Journal of Environmental Biology

Responses of microbial respiration to nitrogen addition in two

alpine soils in the Qinghai-Tibetan Plateau

Y.H. Gao^1,2*, G. Ma³, X.Y. Zeng⁴, S.Q. Xu³ and D.X. Wang³

¹Key Laboratory of Mountain Environment Evolution and Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu-610041, P.R. China

²Institute of Environment Sciences, University of Quebec, Montrea-H3C3P8, Canada

³College of Resources and Environment, Gansu Agricultural University, Lanzhou-730070, P.R. China

⁴Department of Landscape Architecture, Sichuan College of Architectural Technology, Deyang-618000, P.R. China

*Corresponding Author E-mail: yhgao@imde.ac.cn

Publication Data

Paper received:

31 August 2013

Revised received:

17 February 2014

Accepted:

24 July 2014

Abstract

An incubation experiment was conducted to examine the effects of nitrogen (N) application on microbial respiration in alpine meadow and alpine shrub soils from eastern of Qinghai-Tibetan Plateau. Four different levels of nitrogen fertilization were selected in this study: control (CK, 0 mg N g^-1), low (LN, 0.04 mg N g^-1), medium (MN, 0.16 mg N g^-1), high (HN, 0.4 mg N g^-1). The results showed that microbial respiration was higher in alpine shrub than in alpine meadow soil, regardless of the rate of N application. Total microbial respiration over the course of incubation period decreased in both soils with HN and MN treatments relative to control, but no significant differences were observed in soils with LN treatments. There was significantly positive correlation between total microbial respiration and dissolved organic carbon concentration in both soils. The results indicated that DOC may be a useful indicator of microbial respiration rate in alpine soils and the increasing N inputs could drive a negative feedback to global warming effects of carbon dioxide emitted to the atmosphere in alpine soils. ?  

 Key words

Alpine shrub soil, Carbon cycle, Fertilization, Microbial CO₂, Nitrogen deposition 

Copyright ? 2015 Triveni Enterprises. All rights reserved. No part of the Journal can be reproduced in any form without prior permission. Responsibility regarding the authenticity of the data, and the acceptability of the conclusions enforced or derived, rest completely with the author(s).