坡地人工噴植復育區植生演替趨勢調查分析－以臺南市南瀛天文館為例

Investigation of Vegetation succession at landslide scars with hydroseeding: take a site of Tainan Astronomical Education Area as an example

郭玉麟(Yu-Lin Kuo) ； 簡士濠(Shih-Hao Jien)

《水保技術》 14卷3期 (2020/11) Pp. 42-57

摘要

台灣因受1999年的921地震及2009年的莫拉克颱風風災後，山坡地自然崩塌地數量急速增加，又因人為開發利用山坡地的開挖整地皆造成坡地上植被消失，土壤裸露、流失等。為防止土壤因裸露而造成土壤流失及崩塌等，常利用人工噴植復育以減少土壤裸露時間、降低土壤流失量。人工噴植復育之目的除加速植生覆蓋外，亦可加速植生演替。本研究試區位於台南市大內區之山坡地，南瀛天文館自2004年開始興建並施作邊坡穩定人工植生復育工程，本研究自歷年施工工程中規劃1個對照區及5個不同人為復育年份樣區進行植生調查，從人工噴植復育開始至進入自然演替過程中，依據現場植生調查以了解地上植物群落變化及植生演替之趨勢。調查結果顯示，樣區I與對照樣區的物種組成最為相似，而人工噴植的植生種類歷經10年演替己不復見。整體而言，樣區I與對照樣區的植被在演替上仍屬初期的次生林環境；樣區II歷經8年演替，現況未發現人工噴植的植生種類，優勢植物皆為研究區域周邊森林之原生物種，顯示樣區II植被種類主要由周邊森林拓殖，由草生地逐漸演替為先驅樹林。樣區III現況以植生工程噴植的臺灣欒樹為優勢，林下並有其自行下種之小苗，次優勢者為自生之先驅樹種，顯示歷經5年演替，噴植的臺灣欒樹已搶先建立穩定族群、並有自然更新之潛力，不易被其他先驅樹種所取代；林下地被以外來入侵種為優勢，原噴植的草種已被外來入侵種競爭取代。樣區IV現況以大花咸豐草及百喜草為優勢，未發現其他撒播的植生種類，顯示歷經5年演替，原撒播的植生已逐漸被外來入侵種競爭取代。樣區V現況以外來入侵種（大花咸豐草及大黍）為優勢，原噴植的草種僅存部分百喜草族群，顯示歷經2年演替，原噴植草種已逐漸被外來入侵種競爭取代。後續，這項研究還測量了正在復育的崩塌地上的生物量和土壤有機碳儲量，並與該地區未受干擾的低海拔常綠闊葉林進行了比較。研究得出的結果人工植生復育的坡面是強大的碳匯，且可以有效改善崩塌地植被初期的遲滯並加速中後期植被演替。

關鍵字

人工植生復育 ； 植生演替 ； 植生工程

並列摘要

After Ji-Ji Earthquake in 1999 and Typhoon Morakot in 2009, landslide disasters obviously increase in Taiwan. Overuse of slopelands results in rapid disappearing of vegetation cover and serious soil erosion. Artificial hydroseeding at landslide scars could be a critical and effective method to accelerate vegetation cover to prevent bared slopeland soils from erosion. This study tried to evaluate vegetation succession along a chronosequence of landslide scars in southern Taiwan. In this study, we established a chronosequence including four former landslide scars in the mudstone area, southern Taiwan, ranging in age from 1 to 11 years post disturbance as determined by landslide mapping from remote sensing. The younger landslide scars (plot IV) were artificially colonized by Paspalum notatum, Miscanthus and Koelreuteria elegans, while after approx. 5 (plot III) to 8 (plot II) years of succession, natural tree species were dominating. Our results indicated that the aboriginal tree species are dominant at landslide scars after 5 years since artificial hydroseeding exdigenous species such as Bidens pilosa L. var. radiata Sch. and Panicum maximum are dominant after 2 years. Furthermore, this study also measured biomass and soil organic carbon stocks on the recovering landslide scars and compared to an undisturbed low elevation evergreen broad forest stand in the area. Our results from this in-situ study suggest that recovering landslide scars are strong carbon sinks and artificial intervention could effectively overcome an initial lag period of vegetation re-establishment and accelerate vegetation succession.

並列關鍵字

hydroseeding ； vegetation succession ； vegetation engineering

參考文獻

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