The role of stream water carbon dynamics and export in the carbon balance of a tropical seasonal rainforest, southwest China

PLoS One. 2013;8(2):e56646. doi: 10.1371/journal.pone.0056646. Epub 2013 Feb 20.

Abstract

A two-year study (2009 ~ 2010) was carried out to investigate the dynamics of different carbon (C) forms, and the role of stream export in the C balance of a 23.4-ha headwater catchment in a tropical seasonal rainforest at Xishuangbanna (XSBN), southwest China. The seasonal volumetric weighted mean (VWM) concentrations of total inorganic C (TIC) and dissolved inorganic C (DIC) were higher, and particulate inorganic C (PIC) and organic C (POC) were lower, in the dry season than the rainy season, while the VWM concentrations of total organic C (TOC) and dissolved organic C (DOC) were similar between seasons. With increased monthly stream discharge and stream water temperature (SWT), only TIC and DIC concentrations decreased significantly. The most important C form in stream export was DIC, accounting for 51.8% of the total C (TC) export; DOC, POC, and PIC accounted for 21.8%, 14.9%, and 11.5% of the TC export, respectively. Dynamics of C flux were closely related to stream discharge, with the greatest export during the rainy season. C export in the headwater stream was 47.1 kg C ha(-1) yr(-1), about 2.85% of the annual net ecosystem exchange. This finding indicates that stream export represented a minor contribution to the C balance in this tropical seasonal rainforest.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon / chemistry*
  • China
  • Ecosystem
  • Nitrogen / chemistry
  • Rain
  • Rivers
  • Seasons
  • Temperature
  • Trees / physiology*
  • Tropical Climate*
  • Water / chemistry*

Substances

  • Water
  • Carbon
  • Nitrogen

Grants and funding

This study was funded by the National Science Foundation of China (40801035, 40571163), the CAS 135 program (XTBG-T03) and Strategic Priority Research Program-Climate Change: Carbon Budget and Related Issues of the Chinese Academy of Sciences(XDA05020302), the Development Program in Basic Science of China (No. 2010CB833501), and the Yunnan Natural Science Foundation of Yunnan Province, China (2008CD167). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.