- University: University of Copenhagen
- Place of defence: Copenhagen
- Keywords: Restoration, Tree seed system, Seed cooperative, Quantitative genetics
Abstract
This thesis investigates how to evaluate the success of restoration using biophysical and socioeconomic variables. Two native species, Vachellia sieberiana and Vachellia kirkii, endemic to Rwanda, were used for genetic assessment, and the potential socioeconomic impact was assessed utilizing a case study of active members of a seed cooperative who are mainly local farmers. The two complementary components first examined the breeding seed orchards (BSOs) of this research area. Using principles of quantitative genetics, the study evaluated the height for genetic variation present within and among native family populations. Then the second component investigates the baseline income-generating activities of farmers in the seed cooperatives to assess the livelihood quality of seed collectors and their household income. The total height of all families was measured six months after planting at the three trial sites, and Pearson correlation coefficients were used to evaluate family stability. Vachellia sieberiana correlations were moderate: Site 2 and Site 3 (r = 0.69), Site 1 and Site 3 (r = 0.66), and Site 1 and Site 2 (r = 0.65). They showed consistent performance across sites, although environmental variation likely influenced family performance rankings. For Vachellia kirkii, Site 2 and Site 3 showed a strong correlation (r = 0.84), indicating stable performance under similar site conditions. Weaker correlations for Site 1 and Site 2 (r = 0.43) and Site 1 and Site 3 (r = 0.42) reflected greater environmental differences and more variable genetic expression. The interviews also indicated that seed collection offered a small yet dependable addition to household income, and participation in these activities was influenced both by the division of labor between men and women and by the ease of accessing seed sources. These support the need for restoration programs to link genetic performance monitoring with measures that address the economic realities of collectors. Raising seed prices to better reflect the time and effort involved, along with expanding market opportunities, could improve earnings for participants while still supporting restoration targets.
