The Rangeland Livestock Carrying Capacity and Stocking Rate in the Kailash Sacred Landscape in China

Maintaining the health and productivity of rangelands by controlling the livestock stocking rate to remain within carrying capacity is of significance to ensure sustainable management of rangeland ecosystems. But we know little about the safe carrying capacity in particular rangeland landscapes. This has hampered efforts to use rangelands in a risk-averse manner in fluctuating rainfall environments, and especially in arid and semiarid areas. To address this lack of information, we took Kailash Sacred Landscape in China (KSL-China) as our study site and used remote sensing data, meteorological data and statistical data from 2000 to 2015 to analyze rangeland carrying capacity, stocking rate, and major influencing factors. Rangeland carrying capacity presented an increasing trend, while stocking rate was gradually decreasing, resulting in an increase of carrying rate in the study area. The increased carrying capacity was closely related to increased rainfall. Stocking rate declined owing to government regulations, particularly implementation in 2004 of the national policy of Returning Grazing Land to Grassland. There was a sharp reduction of livestock number below 200 000 standard sheep units (SU) after 2005. The decrease of stocking rate had a stronger effect on rangeland carrying rate than did the increase of carrying capacity. Ecosystem restoration programs have provided subsidies to pastoralists to encourage them to reduce livestock numbers. Our findings suggest that a safe rangeland carrying capacity is ca. 170 000 SU in KSL-China. There is a carrying capacity surplus of ca. 50 000 SU for safe animal husbandry development in the study area. More importantly, future climate warming and increases in grazing may jointly play a key role in affecting rangeland carrying capacity.     

Loss of patch-scale heterogeneity on secondary productivity in the arid shrubland of Western Australia

General models of degradation suggest soil and nutrients are lost and conversion of rainfall into primary productivity is diminished when rangeland is degraded. These models are supported by studies on non-resilient landscapes, where loss of primary productivity also translated into loss of secondary productivity, but have not been tested on resilient landscapes. Elsewhere we showed that loss of chenopod shrubs from a landscape characterized as resilient was associated with declines in plant productivity and efficiency of conversion of rainfall into plant mass. To explore whether these differences in primary productivity translated into differences in secondary productivity, we grazed sheep at five rates of stocking for 10 years on 2000 ha of this landscape. The experiment was necessarily replicated in time not space (i.e. pseudo-replicated), which limits confident extrapolation of results to other landscapes.Productivity of sheep at all except highest rates of stocking varied little between sites where shrubs were abundant or scarce. From an animal production point of view, greater rates of stocking were unsustainable through dry years on the degraded site, but animal performance was generally unaffected on the non-degraded site, where shrubs were abundant. While these results provide evidence of economic penalties associated with degrading a resilient landscape, important ecological penalties were only partially explored.     

Patterns of resource use by livestock during and after drought on the commons of Namaqualand, South Africa

The aim of this study was to determine the effect of drought on grazing patterns of livestock in a communal rangeland in Namaqualand. Water points were the foci of almost all grazing routes even after the drought, and the areas away from the water points were less heavily utilized. The mountains could be regarded as key resource areas for livestock since the grazing intensity was higher in the elevated areas of the rangeland than on the surrounding low lying areas during and immediately after drought. Spatial patterns of resource use by livestock on the commons did not differ during the drought and post-drought period. The lengths of the daily grazing routes were similar for both periods. This may be a consequence of the weakness of animals during the drought when forage was scarce which prevented them from walking further. The size of home ranges of the herds did not change during the two monitoring periods. We attribute this to social reasons because herders try to avoid the mixing of herds. In the commons of Namaqualand, herders are also spatially constrained and this restricts their options to adapt to drought, and hence many animals died.     

Environmental perceptions and practices of livestock keepers on the Namaqualand Commons challenge conventional rangeland management

In South Africa, interventions in communal rangelands proposed by most agriculture-sector institutions are still dominated by the belief that communal herders have little technical skills and by the tenets of “the tragedy of the Commons”, assuming that individual livestock keepers are selfish, norm free, and aiming at maximising short-term offtake and that there is no consistent management of the commons. In this study we show that practices of a diversity of livestock keepers on the Leliefontein Commons of Namaqualand are at odds with this viewpoint: access to rangeland and its use are structured by collective norms and concerns regarding both the sharing of resources and their long-term sustainability. We also show that part of the management of the commons relies on grazing practices which involve tacit and formalised technical knowledge that can be described and modelled. Livestock keepers assess the heterogeneity of the grazing quality of the commons. They are aware of the toxicity and unpalatability of some plants, of the way this differs according to the amount ingested and the availability of other forage, and of the variations of these two factors over seasons of grazing. They classify grazing areas and decide on daily grazing routes according to a complex set of criteria. Carrying capacity of each area is not considered as a fixed parameter but rather as a variable dependant on rainfall. Seasonal movements between areas are designed accordingly. These findings offer a new perspective for research agendas on technical models and extension measures for communal rangeland management particularly in arid and semi-arid areas.     

A synthesis of sociological and biological perspectives on sustainable land use in Namaqualand

A transdisciplinary synthesis, grouped into four main themes, of the key papers in this Special Issue on Namaqualand is provided. Perspectives on current environmental, economic and social issues in the region are interpreted in the context of the past and are used to inform future trajectories of change and development needs within the region. Firstly, in terms of the climatic and biophysical environment, Namaqualand's rich biodiversity is not uniformly distributed and is explained in terms of the spatially heterogeneous geological, pedological and topographical gradients that characterize the region. Spatial and temporal variation in rainfall over long time frames would also have promoted speciation within isolated, poorly-dispersed, leaf succulent populations. Future climate models propose a decrease in rainfall across the region with an associated reduction in livestock production. The second theme provides an historical perspective on changing land use practices in Namaqualand over the last 2000 years. It suggests that they have frequently been influenced by events originating far from the region such as colonial expansion, apartheid legislation and globalization. Local people, particularly marginalised communal farmers have had to adapt to these outside influences within an increasingly confined landscape that has progressively eroded their mobility and restricted their ability to utilise the spatial and temporal variability inherent in semi-arid environments. The third theme shows how livelihood diversification has been one of the key ways in which local people from communal areas have adapted to change. While farming makes up a relatively small part of the income of most households it enhances the resilience of livelihoods in the region. The fourth theme is concerned with land reform, conservation and restoration in Namaqualand. While a significant amount of land has been transferred to previously-marginalised groups, equitable access to these resources is lacking. An exclusively commercial orientation within the extension and development programmes of the Department of Agriculture further hampers the effectiveness of land reform as a tool for reducing levels of poverty in the majority of households in the region. Conservation initiatives could enhance livelihood options in Namaqualand but are viewed by some as being in competition with the state's land reform programme and are too recent to reflect significant regional benefits at this stage. While restoration is possible in severely degraded lands, the costs and operational difficulties in these event-driven, semi-arid systems are emphasised. Finally, this synthesis suggests that the important exogenous drivers of change in the 21st century are likely to be climate, biodiversity conservation initiatives, land redistribution and continued processes of de-agrarianisation as a result of macro-economic change. A focus on building institutions, encouraging livestock mobility within a significantly expanded commons and supporting livelihood diversification are some of the approaches necessary to address the development needs of Namaqualand.     

Long-term dynamics of a semiarid grass steppe under stochastic climate and different grazing regimes: A simulation analysis

We built a grid-based spatial explicit stochastic model that simulates grazing events and basic processes like seedling establishment, growth or mortality of the dominant species in the grass steppes of Patagonia. After evaluating the model with field data, we performed simulation experiments aimed to explore the interaction of precipitation and grazing regimes on vegetation dynamics. Grazing generated a reduction in tussock density which results in a decline in aboveground net primary production (ANPP). Both response variables presented a non-linear behavior including high temporal variability and delay effects, which may prolong for decades. There was a clear threshold in the response of the variables to stock density, though changes become evident only when a highly selective grazing scenario was used. Under high stock density conditions, precipitation use efficiency (PUE) was 82% lower than the values for non-grazed runs. The inter-annual variability of precipitation was more important than the grazing regime in explaining differences in tussock density. Simulation results highlight important issues regarding rangeland management: grazing regime might be as important as stocking density as a degradation agent, temporal lags might obscure degradation processes for decades, the definition of monitoring variables need to consider their response time constants.     

高原草地退化遥感监测对象的地学属性分析--以西藏自治区那曲县为例

本文通过分析那曲县草地退化遥感监测对象的空间分布特征、波谱响应特征和时相特征三个地学属性,得出以下结论:(1)那曲县的自然景观单元分异程度比较低;(2)退化草地植被在TM5、6波段具有高反射值,LAND-SAT TM信息源中具有对草地植被退化敏感的波段TM7,TM5和TM3;(3)高原植被返青比较晚,生长期短,7、8月份是牧草生长旺季。并根据地学属性分析结论选择7月下旬的LANDSAT TM图像作为草地退化动态监测的主要遥感信息源。     

Comparison of vegetation changes along grazing gradients with different numbers of livestock

The objective of this study was to clarify whether the changes in percent cover of plant functional types (i.e., life forms and growth forms) along a grazing gradient reflect the livestock number, which would reinforce the reliability of using a grazing gradient design and improve the management of rangeland. We selected two livestock camps that for many years have had different numbers of livestock, with approximately six times more sheep-equivalents at site 1 than at site 2. Vegetation was sampled in 10 quadrats on five transects along the grazing gradient at each site. In each quadrat, we recorded percent cover of each plant species. Our findings suggested that vegetation changes along the grazing gradient under different livestock numbers were characterized by changes in the cover of life forms: perennial species were replaced by annual species near the camps (10–50 m). However, we did not find growth form change that reflected the difference in the number of livestock.     

The impacts of sustained heavy grazing on plant diversity and composition in lowland and upland habitats across the Kamiesberg mountain range in the Succulent Karoo, South Africa

This study explored the impacts of sustained heavy grazing in six vegetation types across an altitudinal and rainfall gradient in the Kamiesberg mountain range in Namaqualand. The study was carried out across the fence separating the Leliefontein communal area and surrounding privately owned farms. The communal area has been stocked over decades at approximately twice the government recommended stocking rate, while adjacent privately owned farms have generally adhered to recommended rates. Plant community data were collected from 66, 0.1 ha modified Whittaker plots and analysed for diversity and compositional changes. Consideration of community-wide responses through NMDS ordination showed that heavy grazing did not result in the dominance of a few wide-spread, weedy species in communal areas. Species richness at the 0.1 ha scale was also not affected by different land use practices. However, there was a significant compositional shift away from large woody and succulent shrubs, and an associated increase in dwarf shrubs and herbaceous perennial plants on the communal areas. This shift was only evident on the sandy lowland habitats, while a reduction in perennial grass was recorded in the rocky upland habitats on the communal areas. Compositional shifts towards smaller and more ephemeral species in the communal area are indicative of a system more closely dependent on rainfall. This has implications for people's livelihoods in the region, particularly in light of predicted climate change.     

Eco- immigr ation Policy for the Degr aded Rangeland and Responses of Herd Family in the Sour ce Region of Yellow River——Case Study Based on Household Investigation in Maduo County

Under the integrated influences of global climate changes and overgrazing, China rangeland has degraded over recent years. Maduo County locates in the Source Region of Yellow River and its rangeland has experienced expansive degradation. The government of Qinghai Province launched an eco- immigration policy in 2004. In order to analyze the responses of herd families to the eco- immigration and the reasons for these responses, the authors used three periods MSS and TM images for recent 25 years and interview survey data of 144 herd families in recent two years, getting the following results: (1) the rangeland had degraded extensively for recent 28 years; and (2) the immigrant families were mainly composed of the old, with little or no livestock. What's more, the percentage of immigrant households that share one rangeland certificate with parents or brothers in the immigrant family was 54.5%. Therefore, it is hard to greatly decrease the overgrazing degree through eco- immigration with those previous characteristics of eco- immigrant family structure.     

Grazing effects on forb diversity and abundance in a honey mesquite parkland

Livestock grazing is the most common use of rangelands, and overgrazing by domestic livestock has stirred much debate concerning the continued use of public rangelands for livestock production. With the increase of wildlife-related enterprises on south Texas rangelands, there are little data available on the compatibility of livestock and wildlife management and in particular the effects of livestock grazing on plant communities in the semi-arid portions of the western South Texas Plains. The objective of this study was to compare forb diversity and density on rangelands subjected to various grazing under a high-intensity, low-frequency grazing system and nongrazed rangelands under controlled conditions. Four rangeland sites that were moderately grazed during the dormant season and 4 rangeland sites receiving long-term deferment from grazing were selected on the Chaparral Wildlife Management Area, Dimmit and La Salle Counties, Texas. Forb density was estimated with 20×50 cm² quadrats during early spring 2000 and 2001. Forb diversity was greatest on grazed sites. Important annuals such as hooker plantain (Plantago hookeriana) and Rough buttonweed (Diodia teres) were more prevalent on grazed sites. Lazy daisy (Aphanostephus spp.) was more frequently encountered on nongrazed sites. Golden dalea (Dalea aurea), a beneficial perennial, was more common on grazed sites. Long-term deferment from livestock grazing appears detrimental to forb communities. A high-intensity, low-frequency grazing system utilizing moderate stocking rates employed during the dormant season is recommended for enhancing forb diversity and abundance.     

Archaeological evidence for pastoralist land-use and settlement in Namaqualand over the last 2000 years

Despite the extreme aridity of the region, there is good evidence that sheep were being herded in small numbers in Namaqualand up to 2000 years ago. Archaeological research at Spoegrivier Cave on the Atlantic coast confirms the presence of sheep at 2100 years ago. Increasing aridity in Namaqualand around 1300 years ago lead to the abandonment of the cave. Jakkalsberg on the banks of the Orange River in the Richtersveld was occupied around 1300 BP by people who were herding sheep rather than hunting game. People with sheep and goats were herding their livestock at Bethelsklip, in central Namaqualand, between 800 and 360 BP. The archaeological evidence clearly supports a long tradition of herding in the region. The question is whether these early herder groups are the ancestors of the Namaqua Khoekhoen pastoralists who occupied Namaqualand during historical times?Historical records from the 17 to 20th centuries testify to the seasonal transhumance of the Namaqua with cattle, sheep and goats between the Kamiesberg Mountains and the plains. On occasions pastoralist groups also moved to the interior plateau of Bushmanland to make use of the seasonal grasses after summer thunderstorms. Traditional land-use practices have a long history in the region and a study of these land-use patterns may assist in interpreting the archaeological record and in developing a sustainable land-use policy for the region.     

Dynamics and sustainable utilization of rangeland ecosystems in arid and semi-arid climates of southern Africa

This review examines the conservation, risk, productivity, viability and acceptability of range management technology as it relates to sustaining rangeland ecosystems specifically in arid and semi-arid climates. The efficiency, cost effectiveness and risk with which rainfall is converted into plant production, and eventually gross farming income, without deterioration of natural resources form the essence of sustainability of rangeland ecosystems in these areas. Range and soil degradation can dramatically influence soil water balance, nutrient cycling, soil loss, production and the economics of a farm unit. Management for long-term sustainability often requires sacrifice of short-term welfare. With respect to deterioration and loss of productivity of natural vegetation, a co-ordinated approach is needed towards establishing a comprehensive inventory of the condition of national vegetation resources on a geographically and scientifically sound basis.     

Physical impact of grazing by sheep on soil parameters in the Nama Karoo subshrub/grass rangeland of South Africa

The direct short-term impact of three rates of stocking (4, 8 and 16 small-stock units [SSU] ha^?1) was quantified in terms of soil characteristics of arid Nama Karoo vegetation (subshrub/grass). Mature Merino wethers grazed in the experimental plots throughout May in 1995 and 1996 (the plots were not subjected to grazing at any other time). Stocking rate proved inversely related to initial infiltration rate. Light trampling (4 SSU ha^?1) loosened the topsoil sufficiently to increase the initial infiltration rate: infiltration capacity of soil in fields stocked at 4 SSU ha^?1 and 16 SSU ha^?1 was 17% higher and 14% lower respectively than that of soil of ungrazed rangeland over the two grazing periods. Increased soil compaction and greater bulk density due to higher stocking rates significant decreased the infiltration rate. Compared to ungrazed rangeland stocking rates of 4, 8 and 16 SSU ha^?1 over the two grazing periods increased bulk density respectively by 2.73%, 6.67% and 8.945% and compaction by 10.90%, 16.78% and 20.90%. No grazing also increased bulk density and soil compaction and decreased infiltration rate. Light stocking (4 SSU ha^?1) influenced all soil parameters most favourably. From a hydrologic point of view, grazing levels and rotation schemes need to be tailored for sustainable utilization of arid subshrub/grass vegetation by livestock.     

Restoring degraded landscapes in lowland Namaqualand: Lessons from the mining experience and from regional ecological dynamics

Three-quarters of a century ago diamond mining was added to livestock grazing and cereal cropping as a serious cause of landscape degradation in the north-western semi-arid region of South Africa, Namaqualand. Since that time the activities of diamond mine operators and prospectors have eclipsed all other land uses as a cause of degradation in this region. Discontinuous patches along virtually all of the 400 km of the Namaqualand coastline have been, or are currently, being mined or prospected. Prior to 1992 little was done to restore the landscapes and ecosystems to their pre-mining state, but since then legislation has placed a clear responsibility for restoration on mining operators. Implementation of ecological restoration was initially slow, but has recently gained momentum, in line with a growing awareness of environmental responsibilities amongst the global mining industry. In general, autogenic recovery of the perennial vegetation does not take place. The low annual rainfall and prevailing strong windy conditions present the greatest climatic challenges to the restoration of the flora. While the unique vegetation, and its features (e.g. poor representation of perennial species in the seedbank) present challenges to understanding the interventions that are critical in achieving ecological restoration. At the same time, climatic conditions such as the strong seasonality and low variability of rainfall, together with floristic features such as the high incidence of succulence, and the extraordinary drought tolerance of many seedlings, present opportunities for restoration. Perhaps the greatest challenges to restoration derive from the unsuitability of much of the mined overburden soils for plant growth. The nature and importance of climatic conditions, mined soils, topsoils, soil nutrients, landscaping, seedbanks, seeding, transplantation, and the interactions between these and other factors are evaluated in the context of this semi-arid environment and the prevailing mining practices.     

Effects of grazing and climate change on sandy grassland ecosystems in Inner Mongolia

To understand the effects of grazing activities and climate change on sandy grassland ecosystems in northern China, a livestock field grazing and enclosure experiment was conducted from 1992 to 2006 in Horqin Sand Land, Inner Mongolia. The results showed that sustained heavy grazing resulted in serious degradation of the vegetation; moderate grazing can maintain vegetation stabilization; and light grazing can promote rapid restoration of degraded vegetation. The livestock productivity was the highest in the moderate grazing grassland, and sustained heavy grazing resulted in rapid decrease of the livestock productivity. Heavy grazing can cause a retrogressive succession of grassland vegetation, whereas moderate and light grazing may promote progressive succession of plant species. The effects of changing climate on succession processes were not significant in the short term; a warm-humid climate is favorable to restoration of degraded vegetation, whereas a sustained warm-drought climate may result in degradation of grassland vegetation. Heavy livestock grazing should be stopped for the sustainable use of grassland; the proper grazing intensity for sandy grassland is two to three sheep or sheep equivalents per hectare in Inner Mongolia.     

Perceptions and realities of land degradation in arid Otjimbingwe, Namibia

We examined the perceptions and realities of land degradation in a communal ranching area, Otjimbingwe, in arid Namibia (in south-western Africa). It is commonly perceived that large-scale degradation of Otjimbingwe has occurred due to a mixture of improper pastoral practices and pressures induced by a high human population growth rate. We sought to determine whether the inhabitants perceived land degradation to have taken place and whether their perceptions were consistent with empirical data on environmental quality. Furthermore, we wished to determine whether these pastoralists had management strategies to help them withstand the harsh environmental conditions in which they live. All respondents in our surveys perceived that the environment had become degraded. The claimed source of this degradation, a decline in annual rainfall, is inconsistent with long-term rainfall records (there was neither change nor cyclicity in rainfall over time). There is also little evidence of a decline in plant cover and soil quality in spite of the very high stocking densities. No overall pastoral strategy exists in Otjimbingwe. Options for management are extremely limited due to a variety of external and internal pressures such as a high human population growth rate, high immigration into Otjimbingwe, restricted water availability due to dams constructed upstream, and limited movement opportunities for livestock in drought periods.     

Visualization and quantification of significant anthropogenic drivers influencing rangeland degradation trends using Landsat imagery and GIS spatial dependence models: A case study in Northeast Iran

Developing countries must consider the influence of anthropogenic dynamics on changes in rangeland habitats. This study explores happened degradation in 178 rangeland management plans for Northeast Iran in three main steps: (1) conducting a trend analysis of rangeland degradation and anthropogenic dynamics in 1986-2000 and 2000-2015, (2) visualizing the effects of anthropogenic drivers on rangeland degradation using bivariate local spatial autocorrelation (BiLISA), and (3) quantifying spatial dependence between anthropogenic driving forces and rangeland degradation using spatial regression approaches. The results show that 0.77% and 0.56% of rangelands are degraded annually during the first and second periods. The BiLISA results indicate that dry-farming, irrigated farming and construction areas were significant drivers in both periods and grazing intensity was a significant driver in the second period. The spatial lag (SL) model (wi=0.3943, Ei=1.4139) with two drivers of dry-farming and irrigated farming in the first period and the spatial error (SE) model (wi=0.4853, Ei=1.515) with livestock density, dry-farming and irrigated farming in the second period showed robust performance in quantifying the driving forces of rangeland degradation. To conclude, the BiLISA maps and spatial models indicate a serious intensification of the anthropogenic impacts of ongoing conditions on the rangelands of northeast Iran in the future.     

Land degradation is not a necessary outcome of communal pastoralism in arid Namibia

In Otjimbingwe, a region of arid south-central Namibia, human population densities are high and these communal pastoralists own large numbers of livestock. Such situations are commonly perceived to lead to the ‘tragedy of the commons'. This region lends itself to a comparison of the effects of communal and commercial farming (with private land ownership) because the communal area is completely surrounded by commercial farms. In spite of far higher stocking densities on the communal areas and the absence of an overall grazing strategy, we found no evidence of the ‘tragedy of the commons' on Otjimbingwe. Indeed, the communal areas did not differ in a number of soil and vegetation parameters from the commercial farms. These results point both to the resilience of arid environments to high stocking levels and the over-riding influence of abiotic variables on environmental quality.     

Cattle grazing effects on annual plants assemblages in the Central Monte Desert,Argentina

Plant assemblages' dynamics have been studied to evaluate the influence of different environmental factors. The aim of our work was to assess the effect of a disturbance in the form of livestock grazing on annual plants, in a South American desert. We tested the exclusion of cattle grazing by comparing the composition of annual plants in three major vegetation types within a MaB Reserve in the Monte Desert of Argentina, with those of an adjacent grazed field. Sampling was conducted in two consecutive years that differed in precipitation. We established three sampling sites within each vegetation type at the reserve and the grazed field. Transects were set to assess plant cover, abundance, and richness. Theoretically, changes in diversity are explained by changes in one of its components: species richness. Species richness of annual plants was not different between the grazed and ungrazed sites. However, plant cover and diversity were lower in grazed sites, whereas abundance increased. Owing to a strong species-specific effect, we propose that it is evenness the main parameter involved in diversity dynamics in the heterogeneous vegetation mosaic of the Monte desert. Finally, vegetation types (spatial heterogeneity) and rainfall regime (temporal heterogeneity) greatly interacted with grazing effects. We endorse the idea that rapid responses of annual plant assemblages to changes in rainfall conditions coupled with herbivore control, might result in a restoration pathway for degraded arid landscapes.