Migration and demographic changes. Its implications on land transformation and changing socio-economic development in the Lake Eyasi Basin in Karatu District, Tanzania

The relationship between population mobility and land transformation holds an important role in research on the linkages between human society and ecological systems. Various studies on population mobility in Tanzania have looked at rural – urban migration with little attention to rural – rural migration which has played a significant role for population change in the Lake Eyasi Basin since the early 1980’s. Besides, the few studies undertaken in areas of study have focused on livestock markets; agriculture and cultural history of population mobility and migration without putting emphasis on its implication on land resource transformation. The primary objective of this study therefore was to obtain a better understanding of the interrelations between population mobility and land transformation processes in the Lake Eyasi Basin in Karatu District in Tanzania. In order to understand the interrelations between population mobility and land transformation a comprehensive conceptual framework which incorporated the political ecology approach and theories of migration and land use change was developed. The analysis drew on empirical data collected from four rural villages in Karatu District, where population mobility rate is currently the highest in Arusha region and Tanzania at large. The study used a mixed-methods approach in data collection and analysis. Secondary socioeconomic and biophysical data provided contextual information for the study area and guided the selection of study communities. In-depth key informant interviews and historical narratives gathered detailed information about land resource management and people interaction experiences in study communities for the development of survey instrument, and provided a contextualized backdrop for the analysis of survey data. The household survey was conducted using a face-to-face questionnaire interview technique to collect data on head of household background and people’s interaction to land resource. The results have addressed the research objectives that population mobility and migration has influenced the population balance and presented a significant change in land resource management and socio-economic development in the receiving area. As the population has increased with the influx of migrant farmers, livestock keepers as well casual laborers in the Lake Eyasi Basin, the pressure on available land resources has increased. Among the migrants in the area are wealthy farmers and agro-business people from urban areas and surrounding villages who claim land from poor local people and heavily invest into agricultural inputs such as fertilizers, water pumps, herbicides and pesticides. As a response to the increased cost of agricultural production the poor farmers have remained with the option of selling, renting or enter into sharecropping agreement with rich migrant farmers. These options seem not to improve people’s livelihood but accelerate poverty and land conflicts among people in the area. Altogether, these findings have implications for the subsequent population change and corresponding land resource management and policy in rural destination areas

GLOWORM-FL:A simulation model of the effects of climate and climate change on the free-living stages of gastro-intestinal nematode parasites of ruminants

Gastrointestinal nematodes are important parasites of livestock and wildlife worldwide, causing mortality and morbidity, regulating host populations and threatening food security through reduced productivity of ruminant livestock. A significant part of the life-cycle of most GINs is completed outside of the host. GINs are therefore susceptible to changes in climate, and evidence of climate-driven changes in the phenology of GINs and the seasonal incidence of disease already exists. A modelling framework, GLOWORM-FL was developed to predict changes in the seasonal dynamics of the free-living stages of trichostrongylid GINs on pasture as a first step towards evaluating potential mitigation strategies. The general model framework was parameterised and validated for three GIN species that infect a range of ruminants worldwide: Haemonchus contortus, Teladorsagia circumcincta and Ostertagia ostertagi. The model builds significantly on previous models of GIN population dynamics by incorporating the behaviour of nematodes in response to climate variability, facilitated by recent advances in our understanding of the ecology of GINs. Simulations using historical and predicted future climatic data for a temperate region reveal the potential for an increase in annual infection pressure of H. contortus and T. circumcincta in small ruminants as increasing temperatures accelerate development and remove constraints on the development of H. contortus during the winter months. In contrast, a significant decrease in annual infection pressure is predicted for O. ostertagi in cattle due to accelerated development being offset by rapid mortality at higher temperatures. A similar trade-off is predicted during the summer months for H. contortus and T. circumcincta resulting in complex seasonal dynamics of the availability of infective stages on pasture. These changes could have significant impacts on the seasonal incidence and pathology of infection by GINs. GLOWORM-FL therefore provides an important tool to predict the seasonal risk of transmission of GINs and will aid in the design of climate-driven, risk-based GIN control strategies