臺灣中低海拔臺灣櫸造林地的白蟻發生普查

Termite Survey of Zelkova Serrata Plantations in Moderate and Low Altitude Areas of Taiwan

邱俊禕(Chun-I Chiu) ； 李後鋒(Hou-Feng Li) ； 葉信廷(Hsin-Ting Yeh) ； 蔡明哲(Ming-Jer Tsai)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 29卷2期 (2015/06) Pp. 69-77

https://doi.org/10.6542/EFNTU.2015.29(2).1

摘要

臺灣櫸（Zelkova serrata (Thunb.) Makino）為臺灣重要的經濟樹種，且為政府推廣造林的樹種之一。白蟻長久以來被認定為森林的重要害蟲，唯至今在臺灣櫸上的白蟻多樣性及危害方式一直沒有量化的調查資料。本研究針對臺灣大學實驗林管理處所轄之溪頭營林區造林地、下坪熱帶植物園及在臺灣糖業股份有限公司屏東區萬隆農場設置之二氧化碳通量研究試驗地所栽植的臺灣櫸進行白蟻發生普查，總共檢查了702棵臺灣櫸，其中有22棵發現有臺灣土白蟻（Odontotermes formosanus (Shiraki)），發生率3.3%，另外，僅1棵臺灣櫸遭小象白蟻（Nasutitermes parvonasutus (Nawa)）取食，發生率僅0.1%。依調查結果，臺灣土白蟻為臺灣櫸上最常出現的白蟻物種，主要取食樹皮部分，唯調查結果得知其並未對臺灣櫸的生存造成威脅。此外，調查低海拔（50-60公尺）的屏東二氧化碳通量研究試驗地的白蟻發生率為11.1%，顯著高於中海拔（771-1,263公尺）的溪頭地區之1.3%。另根據溪頭地區的調查資料，以邏輯迴歸分析臺灣土白蟻的發生與臺灣櫸人工林的海拔、樹胸徑、樹高及採樣地點等四個因子之相關性，發現當海拔較低時，發生機率有顯著增加之趨勢，樹胸徑及樹高則與臺灣土白蟻的發生呈顯著的正相關，而採樣地點則與臺灣土白蟻的發生無相關性，在四個分析因子中，以海拔高低的影響最顯著，其相關性密切。

關鍵字

臺灣櫸 ； 臺灣土白蟻 ； 小象白蟻 ； 森林昆蟲 ； 溪頭

並列摘要

Zelkova serrata (Thunb.) Makino is a native tree species that has high economic importance in Taiwan. Therefore, the government is promoting planting of Z. serrata for reforestation. Although termites are considered a main forest pest, no quantitative study has so far evaluated termite damage patterns, termite diversity, and occurrence of termites on Z. serrata . We inspected 702 Z. serrata trees in Xitou (Nantou County), Xiaping Botanical Garden (Nantou County), and Wan-Long Farm (Pingdong County). In total, 22 trees (3.3%) were infested by Odontotermes formosanus (Shiraki), and 1 tree (0.1%) was infested by Nasutitermes parvonasutus (Nawa). Although O. formosanus was the most common termite species that occurred on Z. serrata, we considered it having low threat to Z. serrata because damage to tree bark caused by this species was limited and the infestation rate was low. Among the three study sites, termite infestation rate in Pingdong at low altitudes (50-60 m) was 11.1%, which is significantly higher than 1.3% in Xitou at moderate altitudes (771-1,263 m). By using logistic regression, we analyzed correlations between occurrence of O. formosanus and altitude, tree diameter at breast height, tree height, and sampling locations of Z. serrata in Xitou. The results showed that altitude was negatively correlated with occurrence of O. formosanus, and tree diameter at breast height and tree height were positively correlated with occurrence of O. formosanus. Sampling locations had no correlation with occurrence of O. formosanus, whereas altitude had the strongest correlation with occurrence of termites.

並列關鍵字

Zelkova serrata ； Odontotermes formosanus ； Nasutitermes parvonasutus ； forest insect ； Xitou