Saproxylic Beetle Community and Influences of Environment Variables in Agroforestry systems in the NTU Experimental Forest

• Main Authors: Ting-Yan Liu, 劉廷彥
• Other Authors: Ping-Shin Yang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/90636568115164802270

碩士 === 國立臺灣大學 === 昆蟲學研究所 === 101 === Agroforestry have been seen as a feasible solution of the conflict about crop production and biodiversity conservation in developing countries. But it still has doubts about introducing agroforestry into the rugged mountain of Taiwan, where used to be forest plantation. The study set up 3 group of sample sites, depend on different altitude, in the NTU Experiment Forest, to compare the diversity and the community structure of saproxylic beetles under the environment of agroforestry and forest plantation. And discussed the ability of environment factor influence the saproxylic beetles, through the orientation technique. From September 2011 to September 2012, 4697 individuals of coleopteran insect, belong to 554＋species and 63 families, were collected from six sample sites, including 18 new type emergence traps. Family Staphylinidae had the most abundant number of species, with 192 taxons；Subfamily Scolytinae had 1849 individuals, were the most abundant group. Comparing the rarefication curve of two kind of usage, Agroforestry sites had higher SChao1 value, but their 95% Confidence interval of SChao1 had large ranges overlap, no significant differences in richness. Every site other than low-medium altitude, Shannon’s diversity indexes were higher in the forest plantation ones, but not significant. Evenness were higher in forest plantation sites. Elevation was the most decisive factor to the distribution of species in all environment variables; canopy as the key variable, had significant differences among sites and usages, correlated with timber volume, timber surface area, and canopy height, and also correlated with evenness, negative correlated with number of individuals. The results of cluster analysis shown the species composition were well depend on the geographical distance, rather than the way of usage. Altitude, canopy, slope, and timber volume on axis 1 and tree height, utilize, and slope on axis 2 were the environment variables that best explained about 34.6% of the variance in saproxylic beetle assemblage on the first two axes. Introducing agroforestry into forest plantation may have higher risk of pest cross infection, lead to higher cost of pest management to maintain profit, efficient ways of pest management were contrary to the goal of maintaining biodiversity.