Taiwania, 59(3): 247‒261, 2014 DOI: 10.6165/tai.2014.59.247 RESEARCH ARTICLE Abiotic Factors and Yushania Influences on Abies Forest Composition in Taiwan Cheng-Tao Lin(1), Tzu-Ying Chen(2), Chang-Fu Hsieh(3) and Chyi-Rong Chiou(1*) 1. School of Forestry and Resource Conservation, National Taiwan University, No. 1, Sect. 4, Roosevelt Rd., Taipei, 10617, Taiwan. 2. Department of Forestry and Natural Resources, National Ilan University, Sect. 1, Shen-Lung Rd., Ilan, 26047, Taiwan. 3. Institute of Ecology and Evolutionary Biology, National Taiwan University, No. 1, Sect. 4, Roosevelt Rd., Taipei, 10617, Taiwan. * Corresponding author. Tel.: +886-2-3366-4640; Fax: +886-2-2365-4520; Email:
[email protected] (Manuscript received 20 March 2014; accepted 26 May 2014) ABSTRACT: Abies kawakamii forests are generally distributed above 3,000 m in Taiwanese high mountains. The community data used in our analysis were derived from the database of the National Vegetation Diversity Inventory and Mapping Project of Taiwan (NVDIMP), and environmental data were obtained from the WorldClim and NVDIMP databases. We used non-metric multidimensional scaling (NMDS) to identify vegetation composition of Abies communities and the structural equation models (SEMs) were used to examine the complex relationships between environmental factors and vegetation composition. The results of ordination showed the most important factors determining species composition of Abies forests involved habitat rockiness, heat load index, warmth index and summer and winter. SEM results approved the warmth index and winter precipitation were the main drivers determining the latent variable—climate, which significantly affect the overstory composition of Abies communities.