- 期刊
樹種、樹高、胸徑與樹冠幅影響白蟻在樹幹的發生率
Termite Occurrence on Tree Trunk Affected by Tree Species, Tree Size, and Its Crown Coverage
摘要
臺灣自2002年開始推動平地造林政策，於2009年時，平地造林面積已逾8,012公頃。這些平地森林具有受白蟻危害之風險，但目前仍未有白蟻危害種類及危害率之量化資料。本研究於屏東縣萬隆農場之台糖平地造林地針對光臘樹（Fraxinus formosana Hay.）、臺灣櫸（Zelkova serrata（Thunb.）Makino）、大葉桃花心木（Swietenia macrophylla King）、印度紫檀（Pterocarpus indicus Willd.）、苦楝（Melia azedarach L.）及欖仁（Terminalia catappa Linn.）等6個主要造林樹種進行白蟻危害普查，結果發現造成危害之白蟻種類僅臺灣土白蟻（Odontotermes formosanus （Shiraki））1種，而光臘樹之白蟻危害率最高。分析白蟻危害率與樹木胸徑、樹高及冠幅之相關性，發現其相關性因樹種而異，白蟻危害率與大葉桃花心木、苦楝及欖仁的胸徑、樹高、東西向冠幅、南北向冠幅及平均冠幅皆無關，但與光臘樹、臺灣櫸及印度紫檀的胸徑、樹高、東西冠幅或平均冠幅呈正相關，推測白蟻危害率可能隨這些樹種的樹齡及材積成長逐漸增加。
並列摘要
The government of Taiwan started to promote lowland reforestation since 2002, and the total area of lowland forests has reached 8,012 ha in 2009. The lowland forests are likely to be damaged by termites; however, we did not find any quantitative study investigating the termite species and infestation rate in lowland forests. In this study, we investigated the termite species and infestation rate of six major tree species, including Fraxinus formosana Hay., Zelkova serrata (Thunb.) Makino, Swietenia macrophylla King, Pterocarpus indicus Willd., Melia azedarach L., and Terminalia catappa Linn, in Wan-Long Farm, Pingdong County. We found that the trees were infested by one single termite species, Odontotermes formosanus (Shiraki), and F. formosana had the highest infestation rate among the six tree species. By using generalized linear model, we analyzed the correlations between termite infestation rate and the four tree characters, including diameter at breast height, tree height, and crown length. The results showed different associations between termite infestation rate and tree characters among tree species. Termite infestation rate was not correlated with all tree characters of S. macrophylla, M. azedarach, and T. catappa, but was positively correlated with diameter at breast height, tree height, east-west crown length or average crown length of F. formosana, Z. serrata, and P. indicus, which indicated that termite infestation rate may increase with the growth of these trees.