Doctoral Dissertation Research: Effects of Management Regime on Forest Structure and Disturbance Patterns in the Usambara Mountains, Tanzania

Indiana University, Bloomington IN

Investigators

Abstract

The fate of tropical forests in human-dominated landscapes relies on interdisciplinary research to better understand ecosystem processes and ecological functioning, while also determining how such forests may be managed to meet the needs of resource-dependent people. Participation by local forest users in tropical forest management continues to gain legal and institutional grounding, but the ecological effects of particular management actions and patterns of resource use under such policies remain understudied. This dissertation research combines tropical forest ecology and institutional analyses to examine differences in local institutional arrangements for forest management, anthropogenic forest disturbance patterns, and ensuing changes in forest structure and composition, among seven Tanzanian forests and forest-adjacent villages. Comparisons will be made horizontally among forests currently under three different management strategies varying by degree of local participation, and longitudinally in each forest before and after national forest policy was revised to facilitate community participation. The objectives of the study are (1) to compare changes in forest condition, spatial patterns and intensity of human forest use, between Joint Forest Management, Community Forest Management and central government forest management strategies and (2) to identify local institutional strategies correlated with comparatively improved forest conditions. Forest condition will be indicated by composition and structural attributes measured from overstory plots and hemispherical photo transects. Current and historical patterns of forest conversion and canopy gap formation, a structural indicator of logging intensity, will be quantified via spectral mixture analysis and multi-temporal change detection using a 12-yr Landsat imagery chronosequence. Semi-structured interviews with forest-dependent villagers, local forest management committees, and Forest Department staff will identify changes in forest access rules, rule enforcement and relationships between these actors in response to national forest policy change. Paired control forests will be used to account for factors other than management change that may drive observed changes in forest condition at the study sites. A minimally disturbed research forest is also included in the study to serve as an ecological reference for comparison of forest structure and composition, and to determine a benchmark rate of canopy gap formation in the absence of significant human disturbance. Research results will determine how differences in the institutional structure and local participation of forest-dependent peoples among different forest management strategies disparately affect human disturbance patterns in the study forests, hence forest condition and ecological dynamics. Study results may enable an improved design for functional local forest management in participatory settings, and increase the currently small body of knowledge about how different patterns and intensities of anthropogenic forest use affect tropical forest structure. Such information is necessary for building a stronger framework for forest management that promotes social and ecological sustainability in human-dominated landscapes worldwide.