted as metaphors for altered states of consciousness. But the paper points further to the possible ways in which the contingencies of particular places and histories may have influenced the production of unique or uncommon images. The art, it is suggested, was not merely the passive reflection of a cultural or rock art tradition but, given particular contexts, was part of its dynamic, on-going elaboration. [ABSTRACT FROM AUTHOR]

Land-use changes have contributed to an increased interest in understanding the drivers of forest regeneration in human-modified landscapes. This is particularly true for arid ecosystems, in which regeneration is relatively less known, but more sensitive to land-use intensification and climate change. This paper aims to identify the relative contribution of seed rain and soil seed banks for the regeneration of the Caatinga dry forest in northeastern Brazil as well as their drivers. We monitored seed rain and soil seed bank of woody plant species during a 14-month period across 15 regenerating (4–70 yr old) and 5 old-growth forest stands. Stand age, precipitation, chronic anthropogenic disturbance, and forest aboveground biomass were our explanatory variables. A total of 5081 seeds from 61 species were recorded in the seed rain across all forest stands (1.81 intact seeds per m2 per month). Regenerating and old-growth stands did not differ relative to average seed rain scores, with the proportion of zoochoric seeds positively associated with forest biomass. In the seed bank, we recorded a total of 5660 seeds from 64 species (5.05 intact seeds per m2 per month), with no differences among stands, except for species richness; with mean seed size positively associated with stand age. Collectively, seed rain and seed bank captured only 40% of the woody regional flora, mostly dry-fruited species (70% of all species). Moreover, assemblages were dominated by a few hyper-abundant species. Our results suggest that the Caatinga dry forest supports relatively low-density and impoverished seed rain and soil seed bank. Additionally, seed rain and soil seed bank do not exhibit directional changes through forest regeneration for most of the attributes, and deviate little from the scores of old-growth forest stands. Compared to resprouting, they may pose limited influence on woody plant recruitment and dry forest regeneration across human-modified landscapes. In this context, Caatinga restoration approaches based on natural seed rain and soil seed banks may be of limited effectiveness. • Seed assemblages in the Caatinga regenerating forests are impoverished and low dense. • Impoverished seed assemblages are linked to low productivity and human disturbances. • Seed assemblages are not affected by forest age, exhibiting little successional trends. • Seed rain and seed bank may play a minor role in the Caatinga forest regeneration. [ABSTRACT FROM AUTHOR]

Abstract: Salinization caused by irrigation mismanagement is a major cause of desertification. Monitoring of land degradation caused by salinization and other processes has been subject to international scientific debates leading to the commitment by global decision-makers to address these threats collectively through the UNCCD. This paper discusses the experience of monitoring land and water degradation in the salinity-prone irrigated arid environments of the Northern Sahara in light of current international scientific developments affecting both conceptual and methodological approaches. The paper integrates a range of simple and accessible methods to achieve a multidisciplinary analysis including remote sensing, use of national research archives, interviews with decision-makers and direct surveys of cultivators. Revised assessments of the extent and ecological processes of salinization emerge from the analysis. As irrigated areas expand globally, the new conceptual and methodological techniques in dryland development science have the potential to enable scientists in affected areas to contribute to global efforts to monitor degradation effects caused by desiccation, salinity and human responses. [Copyright &y& Elsevier]

Abstract: Biofuels are considered as a climate-friendly energy alternative. However, their environmental sustainability is increasingly debated because of land competition with food production, negative carbon balances and impacts on biodiversity. Arid and semi-arid lands have been proposed as a more sustainable alternative without such impacts. In that context this paper evaluates the carbon balance of potential land conversion to Jatropha cultivation, biofuel production and use in arid and semi-arid areas. This evaluation includes the calculation of carbon debt created by these land conversions and calculation of the minimum Jatropha yield necessary to repay the respective carbon debts within 15 or 30 years. The carbon debts caused by conversion of arid and semi-arid lands to Jatropha vary largely as a function of the biomass carbon stocks of the land use types in these regions. Based on global ecosystem carbon mapping, cultivated lands and marginal areas (sparse shrubs, herbaceous and bare areas) show to have similar biomass carbon stocks (on average 4–8 t C ha−1) and together cover a total of 1.79 billion ha. Conversion of these lands might not cause a carbon debt, but still might have a negative impact on other sustainability dimensions (e.g. biodiversity or socio-economics). Jatropha establishment in shrubland (0.75 billion ha) would cause a carbon debt of 24–28 t C ha−1 on average (repayable within 30 year with yield of 3.5–3.9 t seed ha−1 yr−1). Land use change in the 1.15 billion ha of forested area under arid and semi-arid climates could cause a carbon debt between 70 and 118 t C ha−1. This debt requires 8.6–13.9 t seed production ha−1 yr−1 for repayment within 30 years. If repayment is required within 15 years, the necessary minimum yields almost double. Considering that 5 t seed ha−1 yr−1 is the current maximum Jatropha yield, conversion of forests cannot be repaid within one human generation. Repayment of carbon debt from shrubland conversions in 30 years is challenging, but feasible. Repayment in 15 year is currently not attainable. Based on this analysis the paper discusses the carbon mitigation potential of biofuels in arid and semi-arid environments. [Copyright &y& Elsevier]

Abstract: The Namib is a relatively well-studied hyperarid desert. Much of the research effort was coordinated through the institutional framework of the Gobabeb Research and Training Centre, which was established in the middle of this desert fifty years ago. The initial discoveries focused on the Namib''s remarkably high biodiversity and adaptations to desert conditions, analysed against the foundations of research into this desert''s particular climate, geomorphology and geology. The antiquity of this desert, its extreme hyperaridity, and strong climatic gradients provided unusual windows into ecosystem drivers in arid lands, past and present. The Gobabeb Centre itself evolved to translate much of its knowledge into application and is today geared to increase this trend even further, driven by the urgent need for knowledge-based environmental management, such as ecological restoration of mining areas. The current volume collates nine papers which review a cross-section of Namib research, with special focus on projects conducted through Gobabeb. These papers concern different facets of geomorphology where Namib research has led global understanding, reviewed in three papers, and one climatological review of the moisture regime. A review of reptile research illustrates the relationship between biodiversity processes and environmental factors, which is further sharpened in a comparison of dune lizard ecology between continents. The review of botanical research in the Central Namib fittingly binds much of the accumulated knowledge of desert plants into a detailed vegetation map. A review of research on the highly variable ephemeral river systems of the Namib illustrates how academic knowledge accumulated at Gobabeb connects to applied research, which is also the topic of the final paper concerning the knowledge gaps and research needs to provide the information required for ecological restoration. [Copyright &y& Elsevier]

Abstract: This paper argues that soil salinity needs to be more broadly acknowledged as a driving factor in plant ecology—not only in the ecology of halophytes—in order to understand and make more accurate predictions for the impact of environmental change on biodiversity and vegetation patterns throughout the semi-arid world. It summarizes recent research on soil salinity and plant distributions in semi-arid environments throughout the world: there is empirical as well as experimental evidence that soil salinity, even at low levels, is an abiotic stress factor that influences vegetation patterns and diversification. Lines of evidence demonstrating salinity''s potential influence as a selective agent in East Africa and North America are presented. The paper then synthesizes recent results from spatial ecology, plant and insect systematics and behavioral ecology, focusing on Australia, that support a role for salinity in evolutionary ecology of Acacia. On a shorter time scale, soil salinity may play a role in weed invasion and woody vegetation encroachment in Australia. [Copyright &y& Elsevier]

The functional link between the aboveground systems and the below ground microorganisms in a plant system determines the restoration and re-establishment success of degraded ecosystems. This paper examined the arbuscular mycorrhiza fungi (AMF) spore density and root colonization in relation to slope position and age of exclosures. The first age group had less than five years old, the second age group was 5–10 years old and the third age group had 10–15 years old exclosure while the fourth age group had age between 15 and 20 years. The root and soil samples of 23 plant species that belong to 13 families from 12 sites of exclosures and grazing land were collected and analyzed using the magnified intersection and wet sieving method from the highlands of Tigray, Northern Ethiopia. . The AMF root colonization ranged from 24% to 96%. The lowest colonization was observed from plant species that belong to the grazing land, and the highest were from plant roots in exclosures. The spore density was between 30 and 2980 of 100 g −1 of dry soil with the lowest from the grazing lands and the highest was from exclosures of middle slope position. Glomus was the dominant AMF genus found in all soil from both land uses. A significant difference in spore density (p < 0.05) was observed between slope position and age of exclosures. AMF root colonization positively correlated (P < 0.05) with spore density. Exclosures of middle slope showed high spore density and root colonization and it increased significantly with increasing age of exclosures. The presence of abundant AMF spore in exclosures indicated the role exclosures played in the restoration of ecosystem health. Forestland restoration through exclosures could facilitates the survival of planted and regenerated plants by providing enough AMF inoculum in the restored ecosystem. AMF spore density and colonization should be considered as an indicator of restoration in measuring success of restoration in the drylands. [ABSTRACT FROM AUTHOR]

A practical approach for the assessment of surface water and groundwater resources in rain-fed mid-mountain domains of arid to semi-arid zones is much needed, especially in rural areas for which groundwater is the only reliable and permanent water supply source. This is the case in the Coquimbo region (29°15′- 32°10′ S latitude) of north-central Chile, where groundwater is needed for human consumption but also for agricultural and mining activities at a small to medium scale. This paper examines the usefulness of community knowledge, as encoded in the historical record, for identifying water resources. The existing record of wells and springs in the Coquimbo region is used as a guide to the identification and characterization of structural patterns that may influence the distribution of water resources. The proposed approach combines simple graphical, statistical and geostatistical methods to identify patterns, likely related to local and regional structural controls that influence the distribution of groundwater resources. In the Coquimbo area, these influences tend to align in NW and NE orientations that approximately coincide with regional geological trends. The methodology presented has the potential to form a first step in the search for additional water resources in the Coquimbo region, and may be useful for targeting detailed field studies on the basis of community and historical knowledge in many arid and semi-arid rural areas. [ABSTRACT FROM AUTHOR]

Using a 2010 case study, this paper shows that the damage and recovery process following winter disasters in Mongolia depends on the initial level of livestock prior to the disaster. We examined the factors of change in total stock level such as births, sales, and herders' family consumption. We use original, household-level data for herders before and after the 2010 disaster and show that households with a large number of animals before a disaster are more likely to recover quickly. Households with a small amount of stock are unable to recover quickly, mainly because of their high rate of family consumption. [ABSTRACT FROM AUTHOR]