Traditional Mobile Pastoralism in a Contemporary Semiarid Rangeland in Namaqualand,South Africa

Pastoral systems are regarded as complex social-ecological systems with components that interact and change over a range of spatial and temporal scales. As such, herd mobility has traditionally been used to respond to the dynamic nature of these systems. However, mobile pastoral systems around the world are becoming more constrained and increasingly fragmented with important implications for herd mobility. This study assessed the spatial distribution of 256 herds and their mobility patterns over a decade in the 10 villages that comprise the spatially constrained Leliefontein pastoral area in South Africa. We developed a hierarchical model of rangeland use, which showed that several stratified and connected socioeconomic, climatic, and environmental factors determined the spatial and temporal use of grazing areas in this 192 000-ha semiarid environment. At the highest level of use, access to the Leliefontein pastoral area is formally regulated. At the next level, the place of residence of herd owners largely defined which village commons was used by their livestock. At the third level of rangeland use, the wealth status of owners determined where in relation to human settlements their herds were located. At the lowest level in the hierarchy, the locations of water and croplands delineated seasonal grazing areas and the movement of stockposts. These stratified factors, together with the overall variability in grazing resource availability and the different decision making processes involved, resulted in high flexibility and diversity of herd mobility patterns at the lowest level of rangeland use. This, in turn, ensured heterogeneity in resource use over a range of spatial and temporal scales. It was concluded that policies should embrace the complexity of the pastoral system and enable the adaptive management of herds. This could reduce the level of vulnerability experienced by pastoralists to climate variability and wider societal change.     

The influence of Pechuel-Loeschea leubnitziae (wild sage) on grass sward and soil seed bank composition

Soil seed banks provide not only a historical record of vegetation composition but also the potential for post-disturbance revegetation. Pechuel-Loeschea leubnitziae (wild sage) is a multistemmed, aromatic shrub, occurring in Namibia, Botswana, Swaziland, Zimbabwe and the northern regions of South Africa, that colonises disturbed regions on sandy, alkaline soils. The influence of differing levels of P. leubnitziae cover on soil seed-bank characteristics and aboveground herbaceous species composition was determined by examining aboveground species composition, recorded in the field, and soil seed-bank species composition, determined by recording germinations from topsoil samples collected at each of 104 sites in the southern Okavango Delta. No correlation was observed between aboveground and soil seed-bank composition (p = 0.209). Cover of P. leubnitziae did not affect soil seed-bank species composition (p = 0.31) or the grass:non-grass ratio within the seed bank (p = 0.308). It did, however, affect aboveground grass composition (p = 0.018), with increasing P. leubnitziae cover associated with increasing abundance of poor-quality, shade-tolerant grass species. This confirms the observations that encroachment of P. leubnitziae may be associated with a decrease in veld quality and carrying capacity, and highlights the necessity for further study to facilitate a better understanding of the species for management purposes.     

Salinity Effects on Germination of Artemisia herba–alba Asso: Important Pastoral Shrub from North African Rangelands

Artemisia herba–alba Asso (known in Arabic as Shih) is an evergreen aromatic shrub endemic in North African rangelands with high pastoral and medicinal relevance. The present work was designed to determine the effect of four soluble salts (NaCl, Na₂SO₄, MgCl₂, and CaCl₂) on germination of A. herba–alba seeds. Four concentrations (0, 50, 10, and 150 mM) of each salt were used to test the influence of salinities on germination percentage (GP), rate of germination (RG), and germination tolerance index (GTI %). The experiment was conducted in a controlled incubator with a 12h–photoperiod under 15°C dark/25°C light. The results showed that both GP and (RG) decreased significantly with salinity, and the highest GP was observed in the distilled water control (~ 80%). The germination tolerance index (GTI %) revealed that A. herba–alba seeds were more tolerant to CaCl₂ than other soluble salts. Comparatively, at high salt concentrations, MgCl₂ and Na₂SO₄ were generally the most toxic salts followed by NaCl and CaCl₂. The germination of A. herba–alba over a wide range of soluble salts suggests that this species can establish in salt-degraded soils. Therefore, this species appears a promising candidate for the rehabilitation of rangeland with saline soils.     

Salinity an Environmental “Filter” Selecting for Plant Invasiveness? Evidence from Indigenous Lepidium alyssoides on Chihuahuan Desert Shrublands

A better understanding of site-specific factors such as soil salinity that regulate plant invasions is needed. We conducted a 3-mo greenhouse study to evaluate the salinity responses of three local maternal sources of Lepidium alyssoides, which is an indigenous species shown to aggressively colonize disturbed shrubland sites in the southwestern United States, including those affected by high salinity and sodicity. Results indicated that there were little or no population effects on plant evapotranspiration (ET), growth, and tissue Na and Cl concentrations. Significant reductions in seedling growth and ET were largely independent of various isosmotic saline irrigation solutions that included NaCl, Na₂SO₄, and CaCl₂, each at ? 0.1 MPa and ? 0.2 MPa, suggesting that ET and growth were controlled by solution osmotic potential. The combined Na and Cl concentrations in leaves were 9–10% of dry weight with no visible sign of injury. However, increasing leaf mortality and abscission as a proportion of total leaf production was observed in the high-salt treatments (? 0.2 MPa), with a combined Na and Cl concentration reaching 16% with high NaCl. Under saline conditions, considerable foliage salt loads of this species could deposit high-salt litter to potentially alter a landscape to its own favor and to the detriment of other salt-sensitive species. Results of this study add to a limited quantitative database on site-specific salinity factors governing plant invasions by showing the potential for these populations to behave invasively under saline conditions and, thus, potential for soil salinity assessment to predict incipient populations. However, due to its halophytic traits and indigenous status, L. alyssoides may alternatively provide ecosystem services to salinized shrublands of the arid and semiarid southwestern United States.     

高寒退化草地恢复中种子包衣对出苗的影响

采用植物性吸水材料对垂穗披碱草(Elymus nutant)和山野豌豆(Vicia amoena)种子进行包衣处理,在模拟高寒草地条件下观察包衣种子的出苗,同时测定包衣混合物的持水力.结果表明,最适条件下两种牧草种子的出苗率分别为86%和88%;在模拟条件下,种子的出苗率分别为38%和24%.经过包衣处理后,种子的出苗...     

Wildlife or livestock? New directions for developing communal rangelands in South Africa

The paper agrees with three fundamental points raised by Vetter (in this issue), whilst highlighting an emerging trend in wildlife land use, which should be considered in policy making. Firstly, the paper supports the argument that communal rangelands are important as objects of biodiversity conservation and, secondly, the argument that livestock production alone is not sufficient as a mechanism for alleviating poverty, but rather livelihoods diversification and multisectoral strategies are required for this purpose. Lastly, the paper supports the need for mechanisms to ensure tenure security for sustainable use of communal rangelands. I argue that the historical shift to wildlife land use previously observed on private farms in South Africa is now inevitable on communal rangelands and will require explicit consideration in the policy on communal rangelands. Although such development in the communal rangelands has potential to meet the important goals of livelihoods diversification as indicated by Vetter, it also has potential to threaten existing rural livelihoods. The paper suggests several issues to be considered as wildlife becomes part of the rural landscape in some areas, in addition to issues raised by Vetter relevant to policy making.     

The good shepherd: remedying the fencing syndrome

In this paper the use of fenced grazing camps to manage the rangeland commons is challenged. A historical perspective is presented on fencing and rotational grazing in South Africa. Two case studies in KwaZulu-Natal and the Northern Cape illustrate the factors that influence the management of rangelands under communal land tenure without the use of fences. It is argued that herding is preferred over fencing. The reintroduction of herding could reap multiple benefits such as improving rural livelihoods, reviving customary practice, reducing stock theft, reducing predation and improving biodiversity management. The paper concludes with some issues for consideration when implementing herding as a multipurpose strategy for improved rural livelihoods and sustainable management of natural resources.     

Reshaping women's land rights on communal rangeland

This paper aims to contribute to the debates on communal rangelands and analyses the gendered dimension of land rights and land access in the rural areas of Namaqualand. The actual gender relations within rural communities and the emergence of strategies that are being pursued in communal land processes are obscured and often ignored in policies about communal rangelands, which overemphasise ‘the ecological and economic impact’ and the balancing of these dimensions. As active, primary users, women play a central role in livelihoods supported by communal rangelands yet their access to land is mediated through their relationships with men, effectively circumventing women's land autonomy. A wider debate is necessary to advance the largely superficial policy considerations of women's position in relation to communal rangelands land and their social exclusion on the basis of traditional control of land, forms of access and claiming of use rights. The paper discusses the complexity of land rights under communal land tenure and argues that, despite traditional and policy barriers, women in traditional systems of male-dominated land rights have had some success in accessing communal rangelands. Greater policy impetus is necessary to leverage equitable and independent land access for women amidst debates about management of communal rangelands.     

Rain Use Efficiency,Primary Production and Rainfall Relationships in Desert Rangelands of Tunisia

Desert rangelands are characterised by low and highly variable rainfall regime, low forage production and high heterogeneity in the distribution of natural resources. This study was carried out in the desert rangelands of Tunisia to evaluate the response of different rangelands to annual rainfall in terms of aboveground net primary production (ANPP) and rain use efficiency over a 10‐year period (2003–2012). In general, ANPP values were relatively low (123 kg DM ha⁻¹ y⁻¹) but would tend to increase with increasing annual rainfall for all rangeland types. The highest value of ANPP was observed from Stipagrostis pungens and Hammada shmittiana communities (sandy‐soil) during the wet year 2011. In contrast, rain use efficiency tends to decline with the highest annual rainfall and varies among rangeland types and with an average of 1·9 kg DM ha⁻¹ mm⁻¹ y⁻¹. Rain use efficiency tended to be higher during dry years and lower during wet years and tended to be higher on S. pungens and H. shmittiana (sandy‐soils) and lower on Helianthemum kahiricum (loamy soils). Therefore, understanding how rainfall affects productivity in rangelands is critical for predicting the impact of land degradation on the functioning of these ecosystems. It can be used to explain production decline associated with desertification as well as to assess rangeland conditions. Copyright © 2015 John Wiley & Sons, Ltd.