David J. Campbell’s research while affiliated with Michigan State University and other places

POSTER PRESENTED AT THE: 5th AgMIP Global Workshop, Gainesville FL, February 25, 2015. With rising food demand and stagnant production, food insecurity is pervasive in sub-Saharan Africa. Maize yield in East and Southern Africa is inherently low due to imminent water shortage, limited use of improved crop cultivars, and little replacement of plant nutrients. Increasing climate variability and climate change may exacerbate this situation. Increasing yields of major crops through improved management and identifying strategies to improve resilience to climate change are critical goals. Our objectives in this study are: (i) to assess the potential of nitrogen fertilizer to mitigate the impact of current climate variability in sites representing different climate situations, and (ii) to assess the impact of projected climate change on maize productivity across highly heterogeneous East Africa and identify management recommendations. We selected maize due to its importance as a major food crop and its sensitivity to climate and nitrogen limitations. Various climate datasets are linked to CERES Maize DSSAT v.4.5 to examine the effects of climate on maize productivity and the potential for management practices to reduce vulnerability. A local hybrid, H614, is simulated. Point simulations using observed weather from 1984 to 2011 are presented for Katumani, Kenya, and Choma and Kasama, Zambia. The effects of nitrogen fertilizer treatments are analyzed to determine the potential of fertilizer to reduce vulnerability. To assess the impact of projected climate change, we conduct high resolution spatial modeling using WorldClim data to represent current climate and four GCMs to provide data on change between 2000 and 2050. Analysis of the impact of recent climate variability shows that yield variability ranges from 45% CoV in a dry site to 21% CoV in a wet site. Yield response to nitrogen depends on precipitation amounts, season length and temperature. There is little response to nitrogen in hot, dry Katumani when precipitation is below 200 mm. The threshold of low response is 450 mm in cooler and wetter Choma. With warming temperatures, more of East Africa is expected to resemble the Katumani situation and experience declining response to nitrogen. In our wettest site, Kasama, response to nitrogen varies little between years but leaching affects yields. When nitrogen is applied at planting and 40 days, yield variability is considerably lower than when all fertilizer is applied at planting. Split applications are likely to confer resilience to climate variability in sites with higher rainfall. The impact of projected climate change is examined across East Africa. The results are shown as maps of current, future and changes in temperature, precipitation, length of growing season, water deficit and yield. Results indicate high spatial variability in how the climate is projected to change with some areas getting wetter and others drier, and the highlands warming faster than elsewhere. The yield response is complex depending on initial climate and how it is expected to change. A few areas in the highlands and wetter zones are expected to see rising yields, but much of East Africa is expected to see declining yields as the length of the growing season declines and water deficits worsen. Crop management recommendations are highly spatially specific, pointing to the importance of conducting spatially explicit, processed-based crop modeling.

Human African trypanosomiasis (HAT) and animal African trypanosomiasis (AAT) are significant health concerns throughout much of sub-Saharan Africa. Funding for tsetse fly control operations has decreased since the 1970s, which has in turn limited the success of campaigns to control the disease vector. To maximize the effectiveness of the limited financial resources available for tsetse control, this study develops and analyzes spatially and temporally dynamic tsetse distribution maps of Glossina subgenus Morsitans populations in Kenya from January 2002 to December 2010, produced using the Tsetse Ecological Distribution Model. These species distribution maps reveal seasonal variations in fly distributions. Such variations allow for the identification of "control reservoirs" where fly distributions are spatially constrained by fluctuations in suitable habitat and tsetse population characteristics. Following identification of the control reservoirs, a tsetse management operation is simulated in the control reservoirs using capital and labor control inputs from previous studies. Finally, a cost analysis, following specific economic guidelines from existing tsetse control analyses, is conducted to calculate the total cost of a nationwide control campaign of the reservoirs compared to the cost of a nationwide campaign conducted at the maximum spatial extent of the fly distributions from January 2002 to December 2010. The total cost of tsetse management within the reservoirs sums to $14,212,647, while the nationwide campaign at the maximum spatial extent amounts to$33,721,516. This savings of $19,508,869 represents the importance of identifying seasonally dynamic control reservoirs when conducting a tsetse management campaign, and, in the process, offers an economical means of fly control and disease management for future program planning.

The questions of how land use change affects climate, and how climate change affects land use, require examination of societal and environmental systems across space at multiple scales, from the global climate to regional vegetative dynamics to local decision making by farmers and herders. It also requires an analysis of causal linkages and feedback loops between systems. These questions and the conceptual approach of the research design of the Climate–Land Interaction Project (CLIP) are rooted in the classical human–environment research tradition in Geography.This paper discusses a methodological framework to quantify the two-way interactions between land use and regional climate systems, using ongoing work by a team of multi-disciplinary scientists examining climate–land dynamics at multiple scales in East Africa. East Africa is a region that is undergoing rapid land use change, where changes in climate would have serious consequences for people’s livelihoods, and requiring new coping and land use strategies. The research involves exploration of linkages between two important foci of global change research, namely, land use/land cover (LULC) and climate change. These linkages are examined through modeling agricultural systems, land use driving forces and patterns, the physical properties of land cover, and the regional climate. Both qualitative and quantitative methods are being used to illustrate a diverse pluralism in scientific discovery.

This article discusses the evolution of participatory methods and their benefits and pitfalls in contributing to land use and land cover change (LULCC) analyses. Participation has become a practical means of developing a more complete assessment of societal change by bringing local people's narratives and understandings to bear on the interpretation of data collected using more extractive methods, such as the household survey, or data collected remotely, such as satellite images. Their methodological value lies in their ability to provide insights into the local mediation of external political, economic, and cultural processes. However, the realization of these contributions to LULCC analysis requires sensitivity to community differentiation, competing narratives of change, and the broader social context in which participatory forums take place. Examples from Kenya suggest that participatory feedback workshops present distinct empirical advantages that allow researchers to develop an understanding of critical intersections of social and environmental change through a dialogical process whereby participants themselves frame the central categories and change processes.

This landscape-scale study combines analysis of multitemporal satellite imagery spanning 30 years and information from field studies extending over 25 years to assess the extent and causes of land use and land cover change in the Loitokitok area, southeast Kajiado District, Kenya. Rain fed and irrigated agriculture, livestock herding, and wildlife and tourism have all experienced rapid change in their structure, extent, and interactions over the past 30 years in response to a variety of economic, cultural, political, institutional, and demographic processes. Land use patterns and processes are explored through a complementary application of interpretation of satellite imagery and case study analysis that explicitly addresses the local–national spatial scale over a time frame appropriate to the identification of fundamental causal processes. The results illustrate that this combination provides an effective basis for describing and explaining patterns of land use and land cover change and their root causes.

Scientists, governments and NGOs have a critical need to understand the reasons behind land degradation, desertification and loss of biodiversity. Development of this understanding needs to be put on a firmer empirical and analytical footing. Current data deficiencies are due to limited biophysical and socio-economic databases that often are temporally and spatially limited. The socio-economic dimensions in particular are also often too simplistically analysed, without capturing the causal processes behind changing land management and land use practices. This approach to understanding the causes and extent of land degradation and loss of biodiversity would be greatly enhanced by the use of land use or land cover change analysis, coupled with ground assessments of human activities and biophysical measurements. Obtaining this knowledge is greatly enhanced with use of an analytical framework to guide the collection, analysis and interpretation of the root causes data and information. A framework is particularly useful for land use change research due to the complexity of the problem. This paper provides a guide and a framework for designing such research; technical methodological guides are available in other LUCID working papers and elsewhere.

The overriding finding of the LUCID land use changes analyses is how rapidly farming and agro-pastoral systems have changed. Small-scale farmers and pastoralists have changed their entire system several times since the 1950’s. New land uses have been developed, and existing land uses have been transformed. In sum, the most significant land use changes have been: 1) an expansion of cropping into grazing areas, particularly in the semi-arid to sub-humid areas, 2) an expansion of rainfed and irrigated agriculture in wetlands or along streams especially in semi-arid areas, 3) a reduction in size of many woodlands and forests on land that is not protected, 4) an intensification of land use in areas already under crops in the more humid areas, and 5) the maintenance of natural vegetation in most protected areas. These changes have allowed many more people to live on the land as farmers and agro-pastoralists, and the systems have shown flexibility and adaptability in face of changing international and national economic and political structures. Diversification, towards a mixture of crops and livestock, cash and food crops, and farm and non-farm income, has been a critical means for households to reduce their risk in face of these changes. Amid the complexity of socio-economic and environmental driving forces of the land use changes across space and time, six factors appear to explain a large part of the dynamics of land use change in East Africa: 1. Government policy, laws and regulations 2. Economic factors 3. Population growth and migration 4. Changes in land tenure arrangements 5. Access to markets 6. Environmental conditions. Despite the rapid evolution of systems responding to these forces, rural poverty is common and key environmental resources are becoming increasingly scarce, contested and/ or degraded. The LUCID team found that poverty, poor land management and land degradation are much more common and persistent in marginal environments, especially, the remote, semi-arid zones.