Premium
Distribution patterns of shrubby N‐fixers and non‐N fixers in an arid valley in Southwest China: implications for ecological restoration
Author(s) -
Song Cheng Jun,
Ma Ke Ming,
Fu Bo Jie,
Qu Lai Ye,
Xu Xian Li,
Liu Yang,
Zhong Jian Fei
Publication year - 2010
Publication title -
ecological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.628
H-Index - 68
eISSN - 1440-1703
pISSN - 0912-3814
DOI - 10.1007/s11284-009-0685-3
Subject(s) - edaphic , arid , soil fertility , shrub , agronomy , soil water , environmental science , biology , ecology
Shrubs play different key roles in arid regions. Comparisons of shrubs and their site adaptability are essential for correct selection of candidates in developing restoration theory and practice. A survey of topography, soil properties and shrub composition was conducted in fifty‐seven 5‐m × 5‐m plots in an arid valley of the upper Minjiang River, Southwest China. With cluster analysis and critical examinations based on edaphic properties, soil was classified into three groups: dry cinnamon soils (DCS), calcareous cinnamon soils (CCS) and eluvial‐accumulation cinnamon soils (EACS). EACS had the highest fertility level, DCS the next and CCS the lowest level. For non‐N fixers, soil moisture is the primary limiting factor, and nitrogen the next. However, N‐fixers are weakly constrained by soil moisture and nitrogen, the extent of which is species‐specific. N‐fixers had a significantly higher cumulative relative importance value (44.4%) in CCS than in DCS (34.0%) and EACS (17.3%). The results suggest that it would be reasonable to restore non‐N fixers in DCS and EACS and that N‐fixers are appropriate for CCS. Compared with grass, shrubs significantly enhanced the availability of nitrogen and phosphorus and soil electric conductivity, and significantly decreased the soil C/N ratio. The median fertility level of soil dominated by N‐fixers indicates that N‐fixers are suitable driver candidates from grassland to non‐N‐fixing shrub land. Four native shrubby legumes ( Indigofera amblyantha , Sorphora viciifolia , Desmodium podocarpum and Bauhinia faberivar ) and one soil‐conserving shrub ( Ajania potaninii ) are the top‐priority pioneers for ecological restoration.