Biodiversity and human nutrition in a landscape mosaic of farms and forests in the East Usambara Mountains, Tanzania

Abstract

This dissertation sought to add to knowledge of the links between human and ecosystem health by examining relationships between biodiversity and human nutrition in the East Usambara Mountains, Tanzania. Grounded in a theoretical framework drawing from systems approaches to human and EcoHealth this dissertation explores these relationships using qualitative, quantitative and landscape level approaches, with attention to mediators of these relationships. Dietary diversity has been suggested to be an important pathway through which biodiversity contributes to human nutrition and has been separately linked to agricultural diversity and nutrient intake and adequacy; however, there are very few studies that have demonstrated these links in the same population. This research included data for N=274 children, their mothers and households in 6 villages. Dietary diversity was measured 6 ways: food variety score (FVS) and two dietary diversity score (DDS6 and DDS14) of food group diversity (based on 6 and 14 groups respectively), each determined from a 7 day qualitative food use questionnaire and from one 24 hour recall (1 day). Nutrient intake was determined from repeat 24 hour recalls from which an MAR (mean adequacy ratio) was calculated. Growth was assessed using WHO protocols. Biodiversity and landscape level variables were assessed by questionnaire and GIS. Most of the dietary diversity scores showed significant positive correlations to energy intake, in concurrence with local knowledge which emphasizes the importance of dietary diversity for maintenance of appetite. The 1 day FVS, DDS6 and DDS14 were positively correlated with nutrient intake and adequacy (MAR); the correlation between MAR and 1 day DDS6 remained significant after controlling for energy. Conversely, 7 day diversity was positively associated with crop diversity, forest food use and forest cover...