Abstract Leaf beetles (Coleoptera: Chrysomelidae) are herbivorous insects, which are a closely related species of plants, and are widespread in various vegetation environments. This study mainly analyzed the correlations between the species diversities of leaf beetles and the factors of different forest environments in the Xitou Nature Education Area, Taiwan. A 500 m transect was set in each of the four plantation types (red cypress, Japanese cedar, moso bamboo, and broad-leaved) and one natural broad-leaved forest. Insects were collected by sweeping along transects once a month from November 2014 to June 2016. In total 2,462 leaf beetles were collected, which belonged to 73 species and 46 genera. The Shannon’s diversity index (H’) and Pielou’s evenness index (E) were applied to compare the number of species and the abundance of leaf beetles in the different transects. The results demonstrated the diverse species of leaf beetles were found in the different transects. Environmental factors related to the species diversity of leaf beetles in different forest systems were analyzed using redundancy analysis. The result showed that the species quantity of understory plants, illumination (including whole light sky space and diffuse non-interceptance), and altitude of transects had a significant influence on chrysomelid species assemblages. This study demonstrated that environmental factors can affect the species diversity of leaf beetles in forest systems, and the results can be taken as a reference for forest management to maintain the biodiversity of insects in forests.
摘要 金花蟲 (鞘翅目：金花蟲科) 為完全植食性昆蟲，與植物關係密切且普遍存在於各種植被環境中。本研究主要目的為分析不同林相中的金花蟲物種多樣性與其棲地植被組成、環境因子之間的相關性。本試驗於國立臺灣大學實驗林管理處所轄之溪頭自然教育園區內，選定4 條人工林穿越線(紅檜林、柳杉林、孟宗竹林和闊葉林)，及1 條原生闊葉林穿越線，每條穿越線各500 m，從2014年11 月至2016 年6 月，每個月採沿途掃網的方式採集樣本，而後將金花蟲挑出後鑑定至種，前經Shannon-Wiener 多樣性指數 (H’) 以及Pielou 均勻度指數 (E) 分析，發現不同人工林中之金花蟲物種多樣性差異大，再調查5 條穿越線的地面植被組成、平均海拔高度、全天光空域 (Whole Light Sky Space, WLS)，以及樹冠下可見天空比 (Diffuse Non-interceptance, DIFN) 等環境因子，使用重複分析 (Redundancy Analysis, RDA) 比較各林相中金花蟲多樣性與環境因子的相關性。結果顯示地面植被種類數、環境光照程度 (包括全天光空域和樹冠下可見天空比) 以及海拔高度均對金花蟲的群聚組成有顯著的影響。本研究證實森林生態系中的棲境因子會影響其內的金花蟲多樣性，以適當的森林撫育方式來增加人工林中的生物多樣性，是未來森林管理與經營須探討的議題。
| Key words: leaf beetle, forest entomology, species diversity, environmental factors, forestry management | | 關鍵詞: 金花蟲、森林昆蟲學、物種多樣性、環境因子、森林經營 |
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