Biodiv Sci ›› 2019, Vol. 27 ›› Issue (10): 1056-1068.DOI: 10.17520/biods.2019215

• Original Papers:Plant Diversity • Previous Articles     Next Articles

Numerical classification of associations and their stabilities of karst evergreen deciduous broad-leaved mixed forests in Mulun National Nature Reserve

Chen Huijun1,2,Du Hu1,2,Song Tongqing1,2,Peng Wanxia1,2,Zhang Hao1,2,Su Liang1,2,Zeng Fuping1,2,*()   

  1. 1 Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125
    2 Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi 547100
  • Received:2019-07-03 Accepted:2019-10-08 Online:2019-10-20 Published:2019-12-20
  • Contact: Zeng Fuping

Abstract:

Understanding plant composition, community structure and community distribution of karst climax communities can provide a reference for biodiversity conservation and forest management. Based on topographic factors, soil factors and species composition data of a 25 ha forest dynamic plot in Mulun, Guangxi, we numerically classified the association of karst evergreen deciduous broad-leaved mixed forests multivariate regression trees and a modified Godron stability analysis ( Godron, 1971; Zheng, 2000) method to measure the stabilities of associations. The results showed that the forest community was divided into six associations. They were as follows: (I) Ass. Cryptocarya microcarpa + Itoa orientalis + Lindera communis, (II) Ass. Cryptocarya microcarpa + Cleidion bracteosum + Brassaiopsis glomerulata, (III) Ass. Platycarya longipes + Rapanea neriifolia + Clausena dunniana, (IV) Ass. Platycarya longipes + Luculia intermedia + Clausena dunniana, (V) Ass. Cryptocarya microcarpa + Brassaiopsis glomerulata + Eurycorymbus cavaleriei, (VI) Ass. Boniodendron minus + Rubovietnamia aristate + Platycarya Longipes. Except for Ass. I, diversity indices of each association were higher. Shannon-Wiener index, Simpson index and Pielou evenness index showed similar trends: Ass. VI > Ass. V > Ass. IV > Ass. III > Ass. II > Ass. I. Species richness did not follow this trend and decreased in the following order: Ass. VI > Ass. IV > Ass. V > Ass. I > Ass. III > Ass. II. Species diversities of these associations were highest at middle altitudes. The stabilities of associations were highest at medium-high slope positions, while associations were lowest in depressions. Elevation is critical for community structure and composition and may be an important factor affecting community distribution.

Key words: vegetation classification, Godron stability analysis, multivariate regression trees, karst ecosystem, Mulun National Nature Reserve