title: [Evaluation index system of swamp degradation in Zoige Plateau of Sichuan, Southwest China under drainage stress].
abstract: The evaluation index system of swamp degradation is one of the key scientific issues in the frontier field of international wetland science research. On the basis of long-term swamp field reconnaissance, and according to the fixed position ecological investigation of plant communities and the analysis of soil samples in 20 swamp plots in three belt transects of swamp degradation research under the stress of drainage in 2009, the swamps in the Zoige Plateau of Sichuan were classified into three groups with seven swamp communities, i. e., undisturbed (A type), disturbed by long-term and weak drainage (B-D type), and disturbed by short-term and strong drainage (E-G type), according to the species importance value and by Two-Way Indicator Species Analysis (TWINSPAN). The degradation degree of the swamps was graded by the method of Principal Components Analysis (PCA), and the swamp vegetation evaluation index (SVEI) and soil evaluation index (SSEI) were developed. Based on the SVEI, the swamps were classified as pristine swamp, lightly degraded swamp, moderately degraded swamp, and severely degraded swamp. Based on the SSEI, the swamps in Hongyuan County were divided into three grades, i. e. pristine swamp, lightly degraded swamp, and severely degraded swamp, while those in Ruoergai County were divided into lightly degraded swamp, moderately degraded swamp, and severely degraded swamp. The similarity of TWINSPAN classification results and SVEI/SSEI evaluation results was above 70%, indicating that both SVEI and SSEI were effective for the swamp degradation grading, and different classification methods should be combined to comprehensively evaluate the swamps in the Plateau.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse/Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China. wetlands@tongji.edu.cn
authors.forename: Yong-Xing
authors.initials: YX
authors.lastname: Yang
authors.forename: Kei
authors.initials: K
authors.lastname: Li
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
mesh_terms: D002681:China; D003247:Conservation of Natural Resources / Q000379:methods*; D004787:Environmental Pollution / Q000032:analysis; D063245:Plant Development; D010944:Plants / Q000145:classification; D025341:Principal Component Analysis; D012987:Soil / Q000737:chemistry*; D014872:Water Movements; D053833:Wetlands
chemical_list: D012987:Soil