Assessment of Population Status of Melia Volkensii Gürke and Diversity of Tree Species in Kasaala Location in Kitui County Kenya
Author(s): Njehu JM, Wabuyele Emily, Mutune AN
This study was conducted to evaluate the population status of Melia volkensii and the diversity of tree species in Kasaala Location in Kitui County. Subsequently assessing the natural regeneration of M. volkensii and thus promote its propagation and conservation in the dry lands of Kenya. Plant population was determined in situ across seven transect lines measuring 1050 meters in length. Sampling was carried out in five plots measuring 50 × 50 meters established at intervals of 1,000 meters. Transect 1 and 7 were laid in farmland while the transects between these two were laid in bushland. All tree species represented in each plot were counted. Height and diameter at breast height (DBH) were measured for all M. volkensii trees within the plots. Melia volkensii seedlings and coppices were counted in 5 × 5 meter nested plots within the larger plots. One-way analysis of variance (ANOVA) at 95% confidence interval was used to test for variance in parameters measured and means separated using Tukey’s HSD. There were significant differences in mean number of height and DBH of M. volkensii that were found in transect one and two. Transect 2 had the lowest mean height and DBH while the tallest trees were in the other transects. Tukey honestly significant difference (HSD test) was used to test separation of means (of mature trees and coppices of M. volkensii). There were no significant differences between the mean number of coppices and seedlings found in transect two and four. Moreover, relative abundance, species richness and diversity of plant species observed were analyzed using Simpson’s index of biodiversity and Shannon-Wiener species diversity index. Melia volkensii was the most frequently occurring species with 12.2% (n=67) followed by Acacia tortilis10.0% (n=55). Calotropis strophela, Commiphora capensis, Maerua crassifolia were the least represented relative abundance of 0.18%. Values of indices used varied among transects and did not follow the location of transect implying that diversity was not determined by land disturbance. Based on diversity and relative abundance of M. volkensii and associated tree species in the study area, the results show clearly that the risk of tree depletion in Kasaala Location has no significant effects on the population status of M. volkensii.