澎湖海岸林現況及颱風帶來鹽霧危害後林木恢復生長之調查

Survey on the Present Conditions of Peng Hu Coastal Forests and the Recovery of Trees Damaged from Salt-mist Brought by Typhoon

陣財輝(Tsai-Huei Chen) ； 洪富文(Fu-Wen Horng)

《林業試驗所研究報告季刊》 8卷2期 (1993/06) Pp. 129-142

https://doi.org/10.7075/BTFRI.199306.0129

摘要

本研究根據澎湖縣政府提供之造林地籍圖，調查各造林地方位、林帶幅、土壤類別以及現存林分生長實況，並量測澎湖海岸林木颱風後樹體附著鹽分量及受害木樹冠部恢復生長情形。調查結果顯示，造林地從分佈方位區分，東北及北向合計達48.6%，再加上西北向更高達68.5%，造林地受到冬季季節風危害地區極多。同時，由於澎湖曲折式海岸走向，現有造林地大致沿海岸訂定，海岸林林帶幅50公尺以內者佔34.5%，50~100公尺之林帶幅佔30.5%，林帶寬超過200公尺者僅佔8.3%。澎湖海岸環境條件較臺灣本島惡劣，再加上林帶幅縱深不滿200公尺者達九成之多，林帶幅不足使得現有林分難獲相互保護的效果。
造林地土壤受風蝕或水蝕而成之崩積土多達293公頃，其他石質土有132公頃，砂地有127公頃之多，極不利林木生長。現存林木生長較好者亦僅4~5公尺高，大部分為樹高3公尺以下之幼小林木，但此亦是多年來一再新植、補植的結果。目前宜暫緩北端極困難造林地之栽植工作，先從澎湖本島南端造林地條件較好處造林，甚至於就林投、五德、菜園等木麻黃林相較佳處，在其林分空隙地點，積極補植鄉土海岸樹種，以造成複層林分，補救木麻黃純林無法天然更新之缺點。
澎湖海岸林木受到1991年10月底露絲颱風帶來高濃度鹽霧危害，由於此次颱風沒帶來任何雨量，以致地上部枝葉均受鹽霧危害而枯萎，但地下部還在，尚具有恢復生長的能力。同時觀察草海桐與木麻黃樣木之恢復生長，草海桐比木麻黃更適合海岸第一線栽植。

關鍵字

澎湖 ； 海岸林 ； 鹽霧危害 ； 恢復生長

並列摘要

Plantation direction, forest belts, soil classifications and the growth of coastal forests were investigated according to the silvicultural of fered by Penghu county. The amount of salt deposition on leaf-surface of trees after Typhoon was determined and the recovery of damaged tree crowns were investigated.
The area of the northeastern and northern directions of Penghu plantations is 48.6%, and when include west-northern direction is 68.5%. Most plantations were damaged by the winter monsoon.
Since plantation were established along the coast, forest belts were quite narrow. The composition of belt width may be grouped into lesser than 50 meter, 50~100 meters, 100~200 meters and over 200 meters and the areas are 34.5%, 30.5%, 26.7% and 8.3%, respectively. These narrow belts were easily damaged by strong wind and limiting the growth of the coastal trees.
Most plantations grow poorly and their height growth hardly reach 3 meters. Few better existing stands are only 4~5 meters in height. However, this was resulted from many year's forestation and replanting. At the present time, the reforestation on the northern tip of Penghu should stop temporately and replanting of local coastal species under casuarina stands at the Southern region should be emphasized.
The coastal forests of Penghu were damaged by the high salt-mist brought by Lucy Typhoon at the end of October in 1991. Because of no subsequent rainfall after the Typhoon cause the existing stands top drying resulted from the great amount of salt deposited on leaf-surface of the trees. The recovery of scaevola and casuarina from salt-mist was investigated and the recoverable speed of scaevola was obviously faster than casuarina. Thus, scaevola is more suitable to plant at the wind beaten site in Penghu.

並列關鍵字

Penghu ； coastal forests ； salt-mist damage ； recovery