Abstract
Vegetation of Kiboko Range Research Station is a function of the interaction between prevailing biotic and abiotic environmental factors. To determine and explain the relationships between the vegetation and environmental factors, relevant characteristics of sample stands were taken and analyzed. Forty-four vegetation stands were sampled for vegetation foliar cover, frequency, soil, landscape and disturbance (fire and grazing) properties. Reciprocal Averaging ordination was used to describe vegetation relationships to environmental factors. Four major vegetation groups were identified. The vegetation of alluvial clayey soils was dominated by Pennisetum mezxianum, Bothriochloa insculpta, Ischaemum brachyatherum, Acacia drepanolobium and A. xanthophloea. The vegetation of the basement complex system with sandy clay loams was dominated by Chloris roxburghiana, Digitaria milanjiana (marcoblephara), Enteropogon macrostachyus, Eragrostis caespitosa, Commiphora riparia, C. africana, Acacia tortilis, A. senegal, A. mellifera and Duosperma kilimandscaricum. The vegetation of the lower volcanic area was dominated by Sehima nervosum, Heteropogon contortus, Combretum apiculatum and Cordia gharaf. The upper volcanic cone is dominated by Chrysopogon aucheri, Tricholeana eighingeri and Acacia hockii. In specialized wet areas, Themeda triandra, Andropogon distachyus and Combretum apiculatum may be found. In denuded or heavily grazed areas, Microchloa kunthii, Aristida keniensis and Eragrostis caespitosa were the increaser or invader plants. In a seasonally waterlogged area in the basement complex system, Echinochloa haploclada was dominant grass species and Acacia drepanolobium was at the edges of the stand. The complexity of the interacting environmental factors (biotic and abiotic) make it difficult to determine the exact factors that have determined a specific vegetation stand. However, soil properties, disturbance and landscape factors seem to be important in stand composition determination in the short-run. Climate, in addition to the above factors, determines the vegetation composition in the long-run.
Kemei, Isaac Kipkec (1982). Vegetation-environmental relationships on the Kiboko Range Research Station, Kenya. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -394860.