R.L. Kruska

Measuring the costs of African animal trypanosomosis, the potential benefits of control and returns to research

Abstract This paper addresses issues surrounding measurement of the potential productivity gains from new livestock technologies and the returns to international livestock research. The approach, applicable to many livestock production constraints and technologies, uses geographic information systems (GIS) to spatially link a biophysical herd simulation model with an economic surplus model. The particular problem examined is trypanosomosis in cattle in Africa, and the potential research product is a multi-component vaccine. The results indicate that the potential benefits of improved trypanosomosis control, in terms of meat and milk productivity alone, are

Mapping livestock-oriented agricultural production systems for the developing world

700 million per year in Africa. The disease now costs livestock producers and consumers an estimated

Human population growth and the extinction of the tsetse fly

1340 million annually, without including indirect livestock benefits such as manure and traction. Given an adoption period of 12 years, a maximum adoption rate of 30%, a discount rate of 5%, and a 30% probability of the research being successful within 10 years, the net present value of the vaccine research is estimated to be at least

Loss and fragmentation of habitat for pastoral people and wildlife in east Africa: concepts and issues

288 million, with an internal rate of return of 33%, and a benefit/cost ratio of 34:1. ©

Large herbivore responses to water and settlements in savannas

Abstract Questions as to whether public investment in international agricultural research is a ‘Good Thing’ or not may best be addressed using two arguments: (1) justifications based on whether or not past investments have yielded substantial benefits to societies and the resource-poor; and (2) that future investments need to be made as effectively and efficiently as possible, which means they must be targeted as closely as possible. A major component of any impact assessment framework that aspires to comprehensiveness is information on the location of different agricultural systems and pertinent characteristics of the resource-poor who operate them. Given the importance of livestock to the diets and incomes of poor farming households, and the predicted increase in demand for livestock products throughout the developing world over the next few decades, understanding how livestock fit into these systems, and how these systems may evolve in the future, is critical. This is especially true in Africa, where approximately 27% (162 million people) of the worlds poor livestock keepers live. In this paper, we further develop a global livestock production system classification put forward by Sere and Steinfeld in 1996. These livestock systems fall into four categories: landless systems, livestock only/rangeland-based systems (areas with minimal cropping), mixed rainfed systems (mostly rainfed cropping combined with livestock) and mixed irrigated systems (a significant proportion of cropping uses irrigation and is interspersed with livestock). We then describe a method for mapping the classification, based on agro-climatology (length of growing period), land cover, and human population density. We conclude with a discussion of how the maps could be refined, and indicate their potential use in a range of different policy and research and development applications.

Locating poor livestock keepers at the global level for research and development targeting

Abstract Agricultural expansion is a major cause of biodiversity loss worldwide. In Africa, biologists have observed that the populations of some tsetse species, which transmit human and livestock trypanosomosis, decline or disappear as human populations grow and farmers clear fly habitat for cultivation. The objectives of this paper are to synthesize the available information concerning human and tsetse populations and to develop a model to estimate the future effect of human populations on tsetse populations. A spatial, GIS model was developed to estimate future impacts using a combination of fine-resolution human population data for the years 1960, 1980, 2000, 2020, and 2040; field data on the relationships between human and tsetse population densities; and the distribution of different types of tsetse fly. By 2040, many of the 23 species of tsetse fly will begin to disappear and the area of land infested and number of people in contact with flies will also decline. However, none of the species of flies will be under threat of extinction by human agricultural activities in the near term. An area of Africa larger than Europe will remain infested by tsetse and under threat of trypanosomosis for the foreseeable future.

Effects of Climate, Human Population and Socio-economic Changes on Tsetse-transmitted Trypanosomiasis to 2050

Little of the current focus on landscape fragmentation has focused on rangelands or pastoral lands. This paper investigates the existing evidence for causes and processes of fragmentation in pastoral lands and its effects of landscapes and peoples. More conceptual work is needed on the definition of loss and fragmentation, particularly efforts to clarify fragmentation from whose (or whats) perspective. Fragmentation and loss are caused by a suite of underlying demographic, economic, institutional, technological and policy, biological and climatic factors in east Africa, with property rights as a particularly important cause. These underlying causes often originate far from rangelands and drive more local causes like expansion of cropland and settlements and construction of fences and water points. Pastoral systems first fragment in wetter rangelands or in the key resource areas (wetlands, riverine areas) in drier rangelands. Ecological effects of fragmentation range widely across animal and plant populations, nutrient cycling and soils, with strong effects on animals with large body sizes. We have little understanding of the economic consequences of fragmentation and have a strong need to focus future research on valuing ecological services that affect human well-being, to gain a better picture of the complementarities and trade-offs land managers face during the process of fragmentation.

Mapping poverty and livestock in the developing world.

Sustaining wildlife and pastoral communities in savannas worldwide depends on understanding how landscapes provide for their needs. The composite effects of multiple forces shape herbivore distribution in savannas. We propose a model describing the distribution of animal density along two resource utilization gradients. The model estimates where animals are most abundant in relation to water and pastoral settlements and how strongly they respond to these gradients, as indicated by the location of peak densities in landscape space and degree of attraction of animals to these locations. We use the model to show that distances to water and settlements interactively influence the distribution of wild herbivore and livestock densities in a semiarid protected and pastoral African savanna. The herbivores were distributed along distance from water and settlement gradients according to four distinct patterns, suggesting the preponderance of constrained foraging. The impact of distance to water and settlement on herbivore distribution was modified by land use type and temporal variation in rainfall, and also varied among different species of wildlife and between wildlife and livestock. Wild herbivores peaked in density farther from settlements than from water and were much more strongly attracted to their points of maximum density in the pastoral than in the protected land. The point of maximum density was farther removed from settlements in the protected than in the pastoral landscape where the wild herbivores were compressed into smaller suitable habitats. The interaction between distances from settlement and water produced discernible spatial segregation among species in terms of the locations of their points of maximum density, presumably to minimize interspecific competition for forage and water. Settlements exerted relatively stronger influence on livestock distribution than water, resulting in densities that declined exponentially away from settlements at all distances from water.

Mapping climate vulnerability and poverty in Africa.

Many research and development agencies are committed to halving the number of people living in extreme poverty by 2015. Knowledge of where the poor are, and what characterises them, is patchy at best. Here we describe a global livestock and poverty mapping study designed to assist in targeting research and development activities concerning livestock. Estimates of the numbers of poor livestock keepers by production system and region are presented. While these estimates suffer from various problems, improvements in global databases are critical to improve the targeting of interventions that can meet the challenges posed by poverty and to chart progress against international development indicators.

Land-use and land-cover dynamics in response to changes in climatic, biological and socio-political forces: The case of southwestern Ethiopia

This chapter explores the impacts of climate change, human population growth and expected disease control activities on tsetse distribution and trypanosomiasis risk in five agro-ecological environments in sub-Saharan Africa to 2050. These changes will tend to contract areas under trypanosomiasis risk continent-wide; however, this trend will not be uniform. The greatest decrease in the impacts of animal trypanosomiasis will occur in the semi-arid and sub-humid zones of West Africa, where the climate will be drier, human population will increase and disease control will have greater impacts. The risk of animal trypanosomiasis will also decline in many but not all areas of Ethiopia and eastern and southern Africa. The disease situation in the humid zone of central and western Africa will be less changed. Sleeping sickness, particularly the gambiense type, will continue, as now, to be a major problem, if concerted control efforts are not implemented.