恆春半島銀合歡移除後造林對生物多樣性之影響

EFFECTS OF AFFORESTATION ON BIODIVERSITY AFTER REMOVING LEUCAENA LEUCOCEPHALA (LAM.) DE WIT IN THE HENG CHUN PENINSULA

郭家和(Chia-Ho Kuo) ； 陳建璋(Jan-Chang Chen) ； 魏浚紘(Chun-Hung Wei) ； 陳朝圳(Chaur-Tzuhn Chen)

《中華林學季刊》 50卷4期 (2017/12) Pp. 341-364

摘要

外來入侵植物會改變該地區之樹種組成及植群社會並影響整個生態系功能，而屬於外來入侵種植物之銀合歡(Leucaena leucocephala (Lam.) de Wit)在臺灣已影響多處地區之物種多樣性及生態系功能。本研究選擇2002-2005年間，林務局屏東林區管理處於恆春半島所進行之銀合歡移除造林地區為研究樣區，並以未經處理之銀合歡入侵林地為對照區，進行處理樣區及對照區之木本植群及陸域動物之調查，透過生物多樣性分析探討銀合歡移除造林區與對照區兩者間生物多樣性之差異。結果顯示，對照區之銀合歡重要值指標(IVI)為45.9 (山區對照區)及55.8 (海岸對照區)，而銀合歡移除後造林樣區之銀合歡重要值指標(IVI)則降至5.4 (海岸區林下栽植複層林營造作業區)及10.9 (山區帶狀複層林營造作業區)；造林區之銀合歡已由原先優勢種轉變成所造林之樹種及少部分先驅性陽性樹種之林相。研究結果顯示，造林區之植物物種生物多樣性指標皆顯著高於未移除銀合歡之對照區，顯示銀合歡移除造林已成功改變原先以單一銀合歡物種組成之林相，並逐漸恢復為植物物種多樣性較高之林相。在哺乳類、鳥類、兩生類、爬蟲類及蝶類等5種陸域類群動物相之物種及數量部份，由生物多樣性分析結果顯示，銀合歡移除造林區與對照區相比較，顯示銀合歡移除造林區增加植群多樣性，且對於鳥類及蝶類之族群數量有顯著提升。整體而言，以人為介入方式進行銀合歡移除及造林對於植物、動物相之族群量與物種數有提升之趨勢，且對銀合歡外來入侵種的抑制亦有良好成果。

關鍵字

外來種 ； 多樣性指標 ； 森林復育 ； 入侵種

並列摘要

When an alien species evolved into invasive species, it would be changed the local vegetation composition and affected the ecosystem function. The invasive alien species of Leucaena leucocephala have impacted the species diversity and changed the local ecosystem function in some area of Taiwan. In this study, we selected afforestation plots with the removal of L. leucocephala as the study area which was carried out by the Pingtung Forest District, Forest Bureau in the period from 2002 to 2005 and untreated area as the control plots. The woody plants and terrestrial animals of sampling plots had been investigated all year round, and analyzed the effects of the plantation with the removal of L. leucocephala by comparing the difference of biodiversity between treated and untreated plots. The results showed that the important value index (IVI) of L. leucocephala was 45.9 (Mountain control plots) and 55.8 (Coastal control plots) and the IVI was decreased to 5.4 (Coastal Multi-layered Underplanting Silvicultural Systems, CMUSS) and 10.9 (Mountain Belt Multi-layered Silvicultural Systems, MBMSS) after afforestation. It has been transformed from a pure stand of the dominant species of L. leucocephala to a high complexity species stand and the biodiversity index of the woody plants in the afforestation areas was significantly higher than the control plots. The afforestation by removal L. leucocephala has successfully eradicated the species and gradually restored with a high diversity forest type. In this study, the amounts and species of five types of animals including mammals, avian, amphibians, reptiles and butterflies were investigated in the treatment plot (afforestation of removal L. leucocephala) and the control plot (un treatment). The results of indicated that the population and species of woody plants, avian and butterflies are increased in the afforestation area with the removal of L. leucocephala. Overall, the silviculture of afforestation has shown an increasing trend of population and species for biofacies and simultaneously inhibition of L. leucocephala growth.

並列關鍵字

Alien species ； Diversity index ； Forest restoration ； Invasive alien species