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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]

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: 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: Despite the present hyper-aridity, archaeological investigations in South-east Arabia have demonstrated that the region supported extensive human communities throughout the Neolithic and Bronze Age. These early populations utilised the region’s natural environment in a variety of ways, ranging from the exploitation of coastal resources to practicing pastoral and agrarian lifestyles in the interior. Palaeoclimate data suggests the corresponding period was characterised by considerable climatic variability yet, to date, few studies have attempted to investigate the relationship between climate, the environment and early human populations in the region. This paper combines new high-resolution palaeoclimate data from Awafi palaeolake, United Arab Emirates (UAE), with the region’s archaeological record from the Neolithic through to the onset of the Bronze Age. The evidence presented in this paper suggests that the environment of South-east Arabia offered different constraints and opportunities for early human occupation and subsistence. In particular, abrupt phases of aridity are demonstrated to have had a profound impact. Most notable is the change which occurred following the onset of climatic aridity at 5900 cal yr BP, when the region’s semi-nomadic, herder-gatherer populations abandoned much of the landscape and concentrated in selected environmental refugia, such as along the northern Omani coast. Human repopulation during the Bronze Age coincided with a return to more pluvial conditions under which a network of oasis agricultural settlements appeared along the piedmont zone of the northern Hajar Mountains. [Copyright &y& Elsevier]

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: Concern about climate and its impact on human populations in the Sahel since the 1970s was an immediate response to the most recent of recurrent drought periods. Understanding the relative impact of this drought on rural life in the Sahel is, however, not straightforward. This is due to the fact that climate is only one of many factors influencing local adaptation strategies to environmental changes. Another explanation could be that climate in many rural communities in the Sahel is simply no longer the primary worry. The argument presented in this paper, supported by data from a small village in northern Burkina Faso, is that the villagers there are ‘beyond climate’ as their current livelihood strategies are increasingly climate independent. People have over the past decades engaged in livelihood diversification in order to negate the negative impact of climate variability on agriculture. In order to analyse the temporal perspective of climate–livelihood interaction, the paper employs human–environmental timelines. The results document the multiplicity of exposures shaping decisions in the village. While significant correlation exists between recent livelihood diversifications and major climatic events, it is equally obvious that recent political developments and the economic flow of project activities are crucial factors of change. [Copyright &y& Elsevier]

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]

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]

Climate is a major driver of ecosystem dynamics. In recent years there has been considerable interest in future climate change and potential impacts on ecosystems and management options. In this paper, we analyzed minimum monthly temperature (T min ) for ten rural locations in the western U.S. sagebrush steppe. Oregon and Nevada each had five locations, and the period of record ranged from 69 to 125 years. We used structural time series analysis to evaluate trends over time at each location. We also used box plots to compare variation within months at each location. We concluded: 1) T min variation over years is much higher during the winter than during other seasons, 2) there is evidence of decadal trends in both directions (hotter and cooler) for most, but not all sites, and 3) sites exhibited individualistic patterns rather than following a general regional pattern. The analysis shows that sites in relatively close proximity can exhibit different temperature patterns over time. We suggest that ecologists and land managers make use of any available weather data from local weather stations when planning for the future or interpreting past changes in plant and animal populations, rather than relying on regional averages. [ABSTRACT FROM AUTHOR]

Drought is one of the main natural factors in declining tree-ring growth and the production of agricultural crops in Algeria. This paper addresses the variability of growing conditions for wheat in Algeria with climatic data and a tree-ring reconstruction of January–June precipitation from ten Pinus halepensis tree-ring chronologies. A regression-based reconstruction equation explains up to 74% of the variance of precipitation in the 1970–2011 calibration period and cross validates well. Classification of dry years by the 30% percentile of observed precipitation (131 mm) yields a maximum length of drought of five years (1877–1881) and increasing frequency of dry years in the late 20th and early 21st centuries. A correlation-based sensitivity analysis shows a similar pattern of dependence of tree-growth and wheat production on monthly and seasonal precipitation, but contrasting patterns of dependence on temperature. The patterns are interpreted by reference to phenology, growth phases, and – for wheat – agricultural practices. [ABSTRACT FROM AUTHOR]

In West Africa, the channels for information flow from meteorological services to end-users, such as pastoralists, are relatively limited. As meteorological information is key to improving productivity for pastoralists, it represents a challenge at both local and national level to develop an efficient information dissemination system. However, few studies have focused specifically on pastoralists as end-users, and the best mode of delivering meteorological information to pastoralists remains unknown. Drawing on fieldwork conducted in Burkina Faso using a combination of qualitative and quantitative methods, this paper examines 1) the principal modes used by pastoralists to receive information, and 2) in what form and by which type of media pastoralists actually prefer to receive information. It was found that mobile phones have replaced traditional forecasting methods as these were becoming unreliable with increased climate variability. The phone was used to acquire updated informal information on, for example, the arrival of the rain from friends and family staying in other areas. The findings illuminate how mobile phones have a huge potential to deliver more formal information to pastoralists, and we propose that forecasts should be available as voice messages in local languages rather than text messages. [ABSTRACT FROM AUTHOR]

This paper considers two river systems that have been subject to significant development during the last 60 years: the Jordan River in the Middle East and the Colorado River in the western United States. Both play major roles in serving the demands of growing populations, and climate change models predict both semi-arid to arid regions to become hotter and/or drier in the future. The Jordan River basin, shared by five nations, is already experiencing a critical level of environmental damage. Its lower stretch is practically a sewage canal with less than 10% of its natural base-flow. Due to its unique historical, religious and environmental role, restoration efforts have gained momentum and wide public support. In the Colorado River Basin, water law is characterized by the “Law of the River” and water use is managed through regional allocation constraints. The Colorado River, shared by seven U.S. states and Mexico, is highly managed and over-allocated. Shortage declarations have serious implications for low priority users, with the Central Arizona Project being among the lowest. This makes large population centers and agricultural users vulnerable to curtailment of deliveries. We argue that there are common factors with respect to the policy and management options of these two basins that may provide insights into the similarities and divergences of their respective future pathways. These factors are: regional water supply and demand pressures, water governance, transboundary issues and demand for environmental flows. With a particular focus on the Israel and Arizona portions of these respective river basins, we address synergies and tradeoffs between groundwater and surface water usage, sectoral allocation strategies, public vs. private water ownership and legality, transboundary sharing, technical options for addressing growing regional water scarcity, and economic considerations. Difficult and bold decisions are required in both regions. [ABSTRACT FROM AUTHOR]

Abstract: The northeastern Qinghai-Tibetan Plateau (QTP) lies at the convergence of the Asian winter and summer monsoons and westerlies, making it an ideal place for studying the effects of climatic change, owing to its fragile ecological environment and unique geographical location. This paper reports on a multi-proxy analysis consisting of magnetic susceptibility, total organic carbon content (TOC), pollen, grain size, and geochemical parameters from the peat deposit in the Gonghe Basin to reconstruct the Holocene millennial-scale climatic variation. The results indicate that the climate tended to be warm and humid since 10.0 cal ka BP, but it deteriorated obviously (cold and dry) in 8.6–7.1 cal ka BP. The regional optimal warm and humid period was from 7.1–3.8 cal ka BP, although there were frequent climatic fluctuations during that time. Thereafter, the climate became cold and dry. 10 millennial-time-scale cold events were recorded, which were coincident with climatic records from deep sediments in the North Atlantic Ocean, ice cores, lakes, peat, and aeolian deposits in the QTP. In addition, we discovered that the southwestern monsoons forced by solar insolation in the Holocene have crucial effects on regional climatic change, and the millennial-scale cold fluctuations are possibly related to the thermohaline circulation (THC). [Copyright &y& Elsevier]

Abstract: In many parts of the world the boundaries between grassland and shrubland biomes have changed substantially over the course of the last century. Many are projected to shift further from being grass-dominated to shrub-dominated by 2050 under global climate change and land use change projections. This paper used long-term surveys and repeat photography to assess vegetation change at the shrubland-grassland ecotone in semi-arid, South Africa. Changes in several climate variables as well as in the cover of grasses and dwarf shrubs over three time periods (1962, 1989 and 2009) were investigated at eight localities within a broad 500 km ecotone between the Grassland and Nama-karoo biomes. Results showed that for most sites grass cover has increased and that dwarf shrub cover has decreased over time. This contradicts earlier views which warned against the expansion of dwarf shrublands in response to over-grazing as well as more recent views which suggest that more mesic biomes in the Karoo Midlands will contract in response to climate-induced aridification. The decline in stocking densities and more conservation-friendly land management practices together with an increase in large wet events in the Nama-karoo biome may have contributed to the increase in grass cover. [Copyright &y& Elsevier]

Abstract: This paper explores the evolution of land use and natural resource management strategies over the past twenty to fifty years in a remote Sahelian region. The empirical example is Karagou village in SE Niger. Building on an in-depth survey from 1992 and a targeted, follow-up analysis of contemporary land use strategies in 2011, the change process is scrutinized. The analysis uses the conceptual lenses of land systems science, human–environmental timelines, and the notion of multiple exposures. Enabling and constraining conditions for local livelihoods in terms of the resource base (landscape, water, and population) are described. Results characterize how land use strategies have developed and how local people opportunistically use different landscape elements such as dune landscapes, valley bottoms (bas-fonds) and oases (cuvettes). Major concerns are rainfall variability, saturation of cropland, and perceived dwindling groundwater resources. It is concluded that the land use and livelihood strategies have remained remarkably stable in the face of the changing socio-ecological fringe conditions, but that this situation may hamper a sustainable transformation. [Copyright &y& Elsevier]

Abstract: The Namib Desert is an ancient desert on the west coast of southern Africa. The Namib has unique endemic biodiversity and scenic landscapes, with a major part contained in the Namib Naukluft Park and the adjacent Dorob National Park, together forming a major tourism attraction in Namibia. There are currently large exploration and mining developments in the central Namib, fuelled by rising global demand for uranium. Mining contributes significantly to the Namibian GDP, but through destruction of habitats and ecological processes, may cause environmental degradation and loss of ecosystem services. Additionally, Namibia stands to lose a significant part of the biological diversity that makes it unique. These direct impacts are occurring in the context of regional climatic changes that are predicted to have their own severe impacts on biodiversity. A number of tools exist to counter these impacts, among which ecological restoration is an important one. Yet the extent of the damage to ecological processes and functions of the Namib, the interactions with climate change and the mechanisms through which the impacts will occur are still not well known. There is thus a crucial need for a better understanding of these arid ecosystems and their response to disturbance, to devise better restoration techniques, and to inform decision makers about management options. This paper analyses the extent of the threats to the central Namib''s ecosystems and biodiversity due to mining, identifies critical knowledge gaps for restoration, defines policy needs, and proposes a broad strategy which is intended to be a framework for research, planning and management for sustainable use of this unique desert. [Copyright &y& Elsevier]

Abstract: In recent years, there has been an increasing interest in the study of climate change effects on plant phenology. However, the effects of other more localized components of global change such as land degradation have been almost completely ignored. In this paper we evaluate the phenological patterns of 10 plant species at three sites with contrasting levels of land degradation due to overgrazing in the Patagonian Monte, Argentina, and their relationship with plant morphology, browsing intensity, and plant competition. Plant phenology differed among sites in eight species, but plant responses were species-specific. In six species the dormancy and senescence periods were shorter indicating longer growing cycles at high degradation than at low degradation site. Generally, plants growing at high degradation site present longer and frequently incomplete vegetative periods and shorter and less dominant reproductive periods than those at low degradation site. However, in some species the duration of reproductive periods was greater in the high degradation site. Plant size (i.e. height, area, and/or internal cover) affected plant phenology in seven species. In contrast, browsing and neighbor''s cover were rarely related to plant phenology. Our results suggest that other global change components such as land degradation may affect plant phenology. [Copyright &y& Elsevier]

Abstract: Drought severity is conventionally assessed by drought indices. Several drought indices with varying complexity have been used in many geographical areas. Recently, a powerful drought index, the Reconnaissance Drought Index (RDI), is gaining wide acceptance mainly in the arid and semiarid climatic regions. Since RDI is based both on precipitation and potential evapotranspiration (PET), it is interesting to assess the effect of the PET calculation method on the drought severity characterisation obtained by RDI. This paper compares the results of RDI for various reference periods using some popular empirical PET methods with minimum data requirements. The selected methods are: Hargreaves, Thornthwaite, Blaney–Criddle and FAO Penman–Monteith (only temperature). The FAO Penman–Monteith method is used as reference method. The data used are from meteorological stations in Greece representing the mountainous and the coastal Mediterranean climatic conditions. No significant influence on RDI was detected by using the selected PET methods. However, the Hargreaves and FAO P–M (only T) methods performed relatively better. This supports the opinion that RDI is a robust drought index, not dependent upon the PET calculation method. [Copyright &y& Elsevier]

Abstract: This paper presents characteristics of droughts simulated by global climate models (GCMs) under enhanced greenhouse gases conditions. We used a drought index called the Reconnaissance Drought Index (RDI) which takes both rainfall and potential evapotranspiration into account to investigate variations of droughts among 12 regions in Australia. The RDI was applied to simulated climate variables from 14 GCMs performed for the IPCC 4th Assessment Report. The results show a general increase in drought areal extent and/or frequency for most regions. However, the increases are not significant over the North West, North Queensland, Queensland East Coast and Central Queensland. For most regions, the change beyond 2030 is larger than that prior to 2030, but the uncertainty in the projections also increases with time. By 2030, there is a likely (>66% probability) risk of twice or more drought affected area and/or twice as often drought frequency over South West Western Australia. By 2050, this will include the Murray-Darling Basin, South Australia and Victoria, and by 2070 this will extend to New South Wales and Tasmania. For North Queensland such a risk is unlikely (<33% probability) for the next 100 years. This information can be considered indicative in long-term planning focussing on sustainability. [Copyright &y& Elsevier]

Abstract: The nonparametric Mann–Kendall test was used to detect the trends of major hydroclimatic variables in the Tarim River Basin, the largest inland river basin in China for the period of 1960–2007. Results showed that both mean annual air temperature and precipitation experienced an increasing trend, while annual streamflow demonstrated a mixed trend of decreasing and increasing: The mountainous region upstream showed an increasing trend and the region downstream exhibited a decreasing trend. Impacts of the increased air temperature on streamflow have shown different characteristics depending on location and seasons: it has positive effect on the runoff at mountainous region due to snowmelt and glacier-melt in spring, but negative effect on the runoff at plain area due to the increase of actual evaporation in summer. In addition, human activity contributed to the declining of streamflow in the arid plain oases at downstream of the Tarim River Basin. The results obtained in this paper can be used as a reference for the planning and management of water resources to maintain the health of the river system. [Copyright &y& Elsevier]

Abstract: This paper describes a manual-style Decision Support System that integrates land degradation indicators with adaptive management options and is designed for land managers to easily collect data and monitor progress towards environmental sustainability goals. A number of similar tools have been developed for ranchers in southern Africa, but there has been little help for land managers under common property regimes. Manuals were therefore primarily designed for use by communal pastoralists in three study areas in the Kalahari, Botswana. Separate manuals were developed for each study area in response to the differences in indicators and management options deemed relevant for each by local communities. The design of the DSS has been optimised using an “innovation-decision” approach combined with local and external expert review to enhance the likelihood of widespread uptake and application by land managers. Manuals are designed for regular use by pastoralists to identify detrimental environmental change early, and guide sustainable management responses. The recommended assessment procedure is flexible, and designed to make recording and interpretation of results simple for users. Full copies of each manual (in English) are provided (electronic version only). [Copyright &y& Elsevier]

Abstract: This paper documents the main features of climate and climate variability across the Monte Desert for the Last Glacial Maximum, the Glacial–Interglacial transition, and the Holocene on the basis of proxy records and for the 20th century using instrumental observations. The climate in the Monte is determined by interactions between regional physiography and atmospheric circulation in the 25–45°S sectors of South America. Although arid and semi-arid conditions prevail across the Monte, its large latitudinal extent and complex topography introduce many particularities at local scales. Paleoclimatic records and model simulations of past climates suggest significant variations in the atmospheric circulation, temperature and rainfall patterns since the Last Glacial Maximum. High-resolution proxy records east of the Andes support the existence of complex climatic patterns with similar temperature changes across the whole region but opposite precipitation variations between subtropical and mid-latitude sectors in the Monte during the past millennium. The present-day climate is depicted in terms of the space and time variability of the near-surface temperature, rainfall and tropospheric wind patterns. Uneven temperature trends over the Monte were recorded for two separate (1920–44 and 1977–2001) global warming periods in the 20th century. Additional warming evidence in the region is provided by extreme temperature records. The non-homogeneous regional pattern of precipitation shows a positive long-term increase between 30 and 40°S during the interval 1985–2001. Ensemble of climate experiments accomplished with general circulation models provide the most likely changes in temperature and rainfall to occur by the end of this century in relation to present climate. Temperature increases, larger in summer than in winter, will be concurrent with more abundant precipitations in summer, but almost no changes or even small reductions in winter across the Monte. [Copyright &y& Elsevier]

Abstract: Central Sahara rock shelters offer an early and middle Holocene environmental reconstruction. This paper summarises palynological research carried out within a multidisciplinary archaeological research project on the Wadi Teshuinat area (Tadrart Acacus Mts., in south-western Fezzan, Libya). The sites were occupied by hunter-gatherer and pastoralist cultures. On-site pollen data, treated as a single ‘regional site’, showed that different pollen stratigraphies and flora characterised the past phases. Plant macro-remains also helped to understand local plant exploitation and landscape evolution. Pollen spectra showed the following climate oscillations: wet and cool (approx. 8800–8250cal.BC), dry and warm (approx. 7920–7520cal.BC), wet (approx. 7550–7200cal.BC), dry (approx. 6340–6210cal.BC—geoarchaeological evidence), wet and warm (approx. 6250–4300cal.BC, including a wetter and warmer phase at approx. 5500–4600cal.BC); dry and warm (approx. 4250–2900cal.BC); drier and warm (approx. 2900–1600cal.BC, up to the present). Since the early Holocene, both climatic and anthropic factors have played an important and strictly interconnected role in transforming the environment. Thus, while subsistence strategies were adjusting to climatic and environmental changes, the plant landscape was also being slowly and continuously shaped by humans. [Copyright &y& Elsevier]

Abstract: This paper provides a reappraisal of contemporary perspectives on climate change in southern Africa''s Okavango Delta sub-region by drawing on time-line evidence from historical/archival records, field-compiled information and multi-date remotely sensed imagery. By using temporal variations in stream discharge and surface and groundwater distribution as proxies of declining rainfall from the beginning of the 19th century, trends emerging from this reconstruction suggest that progressive contraction of the Delta''s permanent floodplains, the desiccation of Lake Ngami in its distal reaches, fossilization of receiver channels, sustained dewatering of aquifers, and changes in vegetation from grassland to drought-tolerant woody species are non-transient precursors of increasing aridity and deteriorating climatic conditions. With evidence pointing to persistent drying sequences and system failures to revert to moister climate conditions of the recent historical past, hypotheses that characterize deteriorating rainfall and recurring flood failures in this environment as isolated singularities in a punctuated equilibrium need to be reconsidered in order to provide empirically grounded planetary change perspectives that are consistent with evidence over long-term temporal horizons. [Copyright &y& Elsevier]

Abstract: We provide a position paper, using a brief literature review and some new modelling results for a subset of succulent plant species, which explores why Namaqualand plant diversity might be particularly vulnerable to anthropogenic climate change despite presumed species resilience under arid conditions, and therefore a globally important test-bed for adaptive conservation strategies. The Pleistocene climate-related evolutionary history of this region in particular may predispose Namaqualand (and Succulent Karoo) plant endemics to projected climate change impacts. Key Succulent Karoo plant lineages originated during cool Pleistocene times, and projected air temperatures under anthropogenic climate change are likely to exceed these significantly. Projected rainfall patterns are less certain, and projections of the future prevalence of coastal fog are lacking, but if either of these water inputs is reduced in concert with rising temperatures, this seems certain to threaten the persistence of, at least, narrow-endemic plant species. Simple modelling approaches show strong reduction in spatial extent of bioclimates typical of Namaqualand within the next five decades and that both generalist species with large geographic ranges, and narrow-range endemics may be susceptible to climate change induced loss of potential range. Persistence of endemics in micro-habitats that are buffered from extreme climate conditions cannot be discounted, though no attempts have been made to address this shortcoming of broader scale bioclimatic modelling. The few experimental data available on elevated temperature and drought tolerance suggest susceptibility of leaf succulent species, but high drought tolerance of non-succulent shrubs. Both species-level monitoring and further experimental work is essential to test and refine projections of climate change impacts on species persistence, and the implications for conservation. [Copyright &y& Elsevier]

Abstract: Australia has not always been arid, and the central desert was once well watered. This paper traces the changes in climate and vegetation, leading to the present aridity. At the beginning of the Cenozoic, continental Australia had a warm and humid climate, and the vegetation was mainly meso–micro-thermal (warm to cool temperate) rainforest. Central Australia experienced seasonal rainfall and there may have been limited aridity in the northwest. By the mid–late Eocene, rainforest in central Australia was restricted to the well-watered valley bottoms, with sclerophyll vegetation on the slopes and ridges. In the latest Eocene–earliest Oligocene, there was an abrupt cooling of ocean waters and the diversity of megathermal angiosperms decreased. The early–mid-Miocene was warm–humid and there was a considerable diversity of forest types. Woodlands and Casuarinaceae forests became more common. Central Australia was seasonal, with a very warm season of high evaporation. In Western Australia, regular flows in the palaeodrainage systems had stopped by the mid-Miocene and this marked the first major step towards aridity. The late Miocene was cool and dry, with a major reduction of rainforests and an increase of Eucalyptus/casuarinaceous sclerophyll forests in inland southeastern Australia. Regular burning became a feature of the eucalypt forests. Rainforest persisted, however, along the east coast and highlands of Australia. Central Australia became more arid with dry woodland and chenopod shrublands. Rainforests continued to decrease during the Pliocene and grasslands developed in central northern Australia. By the early Pleistocene, the modern climatic regime had been established, but precipitation was higher than today. Cycles of open, shrubland/grasslands/herbfields and wooded vegetation accompanied the arid glacial and humid interglacial cycles (respectively). About 0.5Ma, there was a change to a drier climate, but it was still wetter than today. The last glacial period was particularly harsh, and the present interglacial period is drier than the previous interglacial. Aridity has thus increased in a number of steps, following the first major step towards aridity in the early Miocene. Distinctive elements of the vegetation can be traced back to times when the arid zone was humid and supported rainforest. The elements, which have remained in arid regions, are the few that could tolerate or adapt to the drier climates. The taxa, which could not cope with these changing conditions, were eliminated from the arid regions. [Copyright &y& Elsevier]

Abstract: The objective of this paper is to illustrate the importance of variation in water availability to temporal variation in vegetation dynamics in arid and semi-arid ecosystems. We hypothesize that fine-scale pulses of precipitation interact with longer scale variation in climate and weather to generate temporal variation in plant community composition. Arid and semi-arid regions exhibit great temporal variability in water availability as a result of variation in climate and weather at multiple scales and vegetation-soil water feedbacks. The scales of variation include: shifting climate regimes over centuries and decades, inter-annual variation in weather patterns, seasonal differences in winter and summer precipitation, and within-season variability in precipitation frequency and magnitude. In arid and semi-arid regions, pulses of rainfall are separated by intervening dry periods of variable lengths. This situation results in fluctuating availability of water that limits plant production and controls other ecological processes, such as rates of nutrient cycling. In some semi-arid and arid systems, temporal variation in water availability may create positive feedbacks that facilitate encroachment of C3 woody plant species into areas formerly dominated by C4 grasses. Our ability to predict these complex shifts in vegetation composition may be improved by including temporal variation in climate, weather, and ecosystem processes. [Copyright &y& Elsevier]

Abstract: We investigated the effects of winter and summer drought on a shrub/grass community of the Colorado Plateau in western North America, a winter-cold, summer-hot desert that receives both winter and summer precipitation. Summer, winter and yearlong drought treatments were imposed for 2 consecutive years using rainout shelters. We chose three perennial species for this study, representing different rooting patterns and responsiveness to precipitation pulses: Oryzopsis hymenoides, a perennial bunch grass with shallow roots; Gutierrezia sarothrae, a subshrub with dimorphic roots; and Ceratoides lanata, a predominantly deep-rooted woody shrub. Growth for all three species was far more sensitive to winter than to summer drought. The primary reason was that plants did not grow in summer and also did not appear to use summer-assimilated carbon to support growth in the following spring. We hypothesize that the relative scarcity and uncertainty of summer rain on the Colorado Plateau prevents most species from evolving adaptations that would improve their use of summer rain. Together with the results of the companion paper, which focused on plant water relations, we conclude that variation in fall to spring precipitation would have strong effects on primary productivity, and could cause reversible fluctuations in community composition, while increased variation in summer precipitation, through causing high rates of mortality among shallow-rooted species in dry years, has the potential to cause lasting and perhaps irreversible community change, especially if coinciding with the invasion of western landscapes by cheatgrass, tumble weed and other grazing tolerant exotics. [Copyright &y& Elsevier]

This paper discusses the sources, spatial distribution, frequency and trend of dust storms in China. Most dust storms in China originate from one of three geographic areas: the Hexi (River West) Corridor and western Inner Mongolia Plateau, the Taklimakan Desert, and the central Inner Mongolia Plateau. Dust is most likely from deteriorated grasslands, Gobi, alluvial, lacustrine sediments and wadis at the outer edge of deserts. But deserts themselves contribute only slightly to the dust storm directly. Two geographic areas frequently have dust storms: one is in the western Tarim Basin, a ground surface of deteriorated land and wadi, but it only affects its neighboring areas, and the other one is in the western Inner Mongolia Plateau, a ground surface of Gobi, alluvial and lacustrine sediments, but it causes most of the dust storms in north China. Generally speaking, dust storms have reduced in most regions of China from the 1950 to 2000. Dust storms are highly correlated with human activities and climate changes. [Copyright &y& Elsevier]

This paper analyses climate change in the Yuanmou dry-hot valley area since the 1950s and compares it with that on the Yunnan plateau (Chuxiong City, Wuding County and Dongchuan City). Annual average temperature, the coldest month average temperature, annual evaporation, annual sunshine hours and annual mean wind speed, all have declined, while the annual rainfall and the average relative humidity have slightly increased. The causes of climate change are chiefly the result of large-scale irrigation in the cultivated land and the restoration of vegetation, and also related to local environmental change. [Copyright &y& Elsevier]

Dryland smallholders are faced with the challenges of achieving resilience and agricultural sustainability. This is in addition to constraints such as lack of capital, inputs, and often poor extension services. The risk of extreme weather events poses a great challenge to food security in drylands as the impacts of climate change increases. This paper examines the challenges faced by smallholders and the limitations of traditional farming systems in Sudano-Sahelian zones amidst climate change and emerging armed conflicts with special focus on the Sudano-Sahelian Nigerian drylands. The review reports three key findings as follows: first, smallholders have been active in managing short-term environmental risks and challenges by using local knowledge to improve production and short-term resilience. Secondly, concerns about potential longer-term climatic changes such as longer droughts, desertification, the impact of the drying of the Lake Chad, armed conflicts and extreme weather events could hinder resilience. Third, an increasing rainfall variability, soil/nutrient degradation and farming systems adopted could limit or undermine resilience strategies, especially if new environmental challenges exceed those previously experienced. This review suggests a need for additional research into innovative drylands' sustainability and resilience practices in response to a changing climate linked to other social challenges. • Drylands smallholders are resilient to changes in the climate they have experienced. • Production is restricted by new social challenges. • Climate change, and other challenges will limit food security. • Current adaptation not sufficient if new environmental challenges emerge. • More innovative strategies should be researched into for resilience. [ABSTRACT FROM AUTHOR]

Migration has become an adaptation strategy in response to economic transition and changing climate in the arid Mongolia. This paper reviews migration in Mongolia in the past few decades, particularly from the early 2000s to the mid-2010s using the data during 2001–2014 of the Mongolia National Labor Survey. Urbanization accounted for over 80% of all migration, mostly into the capital city Ulaanbaatar (UB), where nearly 70% of recent population growth was from migration. The results indicated that married and more educated people were more likely to migrate to urban areas and less likely to migrate to rural areas. Higher wage was a major driver for people to move to cities from the pastoral livelihoods. Migratory rates to both urban and rural areas increased during 2011–2014 following a severe disaster, the 2009–2010 dzud. People from the eastern region were more likely to move back to the rural area than those living in the western region as the east had a more favorable climate for pastoralism. The results confirm the importance of climate and weather changes in migration along with several socio-economic indicators. • Urbanization in Mongolia accounted for over 80% of all migration, mostly into the capital city Ulaanbaatar (UB). • Married and more educated people were more likely to migrate to urban areas. Higher wages were a major driver for people to move to cities from the pastoral livelihoods. • The results confirm the importance of climate and weather changes in migration along with several socio-economic indicators. • Migratory rates to both urban and rural areas increased during 2011–2014 following a severe disaster, the 2009–2010 dzud. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to examine the beef value chain and identify climate change adaptation and investment options in the semi-arid areas of northern Kenya. The research uses an innovative approach to value chain analysis, namely the three-step Value Chain Analysis for Resilience in Drylands (VC-ARID) that considers the specific characteristics of semi-arid systems. All the respondents interviewed along the value chain have perceived changes in rainfall, temperature and climate extremes – especially drought – over the past 15 years and have experienced the impacts of these changes on their livestock. The findings show that pastoralist producers need to invest in fattening programmes at their ranches or via feedlots to increase the quality of the beef they produce. There is significant potential to improve the fattening stage in the value chain, since it would contribute towards meeting demand in the expanding high-end markets that require finished, top-quality meats. • Pastoralists beef value chain is more informal, traditional, extensive pastoralism. • Private ranches value chain is formal and incorporates fattening of livestock. • Pastoralists rely on mobility for coping with climate risk. • Climate change has negatively impacted on semi-Arid livestock production. • There is potential to improve and expand the fattening stage of the value chain. [ABSTRACT FROM AUTHOR]

Climate change will likely impact rainfall characteristics in particular locations; the amount, seasonality, variability and spatial patterns. In developing countries, this presents challenges for rural smallholder farmers as their livelihoods are largely based on rain-fed practices. Changes in climate patterns could increase farmers' vulnerability and the need for intervention. In this paper, we develop new metrics of analysis motivated by qualitative research with smallholder farmers. Previous research found that farmers' understanding of historical rainfall change is accurate, yet diverge from some research studies. We analyze meteorological station rainfall data using metrics that are familiar to smallholders. Farmers' perceptions of rainfall in southern Ethiopia were explored through interviews conducted in three communities. Our findings identified some forms of convergence, as well as divergence, in farmers' perception of rainfall trends and meteorological station data results. In asking the question 'Why do data based on farmer experiences of rainfall variability differ from meteorological station data?', we show that using existing data and applying farmer-influenced metrics can improve the information shared with farmers. We argue that, under further climate change, it will be increasingly important to convey meteorological information to farmers in ways that are relevant to them and their agricultural livelihoods. • Smallholder farmer experiences and climate science often diverge. • We develop new metrics motivated by research with smallholders. • New metrics and analyses can bridge some divergences. • Methods developed are relevant for communicating climate science with farmers. [ABSTRACT FROM AUTHOR]

Abstract: The climatic controls on decomposition rates have gained considerable interest in recent years because of a perceived risk that elevated global temperatures could lead to positive green house gas feedbacks from soil ecosystems. Previous relationships between decomposition rates and abiotic variables like temperature and moisture have been proved confounding, particularly for dryland ecosystems. Decomposition rates of two grass species, Pseudoroegneria spicata (Pursh) Á. Löve and Calamagrostis rubescens Buckley, which represent dominant understory cover at either end of a semi-arid grassland to forest ecocline near Kamloops, British Columbia, Canada, were measured. Despite differences in %N and C:N, decomposition rates between the two species were similar. Elevation was strongly correlated with rate of decomposition for both species. We provide evidence of a positive correlation of water availability and a negative correlation of temperature on decomposition rates along the elevational ecocline. Decomposition rates were higher during the wetter spring period than during summer, at higher elevations and in more mesic ecosystems. We found no ‘home-field’ advantage for P. spicata and C. rubescens on decomposition rates. Our results provide evidence that available moisture is an important control on decomposition rates in dryland ecosystems. [Copyright &y& Elsevier]