A UNIQUE MOUNTAINOUS VERTICAL DISTRIBUTION PATTERNS AND

RELATED ENVIRONMENTAL INTERPRETATION – A CASE STUDY

ON THE NORTHERN SLOPE OF THE ILI RIVER VALLEY

 

ZHONG-PING TIAN¹,², XIU-LING WANG¹, XIAO-YI ZHAO¹, LI ZHUANG^1*

 

¹College of Life Sciences, Shihezi University, Shihezi 832003, P.R. China

²Key Laboratory of Species Diversity Application and Control in Xinjiang, College of Life Sciences,

Xinjiang Normal University, Urumqi 830054, P.R. China

*Corresponding author’s email: zhuanglisunny@163.com; Tel: +86-13579767753

 

Abstract

 

Patterns of plant diversity and soil factors along the altitude gradient on the northern slope of Ili River Valley were examined. Plant and environment characteristics were surveyed from 1000~2200 m. There were a total of 155 vascular plant, 133 herbage, 18 shrub, and 7 tree species in 44 sampled plots. The plant richness of vegetation types generally showed a special pattern along altitude, with a bimodal change of plant species number at 100m intervals of altitude samples. The two belts of higher plant richness were in transient areas between vegetation types, the first in areas from low-mountain desert to forest, and the other from dry grass to coniferous forest. Matching the change of richness of plant species to environmental factors along altitude by GAM model and relation analysis revealed that the environmental factors controlling species richness and their patterns were the combined effects of soil salt and nutrition. Water was more important at lower altitude, and temperature at higher altitude, the role of the inversion layer at high altitude coniferous forest species diversity appearing to rise. Soil nutrition and salt also showed a similar distribution pattern of diversity. Especially, diversity index and soil salinity showed a strong correlation. This study provides insights into plant diversity conservation of Ili River Valley in Tianshan Mountain.

 

Key words: Vertical distribution patterns, Species diversity, Environmental factors, Ili River valley.