Chin J Plan Ecolo ›› 2018, Vol. 42 ›› Issue (3): 382-396.DOI: 10.17521/cjpe.2017.0050

• Research Articles • Previous Articles     Next Articles

Soil respiration features of mountain meadows under four typical land use types in Zhaosu Basin

WANG Xiang1,ZHU Ya-Qiong1,ZHENG Wei1,2,*(),GUAN Zheng-Xuan1,SHENG Jian-Dong1   

  1. 1 College of Pratacultural and Environmental Science, Xinjiang Agricultural University, ürümqi 830052, China;
    2 Xinjiang Key Laboratory of Grassland Resources and Ecology, ürümqi 830052, China;
  • Online:2018-03-20 Published:2017-06-16
  • Contact: Wei ZHENG ORCID:0000-0002-5627-9042
  • Supported by:
    Supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA05050405);the Natural Science Foundation of China(31660692);the Modern Agroindustry Technology Research System.(CARS34)

Abstract:

Aims Our objective was to explore the effects of different land use types on soil respiration rates in the mountain meadows of Tianshan Mountain, Zhaosu Racecourse, Xinjiang, China from 2015 to 2016.

Methods Four impermanent plots with different land use types (legume-grass mixture, LG; reseeding grassland, RG; natural grassland, NG; cropland, CR), which were established in 2013, were selected. The soil respiration rates in the growing seasons of two consecutive years (from April to September in 2015 and 2016) were measured using LI-8100A Soil Respiration System. Soil temperatures at 5 cm depth and soil water content at 0-10 cm depth were measured simultaneously. We also investigated soil biological properties including soil microflora structures, soil microbial biomass carbon, and soil enzyme activity. The hydrothermal and soil biological impacts on soil respiration rates were analyzed using the relationship among soil hydrothermal factors, soil microflora factors, and soil enzyme activities.

Important findings We found that: 1) in 2015, the temporal variation of soil respiration showed double peaks in NG and RC plots, but showed a single peak in RG and LG plots, and it reached the maximum in August in all plots. This temporal pattern was different in 2016. Soil respiration reached the maximum at the end of June in RG and LG, and at the end of July in NG and CR. 2) For the whole study period, the average soil respiration rate was in the order of: NG > RG > CR > LG. 3) Soil respiration rate was positively correlated with soil temperature, and negatively correlated with soil volumetric water content. The temperature sensitivity of soil respiration (Q10) was in the order of: NG > CR > RG > LG. 4) Bacteria were dominant among soil microbes in all type of plots, followed by actinomycetes and fungi were the least abundant. The total soil microbial biomass was in the order of: NG > RG > CR > LG, which was consistent with the average soil respiration rate. The fitting analysis showed that soil respiration was positively correlated with the abundance of actinomycetes in RG (p < 0.05), and was positively correlated with the abundances of bacteria and actinomycetes in LG (p < 0.05). 5) The average microbial biomass carbon was in the order of: CR > NG > LG > RG. Fidelity analysis showed that soil respiration rate was significantly positively correlated with microbial biomass carbon in GR and CR (p < 0.05). 6) Among the examined enzymes, only protease and sucrase had a correlation with soil respiration, with sucrase having a greater effect. Changing the degraded mountain meadow to legume-grass mixture and reseeding grassland could decrease soil respiration rates, potentially benefiting carbon sequestration.

Key words: land use type, mountain meadow, soil respiration rate, soil temperature, soil water content, soil microflora, soil microbial carbon, soil enzyme activity