溪頭地區天然林與人工林中的金花蟲 (鞘翅目：金花蟲科) 物種多樣性：森林生態系中具潛力的指標生物

Abstract

本研究主要目的是以調查金花蟲（鞘翅目，金花蟲科）在不同類型的林相中種類組成的多樣性，分析金花蟲種類組成與植群組成、環境因子之間的關聯性，探討以金花蟲做為不同林相代表指標生物的可行性。本試驗於溪頭自然教育園區選定 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 公尺，於 2014 年 11月至 2016 年 4 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，另外調查 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。本研究期間總共採集到 1,744 隻金花蟲個體，共計 45 屬 68 個種類，再利用修改後的指標生物分析 (Indicator species analysis)，發現於天然闊葉林 (3 種)、人工紅檜林 (4 種)、人工孟宗竹林 (2 種) 以及人工闊葉林 (5種) 均有具顯著潛力的指標金花蟲物種；而 Shannon 多樣性指數以及 Pielou 均勻度指數則用於比較不同穿越線內的金花蟲種類組成，分析結果顯示人工柳杉林的多樣性指數最低，而人工及天然闊葉林的指數較高。使用重複分析 (Redundancy Analysis, RDA) 比較各林相的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。本研究提供溪頭地區不同森林型態中的金花蟲物種組成以及具潛力的指標物種，並分析及討論主要影響金花蟲在不同森林型態中物種多樣性的環境因子，期望本研究結果能做為森林生態系的環境監測、林業管理以及生態保育的參考。

The main purpose of this research is to obtain an understanding of species diversity of leaf beetles (Coleoptera: Chrysomelidae) in the different forest environment in Xitou Nature Education Area, and try to estimate the potential of using leaf beetles as bioindicators in forest ecosystems. Four 500 meters transects are set through the plantations (red cypress, Japanese cedar, Moso bamboo, and broad-leaved plantation) and one 500 meters transect are set through the natural broad-leaved forest, and insects are collected by sweeping alone each transect once a month from November 2014 to April 2016. Totally, 1,744 individuals of leaf beetles are collected which belong to 68 species and 45 genera. However, 3 species in natural broad-leaved forest, 4 species in red cypress plantation, 2 species in Moso bamboo plantation, and 5 species in broad-leaved plantation were considered potential bioindicators based on a modified Indicator species analysis. The Shannon‘s diversity index and Pielou’s evenness index are applied in comparing the amount of species and quantity of leaf beetles in the different transects. The result shows that species diversity of leaf beetles are lower in Japanese cadar plantation, but higher in broad-leaved plantation and natural forest. The environmental factors that are related to species diversity of leaf beetles in different forest systems are analyzed by the Redundancy Analysis (RDA). The result shows that the species quantity of understory plants, illumination (including Whole Light Sky Space and Diffuse Non-interceptance) and alttitude of transects have significantly influence on the chrysomelid species assemblages. We offer inventories and potential bioindicator species of leaf beetles of five transects in Xitou Nature Education Area, and discuss the environmental factors that affecting species diversity of leaf beetles in different forest systems.