Chin J Plant Ecol ›› 2017, Vol. 41 ›› Issue (1): 81-94.DOI: 10.17521/cjpe.2016.0085

Special Issue: 中国灌丛生态系统碳储量的研究

• Research Articles • Previous Articles     Next Articles

Effects of nitrogen addition on soil respiration in shrublands in Mt. Dongling, Beijing, China

Jian-Hua ZHANG1,2,*(), Zhi-Yao TANG3, Hai-Hua SHEN2, Jing-Yun FANG2,3   

  1. 1Xinzhou Normal University, Xinzhou, Shanxi 034000, China

    2State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    and
    3College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China
  • Received:2016-03-09 Accepted:2016-09-21 Online:2017-01-10 Published:2017-01-23
  • Contact: Jian-Hua ZHANG
  • About author:KANG Jing-yao(1991-), E-mail: kangjingyao_nj@163.com

Abstract:

Aims Soil respiration from terrestrial ecosystems is an important component of terrestrial carbon budgets. Compared to forests, natural or semi-natural shrublands are mostly distributed in nutrient-poor sites, and usually considered to be relatively vulnerable to environmental changes. Increased nitrogen (N) input to ecosystems may remarkably influence soil respiration in shrublands. So far the effects of N deposition on shrubland soil respiration are poorly understood. The aim of this study is to investigate the soil respiration of Vitex negundo var. heterophylla and Spiraea salicifolia shrublands and their response to N deposition.
Methods We carried out a N enrichment experiment in V. negundo var. heterophylla and S. salicifolia shrublands in Mt. Dongling, Beijing, with four N addition levels (N0, control, 0; N1, low N, 20 kg N·hm-2·a-1; N2, medium N, 50 kg N·hm-2·a-1 and N3, high N, 100 kg N·hm-2·a-1). Respiration was measured from 2012-2013 within all treatments.
Important findings Under natural conditions, annual total and heterotrophic respiration were 5.91 and 4.23, 5.76 and 3.53 t C·hm-2·a-1 for the V. negundo var. heterophylla and S. salicifolia shrublands, respectively and both were not affected by short-term N addition. In both shrubland types, soil respiration rate exhibited significant exponential relationships with soil temperature. Temperature sensitivity (Q10) of total soil respiration in V. negundo var. heterophylla and S. salicifolia shrublands ranged from 1.44 to 1.58 and 1.43 to 1.98, and Q10 of heterotrophic soil respiration ranged from 1.38 to 2.11 and 1.49 to 1.88, respectively. Short-term N addition decreased only autotrophic respiration rate during the growing season, but had no significant effects on total and heterotrophic soil respiration in V. negundo var. heterophylla shrubland. In contrast, N addition enhanced the heterotrophic soil respiration rate and did not influence autotrophic and total soil respiration in S. salicifolia shrubland.

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Key words: nitrogen deposition, soil respiration, carbon cycle, temperature sensitivity, temperate shrublands