This dissertation is conducted in Gedeo, with the aim of revealing the dynamics of IK of agroforestry system of Gedeo. The dynamics were seen from the perspective of the intergenerational variation in IK acquisition and transmission. The study investigated drivers of IK changes and continuities and the implications to sustainability. The study employed an interdisciplinary approach whereby geographical concepts and approaches were supplemented by anthropological and developmental psychology approaches and concepts. Thus, an exploratory mixed research approach was used. The dynamics were seen by employing cross-sectional approach. Thus, synchronic data were collected from several sources, by employing ranges of qualitative and quantitative tools. The respondents were drawn from the local people and agricultural experts. Accordingly, 72key informants were chosen through purposive and snowball sampling. To determine the spatio-temporal variation of IK, 290 informants aged between 12 and 65 were chosen using multistage stratified sampling. For the household survey, 252 participants were selected using multistage stratified and systematic random sampling. The qualitative data were analyzed using thematic content analysis and case summary while for quantitative data mean, standard deviation, ANOVA, chi-square, and t-test were employed. The analysis results have shown that the agroforestry system exhibits both indigenous and modern practices. The indigenous practices, which sustained for longer time through generational transfer, appear to be engulfed by modern practice. The study identified knowledge and skill gap between young people and adults. The gap is more significant in normative dimension of IK. This can be attributed to declining rate of IK transmission and acquisition among successive generations, which in turn is attributed to weak contact between young people and adults, and changes in the lifestyle of the young people. Besides, biodiversity loss, demographic pressure, modernization, introduction of market economy, and top-down development approach are among the drivers of the gradual loss of IK. The gradual loss of IK was to have an impact on sustainability of the system. This calls for concerted efforts to maintain the sustainability of IK through revitalization of IK transmission and acquisition. Finally, joint effort is required to document IK, include in school curriculum, and integrate with the modern practices. / Geography / Ph. D. (Geography)