Abstract

The purpose of this research was to investigate the use of drilled slanted holes filled with different substrates in the revegetation of rock slopes. Slanted holes were drilled on rock slopes using pneumatic drillers in an abandoned limestone quarry area. These holes were filled with twelve different substrates, treated with Trichoderma harzianum. One climbing plant of Ivy (Hedera rhombea), a native woody plant (Lespedeza cyrtobotrya), three native herbaceous plants (Dianthus barbatus, Siberian chrysanthemum and Aster koraiensis) and one exotic grass plant (Festuca arundinacea) were planted in each of the soils. Six months after planting, only Ivy, Festuca arundinacea, Lespedeza cyrtobotrya and Dianthus barbatus were still observed growing on the soils, while the other plant species had already died in all the 12 soil treatments. Leaf mold soil + 50% Trichoderma harzianum provide the best conditions for revegetation of Festuca arundinacea, as this plant had its highest mean height, high survival rate, with impressive growth rate on this soil. Lespedeza cyrtobotrya also had its most favorable growth on Leaf mold soil + 50% T. harzianum. Mixed soil + 100% T. harzianum provide the best conditions for revegetation of Ivy. Leaf mold soil + 100% T. harzianum provide the best condition for revegetation of Dianthus barbatus as it had its highest mean height, highest growth rate and high survival rate on this soil. Siberian chrysanthemum and Aster koraiensis had the worse results as all of the plants died within a short period of time after planting. Ivy had the highest mean height, followed by Festuca arundinacea. The planted Ivy and Festuca arundinacea now form the vegetation of the research site which together with the substrate is now providing habitat to some wildlife like some species of centipedes, earthworms, insects and wild plants. Less than one year after planting, F. arundinacea already produced flowers and seeds which would further increase the plant population after dispersal and germination. Drilling slanted holes on rock slopes is therefore a feasible method to be used for revegetation and restoration of degraded quarries.

The revegetation of steep rock slopes of quarries is a very challenging activity. However, the method of drilling slanted holes on rock slopes is a feasible method to be used for restoration of degraded quarries. These holes could serve in soil deposition and water retention that will further enhance plant growth.

Methods of improving seed germination as well as enhancing growth of plants are also imperative in revegetation success of such degraded landscapes. Different percentage mixtures of T. harzianum in different soils could enhance plant growth depending on the target plant species. Different substrates could thus be used in such revegetation process depending on the target plant species.

Revegetation would provide habitat and improve landscape beauty and stability, thus it is important for successful restoration of rock slopes 

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