Chin J Plan Ecolo ›› 2016, Vol. 40 ›› Issue (10): 1037-1048.DOI: 10.17521/cjpe.2016.0020

• Research Articles • Previous Articles     Next Articles

Trade-offs between water yield and carbon sequestration for sub-alpine catchments in western Sichuan, China

Peng-Sen SUN1,*, Ning LIU2, Shi-Rong LIU1, Ge SUN3   

  1. 1Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Key Laboratory of Forest Ecology and Environment, State Forestry Administration, Beijing 100091, China

    2School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, WA 6150, Australia

    3Eastern Forest Environmental Threat Assessment Center, USDA Forest Service, Raleigh, NC 27606, USA
  • Online:2016-10-10 Published:2016-11-02
  • Contact: Peng-Sen SUN


Aims There is increasing concern on the trade-off between carbon sequestration and water yield of forest ecosystems. Our objective was to explore the effects of vegetation composition on water and carbon trade-off in the sub-alpine watersheds of western Sichuan during 1982-2006.Methods The WaSSI-C, which is an eco-hydrological model with coupled water and carbon cycles, was employed to calculate the key components in water balance and carbon sequestration for the 22 sub-catchments in the upper reaches of Zagunao River. Spearman’s Rho trend analysis was used to examine the trends in runoff and net ecosystem productivity. Important findings Compared with either subalpine meadow or mixed forest dominated catchments, the conifer-dominated catchments had much higher water loss due to high evapotranspiration, and the loss was not offset by its higher soil water infiltration during the growing season. The change in soil water storage for subalpine meadow, mixed forest and coniferous forest are -44 mm, -18 mm and -5 mm, respectively, which indicated significant decline in soil water storage and thus water yield particularly in alpine meadow catchments. Significant negative relationship was found between runoff and net ecosystem productivity, the alpine meadow as the dominant vegetation type showed high water yield and low carbon sequestration, and the conifer-dominant and mixed forest vegetation showed low water yield and high carbon sequestration, moreover, the higher the forest coverage, the lower the water yield. Upward trends in net ecosystem productivity were observed in the three vegetation types during the study period and the alpine meadow type was significant.

Key words: water and carbon trade-off, coupling, hydrological response unit, change in soil water storage, WaSSI-C model