Stem cracks and decay in Newtonia buchananii trees in the Mazumbai Forest Reserve, West Usambara Mountains, Tanzania

Abstract

Stem cracks, decay and bark pattern in Newtonia buchananii trees were investigated and compared in a submontane rain forest in the Mazumbai Forest Reserve and adjacent human disturbed forest. One third of the trees growing in the reserve (32 %) and more than half of those in the disturbed forest (60 %) had stem cracks and/or decay-mainly as butt rot, often accompanied by brackets of wood-rotting fungi. One fifth (20 %) of the trees growing in the reserve and three quarters (76 %) in the disturbed forest showed rough and rugose bark. As N. buchananii is a main climax species in the area, the outcome of the death of the trees will be the formation of big gaps. Gap formation in the reserve seems to be accelerating and going beyond the 'normal' levels of a natural rain forest ecosystem, whereas in the disturbed areas it seems that N. buchananii will be extinct in the future.

Journal of East African Natural History Vol. 87 (1&2) 1998: pp. 327-338