Anthropogenic and Environmental Influences on the Composition, Distribution and Utilisation of Plant Species in the Embobut River Basin, Elgeyo Marakwet County, Kenya

By Bernard K. Wanjohi



Embobut Forest Reserve is the largest of the 13 blocks that constitute the Cherangani water tower. The area is one of the major water towers (catchment basins) in the Cherangani Hills. This area, collectively with other water towers, supplies Eldoret town and its environs.  The Embobut River flows along the floor of Kerio Valley, joining the Kerio and flowing into Lake Turkana to the North. Embobut Forest Reserve lies between latitude 01°15′N and longitude 35°35′E.

Project Summary

My Doctoral research is carrying out inventories and monitoring of plant biodiversity as a natural resource, including challenges, threats, and the exploitation of natural vegetation along the Embobut River by adjacent communities, with the specific objectives of:

  • Determining the composition, abundance and distribution of different plant species in relation to altitude, aspect, slope, geographical location and disturbances;
  • Determining the man-made and natural disturbances in different ecological zones of the Embobut River Basin;
  • Documenting the current plant species used by the local community and assessing potential uses of the species occupying the Embobut River Basin and adjacent areas.

Based on altitudinal gradient, the basin was stratified into four major blocks; Valley Floor (Site 1), the Escarpment (Site 2), Upper Forested Area (Site 3), and the Moorland/Montane Vegetation (Site 4).

Transect and quadrant methods from Stergios (1996), Stohlgen et al. (1995) and Mligo (2015) were employed in carrying out the research sampling. Each site comprised three transects measuring 20m x 500m. In each of these transects, a further three 20m x 20m quadrats were systematically laid at interval of 230m to assess trees. Also two 5m x 5m quadrats were randomly nested within the 20m x 20m grid for the quantitative assessment of shrubs. Also a further three 1m x 1m sub-quadrats were randomly nested within the 5m x 5m quadrats for the assessment of herbaceous species.

Data collected include tree species lists, their counts, diameter at breast height and their general average heights. For the case of shrubs, their species list, counts, cover and average height data was collected. The same was done for the herbaceous species by collecting their species list, counts, cover and average heights. Human activities and disturbances were also recorded within each transect and the large quadrats.

All the plant species encountered, both in the sampling plots and the adjacent areas, were recorded, collected and pressed for further verification and documentation in both the University of Eldoret and the East African Herbarium. Photo images were taken to be posted to the iNaturalist website for use by the wider academic fraternity and other possible stakeholders in the future.

With the assistance of a BIEA thematic grant, the first phase of data collection started at Site 1 between 18th March and 20th March 2016. This was done by myself accompanied by one of my supervisors, Dr Wilson Kipkore, and three of my field assistants; Mr. Timothy Kipkeu, Mr Nelson Kirotich and Mr Boniface Mwangi Haruki (MSc student at the University of Eldoret). The second field data collection took place during the Easter holidays between 27th and 29th March 2016, and the third and fourth field seasons were conducted in July and August 2016. The raw data is currently being organized for the next phase of data analysis and a final phase of field data collection.


Mligo Cosmas (2015) ‘Plant Species Composition and Distribution in Relation to Land Use Patterns in Serengeti Ecosystem Tanzania’ Open Journal of Forestry 5 (6)

Stergios, B. (1996)  Plotless vegetation sampling methods. The 0.1-hectare method.

Stohlegen T.J. et al. (1995) ‘A Modified-Whittaker Nested Vegetation Sampling Method’ Vegetatio.117 (2): 113-121


12th October 2016

Bernard Wanjohi is a lecturer and PhD student at the University of Eldoret Kenya and a member of the Marakwet Research Team.


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