Composition and geographical affinity of the tree species Caryota obtusa forests in the Honghe region, SW China
(2.Karst Biodiversity Conservation Institute of Yunnan, Kunming, China 650201)
(3.Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China 666303)
(4.United States National Herbarium, Department of Botany, Smithsonian Institution, National Museum of Natural History, Washington, DC, USA)
【Abstract】 Caryota obtusa forests are characterized as showy vegetation with rich species diversity and a unique habitat in the Honghe region of China. Due to its food and horticulture value, mature Caryota obtusa individuals have become more rare in the field. Here, we sampled six plots in a deep karst valley of the Honghe region of Yunnan, China. In each 20 m × 20 m plot, our examination focused on species composition of trees via the measure of any trees with DBH ≥ 4 cm. Importance values were produced from datasets of their relative abundance (RA), relative frequency (RF), and relative prominence (RP). On one hand, we analyzed the composition and geographical affinity of the tree species in Caryota obtusa forests based on the two patterns of geographic distributions (areal-type and natural geographic unit), respectively. On the other hand, we selected the top 5 dominant tree species based on importance value and illustrated their distributions to confirm the position of sampled vegetation in the background of the entire distribution of the target species. The above survey and analysis revealed that there were 67 tree species contained in the sampled vegetation, which was a Caryota obtusa + Streblus macrophyllus community and the geographic affinity of the vegetation belonged to the geographic unit of Indo China Peninsula with some strong karst background. Our study implies that the vegetation sampled here reached its northernmost distribution and deserved to be prioritized in conservation as it was a biodiversity hotspot in IndoChina Peninsula.
【Keywords】 northernmost tropic; karst valley; palm; relic habitat; tropic vegetation;
Chen WH, Moller M, Shui YM, Zhang MD (2008) A new species of Paraboea (Gesneriaceae) from a karst cave in Guangxi, China, and observations on variations in flower and inflorescence architecture. Botanical Journal of the Linnean Society, 158, 681–688.
Everett Y (1995) The kitul palm:ethnobotany of Caryota urens L. in highland Sri Lanka. Journal of Ethnobiology, 15, 161–176.
Fang RZ, Bai PY, Huang GB, Wei YG (1995) A floristic study on the seed plants from tropics and subtropics of DianQian-Gui. Acta Botanica Yunnanica, (Suppl. VII), 111–150 (in Chinese with English abstract).
Hahn WJ, Sytsma KJ (1999) Molecular systematics and biogeography of the Southeast Asian genus Caryota (Palmae). Systematic Botany, 24, 558–580.
Huang SH, Chen CJ, Shui YM, Li QR (1999) A study on the ecology and floristic composition of Cycas multipinnata community. In: Biology and Conservation of Cycads—Proceedings of the Fourth International Conference on Cycad Biology (ed. Chen CJ), pp. 41–49. International Academic Publishers, Beijing.
Nguyen NT (1997) The vegetation of Cucphuong National Park, Vietnam. Sida, 17, 719–759.
Shui YM, Chen WH (2005) New data of sect. Coelocentrum in Begoniaceae. Acta Botanica Yunnanica, 27, 355–374.
Song YC (2001) Vegetation Ecology. East China Normal University Press, Shanghai (in Chinese).
Wang B, Huang YS, Li XK, Xiang WS, Ding T, Huang FZ, Lu SH, Han WH, Wen SJ, He LJ (2014) Species composition and spatial distribution of a 15 ha northern tropical karst seasonal rain forest dynamics plot in Nonggang, Guangxi, Southern China. Biodiversity Science, 22, 141–156 (in Chinese with English abstract).
Wang H, Zhu H, Li BG (1997) Vegetation of limestone in Xishuangbanna Southwest China. Guihaia, 17, 101–117 (in Chinese with English abstract).
Wang WT (2012) Two new series and eight new species of Elatostema (Urticaceae) from Yunnan. Guihaia, 32, 427–435 (in Chinese).
Wang WT (2014) Elatostema (Uriticacea) in China. Qingdao Publishing House, Qingdao (in Chinese).
Wang XP, Sun SZ, Li XX (1998) Study of limestone seasonal rain forest classification in Guangxi. Bulletin of Botanical Research, 18, 428–460 (in Chinese with English abstract).
Wijeyaratne SC, Jayathilake AN (2000) Characteristics of two yeast strains (Candida tropicalis) isolated from Caryota urens (Kithul) Toddy for single cell protein production. Journal of National Science Foundation of Sri Lanka, 28, 79–86.
Wu ZY (1995) Vegetation of China, pp. 376–379. Science Press, Beijing (in Chinese).
Wu ZY, Zhou ZK, Sun H, Li DZ, Peng H (2006) The Areal-Types of Seed Plants and Their Origin and Differentiation. Yunnan Science&Technology Press, Kunming (in Chinese)
Wu ZY, Zhu YC (1987) Vegetation of Yunnan, pp. 188–192. Science Press, Beijing (in Chinese).
Ying JS, Zhang YL, Boufford DE (1994) Endemic Genera of Seed Plants in China. Science Press, Beijing (in Chinese).
Zhu H, Wang H, Li BG (1998) The structure, species composition and diversity of the limestone vegetation in Xishuangbanna, SW China. Gardens Bulletin Singapore, 50, 5–33.