- 期刊
遭受互花米草入侵之海岸溼地生態復育策略之研析
Analysis of Restoration Strategy for Coastal Wetlands Invaded by Exotic Species of Spartina alterniflora
摘要
米草屬（Spartina）是一種耐鹽水生植物，原產於西歐與北美洲海岸鹽沼濕地之地區，為保護海岸線，不受到侵蝕，提供生態服務功能。為保護日益消失的沿海灘塗地，20世紀60年代至80年代，中國陸續引進互花米草、大米草、狐米草等不同種類的米草植物。然而迄今為止，中國沿海之鹽沼與紅樹林等海岸濕地，近乎一半已被互花米草所佔據，總面積超過600平方公里。互花米草種子藉由海流傳播，跨越台灣海峽，而在台灣的沿海濕地著陸生長，分別在北部的淡水河口關渡附近紅樹林濕地，以及中部的台中清水高美濕地與彰化大城灘地等處，發現有該外來種鹽沼植物入侵。尤其是在高美濕地，濕地內原生之瀕危鹽沼物雲林莞草（Bolboschoenus planiculmis），其棲息地生長範圍，已遭受到互花米草的威脅。目前中國與台灣皆採取根除方式，管理遭受互花米草入侵的海岸濕地，包含機械挖除深埋、噴灑化學藥劑、人工拔除，以及引入其他外來種生物等，以試圖完全清除互花米草。但中國在四、五十年來之整治下，其效果不彰，互花米草生長範圍更形擴大；同時這些清除方法，亦將造成濕地生態棲地環境之二次破壞。其中，包括機械或人力踩踏濕地的挖掘和割草、噴灑化學除草劑，以及移植生長更為快速的外來植物，例如像喬木型紅樹植物無瓣海桑。無法根除互花米草的原因，在於其數量龐大的種子會殘留在濕地土壤中，會繼續發芽成長。因此，根除並不是理想的管理與控制策略。另一種策略則是可嘗有效管控部分棲地空間，減低互花米草面臨滅絕之威脅，而能有機會得以繼續繁衍，替代根除。有可能因而會減緩其加速生長之速度。此種有效的管控策略，可限制外來物種的擴張，同時保護本土種物種的生長，而增強其對強勢外來種互花米草的競爭優勢。最終達到能讓外來物種成為馴化物種，而與本土物種共生共存，以增加生態系多樣性，擴大生態服務功能。
並列摘要
Spartina sp. is a saline-tolerant aquatic plant native to coastal salt marsh areas in West Europe and North America providing ecological service of coastline protection. In order to protect the increasingly disappearing coastal beaches, from the 1960s to the 1980s, China successively introduced different species of Spartina, such as Spartina alterniflora, Spartina patens and Spartina cynosuroides. Until now it is found that 48.3% of China's coastal wetlands have been occupied by Spartina alterniflora, covering an area of about 600 square kilometers. In Taiwan this alien species was also found invading some coastal wetlands, especially in the Kaomei Salt Marsh Wetland, where the original endangered salt marsh species of Bolboschoenus planiculmis is now threatened for its habitat invaded by Spartina alterniflor. Both China and Taiwan adopted various eradicative methods, including mechanical appliances, chemical agents, biological treatments, tried to clean up Spartina alterniflora. However, the effect is not obvious, and meanwhile these methods caused more serious problem of secondary damage to the wetland habitats through both manual and mechanical destruction. Among them, the excavation and mowing by trampling wetlands with either machines or manpower, the spraying of chemical herbicides, and the transplantation of faster-growing exotic plants, such as arbor-type mangrove species of Natalia apetalum. Since the seeds of Spartina alterniflora were still left in wetland sediments. Thus, eradication is not an ideal control method. An alternative strategy to provide some space to give a chance to let such exotic species grow and reproduce instead of eradication might be able to slow down its fast growth rate. Such strategy of effective management might restrict the expansion of exotic species, and meanwhile let native species can grow, and then increase their competitiveness against the exotic species. Finally, the invasive alien species may become domesticated species, co-exist with the native species in the coastal wetland habitat increasing the ecosystem diversity in coastal wetlands.