Influence of Land Use Activities on Riparian Vegetation, Soil and Water Quality: An Indicator of Biodiversity Loss, South West Mau Forest, Kenya ()
ABSTRACT
Watershed
and riparian areas of Mau Forest Complex in Kenya are experiencing increased
threats due to unsustainable land use activities geared towards economic growth
amidst growing population. This study was carried out to examine effects of
land use activities on riparian vegetation, soil and water quality along two
major rivers (Chemosit and Kipsonoi) of South West Mau Forest (SWMF). Land use
activities adjacent to these rivers and biodiversity disturbance on the
riparian zone were identified and underpinned to changes on Total Nitrogen,
Total Phosphorous, Potassium, Sulphur, Cadmium, Copper, Lead, Total Suspended
Solids and soil Organic Carbon. Three sampling sites designated(upstream,
midstream and downstream) were identified and established along each river as
guided by existing land use activities represented by forest, tea plantation
and mixed agricultural farming respectively. At each sampling site, a 200 m ×
50 m section was systematically marked on each side of the river bank; the
longest side being parallel to the river flow and divided into three belts
transects each 20 m × 50 m, spaced 70 m apart. Six distinct land use activities
(indigenous forest, food crop, tree and tea farming, livestock keeping and
urban settlement) were identified as the major land use activities in SWMF.
Plant species richness decreased and overall riparian disturbance increased
from upstream (intact canopy with native vegetation) to mid-stream and
downstream as epitomized by the structure, biodiversity disturbance resulting
from extensive and intensive farming, intrusion of exotic species to livestock
grazing and urban settlement. Variation among sampling sites in Total Suspended
Solids, pH, Total Nitrogen, Phosphorus and Potassium were associated to
different land use activities along the riparian zone. Total Nitrogen and water
pH showed significant sensitivity to land use changes (p < 0.05). Put together these results indicate loss of
biodiversity, riparian disturbance hence a need to adopt environmental-friendly
land use planning and sustainable farming systems in SWMF.
Share and Cite:
Njue, N. , Koech, E. , Hitimana, J. and Sirmah, P. (2016) Influence of Land Use Activities on Riparian Vegetation, Soil and Water Quality: An Indicator of Biodiversity Loss, South West Mau Forest, Kenya.
Open Journal of Forestry,
6, 373-385. doi:
10.4236/ojf.2016.65030.