Soil-Plant Relationships in the Hetao Irrigation Region Drainage Ditch Banks, Northern China

Abstract

Species-environment relationships is a central issue in ecology and important to plant reconstruction and management in degraded ecosystems. We explored how the interactions among soil nutrients, salinity, and ion ratios influence vegetation distribution in the Hetao Irrigation Region drainage ditch banks. Twoway indicator species analysis (TWINSPAN) techniques and Canonical Correspondence Analysis (CCA) were used to classify the vegetation and to examine the relationships between vegetation and soil chemical properties. The plant communities of Saussurea salsa–Phragmites australis–Sonchus arvensis and Leymus chinensis–Sonchus arvensis occurred within 161 of a total 245 plots. Edaphic factors exerted the strongest influence on vegetation patterns and distributions, with available soil nutrient content being identified as the dominant factor, followed by soil salinity and soil pH. Maintaining soil nutrient and salinity at moderate levels is an efficient approach to prevent species loss in the drainage ditch banks.

Keywords:

• available nutrient
• CCA
• ion ratios
• soil salinity
• vegetation distribution

Acknowledgments

The authors gratefully acknowledge two anonymous reviewers for valuable comments on the manuscript, as well as Christine Verhille at the University of British Columbia for her assistance with English language and grammatical editing of the manuscript. This work was sponsored by the National Basic Research Program of China (2013CB429901) and the National Natural Scientific Foundation of China (41271061, 31170385, and 41101081).

Notes

*p < 0.05. **p < 0.01.

Notes: Cl-, , Ca²⁺, Mg²⁺, and Na⁺ + K⁺ at the 0–20 cm soil depth. Mean ± SE in the sites representing the six vegetation groups (G1: Polygonum aviculare; G2: Typha angustifolia - Scirpus trigueter - Cyperus fuscus; G3: Saussurea salsa - Phragmites australis - Sonchus arvensis; G4: Leymus chinensis - Sonchus arvensis; G5: Peganum nigellastrum; G6: Lappula myosotis - Tamarix ramosissima - Swainsonia salsula) obtained by TWINSPAN.