The role of functional uniqueness and spatial aggregation in explaining rarity in trees

Department of Biology, University of Maryland, College Park, Maryland 20742 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, China Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721 Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shengyang 110016, China Department of Natural and Applied Science, University of Wisconsin – Green Bay, Green Bay, Wisconsin 54311 Kyushu Research Center, Forestry and Forest Products Research Institute, Kumamoto 860-0862, Japan Yale School of Forestry and Environmental Studies, New Haven, Connecticut 06511 Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China Department of Natural Resources and Environmental Studies, National DongHwa University, Hualien 97401, Taiwan Centre for Ecology & Hydrology, Penicuik, Midlothian, United Kingdom Department of Environmental Science, University of Puerto Rico, PO Box 70337, San Juan, Puerto Rico 00936 Department of Ecology Evolution and Environmental Biology, Columbia University, New York, New York 10027 The Santa Fe Institute, 1399 Hyde Park Rd, Santa Fe, NM 87501, USA