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To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1477-8947.2007.00154.x Byline: Lindsay C. Stringer (1), Mark S. Reed (2), Andrew J. Dougill (2), Mary K. Seely (3), Martin Rokitzki (4) Keywords: UNCCD; Participation; Land degradation; Swaziland; Botswana; Namibia; Africa Abstract: Abstract The United Nations Convention to Combat Desertification (UNCCD) emphasizes the need for public participation in land degradation assessment and rehabilitation. While participatory approaches are supported by a growing body of research and practice, meaningfully involving the people affected by land degradation is far from straightforward. This paper investigates the challenge of using the UNCCD as a guide to influence community participation in policy-making and practice at national and local levels by analyzing experiences from three southern African countries. We show that the UNCCD represents a useful normative framework for addressing degradation problems, but that the participatory ethos is difficult to enact at the national level. Whilst there is increasing evidence that combining local and scientific knowledge using participatory mechanisms can deliver the benefits that the Convention strives to achieve, communication between researchers and practitioners, and those involved in implementing the UNCCD at the national level needs to be strengthened. Broad lessons and best practices in incorporating participatory practices into policy development are elucidated. Our case studies show that a range of mixed-method, interdisciplinary approaches can enable policy-makers and practitioners to meaningfully engage those who are affected by land degradation in its definition, assessment and rehabilitation. Author Affiliation: (1)Development Policy and Management, School of Environment and Development, University of Manchester, UK (2)School of the Environment, University of Leeds, UK (3)The Desert Research Foundation of Namibia, Windhoek, Namibia (4)Agricultural Development, Programme Management Department, Eastern and Southern Africa Division, Rome, Italy Article note: Lindsay Stringer is with the Institute for Development Policy and Management, School of Environment and Development, University of Manchester, UK. E-mail: Lindsay.stringer@manchester.ac.uk, Mark Reed and Andrew Dougill are with the Sustainability Research Institute, School of the Environment, University of Leeds, UK., Mary Seely is with The Desert Research Foundation of Namibia, Windhoek, Namibia., Martin Rokitzki is with the International Fund for Agricultural Development, Programme Management Department, Eastern and Southern Africa Division, Rome, Italy.

All perennial plants harbor diverse endophytic fungal communities, but why they tolerate these complex asymptomatic symbioses is unknown. Using a multi-pronged approach, we conclusively found that a dryland grass supports endophyte communities comprised predominantly of latent saprophytes that can enhance localized nutrient recycling after senescence. A perennial bunchgrass, Stipagrostis sabulicola , which persists along a gradient of extreme abiotic stress in the hyper-arid Namib Sand Sea, was the focal point of our study. Living tillers yielded 20 fungal endophyte taxa, 80% of which decomposed host litter during a 28-day laboratory decomposition assay. During a 6-month field experiment, tillers with endophytes decomposed twice as fast as sterilized tillers, consistent with the laboratory assay. Furthermore, profiling the community active during decomposition using next-generation sequencing revealed that 59–70% of the S. sabulicola endophyte community is comprised of latent saprophytes, and these dual-niche fungi still constitute a large proportion (58–62%) of the litter community more than a year after senescence. This study provides multiple lines of evidence that the fungal communities that initiate decomposition of standing litter develop in living plants, thus providing a plausible explanation for why plants harbor complex endophyte communities. Using frequent overnight non-rainfall moisture events (fog, dew, high humidity), these latent saprophytes can initiate decomposition of standing litter immediately after tiller senescence, thus maximizing the likelihood that plant-bound nutrients are recycled in situ and contribute to the nutrient island effect that is prevalent in drylands. [ABSTRACT FROM AUTHOR]

The future of fog‐dependent habitats under climate change is unknown but likely precarious; many have experienced recent declines in fog. Fog‐dependent deserts particularly will be threatened, because, there, fog can be the main water source for biota. We review the interactions between fog and fauna of the Namib Desert, about which there is 50 yr of research. We resynthesize the data, seeking patterns and mechanisms that could provide a framework for predicting outcomes of changes in fog regime in other fog‐dependent deserts. In the Namib, fog constitutes the most‐predictable form of free water. At least 48 Namib animal species consume free water from fog, or are likely to do so, employing both liquid and vapor phase. Fog also sustains plants that form the base for metabolic water production and wets the diet to provide pre‐formed water. So fog provides or underpins all the water intake of Namib fauna. Only a few species are active fog‐harvesters, though. Among Namib beetles, two species are unique in that they fog‐bask; they assume stereotyped postures in wind‐driven fog and droplets deposit on their carapaces. Some Namib beetle species construct surface ridges that trap fog water, which they consume. Some arthropods emerge from their subsurface habitats, or occupy its wet top layers, to access fog water, at times and in conditions outside their usual surface activity. Many more taxa, including vertebrates, use fog water opportunistically. They do not actively seek it out but use it when available. Acquiring fog water from droplets requires overcoming spherical surface tension so is possible only for animals heavier than ~100 mg. Smaller animals extract water from films or acquire it in the vapor phase. Some Namib animals use hygroscopic surfaces to extract vapor from unsaturated air, at ambient humidities attained in fog or sometimes between fogs. Rapid acquisition of water during episodic fog events creates problems for storage and osmoregulation, which some Namib animals have solved in enterprising ways, including long‐term internal storage of water and sequestering of osmolytes. Although not yet comprehensive, the body of research reviewed, and the principles that we have elucidated underlying fog usage, should inform future research on fauna throughout fog‐dependent deserts. [ABSTRACT FROM AUTHOR]

The present work considers morphological and sedimentary evidence from floodplain island sediments in the ephemeral Kuiseb river of central coastal Namibia. Morphologically the islands constitute point bars, curvilinear ridges and composite megaforms. The island sediments consistently comprise two lithofacies - a lower relatively thick often massive silt-very fine sand which is overlain by an upper, thinner, intermittent fine sand. The structure and texture of the lower beds suggest that early island deposition took place as a series of mass flows in association with low velocity stream flow. Originating from preexisting upstream silt and very fine sand, the mass flows appear to have entered the main Kuiseb valley under unusual conditions of relatively heavy, coastal rainfall during the generally drier conditions of the Little Ice Age. Upon desiccation the sediments were soon partially indurated due to extreme evaporation effects. The upper fine sand lithofacies are regarded as being the product of more recent major flood events. The fine sands were deposited as a result of upper catchment rainfall leading to the formation of mainly overbank and levee deposits, in addition to eroding the islands into their current morphology. Hence the Kuiseb floodplain islands are characterised as hybrid deposits reflecting changing palaeo-climatic conditions over the last 600 years or so. This type of hybridisation involving infrequent earlier mudflow deposition, the induration and retention of the deposits and their later modification by renewed flooding, might be regarded as an important characteristic of moderate to low energy hyper-arid rivers worldwide. [ABSTRACT FROM AUTHOR]

The Archaeology of the Wadi Al-Hasa, West-Central Jordan, Volume 1: Surveys, Settlement Patterns and Paleoenvironments. NANCY R. COINMAN, editor, 198. Arizona State University Anthropological Research Papers, Tempe, AZ. v + [...]

Non-rainfall water inputs ( NRWIs) are the least studied hydrological components in most ecosystems. These NRWI components potentially play an important role in ecosystem dynamics and are particularly important for water-limited systems. In this review, we summarized recent advances investigating the effects of NRWIs on various ecosystem functions, including vegetation-water relations, biogeochemical cycling, groundwater recharge, as well as reptile and invertebrate adaptations. We also identified key knowledge gaps such as the mechanisms of NRWIs alleviating vegetation water stress, sources of the NRWI components and their quantitative contributions to ecosystem functions. To better predict the ecosystem responses to climate change especially in drylands, a better understanding and quantification of NRWI contributions is essential. WIREs Water 2017, 4:e1179. doi: 10.1002/wat2.1179 For further resources related to this article, please visit the . [ABSTRACT FROM AUTHOR]

Soil moisture is a key variable in dryland ecosystems since it determines the occurrence and duration of vegetation water stress and affects the development of weather patterns including rainfall. However, the lack of ground observations of soil moisture and rainfall dynamics in many drylands has long been a major obstacle in understanding ecohydrological processes in these ecosystems. It is also uncertain to what extent rainfall controls soil moisture dynamics in fog dominated dryland systems. To this end, in this study, twelve to nineteen months’ continuous daily records of rainfall and soil moisture (from January 2014 to August 2015) obtained from three sites (one sand dune site and two gravel plain sites) in the Namib Desert are reported. A process-based model simulating the stochastic soil moisture dynamics in water-limited systems was used to study the relationships between soil moisture and rainfall dynamics. Model sensitivity in response to different soil and vegetation parameters under diverse soil textures was also investigated. Our field observations showed that surface soil moisture dynamics generally follow rainfall patterns at the two gravel plain sites, whereas soil moisture dynamics in the sand dune site did not show a significant relationship with rainfall pattern. The modeling results suggested that most of the soil moisture dynamics can be simulated except the daily fluctuations, which may require a modification of the model structure to include non-rainfall components. Sensitivity analyses suggested that soil hygroscopic point (sh) and field capacity (sfc) were two main parameters controlling soil moisture output, though permanent wilting point (sw) was also very sensitive under the parameter setting of sand dune (Gobabeb) and gravel plain (Kleinberg). Overall, the modeling results were not sensitive to the parameters in non-bounded group (e.g., soil hydraulic conductivity (Ks) and soil porosity (n)). Field observations, stochastic modeling results as well as sensitivity analyses provide soil moisture baseline information for future monitoring and the prediction of soil moisture patterns in the Namib Desert. [ABSTRACT FROM AUTHOR]

The sand dunes and inter-dune zones of the hyper-arid central Namib Desert represent heterogeneous soil habitats. As little is known about their indigenous edaphic bacterial communities, we aimed to evaluate their diversity and factors of assembly and hypothesized that soil physicochemistry gradients would strongly shape dune/interdune communities. We sampled a total of 125 samples from 5 parallel dune/interdune transects and characterized 21 physico-chemical edaphic parameters coupled with 16S rRNA gene bacterial community fingerprinting using T-RFLP and 454 pyrosequencing. Multivariate analyses of T-RFLP data showed significantly different bacterial communities, related to physico-chemical gradients, in four distinct dune habitats: the dune top, slope, base and interdune zones. Pyrosequencing of 16S rRNA gene amplicon sets showed that each dune zone presented a unique phylogenetic profile, suggesting a high degree of environmental selection. The combined results strongly infer that habitat filtering is an important factor shaping Namib Desert dune bacterial communities, with habitat stability, soil texture and mineral and nutrient contents being the main environmental drivers of bacterial community structures. [ABSTRACT FROM AUTHOR]

The hyper-arid western Namib Sand Sea (mean annual rainfall 0–17 mm) is a detritus-based ecosystem in which primary production is driven by large, but infrequent rainfall events. A diverse Namib detritivore community is sustained by minimal moisture inputs from rain and fog. The decomposition of plant material in the Namib Sand Sea (NSS) has long been assumed to be the province of these detritivores, with beetles and termites alone accounting for the majority of litter losses. We have found that a mesophilic Ascomycete community, which responds within minutes to moisture availability, is present on litter of the perennial Namib dune grass Stipagrostis sabulicola. Important fungal traits that allow survival and decomposition in this hyper-arid environment with intense desiccation, temperature and UV radiation stress are darkly-pigmented hyphae, a thermal range that includes the relatively low temperature experienced during fog and dew, and an ability to survive daily thermal and desiccation stress at temperatures as high as 50°C for five hours. While rainfall is very limited in this area, fog and high humidity provide regular periods (≥ 1 hour) of sufficient moisture that can wet substrates and hence allow fungal growth on average every 3 days. Furthermore, these fungi reduce the C/N ratio of the litter by a factor of two and thus detritivores, like the termite Psammotermes allocerus, favor fungal-infected litter parts. Our studies show that despite the hyper-aridity of the NSS, fungi are a key component of energy flow and biogeochemical cycling that should be accounted for in models addressing how the NSS ecosystem will respond to projected climate changes which may alter precipitation, dew and fog regimes. [ABSTRACT FROM AUTHOR]

Most ecological research on hypoliths, significant primary producers in hyperarid deserts, has focused on the diversity of individual groups of microbes (i.e. bacteria). However, microbial communities are inherently complex, and the interactions between cyanobacteria, heterotrophic bacteria, protista and metazoa are likely to be very important for ecosystem functioning. Cyanobacterial and heterotrophic bacterial communities were analysed by pyrosequencing, while metazoan and protistan communities were assessed by T-RFLP analysis. Microbial functionality was estimated using carbon substrate utilization. Cyanobacterial community composition was significant in shaping community structure and function in hypoliths. Ecological network analysis showed that most significant co-occurrences were positive, representing potential synergistic interactions. There were several highly interconnected associations (modules), and specific cyanobacteria were important in driving the modular structure of hypolithic networks. Together, our results suggest that hypolithic cyanobacteria have strong effects on higher trophic levels and ecosystem functioning. [ABSTRACT FROM AUTHOR]

Science education and outreach for sustainable development in arid Namibia encompasses a wide range of topics referring to economic, social and environmental issues. This paper reviews selected programmes implemented at Gobabeb over the past several decades as case studies in effective and innovative education and outreach. Programmes at Gobabeb contribute to testing approaches to capacity building – enhanced knowledge, skills and attitudes – over a wide front. [ABSTRACT FROM PUBLISHER]

Topographic and sediment work in the Kuiseb river, currently an ephemeral stream in central Namibia, has shown that floodplain deposition took place mainly downstream from zones of significant external sediment input. Two floodplain types are identified as floodplain islands which developed as braided river deposits in the midstream section of the river, and infill deposits developed from anastomosing streams in the downstream section. The two types are dependent on the geometry of the river cross section and the amount of sediment available. The topography, sediment content (fine sand and silt units) and structure all imply the deposition of floodplain deposits under wetter conditions. Particle size analysis of floodplain silts in relation to river bed and sand dune silt, indicates a closer association between the floodplains and Quaternary Homeb deposits. These data suggest that the floodplains likely formed under locally wet conditions which eroded the Quaternary Homeb deposits during the early-mid Holocene. [ABSTRACT FROM PUBLISHER]

For the past fourteen years, two Grinnell College graduates have been selected each year for a competitive one-year Grinnell Corps Service Fellowship at the Gobabeb Research and Training Centre in Namibia. A recent survey of the 28 Fellows that completed the program revealed that this is an invaluable experience for the participants, with more than half revealing that it was “life-changing” and a further 43% reporting that it re-affirmed their life goals. Most Fellows felt that their most valuable contribution to Gobabeb was teaching and mentoring Namibian secondary and tertiary students. All Fellows are now either in graduate school or employed in a diverse array of positions reflecting their professional interests that in some fashion “support the common good”, an integral part of Grinnell's mission statement. Synergistic activities that have arisen from this Grinnell–Gobabeb relationship include visiting lecturer opportunities at Grinnell for Namibians; internships for Grinnell students and service fellowships for Grinnell faculty in Namibia; a faculty development seminar in Namibia resulting in more class modules on dryland and southern African topics; a course with embedded travel to the Namib Desert; and independent research projects for students. These exchanges are invaluable for cultivating the cross-cultural understanding needed to address the vexing global environmental challenges of this century. [ABSTRACT FROM PUBLISHER]

Namibia's variable environment has been punctuated by droughts and floods for as long as records are available. Since independence of Namibia in 1990, the challenge of desertification and drought has been high on the agenda of government, various NGOs and farmers of every ilk. Several major programmes and a number of ancillary projects addressed the challenge from a variety of angles, with moderate success, although with limited uptake and long-term implementation. Key results included,inter alia, recognition of the importance of interactive communication from community to policy level, formation of and long-term back-stopping for community institutions as well as individuals, and local level monitoring of land condition. With Namibia's opportunity to host the Conference of Parties (COP11) of the United Nations Convention to Combat Desertification (UNCCD) in September 2013 came the opportunity to review and consolidate the diverse efforts. Under the overall title: ‘Combating Land Degradation in Namibia over 23 years: Learning what matters in DLDD’, five side events were presented. The purpose of this paper is an overall review of efforts to combat desertification in Namibia. [ABSTRACT FROM PUBLISHER]

Endemic to the Namib Desert, Fairy Circles (FCs) are vegetation-free circular patterns surrounded and delineated by grass species. Since first reported the 1970's, many theories have been proposed to explain their appearance, but none provide a fully satisfactory explanation of their origin(s) and/or causative agent(s). In this study, we have evaluated an early hypothesis stating that edaphic microorganisms could be involved in their formation and/or maintenance. Surface soils (0–5cm) from three different zones (FC center, FC margin and external, grass-covered soils) of five independent FCs were collected in April 2013 in the Namib Desert gravel plains. T-RFLP fingerprinting of the bacterial (16S rRNA gene) and fungal (ITS region) communities, in parallel with two-way crossed ANOSIM, showed that FC communities were significantly different to those of external control vegetated soil and that each FC was also characterized by significantly different communities. Intra-FC communities (margin and centre) presented higher variability than the controls. Together, these results provide clear evidence that edaphic microorganisms are involved in the Namib Desert FC phenomenon. However, we are, as yet, unable to confirm whether bacteria and/or fungi communities are responsible for the appearance and development of FCs or are a general consequence of the presence of the grass-free circles. [ABSTRACT FROM AUTHOR]

To investigate whether the sensitivity to environmental temperature varies between nocturnal and diurnal species of tenebrionid beetle, the metabolic rates of three diurnal species (Onymacris plana Peringuey, Onymacris rugatipennis Haag and Physadesmia globosa Haag) and three nocturnal species (Epiphysa arenicola Penrith, Gonopus sp. and Stips sp.) of beetles from the Namib Desert are measured over a range of temperatures (15-40 °C) that are experienced by these beetles in their natural habitat. The diurnal species O. plana, O. rugatipennis and P. globosa exhibit temperature-independent metabolic rates (mean Q10 = 1.2) within temperature ranges that are ecologically relevant for diurnal desert beetles (30-40 °C). Onymacris plana, in particular, has a 20-40 °C rate-temperature slope (0.007 log10 mL O2 h-1 g-1 °C-1; Q10 = 1.1) that is less than half that of the other five beetle species (0.022-0.063 log10 mL O² h-1 g-1 °C-1; Q10 ranges from 1.3-1.9), suggesting that O. plana is more metabolically independent of temperature than the other nocturnal and diurnal tenebrionids being investigated. Animals with metabolic rates that are decoupled from body temperature (or ambient temperature) may have an ecological advantage that allows them to exploit thermal and spatial niches during extreme temperature conditions. [ABSTRACT FROM AUTHOR]

A study on flood water infiltration and ground water recharge of a shallow alluvial aquifer was conducted in the hyperarid section of the Kuiseb River, Namibia. The study site was selected to represent a typical desert ephemeral river. An instrumental setup allowed, for the first time, continuous monitoring of infiltration during a flood event through the channel bed and the entire vadose zone. The monitoring system included flexible time domain reflectometry probes that were designed to measure the temporal variation in vadose zone water content and instruments to concurrently measure the levels of flood and ground water. A sequence of five individual floods was monitored during the rainy season in early summer 2006. These newly generated data served to elucidate the dynamics of flood water infiltration. Each flood initiated an infiltration event which was expressed in wetting of the vadose zone followed by a measurable rise in the water table. The data enabled a direct calculation of the infiltration fluxes by various independent methods. The floods varied in their stages, peaks, and initial water contents. However, all floods produced very similar flux rates, suggesting that the recharge rates are less affected by the flood stages but rather controlled by flow duration and available aquifer storage under it. Large floods flood the stream channel terraces and promote the larger transmission losses. These, however, make only a negligible contribution to the recharge of the ground water. It is the flood duration within the active streambed, which may increase with flood magnitude that is important to the recharge process. [ABSTRACT FROM AUTHOR]

Abstract: Increasingly there is need for efforts integrating natural resource management inclusive of water, land, and biodiversity with actions and developments of humans, particularly in heavily used, sensitive environments such as arid river basins. Integrated Water Resource Management (IWRM) provides the basis for this integration. One such approach used in Namibia is known as the Forum for Integrated Resource Management (FIRM), which aims to enable communities to take a central role in management and development processes in their areas. This approach has recently been tested in the Kuiseb Ephemeral River Basin with the active participation of basin stakeholders. The use of FIRM in basin management requires certain adaptations, especially in the context of ephemeral river basins. The main focus of discussion is how FIRM may be applied to basin management in ephemeral basins, highlighting a case study of the basin management process in the Kuiseb Basin in Namibia. An analysis of similarities and differences between FIRM and its application in basin management is also undertaken, illustrating how the concept is applied to basin management in ephemeral basins, particular lessons learnt and strengths of this approach. The paper concludes with recommendations on how FIRM may be established in basin management with the Kuiseb River basin providing empirical evidence of the positive potential of such an approach. [Copyright &y& Elsevier]

Long-term (25 yr) measures of weather and populations of the 28 most frequently trapped Namib Desert Tenebrionidae (darkling beetles) revealed a population-sustaining effect of fog for eight species using specialized behavioural mechanisms to collect fog water. During a prolonged (18 yr) low-rainfall interval, populations of these fog-collecting species maintained more of their relative abundance than all but one species that does not collect fog. Fog-collecting adaptations include complete change in diel activity period, sand trench and sand parapet building, and fog basking. All eight fog-collecting species persisted during the dry period, whereas 17 of the 19 species lacking fog-collecting adaptations disappeared or declined to less than 1% of their mean abundance. Populations of two species reported to collect fog facultatively during their usual diel rhythm declined as rapidly as species lacking fog-collecting adaptations. These demographic comparisons of fog-collecting species and species that do not do so depended upon monitoring highly variable population fluctuations under the particular climatic events that occurred during this study. The population consequences of adaptations to collecting fog water could not have been identified by any study lasting less than 17 years. [ABSTRACT FROM AUTHOR]