Community Structure and Survival of Tertiary Relict Thuja sutchuenensis (Cupressaceae) in the Subtropical Daba Mountains, Southwestern China.
A rare coniferous Tertiary relict tree species, Thuja sutchuenensis Franch, has survived in the Daba Mountains of southwestern China. It was almost eliminated by logging during the past century. We measured size and age structures and interpreted regeneration dynamics of stands of the species in a variety of topographic contexts and community associations. Forest communities containing T. sutchuenensis were of three types: (1) the Thuja community dominated by T. sutchuenensis, growing on cliffs; (2) the Thuja-Quercus-Cyclobalanopsis community dominated by T. sutchuenensis, Quercus engleriana and Cyclobalanopsis oxyodon, along with Fagus engleriana and Carpinus fargesiana, on steep slopes; (3) the Thuja-Tsuga-Quercus community dominated by T. sutchuenensis, Tsuga chinensis, and Quercus spinosa, on crest ridges. The established seedlings/saplings were found in limestone crevices, on scarred cliff-faces, cliff-edges, fallen logs, canopy gaps and forest margins. The radial growth rate was 0.5-1.1 mm per year. Its growth forms were distorted. It had strong sprouting ability after disturbances. The T. sutchuenensis population thrives on cliffs where there is little competition from other species because of harsh conditions and rockslide disturbances. It is shade-intolerant but stress-tolerant. Its regeneration has depended on natural disturbances.
Institute of Ecology and Geobotany, Yunnan University, Kunming 650091, China.
Cindy Q
CQ
Tang
Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China; National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing 400045, China.
Yongchuan
Y
Yang
Institute of Ecology and Geobotany, Yunnan University, Kunming 650091, China.
Masahiko
M
Ohsawa
Graduate School of Horticulture, Chiba University, 648 Matsudo, Chiba 271-8510, Japan.
Arata
A
Momohara
Institute of Medicinal Plant Cultivation of Chongqing, Nanchuan 408435, China.
Si-Rong
SR
Yi
Tall Timbers Research Station and Land Conservancy, 13093 Henry Beadel Drive, Tallahassee, Florida 32312 United States of America.
Kevin
K
Robertson
Department of Environmental Science, East China Normal University, No. 3663 North Zhongshan Road, Shanghai 200062, China.
Kun
K
Song
Dabashan National Nature Reserve, Chengkou 405900, China.
Shi-Qiang
SQ
Zhang
Institute of Ecology and Geobotany, Yunnan University, Kunming 650091, China.
Long-Yuan
LY
He
D002681:China; D029779:Cupressaceae / Q000254:growth & development*; D017753:Ecosystem; D029964:Fagus / Q000254:growth & development; D029963:Quercus / Q000254:growth & development; D029783:Thuja; D014197:Trees / Q000254:growth & development*; D028225:Tsuga / Q000254:growth & development