关键词: 可持续发展指数, 山东, 能值, 种养系统, 时空格局

Abstract: Ficus trees, as a key group in the tropical rainforest ecosystem, play an important role in biodiversity maintenance. In this study, we investigated nine functional traits of fine root of ten Ficus species (5 hemiepiphytic species and 5 non-epiphytic species) grown in the Ficus collection garden of the Xishuangbanna Tropical Botanical Garden of Chinese Academy of Sciences, including root diameter, root length, specific root length, specific surface area, branching intensity, root tissue density, nitrogen content, carbon content and carbon to nitrogen ratio. To explain the role of fine root traits in determining the survival strategy of Ficus species, we analyzed the difference in fine root traits between hemiepiphytic and non-epiphytic Ficus species by comparing the natural habitats of the species. The results showed that root length and root diameter of the hemiepiphytic species were significantly higher than that of the non-epiphytic species (P<0.01). Specific root length and branching intensity were significantly lower in hemiepiphytic species than in non-epiphytic species, while no significant difference was found for other traits (P>0.05). Moreover, morphological traits of fine roots in ten Ficus species showed weak relationships with their nutrient traits. Branching intensity, specific root length, and specific surface area of fine roots showed significant negative correlation with root diameter. Our findings suggest that the differences of structure and functional traits of fine roots between two different life forms of Ficus species are adaptive to the environment. The hemiepiphytic Ficus species that were distributed on mountain ridge with dry environment exhibited thick and long fine root, but lower specific root length and branching intensity as compared to non-epiphytic species. These characteristics of hemiepiphytic species may contribute to their strong water absorption. These species might have a close symbiotic relationship with mycorrhizal fungi, allowing their adaptation to relatively dry environment.

Key words: spatial and temporal pattern, emergy, sustainable development index, crop-livestock system, Shandong.