The Allelopathic Effects of Humus Soil from &lt;em&gt;Betula platyphylla&lt;/em&gt; and &lt;em&gt;Quercus liaotungensis&lt;/em&gt; on Undergrowth Medicinal Species in the Qiaoshan Area

Xiaobo Liu,Zengwen Liu,Xiaoxi Zhang,Xiao Liang

doi:10.19026/ajfst.10.2192

Abstract

In this research, eleven medicinal species were planted in pots containing humus horizon soils collected from Betula platyphylla and Quercus liaotungensis woodlands in the Qiaoshan Area in the Loess Plateau. The seed germination, seedlings growth and physiological indexes of medicinal species were measured and the allelopathic effects of humus horizon soil on medicinal species were studied. The results showed that the humus soil of B. platyphylla woodland showed obvious allelopathic inhibitory effects on Achyranthes bidentata, Bupleurum chinense, Glycyrrhiza uralensis and Arisaema heterophyllum, followed by Astragalus membranaceus, Isatis tinctoria, Belamcanda chinensis and Polygala tenuifolia. The humus soil of Q. liaotungensis woodland showed remarkable all elopathic inhibitory effects on A. membranaceus, A. bidentata and I. tinctoria, followed by P. tenuifolia, B. chinense, A. heterophyllum and G. uralensis. Based on our results, these medicinal plants were not recommended to be planted in B. platyphylla and Q. liaotungensis forests, or they could be planted after intermediate cuttings of forests and removing of litters, in order to impair the allelopathic inhibitory effects of tree species on the medicinal plants.

Highlights

Betula platyphylla and Quercus liaotungensis are two kinds of the widely planted broad-leaved tree species in Qiaoshan Area of the Loess Plateau, China
The results revealed that humus soil from B. platyphylla pure forest showed the most obvious inhibitory effects on A. bidentata, followed by G. uralensis, B. chinense, A. heterophyllum, A. membranaceus, I. tinctoria, B. chinensis and P. tenuifolia, while it showed the most obvious promoting effects on P. grandiflorus and A. dahurica, followed by S. divaricata
Our results indicated that both of the humus soil from B. platyphylla and Q. liaotungensis pure forests significantly inhibited the seeds germination of A. dahurica, B. chinensis and S. divaricate, which was similar with the findings of Li et al (2011)

Summary

Introduction

Betula platyphylla and Quercus liaotungensis are two kinds of the widely planted broad-leaved tree species in Qiaoshan Area of the Loess Plateau, China. Previous studies mainly investigated allelopathic effects by treating receiver plants (or their seeds) using the water extracts (or leaching solutions) of donor plants (or their litters) and soil and assessing the allelopathic effects based on the obtained data of germination, growth and physiological indicators (Li et al, 2013a). These methods might cause extremely high concentrations of allelochemicals (Li et al, 2013b). Using humus soil of pure forests as the source of allelochemicals for testing might be a better approach to study the practical allelopathic effects of tree species on medicinal plants

Methods

Discussion

Conclusion