| dc.description.abstract | The objective of the study was to investigate the distribution and some ecological aspects
of land snails in Shimba Hills National Reserve, Kenya. This study was important
because no scientific study on snails has been done in this forest, therefore this study will
increase malacological knowledge which will in turn necessitate proper management plan
for both ecosystem and the terrestrial snails. Molluscs were sampled using standardized
direct search and litter sample methods in plots measuring 1m x1m in the different habitat
types. Environmental parameters notably temperature, relative humidity, soil, vegetation
were investigated. Soil parameters analysed were soil pH, electro-conductivity, soil
calcium and soil texture. For vegetation, sampling was done for trees, shrubs and herbs
and the plant species identified.
In total, 1,748 snail specimens were recorded during the entire study; yielding 28 species
from eight families, with family Streptaxidae having the highest number of species with
nine species, followed by Subulinidae with six species. The families Maizaniidae,
Pomatiasidae and Endodont~~e had one species each. The most abundant species was
Gonaxis quadrilateralis belonging to family Streptaxidae, and comprised 12% of the total
specimens recorded. The least abundant species was Morphospecies 2.
Comparison of snail metrics in three different seasons showed that the wet season had the
highest number of individuals with 703 followed by the dry/wet season with 579
individuals and the least in the dry season (466). There were significant influences of
season on land snail diversity (F (2,407) = 6.324, P <0.05) with the wet season recording the
highest diversity.
When snail abundance was tested using ANOVA, there were significant differences of
land snails due to vegetation types (F (4,407) =56.039, P <0.05). Shannon Weiner diversity
levels of land snails were highest in the indigenous forest with 0.984 while the grasslands
recorded the least diversity of snails with 0.009. Rainfall and other environmental
variables such as litter cover, relative humidity and canopy cover had a positive and
significant influence on the snail richness while the temperature significantly affected the
abundance and richness.
The findings ranked Shimba Hills as the richest coastal forest in terrestrial snails in
Kenya; having been compared with studies done in Arabuko Sokoke where 25 species
were recorded. These results are 'important in exposing the role the forest plays in
conservation of land snails and therefore sound conservation strategies should be put in
place to protect the ecosystem. | en |
