Chin J Plant Ecol ›› 2012, Vol. 36 ›› Issue (2): 99-108.DOI: 10.3724/SP.J.1258.2012.00099

• Research Articles •     Next Articles

Response of Betula luminifera leaf litter decomposition to simulated nitrogen deposition in the Rainy Area of West China

TU Li-Hua1, HU Hong-Ling1,2, HU Ting-Xing1,*(), ZHANG Jian2, LUO Shou-Hua1, DAI Hong-Zhong1   

  1. 1College of Forestry, Sichuan Agricultural University, Ya’an, Sichuan, 625014, China
    2Sichuan Provincial Key Laboratory of Forestry Ecological Engineering in Upper Reaches of Yangtze River, Chengdu 611130, China
  • Received:2011-11-23 Accepted:2011-12-16 Online:2012-02-20 Published:2012-02-22
  • Contact: HU Ting-Xing

Abstract:

Aims Our objective was to determine the effect of simulated increased nitrogen (N) deposition on decomposition of Betula luminifera leaf litter, under a high wet-nitrogen deposition background.
Methods From January 2008 to February 2009, a field experiment of simulated N deposition was conducted in a B. luminifera plantation in the Rainy Area of West China. The levels of nitrogen deposition were control (CK), low, medium and high N (0, 5, 15 and 30 g N·m-2·a-1, respectively). A field experiment using the litterbag method was conducted on the decomposition of leaf litter of B. luminifera. In the end of each month, NH4NO3 was added into N-treated plots.
Important findings Despite the high background N deposition, there were significant effects of simulated increased N deposition on B. luminifera leaf litter. N treatments significantly slowed the decomposition of B. luminifera leaf litter through inhibiting the decay of lignin and cellulose. The time of 95% mass loss (T95%) of B. luminifera leaf litter was increased by 1.14-1.96 a from 2.65 a (T95% of CK) caused by simulated N deposition. Simulated N deposition significantly increased the remaining amount of carbon, N, phosphorus, potassium, and magnesium after one year of decomposition. However, calcium release rate was stimulated by simulated N deposition in all three N treatments. The initial chemical characteristics of litter determined the response direction of litter decomposition to simulated N deposition, as well as the nutrient release pattern during litter decomposition.

Key words: Betula luminifera, leaf litter decomposition, nitrogen deposition, nutrient dynamics, Rainy Area of West China