干旱区生态环境知识资源中心

Our aim was to study how diversity and dominance of plant species and plant functional types (PFTs) change and covary across three dune fixation stages in the Chinese steppe zone.

In the Chinese steppe zone, we measured coverage, mean height and density of each plant species in three types of dunes (mobile, semi-fixed and fixed dunes) in four sites (Mu Us, Otindag, Hulunbeir and Horqin). Plant species were grouped into 24 PFTs according to their lifespan, photosynthetic pathway, reproductive mode and life form. Dominance of each plant species and PFT were determined, and species diversity and PFT diversity were quantified using Shannon-Wiener index.

PFT diversity was positively related to plant species diversity in each dune stage, but PFT diversity increased more with increasing plant species diversity in the mobile and semi-fixed dunes than in the fixed dunes. Dune fixation stage explained 87.2% of the variation in plant species diversity and 84.8% of the variation in PFT diversity. Dominant species and PFTs differed among the three dune fixation stages; the more fixed the dunes were, the more perennial, shrubby, clonal and C-3 species co-dominated. Specifically, in mobile dunes annual C-4 non-clonal herbs were the most dominant, and in semi-fixed and fixed dunes perennial C-3 clonal shrubs were most dominant.