PARENT SESSION
Oral Session 81: Forest Ecology IV: Seeds, Growth, and Recruitment.
Presiding: J Kush
Wednesday, August 4, 1:30 PM to 5:00 PM, Meeting Room C 120.

Serengeti riparian forests: Persistence of a naturally fragmented system.

Sharam, Gregor^*,1, Sinclair, A.R.E.¹, Turkington, Roy¹, ¹ University of British Columbia, Vancouver, BC, Canada

ABSTRACT- The riparian forests of Serengeti National Park, Tanzania, occur as long and narrow but naturally fragmented, high diversity patches in a savanna matrix. These forest patches have declined in number by over 50% during the past 30 years. We are interested in the factors causing the decline of these forests as a model for managing human-induced fragmented systems. We conclude that two major factors limit these forests; first, area and edge-expansion is limited by the frequency of grassland fires that remove nurse trees on the forest edge. Second, and more importantly, seedling recruitment is currently insufficient to replace lost canopy trees in gaps, leading to the fragmentation of a closed, fire resistant canopy. Tree seedling recruitment is limited in two ways; first, the seeds must be flooded in order to germinate, and second, by browsing of seedlings by impala (Aepyceros melampus) and other ungulates. We propose that to allow seedling establishment and forest expansion that fire control be imposed during periodic declines in impala populations.

Key words: fire ecology, impala (Aepyceros melampus), serengeti, riparian forest