WOODY SPECIES COMPOSITION AND RECRUITMENT STRUCTURES OF FOUR COMMON SPECIES IN AN ARID AND SEMI-ARID

In dry and semi-arid ecosystems, spatial changes in woody species composition and recruitment structures are little studied. We set out to fill this gap by conducting research at three sites in the Awash River Basin that were purposefully chosen for their geographical expanse and altitudinal gradients. We laid out one transect line in each vegetation location and placed 12 sample plots (each measuring 50 x 50 m) with 200 m intervals on each transect, totaling 36 sample plots. The Adonis2 function was used to examine the difference in woody species composition across the three sites. To show the species composition in relation to the vegetation locations in ordination space, a nonmetric multidimensional scaling ordination analysis was performed. A generalised linear model with the Poisson family was used to examine the difference in species richness across the locations as well as the effect of altitudinal change. The findings revealed that the species composition varied between sites and was significantly influenced by altitudinal variance (P=0.001). When compared to the other two sites, the Mille site had a larger species richness and number of unique species, and the alpha diversity of vegetations was proportional to the magnitude of beta diversity. Although the overall trends differ among sites, recruitment structure was weak in areas with lower species richness. Our findings imply that, in order to improve the overall health of vegetative ecosystems, restoration programmes should take into account the recruitment structure of specific species, particularly in dry and semi-arid habitats.

Please see the link :- https://www.ikprress.org/index.php/JOGEE/article/view/7419