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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]

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]

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]

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]

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]

"Valles Cruceños" rural region, Bolivia, is characterized by intrinsic water scarcity and increasing pressure for food production by the neighboring and fast-sprawling city of Santa Cruz de la Sierra. Here, orographic fog is a phenomenon occurring all year round, representing a sustainable water source for improving farmers' resilience to dry spells and for promoting food security and sovereignty. With the present study, we aim at a first assessment of the potential of fog collection in the area by a 1-year experimental analysis made through 1-m2 fog collectors in 10 different locations. Starting from these data, we design under safe assumption (including sensitivity analysis) a fog water irrigation system providing water for a standard theoretical field with four local crops (maize, green beans, potato, and tomato) in the dry season. The present paper represents the first study on fog collection in Bolivia, showing that, on annual basis, an average of 6.01 l/m2/d can be obtained from most productive areas, with peaks up to 8.93 l/m2/d. Moreover, to the best of our knowledge, the work represents one of the first consistent studies on the productive use of orographic fog, while a large part of the literature focuses on advection fog, mostly occurring on the Pacific Coast of South America. • Orographic fog can improve farmers' resilience to dry spells in sub-Andean Bolivian ridges. • An average of 6.01 l/m2/d can be obtained from most productive areas, with peaks up to 8.93 l/m2/d. • Such fog collection rates can enhance crop production in the dry season. • The study represents the first fog collection study for the Country. • And one of the first on orographic fogs for the region. [ABSTRACT FROM AUTHOR]

The characteristics of the wind regime and the development of dune morphology in the Taklamakan Desert have been the focus of scholars. In this study, we used ERA5 reanalysis wind data at a height of 10 m from 1979 to 2019 to examine the sand transport and wind regime characteristics of the entire Taklamakan Desert. We combined the two latest dune development modes, i.e., bed instability and elongation modes, and determined that: (1) Taklamakan Desert is overall characterized by a lower wind energy environment; the wind and sand activity intensities are highest in the eastern part of the desert, with a decreasing trend from the east to the west. The wind direction in the eastern region shows unimodal characteristics due to the backward easterly wind; the wind regime gradually becomes complicated from the northeast to the southwest; (2) the morphological alignments of dunes can be predicted by such modern wind regimes combined with the latest dune development modes. Large longitudinal dunes in the middle of the desert can be predicted with the elongation mode, whereas secondary transverse dunes, which derive from these composite dunes, can be predicted using the bed instability mode. Collectively, this paper fills the gap of the lack of uniform and standardized macro-scale wind data in the Taklamakan Desert, and the two modes of dune development derived from ERA5 reanalysis data can match the morphology and trend of most modern dunes. • The wind regime in Taklamakan Desert was examined using ERA5 reanalysis data. • ERA5 reanalysis wind data can be used to explain the morphology of modern dunes. • Two dune development modes can predict the alignments of most sand dunes in the desert. [ABSTRACT FROM AUTHOR]

The mechanisms influencing livestock pricing in Kenya are well studied. The determinants of quality-based payments on markets in conflict-affected areas, however, are hardly documented. In this paper, we offer a deeper understanding of transitions towards quality-based payments from the perspective of livestock buyers in the Kerio-Valley, Kenya. The location is known for protracted communal conflicts. Transcripts from qualitative interviews, focus group discussions and field notes from participant observation we coded and analysed using MAXQDA. Our data identify three broad determinants (chain organisation and financing, market system development, quality and value of livestock) relevant for the transition from traditional to quality-based payments for livestock in conflict prone drylands. We then discuss the standard definition of livestock quality by market players, the behaviours of traders, and market institutions as entry points to leverage transitions to quality-based payments in future. Also, seasonal changes and security perceptions influence the potential for introducing quality-based payments. Although limited to the Kerio-Valley, key insights we offer could apply to similar conflict-prone settings in the region. • Quality-based payments for livestock drylands could contribute to peacebuilding. • Value chain organisation and financing supports quality-based payments. • Market system development will be essential for quality-based payments. • Quality and value of livestock requires redefinition. [ABSTRACT FROM AUTHOR]

This paper discusses developing a novel spectral index for desert sand dunes detection using four bands from Sentinel-2 data. This index, called Normalized Difference Enhanced Sand Index (NDESI), uses the blue band (492 nm), the red (664 nm) or the Vegetation Red Edge (VRE) band (782 nm), and two of the Shortwave Infrared (SWIR) bands (1613 and 2202 nm) to generate a grayscale image, where DN values are within −2 to 2. The lowest and highest values represent water bodies and sand dunes, respectively. A threshold calculation technique was used to generate a unique threshold for each image. This index application on several images covering the northern region of Figuig city seems to perfectly highlight sand dunes all over the image, with an overall accuracy of 97.9% and a kappa coefficient of 83.4%. This index is adapted for Landsat 8 data and can track sand dunes change over time. • New spectral index for desert sand dunes detection and monitoring. • Made for Sentinel-2, Landsat-8 and any sensor that have the required bands. • Can discriminate sandy surfaces from soils and alluvium. • Have good accuracy for sand dunes detection. [ABSTRACT FROM AUTHOR]

The Eastern Cape Province, and in particular, it's interior western Karoo region, has long been subject to periodic droughts, with significant implications for it's agricultural sector. From 2015, with some recovery in 2020, the area experienced a severe multi year drought, with negative impacts for a range of sectors, including extensive livestock farming. At the time of the drought, a common narrative in the media stated that the drought was unprecedented. In this paper, we analyze how the drought evolved climatically, as well as its impacts on vegetation and farming conditions. Our findings indicate that it would appear that the drought was not unprecedented. It was, however, considered to be extremely severe – with some local impacts found to be critical. Loss of production impacts, and loss of income, now compounded by the difficulties resulting from the COVID19 pandemic (which has impacted the South African economy severely) are likely to continue to impact the agricultural sector in the Eastern Cape for some time – and given the likelihood of increased frequency of extreme events in southern Africa in the future, we may see more frequent subsequent severe multi-year events. • From 2015, the interior Eastern Cape experienced a severe multi year drought • Popular media narratives described the drought as unprecedented. • In fact, the drought was not unprecedented, but was extremely severe. • The agricultural sector in the Eastern Cape is likely to continue to be vulnerable. [ABSTRACT FROM AUTHOR]

Specific guidelines are needed to overcome dichotomous classifications of lands into degraded or not for leveraging the Land Degradation Neutrality (LDN) concept. Overlooking degrading lands or those at risk of degradation can block LDN. Therefore, this paper proposes a detailed land classification method, and complements LDN with an indicator α (wildfires, landslides and insights on aridity). Indicator α taps the rarely studied LDN-natural hazards nexus. For separating degrading, degraded and non-degraded lands, twelve categories were defined, and indicators were then established. Subsequently, a land potential-hazard informed LDN intervention was planned. These methods target sub-national scales via the Lebanese/Mediterranean Aley district. Findings first revealed that Aley's land cover developed without considering land potential or hazard potentiality. Second, land status categories are distributed as 65% stable (of which 20.18 are lightly used), 8.14% non-degraded (adequately used, recovered and improving), 13.67% degraded, and 13.13% at risk of degradation. However, the district risks shifting towards less healthy land states due to unplanned development and natural hazards inconsideration. Accordingly, the LDN intervention targeted the stable/lightly used, at risk of degradation-/lightly used, overused and lightly used lands for optimization. This approach shifted 33.33% of Aley to adequately used lands, increasing the latter from 8.05% to 41.38%. • The land degradation neutrality-disaster risk reduction nexus is investigated. • A comprehensive classification of land use/health status is presented. • Land Degradation Neutrality concept framework complemented by natural hazards. • A focus on land degradation in Mediterranean settings. • The proposed approach can serve as an inclusive land use planning tool. [ABSTRACT FROM AUTHOR]