Using woody community structure as an indicator of riparian ecological integrity in Ghana’s Ashanti Region

Despite the rich diversity of riparian ecosystems and their ecosystem services, disturbances increasingly threaten them. This study examined how disturbances influenced the ecological integrity of four riparian zones: the intact Amobia, slightly disturbed Onwame, moderately disturbed Ninian, and the degraded Pame riparian zones. Tree species were evaluated using their importance value index (IVI), while Chao-1, Jackknife and Hill numbers were used to estimate species richness and diversity, respectively. The results revealed the moderately disturbed zone, which recorded the highest IVI (186.174), tended to be the least species-rich (14.25 ± 0.72, Chao-1 estimate and 14.02 ± 2.41, 2nd Order Jackknife), whereas the intact Amobia was the most species-rich (48.74 ± 1.92, 47.11 ± 6.42) and diverse, but with the lowest IVI (92.69). This outcome contradicted our initial hypothesis that higher IVI would coincide with higher species richness and diversity. The findings suggest that the highest IVI of species such as Pseudospondias macrocarpa, and Combretum smeathmanii, in the moderately disturbed Ninian zone, have, over time, developed resistance biomechanical cues to thrive in disturbed environments, while the high species richness/diversity in the intact zone was probably due to fewer disturbances. The study highlights how community assemblages are shaped by their varied responses to disturbances.