Impacts of Prosopis juliflora on Abundance and Species Diversity of Forage Species in Turkana County

Aims: This study sought to determine the effects of P. juliflora on the abundance and relative diversity of other forage species in Turkana County.

Study Design:Ecological data collection entailed cross-sectional surveys across riverine and non-riverine ecosystems.

Place and Duration of Study: The study was undertaken in three sub-counties within Turkana County namely Turkana Central, Turkana West and Turkana South between 15th January to 17th May, 2020.

Methodology: Sampling plots were used to collect plant abundance data from the various parts of the study area. The plots were of three types; main plots of 30 m× 40 m (1200 m2), sub-plots of 5 m × 2 m (10 m2) and square quadrats of 1 m×1 m (1 m2). The sub-plots and quadrats were nested within the main plots which were in turn laid down along transect belts. The transects of width 40 m and 400m in length were laid down in two main habitats (riverine and non-riverine) of the three sub-counties. Control plots were also laid in non P. juliflora sites.

Results: Prosopis juliflora was the most abundant species covering about 63% of the sampled individuals (N=6390). This was followed by Acacia tortilis at 18% while Acacia mellifera was the least. There was significant difference in abundance between sites and among counties (p˂0.05). The Shannon diversity index (H´) in areas with Prosopis juliflora ranged between 0.40-1.27 while in areas without Prosopis juliflora (or Control) it ranged between 1.5-2.1, indicating high diversity in the areas without P. juliflora compared to areas colonized by it. Prosopis juliflora was also high in the riverine areas compared to non-riverine areas across the three sub counties. Results show that Prosopis juliflora has invaded vast areas especially the riverine ecosystem leading to a decline in the population of key forage species and thus threatening the socio-economic livelihoods of Turkana County.

Conclusion: Prosopis juliflora was the most abundant and dominant plant species in both the riverine and non-riverine sites. The study also showed that P. juliflora has led to the decreased plant species richness and diversity in the area because of its invasive nature.

Please see the link :- https://www.journalcjast.com/index.php/CJAST/article/view/31026