Chin J Plan Ecolo ›› 2018, Vol. 42 ›› Issue (2): 153-163.DOI: 10.17521/cjpe.2017.0184

Special Issue: 青藏高原植物生态学:种群生态学

• Research Articles • Previous Articles     Next Articles

Dynamics in foliar litter decomposition for Pinus koraiensis and Quercus mongolica in a snow-depth manipulation experiment

WU Qi-Qian,WANG Chuan-Kuan()   

  1. Center for Ecological Research, Northeast Forestry University, Harbin 150040, China
  • Online:2018-02-20 Published:2018-04-16
  • Contact: WU Qi-Qian ORCID:0000-0002-4371-6303 Chuan-Kuan WANG ORCID:0000-0003-3513-5426
  • Supported by:
    Supported by the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2011BAD37B01);the Program for Changjiang Scholars and Innovative Research Team (IRT_15R09) and the Fundamental Research Funds for the Central Universities(2572014AA11)

Abstract:

Aims Changes in snowpack induced by climate change may alter water and heat regimes at the ground surface, thus influencing activities of decomposers and litter decomposition in snow-covered regions. However, effects of snow-depth changes on litter decomposition are unclear. Our objective was to characterize the decomposition dynamics of two contrasting tree species—Korean pine (Pinus koraiensis) and Mongolian oak (Quercus mongolica) in a snow-depth manipulation experiment.

Methods The snow-depth manipulation experiment that included three treatments (i.e., snow-addition, snow-removal, and control) was conducted in a temperate Korean pine plantation in the Maoershan Forest Ecosystem Research Station, Northeast China. Air-dried foliar litter of the pine or oak (10 g litter per bag) was sealed in a nylon litterbag (15 cm × 20 cm). A total of 648 litterbags (3 plots × 3 treatments × 2 tree species × 3 replicates × 12 sampling dates) were placed evenly on the forest floor in October 2014. Three replicate litterbags per species were buried in each treatment plot and sampled 12 times (i.e., freezing onset stage, deep freezing stage, thawing stage, early, middle and late snow-free seasons) during the two-year period (2014-2016) to determine the temporal variation of the decomposition rate. Associated factors (i.e., mean temperature at litter layer, freeze-thaw cycle, available nitrogen and phosphorus at the organic layer) were measured simultaneously.

Important findings Tree species, snow-depth treatment, decomposition stage, and the measured associated factors all influenced the decomposition rates of the foliar litter. The litter mass loss was 52.1%-54.5% for the pine, and 53.9%-59.1% for the oak during the two-year period. The decomposition coefficients for the litter of the two species were the highest in the snow-addition plot, and the lowest in the snow-removal plot. Moreover, the snow-depth manipulation dramatically changed the relative contribution of the mass loss (R ratio) during the snow-covered or snow-free seasons to the yearly total loss. Compared with the control, the snow-addition treatment increased the R ratio during the snow-covered season by 9.1% for the pine and 10.4% for the oak, while the snow-removal treatment increased the R ratio during the snow-free season by 10.4% and 12.7%, respectively. In conclusion, changes in snowpack induced by climate change may significantly affect the foliar decomposition in temperate forests, and also alter the relative contribution of the litter decomposition in the snow-covered and snow-free seasons to the yearly decomposition.

Key words: snow-depth manipulation, temperate forest, foliar litter decomposition, climate change, snow-covered season, snow-free season