Arid Zone Research ›› 2023, Vol. 40 ›› Issue (9): 1457-1464.doi: 10.13866/j.azr.2023.09.09

• Plant Ecology • Previous Articles     Next Articles

Changes in vegetation biomass and its relationship with soil carbon during restoration processes in degraded sandy grasslands

ZHOU Jing1(),SUN Yongfeng2,DING Jieping1,BAI Haojiang3,MA Xiang4,WANG Xuyang3,Luo Yongqing3()   

  1. 1. Gansu Academy of Eco-environmental Sciences, Lanzhou 730020, Gansu, China
    2. CSCEC AECOM Consultants Co., Ltd., Lanzhou 730000, Gansu, China
    3. Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
    4. Academy of Animal Science and Veterinary Medicine, Qinghai University, Xining 810016, Qinghai, China
  • Received:2023-03-11 Revised:2023-05-23 Online:2023-09-15 Published:2023-09-28
  • Contact: Yongqing Luo E-mail:fallzhouj@aliyun.com;luoyongqing@nieer.ac.cn

Abstract:

The allocation pattern of plant biomass and its input into the soil are key processes for restoring degraded sandy grassland, especially regarding soil carbon accumulation. In this study, mobile dunes, semifixed dunes, fixed dunes, and fenced grasslands in Horqin Sandy Land at different restoration stages were investigated. By analyzing the biomass allocation of herbaceous vegetation, root traits, soil physicochemical properties, and their interrelations, it was found that the aboveground biomass, root biomass, surface litter, and underground necromass all increased significantly (P<0.05) with the extent of desertified grassland restoration. Compared to severely desertified mobile dunes, the total dry matter (biomass+litters) in semifixed dunes, fixed dunes, and fenced grasslands increased by 11.01%, 116.29%, and 151.18%, respectively. Similar to the changes in biomass, soil carbon content also increased significantly (P<0.05) with the extent of desertified grassland restoration, with a higher increase rate observed in the 0-10 cm layer than the 10-20 cm layer. Structural equation modeling indicated that the soil carbon content in the 0-10 cm layer was influenced by the surface litter mass, underground necromass, and root surface area. Conversely, soil carbon content in the 10-20 cm layer was affected only by underground necromass and root surface area. Moreover, the soil carbon content in both layers showed an insignificant relationship with aboveground biomass. In conclusion, the soil carbon content in degraded sandy grassland is primarily affected by litter input and root traits but has an insignificant relationship with aboveground biomass.

Key words: degraded sandy grassland, soil carbon content, plant biomass, litter, root traits