Chin J Plan Ecolo ›› 2018, Vol. 42 ›› Issue (3): 265-276.DOI: 10.17521/cjpe.2015.0300

• Research Articles • Previous Articles     Next Articles

Spatial distributions of biomass and carbon density in natural grasslands of Hebei, China

CEN Yu1,2,WANG Cheng-Dong1,2,ZHANG Zhen3,REN Xia4,LIU Mei-Zhen1,2,*(),YANG Fan1,2   

  1. 1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2 University of the Chinese Academy of Sciences, Beijing 100049, China
    3 College of Resources and Environment, Anhui Agricultural University, Hefei 230036, China
    4 Ordos Soil and Water Conservation Bureau, Ordos, Nei Mongol 017010, China
  • Online:2018-03-20 Published:2017-06-16
  • Contact: Mei-Zhen LIU ORCID:0000-0003-3557-7777
  • Supported by:
    Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences.(XDA0505040302);the National Natural Science Foundation of China.(41371056)

Abstract:

Aims Grassland is an important component of the global terrestrial ecosystem and plays a significant role in the global carbon cycle. Knowledge of the spatial distribution of biomass and carbon density and their constraining environmental factors in different types of grasslands is crucial for revealing the variations of grassland carbon pool and understanding the grassland ecosystem carbon sequestration in China. The objective of this study was to determine the spatial patterns of biomass and carbon density distribution in natural grasslands of Hebei Province, China.

Methods The aboveground biomass, root biomass, litter mass, and their carbon densities were investigated in 390 grassland plots from 78 sites representative of six different types of natural grasslands based on vegetation, soil and climate from 2011 to 2013. The grassland types include temperate steppe, temperate meadow, temperate mountain meadow, low-land saline meadow, warm-temperate tussock and warm-temperate shrub tussock.

Important findings There were significant differences (p < 0.05) in the total biomass among the six grassland types, with the highest value of 2770.2 g·m-2 in the low-land saline meadow and lowest value of 747.6 g·m-2 in the temperate steppe. The low-land saline meadow also had the highest value in the aboveground biomass (285.0 g·m-2), followed by the warm-temperate shrub tussock (235.1 g·m-2) and the temperate mountain meadow (203.1 g·m-2); the lowest value in aboveground biomass was found in the temperate steppe (110.6 g·m-2). The litter mass was largest in the lowland saline meadow (584.0 g·m-2), followed by the temperate mountain meadow (187.9 g·m-2) and the warm-temperate shrub tussock (91.0 g·m-2). The values of root biomass were 1.9-4.3 times greater than that of aboveground biomass across the six types of grasslands, resulting in average root:shoot ratio of 3.1. The root biomass was largest in the lowland saline meadow (1901.3 g·m-2), and smallest in the temperate steppe with only 1/3 of that in the former. In terms of carbon density, lowland saline meadow also displayed the largest values among all the types of grasslands. The values of carbon density in the aboveground vegetation, litter and root were respectively 132.7, 81.2, and 705.9 g C·m-2. In all grassland types, the biomass of aboveground vegetation and root, litter mass, and total biomass decreased initially and then increased with elevation (p < 0.05). With the increasing accumulative temperatures >10 °C, the root biomass and the total biomass decreased initially and then increased (p < 0.01). In this study, the warm-temperate shrub tussock mostly distributes in the rocky mountain area where the soil layer is very thin, leading to the lower biomass relatively to the temperate meadow. Therefore, climate, soil and geographical factors should be comprehensively considered when comparing the biomass among different grassland types in large area.

Key words: aboveground biomass, litter mass, root biomass, carbon density, environmental factor, natural grassland