Mistletoes and their diversity in the Bwindi Impenetrable National Park, Uganda

Abstract

This study examined mistletoes in the Bwindi Impenetrable National Park in South Western Uganda. In 6.4 ha, comprising 64 plots, divided between disturbed and less disturbed forests, spanning on an elevation range of 1160 to 2607 m a.s.l. 1,496 mistletoescounts were recorded, comprising of 21 species in seven genera and two families. These were hosted on 542 host trees comprising of 45 species in 18 unique mistletoes –host families. These mistletoes showed a preference for stems growing in open conditions with the mean density of 356 ha-1 versus 129 ha-1 in denser forest. The most abundant mistletoe species were found in the altitudinal range of a1000.5-1500m and 1500.5-2000.5m a.s.l with minimum numbers of counts dominated by Englerina woodfordiodes (with a count of 151 contributing to 23.18 %.) and Phragamenthera usuiensis (with155 counts contributing to f 42.8% of mistletoes in Bwindi forest).Mistletoe abundance differed significantly between altitude ranges (P < 0.001) although it was similar between the forest edge and interior sites (P= 0.565).Nevertheless, six mistletoe species were recorded over one hundred times each and another six species were recorded only once implying that the species list is incomplete. Application of Chao’s estimator indicated that mistletoe species richness is likely to exceed 40 species suggesting that mistletoes represent a significant component of the forest’s botanical diversity.