| Summary: | 碩士 === 環球科技大學 === 觀光與生態旅遊系環境資源管理碩士班 === 102 === Typhoon Morakot seriously destroyed southern Taiwan, especially upstream Gaoping River. This study set sample plots on the landslides in Gaoping River basin to investigate the environmental factors, vegetations, and soil seed banks. We monitored the vegetation restoration and studied the composition and structure of the nearby vegetation. The result showed that the soil hardness of major recovery applied plots was in the suitable level for root growth and seed germination and development. Among the broadcast sowing woody species, Fraxinus griffithii and Melia azedarach grew better. Paspalum notatum, Eremochloa ophiurides, and Axonopus affinis were major sowing herbs, and they grew well in the most recovery applied plots. There were also dominant herbs exotic, like Chromolaena odorata, Mikania micrantha, Bidens pilosa var. radiata, and Ageratum houstonianum, that were suggested to pay attention on their population expansion.
The natural restoration was more effective than the artificial recovery in Gaoping River basin. However, after the human sowing and slope surface processing, the biodiversity enhanced as well as the succession speed. It was helpful to return to originally natural ecology. We suggested broadcasting sow fast-growing woody species as Kleinhovia hospita, Trema orientalis, Macaranga tanariu, Koelreuteria henryi, Sapindus saponaria, Ficus septica, Lagerstroemia subcostata, Mallotus japonicus, M. paniculatus, Bridelia tomentosa, Glochidion philippicum, Rhus chinensis var. roxburghii, and Pistacia chinensis. The native species, e.g. Condon dactyl on, Miscanthus floridulus, Arundo formosana, Artemisia indica, Eupatorium formosanum, and Lespedeza cuneata are suggested herbs.
Most landslides were classified into the expanding type and adding type. The landslide management should be planned by cases. For example, while considering the safety of the protected objects and the traffic accessibility, the dam should be installed on the appropriate position to avoid immediate rocksliding during the heavy rainfall disrupting the stability of the upstream land base that is bad for vegetation restoration. Using stakes and railings and the vegetation process to stabilize the slope is good to maintain the convenience and safety of the outward roadways. Lagerstroemia subcostata, Vitex quinata, and Cordia dichotoma sprout easily, so they are great choices for stakes. It must be helpful for the recovery effect. The database of landslide treatment and management set in this study is able to supply as references and evidences for the future operation.
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