Chin J Plant Ecol ›› 2020, Vol. 44 ›› Issue (9): 962-972.DOI: 10.17521/cjpe.2020.0083

• Research Articles • Previous Articles     Next Articles

Stoichiometric characteristics of fine roots and rhizosphere soil of Broussonetia papyrifera adapted to the karst rocky desertification environment in southwest China

HU Qi-Juan1,3, SHENG Mao-Yin1,2,*(), YIN Jie1,3, BAI Yi-Xin1,3   

  1. 1Institute of Karst Research, Guizhou Normal University, Guiyang 550001, China
    2National Engineering Research Center for Karst Rocky Desertification Control, Guiyang 550001, China
    3Guizhou Engineering Laboratory for Karst Rocky Desertification Control and Derivative Industry, Guiyang 550001, China
  • Received:2020-03-26 Accepted:2020-06-18 Online:2020-09-20 Published:2020-08-27
  • Contact: SHENG Mao-Yin
  • Supported by:
    Supported by the National Natural Science Foundation of China(31660136);the Science and Technology Foundation of Guizhou Province([2019]1224);the Key Project of Guizhou Science and Technology Fund([2017]5726);the Support Plan for Excellent Young Science and Technology Talents of Guizhou Province([2017]5638)

Abstract:

Aims The objectives of this study were to estimate the adaptation strategies of Broussonetia papyrifera to the poor soil nutrients in karst rocky desertification area in Southwest China, and to explore the response of stoichiometric characteristics of fine roots and rhizosphere soil to the degree of rocky desertification.
Methods The contents of carbon (C), nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg) and C:N:P ratios of fine roots and rhizosphere soil of B. papyrifera were studied.
Important findings Results indicated that, except Ca content, the nutrient content of the fine roots and rhizosphere soil of B. papyrifera in karst rocky desertification environment remained at the low level. N:P ratio of fine roots was 12.59, which indicated that the growth of B. papyrifera was co-limited by N and P. With the increase of the degree of rocky desertification, the content of C and N as well as C:N and C:P ratios of fine roots decreased first and then increased; while the content of K and P increased first and then decreased; and neither the content of Ca, Mg nor N:P ratio changed significantly. The content of N, P, K, Ca in rhizosphere soil was different when the degree of rocky desertification was different, while none of C, Mg and C:N:P ratios in rhizosphere soil changed significantly. Additionally, the content of C, P, Ca, Mg as well as C:N and C:P ratios in the fine roots were positively correlated with their values in rhizosphere soil, while N content in fine roots was negatively correlated with its value in the rhizosphere soil. Moreover, the content of K in fine roots was relatively stable, and was hardly affected by the nutrients of rhizosphere soil.

Key words: desertification, ecological stoichiometry, Broussonetia papyrifera, fine roots, rhizosphere soil nutrients