Physical and chemical properties in rhizosphere and bulk soils of Tsuga and Yushania in a temperate rain forest

Abstract

The objectives of this study were to investigate selected physical and chemical properties, and availability of metals in rhizosphere and bulk soils of Tsuga and Yushania of alpine forests. The pH of rhizosphere soils was lower than bulk soils. Mean CEC, organic carbon, carbon/nitrogen (C/N) ratio, and clay contents in rhizosphere soils were greater than in bulk soils Concentrations of exchangeable potassium (K) and magnesium (Mg) were also greater in rhizosphere soils than in bulk soils. The availability of aluminum (Al), iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in rhizospheres was influenced by the ionic species and concentrations, which depend on the pH change and chemical compositions of root exudates.

Keywords:

• Exchangeable cations
• Rhizosphere
• Root exudation
• Tsuga
• Yushania

Acknowledgments

The authors thank the National Science Council, Taiwan, Republic of China, for financial support (NSC 87-2312-B002-014, 87-2621-B002-030-A07 and 88-2621-B002-023-A10) of the long-term ecological research (LTER) under forest soil projects.