Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 13, issue 19
Biogeosciences, 13, 5487–5497, 2016
https://doi.org/10.5194/bg-13-5487-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Biogeosciences, 13, 5487–5497, 2016
https://doi.org/10.5194/bg-13-5487-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 04 Oct 2016

Research article | 04 Oct 2016

Hydrologically transported dissolved organic carbon influences soil respiration in a tropical rainforest

Wen-Jun Zhou1,2,3, Hua-Zheng Lu1,2,3, Yi-Ping Zhang1,2, Li-Qing Sha1,2, Douglas Allen Schaefer1,2, Qing-Hai Song1,2,3, Yun Deng1,2, and Xiao-Bao Deng1,2 Wen-Jun Zhou et al.
  • 1Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
  • 2Xishuangbanna Station for Tropical Rain Forest Ecosystem Studies, Chinese Ecosystem Research Net, Mengla, Yunnan 666303, China
  • 3Graduate University of the Chinese Academy of Sciences, Beijing 100039, China

Abstract. To better understand the effect of dissolved organic carbon (DOC) transported by hydrological processes (rainfall, throughfall, litter leachate, and surface soil water; 0–20 cm) on soil respiration in tropical rainforests, we detected the DOC flux in rainfall, throughfall, litter leachate, and surface soil water (0–20 cm), compared the seasonality of δ13CDOC in each hydrological process, and δ13C in leaves, litter, and surface soil, and analysed the throughfall, litter leachate, and surface soil water (0–20 cm) effect on soil respiration in a tropical rainforest in Xishuangbanna, south-west China. Results showed that the surface soil intercepted 94.4 ± 1.2 % of the annual litter leachate DOC flux and is a sink for DOC. The throughfall and litter leachate DOC fluxes amounted to 6.81 and 7.23 % of the net ecosystem exchange respectively, indicating that the DOC flux through hydrological processes is an important component of the carbon budget, and may be an important link between hydrological processes and soil respiration in a tropical rainforest. Even the variability in soil respiration is more dependent on the hydrologically transported water than DOC flux insignificantly, soil temperature, and soil-water content (at 0–20 cm). The difference in δ13C between the soil, soil water (at 0–20 cm), throughfall, and litter leachate indicated that DOC is transformed in the surface soil and decreased the sensitivity indices of soil respiration of DOC flux to water flux, which suggests that soil respiration is more sensitive to the DOC flux in hydrological processes, especially the soil-water DOC flux, than to soil temperature or soil moisture.

Publications Copernicus
Download
Short summary
Throughfall and litter leachate DOC fluxes amounted to 6.81 and 7.23 % of the net ecosystem exchange, respectively. The surface soil was a sink of above water transported DOC. The analysis of 13° C hydrological water DOC and soil, leaf and litter indicated that DOC is transformed in the surface soil. Soil respiration is more dependent on water transported DOC flux than soil-water content (at 0–20 cm), and most sensitive to soil-water DOC flux (at 0–20 cm) compared to soil temperature.
Throughfall and litter leachate DOC fluxes amounted to 6.81 and 7.23 % of the net ecosystem...
Citation