臺灣地區歸化植物之侵略性評估系統建立

Invasiveness Assessment System of Naturalized Plants in Taiwan

本研究之目的在建立一量化且適用於臺灣地區歸化植物之侵略性評估系統。研究內容主要分為三部分：（1）藉由參考相關文獻，擬定出可能造成歸化植物侵略的因子，作為臺灣地區歸化植物侵略性的評估指標；（2）利用分析階層程序法（analytic hierarchy process, AHP）架構各評估指標間的階層關係，得到各指標的權重，建構臺灣地區歸化植物侵略性評估表；（3）選取臺灣地區的歸化植物，套入評估表，以檢驗本評估系統是否能反應出臺灣地區歸化植物侵略性的差異。利用AHP法得到之臺灣地區歸化植物侵略性評估系統中，大指標中之生物學特性（63%）較環境適合度（37%）重要；中指標以繁殖能力（24%）最為重要；小指標則以原產地所佔的權重（15%）最重。測試結果顯示，目前已造成侵略的歸化植物29種與33種侵略狀態不明確的物種，兩者在侵略現況評估及先天侵略潛能評估的得分皆有顯著差異，顯示本評估系統能夠以定量的方法，界定歸化植物在臺灣地區侵略性的差異，並反應出歸化植物目前及未來對臺灣生態體系的威脅性。本研究針對近10年所發表的新歸化植物分析顯示，牙買加長穗木（Stachytarpheta jamaicensis（L.）Vahl.）先天侵略潛能得分偏高，推測此物種在未來有可能成為侵略植物。 The aim of this study was to develop a quantitative assessment system on the invasiveness of naturalized plants in Taiwan. The processes were separated into three parts: (1) revision of pertinent literature to identify traits of invasiveness for assessment indices; (2) using analytic hierarchy process (AHP) to construct the hierarchy of invasiveness for assessment system of naturalized plants in Taiwan; (3) examination whether this system responded the difference of invasiveness among naturalized plants in Taiwan. In this system, from the results by AHP, the biological attribute (63%) was more important than environmental fitness (37%) among arch-indices; reproduction ability (24%) had the most weight among sub-indices, and country of origin (15%) had the most weight among small indices. Examining this system with 29 invaded species in Taiwan and other ambiguously invasive species, score of invasion likelihood both current status and connatural potency were significantly higher than those of the latter. This system would provide a good predictor for assessing the threats of naturalized plants and their invasive ability. Furthermore, a newly naturalized plants, light-blue snakeweed (Stachytarpheta jamaicensis (L.) Vahl) with high score of connatural potency indicated that it may be a potential invasive species. Results of this study exhibited this assessment system for invasiveness would be a useful qualifier for placing minacity of naturalized plants in Taiwan.

The aim of this study was to develop a quantitative assessment system on the invasiveness of naturalized plants in Taiwan. The processes were separated into three parts: (1) revision of pertinent literature to identify traits of invasiveness for assessment indices; (2) using analytic hierarchy process (AHP) to construct the hierarchy of invasiveness for assessment system of naturalized plants in Taiwan; (3) examination whether this system responded the difference of invasiveness among naturalized plants in Taiwan. In this system, from the results by AHP, the biological attribute (63%) was more important than environmental fitness (37%) among arch-indices; reproduction ability (24%) had the most weight among sub-indices, and country of origin (15%) had the most weight among small indices. Examining this system with 29 invaded species in Taiwan and other ambiguously invasive species, score of invasion likelihood both current status and connatural potency were significantly higher than those of the latter. This system would provide a good predictor for assessing the threats of naturalized plants and their invasive ability. Furthermore, a newly naturalized plants, light-blue snakeweed (Stachytarpheta jamaicensis (L.) Vahl) with high score of connatural potency indicated that it may be a potential invasive species. Results of this study exhibited this assessment system for invasiveness would be a useful qualifier for placing minacity of naturalized plants in Taiwan.