Shade tolerance and regeneration of some tree species of a tropical rain forest in Western Kenya
Kiama, D.K.yiapi, J.
Plant ecology 156(2): 183-191
Shade tolerance and regeneration of some heavily exploited timber species (Uvariopsis congensis, Antiaris toxicaria, Funtumia africana, Prunus africana and Aningeria altissima) were studied in two adjacent sites in Kaka-mega tropical rain forest. The two sites have been subjected to different logging intensities. Within one of the sites, relatively intact areas were compared with adjoining more disturbed ones. Seedling presence or absence in in mature forest phase, sapling proportions in gap and the mature phase and diameter distributions were used to classify the species into shade tolerance groups. Results indicate that except for Uvariopsis, the species are non-pioneer light demanders and could fit into three shade tolerance groups: A group resembling pioneers but with seedling in shade, a mid-tolerant group and one showing a high shade tolerance. Amount of regeneration and disturbance were related: regeneration being higher in the more disturbed site except for Uvariopsis. The intersite differences were mirrored when disturbed and adjoining more intact areas within one of the sites were compared. Species more abundant in the disturbed site also generally scored low in shade tolerance. However, the mid-tolerant Funtumia and not Prunus or Aningeria that had lower shade tolerance scores, dominated regeneration in the disturbed forest parts. The shade tolerance data suggest that Uvariopsis, Funtumia and Antiaris could be amenable to natural forest management. For Prunus and Aningeria, artificial regeneration in buffer plantations around the natural forest may be a better option.