Ecology and sustainable management of African mahoganies and other selected timber species in northeastern Congo Basin, Democratic Republic of Congo.
Published: 2004
Language: eng
Number of pages: 212
Description: This thesis reports on a study that assessed management options for African mahoganies and other major timber species in the Ituri region through analyses of regeneration ecology and the performance of these species in disturbed and undisturbed forests, and the impacts of selective logging and shifting cultivation on forest structure, tree diversity and composition. The main hypotheses tested were: (1) insufficient seed availability and dispersal limit seedling recruitment in logged forests; (2) soil disturbance promotes seedling establishment; (3) single tree harvesting provides insufficient light levels for the successful recruitment of African mahoganies; and (4) the combined effects of selective logging and agriculture result in severe degradation and impoverishment of natural forests. The first three hypotheses were tested using a factorial split-plot experiment involving seed addition, litter removal, and canopy cover (gap vs. understory). The fourth hypothesis was evaluated by comparing forest structure, tree diversity and composition between secondary and mature forest stands in logged and unlogged forests. In addition, long-term ecological data were used to examine whether size distributions and wood density were correlated with the life history parameters of common timber species in the region.These findings suggest that intensive silviculture, perhaps involving the use of shifting cultivation in a taungya-like system, appear necessary to achieve sustainable management of African mahoganies and other disturbance-adapted timber species. In this context, biodiversity conservation will likely be assured by the zoning of forests into multiple-use, timber production and strict protection areas.The results showed that timber species in the Ituri region varied widely in their regeneration requirements and their performance in natural forests. There was a strong dispersal limitation effect on seedling establishment and seed addition greatly increased seedling recruitment. Litter removal did not improve seedling establishment. However, the combined occurrence of canopy gaps and litter removal offered the best conditions for seedling survival and growth. Secondary forests had lower diversity of large trees than mature forests and the dominant species of mature forest were poorly represented in them. The regeneration of African mahoganies was 10 times greater in secondary forests than in adjacent mature forest stands.
Notes: Adviser:  Sean C. Thomas.

Forestry theses.

Thesis (Ph.D.)--University of Toronto, 2004.

Electronic version licensed for access by U. of T. users.

Source: Dissertation Abstracts International, Volume: 65-10, Section: B, page: 4918.