Chin J Plant Ecol ›› 2016, Vol. 40 ›› Issue (6): 533-542.DOI: 10.17521/cjpe.2015.0478

Special Issue: 稳定同位素生态学

• Research Articles •     Next Articles

13C and 15N isotopic signatures of plant-soil continuum along a successional gradient in Dinghushan Biosphere Reserve

Xin XIONG1,2, Hui-Ling ZHANG1,2, Jian-Ping WU1,2, Guo-Wei CHU1, Guo-Yi ZHOU1, De-Qiang ZHANG1,*()   

  1. 1South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China

    2University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2015-12-29 Accepted:2016-04-23 Online:2016-06-10 Published:2016-06-15
  • Contact: De-Qiang ZHANG


Aims The optimal patterns of plant community for water use and nutrient utilization, the responses of soil carbon and nitrogen turnover processes to forest succession, and the mechanisms of soil organic carbon accumulation, are three critical issues in forest ecosystem study. It is difficult to accurately detect these ecological processes with conventional methodologies in the short term, yet the application of 13C and 15N natural abundance technique may yield important information about these processes.Methods This study was conducted in Dinghushan Biosphere Reserve. We investigated the natural isotopic abundance of both 13C and 15N of plant-soil continuum along a successional gradient from Pinus massoniana forest (PF) to coniferous and broad-leaved mixed forest (MF), and monsoon evergreen broad-leaved forest (BF). We also analyzed the correlations of foliar stable carbon isotope ratio (δ13C) and stable nitrogen isotope ratio (δ15N) with foliar elemental contents and the variations of soil δ13C and δ15N along soil profiles at different successional stages.Important findings A significant positive correlation between foliar δ13C and foliar C:N was observed. In both litter and soil, the δ13C values tended to decrease along the forest succession, with the order as PF > MF > BF. Foliar δ15N was positively correlated with foliar N content. The δ15N values of litter and upper soil (0-10 cm) increased with successional status. Both soil δ13C and δ15N values increased with increasing soil depth at all three forests. Our results imply that 1) trade-off between water use efficiency and nitrogen use efficiency did not necessarily exist in subtropical forests of China; 2) the application of isotopic technique could assist understanding of the mechanisms of soil carbon accumulation in subtropical forests, especially in old-grow forests; 3) the 15N natural abundance of plant-soil continuum could be a potential indicator of soil nitrogen availability and ecosystem nitrogen saturation status.

Key words: stable carbon isotope ratio, stable nitrogen isotope ratio, succession, forest, Dinghushan