More People, More Trees: Social and Ecological Factors for Tree Cover Distribution and Their Implications for Forest Connectivity in Southern Tanzania

Abstract

Fragmented habitats are a core concern for biodiversity, as isolation threatens survival of vulnerable species. Conservationists recognize that the creation of protected areas is insufficient for long-term preservation of biodiversity. Whereas protected areas are designated as zones of no-use that provide a safe haven for the life within their borders, the areas outside are free to be transformed to other land uses. As a result, protected areas become islands that provide both a refuge and an entrapment for the wildlife within. Landscape-scale conservation aims to create a network of habitats both by linking the protected areas and by softening the sharp transitions between the protected and the human use areas. Methods used for achieving landscape-scale conservation include creation of corridors, buffer zones, community wildlife management areas, agroforestry initiatives, and payments for ecosystem services. The major puzzle for these landscape-scale approaches is the degree to which conservation goals can align with other land uses, agriculture in particular. This thesis explores prospects for enhancing habitat connectivity at Bujingijila Gap in the Southern Highlands of Tanzania, an area of globally significant endemism and high human population density. Specifically, I look at trends in tree planting and natural forest regeneration in the Bujingijila Gap that separates two protected areas: Mount Rungwe Nature Reserve and Livingstone Forest (managed as part of Kitulo National Park). Connecting these forest blocks is vital to the survival of an endangered primate: Rungwecebus kipunji. In fact, researchers have identified this as high priority area for a corridor. The stakes are potentially high also for local agriculturalists, some of whom depend on access to farmland in the Gap for their livelihood. My primary research questions are: 1. For the farmers that own plots in the Gap, how do their land use along forest edges compare to how they use plots in the rest of their land portfolio? 2. What natural and human-mediated factors explain the distribution of natural tree seedlings in the Gap? My research project, then, is a case study that assesses the social and biophysical factors linked to increased tree cover in one proposed corridor in Southern Tanzania. This research is meant to contribute to literature about habitat connectivity, forest regeneration and park edge land use in tropical highlands, particularly in Africa. It furthers efforts to understand how conservation needs can be balanced with human needs, using the specifics of the case study to compare tree cover outcomes from regeneration and from cultivation. The project is a direct response to the need to combine research and conservation practice that can be broadly applicable to the Rift Valley montane forests. It is my hope that a detailed understanding of land use and natural seedlings patterns will help guide efforts to create a connective corridor that is both ecologically viable and socially equitable.