Comparing landscape and infrastructural heterogeneity within and between ecosystems

Ecological research throughout much of the last century focused upon manipulative experiments on areas of a few square meters or less (Kareiva and Andersen 1988). The last quarter of the century saw the development of landscape ecology and the emergence of macroecology as a bonafide method of research and discovery (e.g., Brown 1995, Blackburn and Gaston 2002). Geographical and human-ecological research increasingly has successfully integrated human populations and their behaviors into analyses of land use change (Rindfuss and Stern 1998). Today, readily available broad-scale data, such as satellite images and global spatial databases, make comparing attributes of landscapes and the people who inhabit them uniform, thorough, repeatable, and relatively inexpensive (Roughgarden et al. 1991)

Processes of fragmentation in the Amboseli ecosystem, Southern Kajiado district, Kenya

The Amboseli ecosystem is known worldwide as one of Kenya’s “conservation jewels,” and is recognized as a landscape where humans, livestock, and wildlife have co-existed for centuries. However, there is a long-term shift underway, pushed by a transition in human land-use from extensive pastoralism by Maasai to intensive pastoralism carried out within legally-prescribed private parcels of land. In the face of this transition, the region’s wildlife populations and its system of seasonal livestock and wildlife movements appear increasingly fragile, and Maasai pastoralists themselves are facing significant challenges to their economic and cultural well-being

Modelling the impacts of group ranch subdivision on agro-pastoral households in Kajiado, Kenya

Pastoral communities in East Africa are facing considerable challenges arising from shifts in land tenure policy from communal to individual landholdings and high human population growth rates. Over the last 30 years, livestock-to-human ratios have generally declined to levels that will no longer support pure pastoralism. Many Maasai have thus diversified into cultivation, wage labour, and small businesses. Livelihood expectations are rising, with concomitant increases in the need for cash. We describe the modification of PHEWS, a simple rule-based model that tracks cash flow and calories in agro-pastoral households. We use it, coupled to Savanna, a sophisticated ecosystem model, to quantify some of the effects of subdivision and land fragmentation on household livestock numbers and on food security. For the group ranches simulated, model outputs indicate that subdivision results in substantial reductions in livestock numbers, partially because households have to sell more animals to generate the cash needed, with serious long-term consequences on herd sizes and food security. If subdivision occurs, even to parcels as large as 196 km2, livelihood strategies may need to be modified to maintain current levels of household well-being. Model results have been discussed in community meetings in southern Kajiado, but more work is needed on communication mechanisms to utilise more effectively the results of imperfect but useful integrated assessments of complex problems concerning land use and human well-being

Large-scale movements of large herbivores: livestock following changes in seasonal forage supply

Large-scale movements allow large herbivores to cope with changes in seasonal forage supply. Pastoralists use mobility to convert low-value ephemeral forage into high-value livestock. Transhumant pastoralists may move livestock less than ten to hundreds of kilometres. In semi-arid tropical sites, water and forage shortages in the dry season cause pastoral livestock to move to water or key resource areas. In temperate summers, livestock may be moved to higher-elevation snow-free meadows. In winters, animals may be moved lower to warmer sites, or to mountain valleys protected from steppe winds. Despite the recognised value of mobility, pastoral mobility is being reduced around the world. Changes in the mobility of three pastoral groups are reviewed, the Aymara of the South-American highlands, Mongolians, and the Maasai of Kenya and Tanzania, for which quantitative results are given. The Maasai of Kajiado District, Kenya are subdividing some group ranches into individually owned parcels. In subdivided Osilalei Group Ranch, herders moved an average of 5.6 km per day, whereas in undivided northern Imbirikani, herders moved 12.5 km per day. Residents of northern Imbirikani accessed more green vegetation the more they moved, whereas those in subdivided southern Imbirikani did not. Maasai selected areas with more heterogeneous vegetation during the dry season than found at their permanent households. In modelling, subdividing to 100-ha parcels allowed Eselengei Group Ranch to support 25% fewer livestock by mass, even though the area remained the same. For any pastoralist, the costs of mobility must be weighed against benefits, but pastoralists have demonstrated flexibility in their mobility, if constraints such as human population growth and limitations in land access are not too great. We show that pastoralists have successfully evolved methods of herding livestock to access adequate forage in areas of variable climat

Coping strategies in livestock-dependent households in East and southern Africa: a synthesis of four case studies

Integrated assessment seeks to combine models of the ecological as well as the social system to allow different scenarios to be tested in terms of their likely impacts on ecological functioning and household well-being. We outline such work undertaken in four case studies in East and southern Africa: pastoralist communities in northern Tanzania, agro-pastoralists in southern Kenya, communal and commercial ranchers in South Africa, and mixed crop-livestock farmers in western Kenya. Results from these case studies are synthesised to test the hypothesis that households’ capacity to adapt in the face of increasing external stresses is governed by flexibility in livelihood options. The results support this hypothesis. There is considerable variation in how households in these places cope with external stresses. Options include intensification, diversification, and increasing off-farm economic activities, and these depend on household objectives and attitudes as well as on access to natural resources, inputs and output markets. The results also indicate that generally it is the poorer households that can gain the most from implementing such options for coping and managing risk. Quantifying likely household and ecosystem impacts of different options is a crucial step in targeting appropriate technology, policy and adaptation interventions in the face of considerable system changes. We conclude with some research needs to improve integrated assessment tools that may allow us to represent more realistically the highly complex decision-making milieu of householders in sub-Saharan Africa who are dependent on ecosystem goods and services for a large part of their livelihoods

Evolution of models to support community and policy action with science: Balancing pastoral livelihoods and wildlife conservation in savannas of East Africa

We developed a “continual engagement” model to better integrate knowledge from policy makers, communities, and researchers with the goal of promoting more effective action to balance poverty alleviation and wildlife conservation in 4 pastoral ecosystems of East Africa. The model involved the creation of a core boundary-spanning team, including community facilitators, a policy facilitator, and transdisciplinary researchers, responsible for linking with a wide range of actors from local to global scales. Collaborative researcher–facilitator community teams integrated local and scientific knowledge to help communities and policy makers improve herd quality and health, expand biodiversity payment schemes, develop land-use plans, and fully engage together in pastoral and wildlife policy development. This model focused on the creation of hybrid scientific–local knowledge highly relevant to community and policy maker needs. The facilitation team learned to be more effective by focusing on noncontroversial livelihood issues before addressing more difficult wildlife issues, using strategic and periodic engagement with most partners instead of continual engagement, and reducing costs by providing new scientific information only when deemed essential. We conclude by examining the role of facilitation in redressing asymmetries in power in researcher–community–policy maker teams, the role of individual values and character in establishing trust, and how to sustain knowledge-action links when project funding ends