The Correlation between Opuntia stricta Distribution and Soil Chemical Composition in Tsavo East National Park

Abstract

Biological invasions have been observed in Kenya some of which are deemed to have significant socio-economic repercussions on affected communities altering the composition and structure of ecosystems. Data from the East African region indicates that Kenya has been invaded by 34 distinct species with notable examples including Opuntia stricta (Haw) and water hyacinth (Eichhornia crassipes). This study aimed to examine the relationship between the distribution of the invasive species O. stricta and the soil chemical composition in Tsavo East National Park, Kenya (TENP). The study area was divided into twelve 2km-long transects with ten 5m by 5m quadrats systematically established along each transect. Data on O. stricta coverage and soil chemical concentration were collected in each quadrat. Analysis of variance (ANOVA) was conducted on O. stricta coverage revealing significant differences in its distribution across the sampled transects. Correlation analysis between O. stricta and soil chemical composition was performed. Among the soil chemical components examined, phosphates exhibited a negative correlation with O. stricta cover at a significance level of p=0.002 for α=5%. Conversely, sodium content and O. stricta cover showed a positive correlation at a significance level of P=0.039 for α=5%. These findings are critical for guiding strategies aimed at controlling the rapid spread of O. stricta in Tsavo East National Park and similar ecosystems.