Vegetation-environment Relationships Between Northern Slope of Karlik Mountain and Naomaohu Basin, East Tianshan Mountains

Key words: 
• vegetation pattern /
• environmental factors /
• canonical correspondence analysis (CCA) /
• vegetation-envi-
  ronment relationships /
• Tianshan Mountains /
• Xinjiang

Abstract:  Based on data from 22 sample plots and applying the Canonical Correspondence Analysis (CCA), this paper discusses the
vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu Basin, which is situated in the
easternmost end of the Tianshan Mountains, Xinjiang Uygur Autonomous Region, China. For the zonal vegetation, community diversity of
mountain vegetation is higher than that of the desert vegetation due to environmental factors. The CCA ordination diagram revealed that
the composition and distribution of vegetation types are mainly determined by altitude, soil pH and soil salt content. With increasing
elevation, the soil pH and total salt content decrease but the contents of soil organic matter, soil water, total nitrogen and total
phosphorus increase gradually. In the CCA ordination diagrams, the sample plots and main species can be divided into five types
according to their adaptations to the environmental factors. Type I is composed of desert vegetation distributed on the low mountains,
hills, plains and deserts below an elevation of 1900 m; type II is distributed in the mountain and desert ecotone with an elevation of 1900
–2300 m, and includes steppe desert, desert steppe and wetland meadow; type III is very simply composed of only salinized meadow;
type IV is distributed above an elevation of 2300 m, containing mountain steppe, meadow steppe, subalpine meadow and alpine meadow;
type V only contains salinized meadow. The results show that with increasing elevation, species combination changes from the xerophytic
shrubs, semi-shrubs and herbs distributed in the low altitude zone with arid climate to the cold-tolerant perennial herbs growing in the
high altitudinal zone with cold climate.