Origins of Specialized Pastoral Production in East Africa

The results of recent archeological research in the Loita-Mara area of Kenya offer new information on the timing and process of the development of pastoralism in East Africa. They suggest that a pattern of specialized pastoral production, similar to that of contemporary East African pastoralists such as the Maasai, was present in parts of East Africa 2,000 years ago. It may have developed as a result of new opportunities for increased pastoral production. A bimodal pattern of rainfall with a short dry season, similar to the modern climatic regime, appeared about 3,000 years ago, which allowed year-round milk production from cattle herds. The development of pastoralism in East Africa preceded agriculture and took place in a social and economic context of relationships between hunter-gatherers and pastoralists. Environmental opportunity, combined with cultural competition, may have provided the impetus toward pastoral specialization.     

Coping with Uncertainty and Variability: The Influence of Protected Areas on Pastoral Herding Strategies in East Africa

A large number of East African pastoralists reside around protected areas (PAs). Over the last few decades pastoralists have been affected by the loss of grazing lands and increasing climatic variability. Many pastoralists who reside around PAs have resorted to grazing inside PAs to counter environmental variability. However, there is little information on how PAs influence the herding strategies of pastoralists. This case study from southern Kenya employs a spatially and temporally explicit mixed-methods approach to understand and evaluate the herding strategies of pastoralists around a PA. The results find that pastoralists access PAs on a regular basis, regardless of seasonality or herd size. Movement into PAs was partly driven by the loss of grazing land to conservancies. PAs affected pastoral herding by presenting differential opportunity costs to disparate groups. However, households with large herd sizes utilized the most flexible strategies to counter environmental variability and uncertainty.     

Individual and Collective Rationality in Pastoral Production: Evidence From Northern Kenya

This study explores the individual and collective rationality of livestock accumulation in pastoral production using data gathered in northern Kenya. Results suggest accumulating wealth in livestock even when facing the prospect of sudden dramatic loss makes sense at the household level, and that there is limited empirical support to the contention that herd accumulation at the household level imposes a cost on other households. I conclude by arguing the record of failure in pastoral development may be at least partially due to a faulty conceptual foundation, and suggest facilitating herd accumulation may offer more promise than discouraging it.     

Herding Strategies of the Datoga Pastoralists of Tanzania: Is Household Labor a Limiting Factor

Datoga herding follows a cyclical pattern depending on the availability of grazing and water. This analysis focuses on two questions: (a) Is the herding strategy followed by individual households limited by the amount of labor available to that household? and (b) does the herding strategy followed by individual households influence the dynamics of cattle herds? The results show that the availability of labor on a household level does not influence either the herding strategies used by individual households, or the dynamics of cattle herds. This suggests that once minimum labor requirements are met, livestock productivity is insensitive to additional labor inputs.     

Access to Land and Water in the Zamfara Reserve. A Case Study for the Management of Common Property Resources in Pastoral Areas of West Africa

In this paper, the link between traditional rights of access to land and water and present day practices is established and illustrated. Data collected during various studies in the Zamfara Forest Reserve, northwest Nigeria, provided information on the different resources utilized (land, pastures, water) and the views and practices of different user-groups and stakeholders. The findings are discussed with a view to improving existing common property resource management (CPRM) in the area.     

The two-horned chamaeleons of East Africa

There have been numerous attempts to resolve the taxonomy of the two-horned chamaeleons of East Africa. However, the high levels of intraspecific variation and reported sympatry of morphologically distinct taxa indicate that their current classification is unsatisfactory. Tissue samples were collected from specimens from most mountain massifs (excluding the Nguu) where two-horned chamaeleons are known to occur and were used to sequence partial 12S and 16S rRNA, as well as ND2 mtDNA genes. These specimens and further museum material were used to review morphological variation and to define discriminating characters for each taxon. Phylogenetic analyses of gene sequences show clear genetic divergence between allopatric populations, although two lineages occur in sympatry in the East Usambara Mountains, and is supported by divergent morphology. In light of these results a formal revision of the taxonomy of all East African two-horned chamaeleons is proposed and seven species are recognized ( Kinyongia boehmei , K. fischeri , K. matschiei , K. multituberculata , K. tavetana , K. uluguruensis and K. vosseleri ). These taxa form a monophyletic group except for K. uluguruensis , which seems to be more closely related to one-horned species. Most of these taxa have been previously described and subsequently reduced to synonyms. Two other previously described two-horned taxa are not recognized as valid: Chamaeleo tornieri is considered species inquiriendae , and C. fischeri werneri is placed in synonymy with K. multituberculata . A dichotomous key is provided for the identification of these taxa and some aspects of their conservation, ecology and evolutionary origins are also discussed.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 367–391.     

景观生态学的核心:生态学系统的时空异质性

1　景观生态学与景观异质性景观生态学是研究在一个相当大的区域内 ,由许多不同生态系统所组成的整体 (即景观 )的空间结构、相互作用、协调功能以及动态变化的生态学新分支[1 ] 。它的出现促进了空间关系模型和理论、空间格局与动态的数据类型的获取以及经典生态学很少涉及的空间尺度检测等方面的发展[2 ] 。Ｒｉｓｓｅｒ等认为景观生态学研究就是异质性的研究[3] 。其实 ,“景观”本身就具有“变化的异质性整体”的含义[4] 。景观生态学集中关注于对生态系统空间关系的研究 ,它把景观视为空间上镶嵌出现和紧密联系的生态系统组合 ,景观可…     

Labor Process and the Environment: The Effects of Labor Availability and Compensation on the Quality of Herding in the Sahel

The relationship between investments of labor to agricultural production and environmental degradation in rural areas of the developing world is complex. This paper reports on qualitative and quantitative research focused on the effects of labor availability and its compensation on the way in which cattle are herded in the Maasina region of Central Mali. Within this particular region, two social relationships determine the level and form of herder compensation: that between herd patriarch and cattle owner, and that between herd patriarch and herder. Both the nature of these relationships and variations in herding practice are described prior to a presentation of statistical analyses of the effects of household labor availability and cattle wealth on travel and grazing management decisions. Reductions in both the availability of herding labor and in the economic security of Fulsse households are shown to lead to reduced herd mobility and more constricted grazing patterns with significant environmental implications.     

A Multilevel Analysis of the Impact of Land Use on Interannual Land-Cover Change in East Africa

Abstract The aim of this study was to characterize the short-term land-cover change processes that were detected in Eastern Africa, based on a set of change metrics that allow for the quantification of interannual changes in vegetation productivity, changes in vegetation phenology and a combination of both. We tested to what extent land use, fire activity and livestock grazing modified the vegetation response to short-term rainfall variability in East Africa and how this is reflected in change metrics derived from MODerate Imaging Spectrometer (MODIS) time series of remote sensing data. We used a hierarchical approach to disentangle the contribution of human activities and climate variability to the patterns of short-term vegetation change in East Africa at different levels of organization. Our results clearly show that land use significantly influences the vegetation response to rainfall variability as measured by time series of MODIS data. Areas with different types of land use react in a different way to interannual climate variability, leading to different values of the change indices depending on the land use type. The impact of land use is more reflected in interannual variability of vegetation productivity and overall change in the vegetation, whereas changes in phenology are mainly driven by climate variability and affect most vegetation types in similar ways. Our multilevel approach led to improved models and clearly demonstrated that climate influence plays at a different scale than land use, fire and herbivore grazing. It helped us to understand dynamics within and between biomes in the study area and investigate the relative importance of different factors influencing short-term variability in change indices at different scales.     

The Distribution of Grazing Pressure in Relation to Vegetation Resources in Semi-arid West Africa: The Role of Herding

In semi-arid West Africa, livestock are increasingly managed by sedentary producers in close proximity to expanding cropped lands. To evaluate the agricultural and environmental implications of this trend, a study was conducted to investigate the effect of grazing management on the spatial distribution of grazing pressure, the forage provided animals during the grazing period, and local herd-forage ratios across three agropastoral landscapes characterized by varying cultivation pressure. During the 19-month study period, data on herbaceous vegetation, livestock populations, and grazing itineraries were collected. These data were referenced to land units averaging 70 ha in area. Using this approach, each of 3,819 grazing itineraries was characterized as to: 1. the sum of the products of the palatable forage mass of a particular land unit and the time spent grazing by the herd within that unit (FAT, expressed in kg-hours ha⁻¹); and 2. the average palatable herbaceous forage mass encountered by livestock across the itinerary weighted by the time spent in the land units crossed (FA, expressed in kg ha⁻¹). The spatial dispersion of livestock grazing around human settlements was found to decline with a reduction in herding labor investment (herded>herd-release>free pasture). Multiple regression analyses of itinerary data demonstrate that both FAT and FA also decline with a reduction in herding labor investment. Herded and herd-release managed livestock were offered more palatable forage and grazed areas of higher forage availability than free-pastured animals. This supports arguments that as the investment of time and effort into herding declines, feed supply to livestock will decline and the potential for grazing-induced environmental change will increase.     

Stability and resilience in East African Pastoralism: The Rendille and the Ariaal of northern Kenya

The social organizations of two closely related nomadic pastoral societies of northern Kenya, the Rendille and Ariaal, are compared in the context of the relative constancy and variability of their herding environments. It is concluded that the application of Brooks and Yellen's model of stability and resilience in human populations is of value in understanding the impact of environmental constraints on social organization, but it is argued that other social features including the organization of labor and ownership of different livestock types directly bear on the differences between the Rendille and Ariaal.     

Families and Firewood: A Comparative Analysis of the Costs and Benefits of Children in Firewood Collection and Use in Two Rural Communities in Sub-Saharan Africa

Domestic firewood collection is compared across study sites in Malawi and Tanzania. The study focuses on accommodation of infant-care within wood collection, the influence of family size on firewood demand and the contribution of girls to firewood collection. Malawian women carry their infants on wood collection trips. The Tanzanian women leave their infants behind. The shorter trips of the Tanzanian women, and the ready availability of alloparental care may facilitate this. Mean per capita wood consumption was similar across the two sites. However, a marked economy of scale was evident in wood use at the Malawi site. Girls at both sites assist with wood collection. Their contribution appears more than sufficient to compensate for their own wood use. Having a daughter therefore need not represent a net energetic cost to a woman in terms of firewood acquisition and consumption. While family size and structure appear to influence firewood consumption and acquisition, differences in the environment between the two sites may underpin much of the variation. The longer journey times, heavier load, and less frequent journeys undertaken by Malawian women may reflect the steep terrain and risks associated with firewood collection within a national park.     

Transition of Mountain Pastoralism: An Agrodiversity Analysis of the Livestock Population and Herding Strategies in Southeast Tibet,China

Vertical mobile grazing is typical in undulating mountain landscapes. However, recent social, economic, and political changes in China are impacting these traditional practices. This paper presents findings of a study conducted in the Tibetan communities of southwest China to assess the current status of mountain pastoralism and its future viability. Rangeland environment, livestock variety, and grazing form were found to be significantly related factors, which made it possible to analyze livestock distribution. The yak population—the main mobile grazer in alpine pasture— is currently stagnating while the population of cattle raised around settlements is steadily increasing. This situation is likely closely related to labor shortages in households, which have triggered the imbalanced distribution of livestock. The fact that the key to rangeland sustainability is to stimulate mobile grazing runs counter to current privatization policies.     

Spatial and Social Boundaries and the Paradox of Pastoral Land Tenure: A Case Study from Postsocialist Mongolia

Mobile pastoralists are subject to potentially conflicting needs for secure resource tenure and socially and spatially flexible patterns of resource use. This paradox of pastoral land tenure poses problems for the application of common property theory to the management of pastoral commons. The vagueness, permeability, and overlap of boundaries around pastoral resources and user groups complicate the implementation of formal tenure regimes designed to address insecure pastoral tenures and unsustainable land use patterns. A case-study from postsocialist Mongolia is used to illustrate the problem of spatial and social boundaries for managing pastoral commons. Three solutions to the paradox are evaluated: tenure formalization, rangeland comanagement, and regulation of herders' seasonal movements. An approach that develops and tests institutions to coordinate pastoral movements is recommended over formal tenure for pasturelands, which should be approached with caution in Mongolia.     

Fauna,Fire, and Farming: Landscape Formation over the Past 200 years in Pastoral East Pokot,Kenya

Fire was a key element of grass savanna formation all over eastern Africa. In the northern Baringo plains, Pokot pastoralists prospered in the nineteenth century, coexisting with huge herds of wildlife. During the twentieth century, the savanna ecosystem changed from a grass-dominated to bush-dominated as a result of growing numbers of livestock and people, which brought not only elephant hunts but also intensive grazing and changing fire regimes. Subsequently, herders diversified their livelihoods, and these land-use changes in the East Pokot highlands led to the spread of the endemic plant Dodonaea viscosa (Sapindaceae) beyond its original habitat. Ingolds’ concept of taskscape is applied here to illustrate a temporal, consecutive perspective of landscape transitions against the background of disappearing landscape agents (in this case large herbivores and fire).