達悟民族林業與蘭嶼生物多樣性－以園藝果樹林的螞蟻相指標為例

Tao Ethno-Forestry, and Biological Diversity in Orchid Island (Lanyu), Focused on Understory Ant Indicators of Horticulture Gardens

胡正恆(Hu, Cheng Heng)

《東台灣研究》 26期 (2019/02) Pp. 23-48

https://doi.org/10.6275/JETS.201902_(26).0002

摘要

達悟／雅美社會的民族林業是對在地苗木和森林進行管理的一套經驗科學，同時對其相關的野生動植物資源進行維護。迄今，蘭嶼的林地整理，尤賴大船造舟文化，以及開墾山田使用後定時休耕，讓內陸林、海岸林、海崖栽植園、乃至林緣鑲嵌的灌叢草地等四種林地植被型，持續供應歲時祭儀所需的植物資源。此一園藝林業地景、熱帶森林特徵、乃至野生動物指標，乃是相互連接作用的三組區域尺度因素。本研究於2000－2002年間在蘭嶼六村的林地調查農藝慣習，應用柏氏漏斗快速檢驗蘭嶼土棲昆蟲蟻科之多樣性，並在蘭嶼全島25處沿岸流域、小蘭嶼1處林地內，取樣274位點。共記錄蘭嶼螞蟻之種豐度達40種以上，並描述林下20種優勢蟻種的互動，其佔所有個體數量的95%。螞蟻是主要地面清除者，四種林地內以海崖林螞蟻密度最大，受益於達悟人經營的果樹林整理技術。就林地的物種組成來看，三種森林地景之螞蟻種豐度都在平均5.1～5.4種之間，唯有草地上物種數顯著下降，只剩平均3.7種；香儂多樣性指出林地保育以海岸林最優、其次為內陸森林及海崖栽植園，到林緣草地則顯著下降。若螞蟻群落作為主要地面清除者的密度來看，海崖林密度最大值達每平方米22.1隻，在草原則衰減至13.0隻，是海崖林數量的59%。經營強度最高的海崖果樹林蟻相，分別在種豐度、族群量、獵／雜食功能群等指標中呈現極大值；顯示園藝經營帶來邊緣性的干擾物種，應與內部森林的優勢種間有競爭關係。蘭嶼熱帶森林主要仰賴天然林倒機制、加上達悟民族林業的慣行經營，使林隙有節制地出現於內陸林到海崖林間，並讓山田休耕後的灌叢逐步地回復地力，成為人文景致下的生態交會帶。建議國家建設需尊重部落林業的土地使用傳統，理解當地園藝技藝所扮演之積極森林更新與生態保育角色，避免強勢工程手段在脆弱島嶼環境上所造成之深遠衝擊。

關鍵字

蘭嶼 ； 達悟／雅美 ； 熱帶森林 ； 螞蟻 ； 民族林業 ； 生物多樣性

並列摘要

Ethno-Forestry in Lanyu among the Tao/Yami people is the tribal scientific craft of creating, managing, using, conserving, and repairing forests, which has been largely associated wildlife resource management to meet desired cultural goals, material needs, and ethic values for both human and environment benefits. Their horticulture gardens within tropical forest are culturally and ecologically maintained as the inland g, coastal forest, cliff plantation, and grassland with shrubs, continuing to supply the plant resources needed for the daily rituals. In this study, the forest garden ants were investigated across six villages of Lanyu from 2000 to 2002. The Berlesse funnel for ant detections was set to quickly estimate the biological diversity and composition across 25 coastal watersheds in Lanyu Island and one shrubland in Xiaolanyu, totally 274 sites. A total of more than 40 ant species has been recorded, and the interaction of 20 dominant ant species was described, accounting for 95% of all individuals. The horticultural gardens in Lanyu mainly rely on the disturbance mechanism of natural forests and the custom management of Tao/Yami ethno-forestry. Gaps have been regenerated differently according to inland forests, sea cliffs, shrubland and fallows that gradually returned to fertility. Historically ecotones are created upon human landscape. Modern state constructions are recommended to respect the land use tradition of tribal forestry, to understand local roles of forest renewal and ecological conservation through aboriginal horticultural skills, and to avoid profound impacts of modern engineering methods on the fragile island environment.

並列關鍵字

Orchid Island (Lanyu) ； Tao/Yami ； Tropical Forest ； Ant (Formicidae) ； Ethno-Forestry ； Biological Diversity

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