ABSTRACT

Field studies were carried out at Ahaba. Amaba and Uturu in Isuikwuato Local Government Area. Abia Slate. Nigeria, to determine the effect of quarrying and rock excavation on the vegetation and slope of the area, fen species of plants, Alcliornea cordifolia, Chromolaena odorata. Daniellia olivein, I'icns capensis, Millellia aboensis, Nauclea lalijolia, Newbonldia laevis, Trema orientalis, Urena lohaia and I ilex doniana were randomly selected for leaf and stomatai investigation. Pairs 61 these plants comprising one exposed (very close to the mechanical quarrying site), and the other considerably unexposed (very distant from the quarrying site) were used lor this study. Leaves of these pairs of plants were subjected to various chemical treatments to remove their epidermis for microscopic assessment ol (heir stomata Their leaf areas were also compared. Samples of the quarry dust on the exposed leaves were collected and analysed chemically. Furlbcimore, the effect of the excavation of rocks on the vegetation and slope of the area was determined using transects, quadrats and Abney Level. The results obtained for stomatai assessment, showed a significant reduction in number and size of stomata of the leaves due to dust accumulation, in all the species except in the lower layers of/ /<7/s capensis and Nauclea lalifolia. Unlike their dust-free samples, which had stomata only on (heir lower layers, the dusty biciis capensis and Trema orientalis had stomata on both surfaces. Whereas (he dust-infested Newbou/dia laevis had both dnomocyiic and Mesoyenous stomata, the dust-free ones had only the . Iiiomocylic tx pc. Flic leaf area analysis indicated significant differences in seven species excluding Daniellia ohveiri, Nauclea lalifolia and Urena lobala. Result of the dust analysis showed that the major elements were Pb. Fc. Zu. Cu. As, and ( d winch arc mostly heavy elements. Inventory of the flora along the excavated and uncxcavatcd slopes showed no significant effect due to the excavation (P<().()l). Conversely, the slope study revealed that excavation affected (he angle of declination of the slope significantly (P'.OI, df 22). It would be advocated (hat excavation for rocks and other materials in the area should be carefully monitored Io forestall environmental degradation and related landslide.