Five years experiment on vegetation recovery of drought deciduous woodland in Kitui, Kenya

Species composition and tree growth were recorded in plots protected and unprotected from livestock grazing and fuel wood collection in Kenyan semi-arid region from 1989 to 1994. The number of tree species per 0•2 ha was 13 in 1989, changing to 15 in the protected plot and 10 in the unprotected plot after 5 years. Dominant trees wereLannea triphyllaandCommiphora africanain all plots: both species are unexploited due to their soft wood. Valuable tree species such asAcacia mellifera, Acacia senegalandAcacia tortiliswere scarce. The density of shrubs per 400 m2were 77 in 1989, 72 in unprotected plots and 130 in protected plots in 1994.Premna oligotricha, Hermannia oliveriandGrewiasp. increased in number in protected plots. In contrast,Solanum incanumincreased in unprotected plots. The former three species appeared to be good fodder for goats. The diameter at breast height (DBH) of a sample tree ofAcacia senegalwas 10•1 cm in 1989 and 13•7 cm in 1994. Estimated height of the tree was 5•37 m in 1989 and 6•18 m in 1994. The bare area due to over-grazing by cattle was covered by grasses and herbs, includingChloris roxburghiana, over 5 years enclosure. Seedlings ofAcacia senegal, Acacia melliferaandAcacia tortilisappeared in the herb layer.