Abstract:

Carbon is one of the primary elements， and the carbon cycle is an important link between nature and social systems. There are two pathways of natural carbon sequestration in terrestrial ecosystems， one is plant carbon assimilation， the other is soil carbon assimilation. People always pay attention to the plants organic carbon sequestration， and little attention on the soil inorganic carbon sequestration. In this paper， we reviewed the research progress on C₄ woody plants which have strong carbon sequestration ability， and soil inorganic carbon sequestration in desert region of China. Comprehensive analysis of the anatomical structure observation， δ¹³C values and gas exchange characteristics， it was concluded that the desert plants Haloxylon ammodendron and Calligonum mongolicum are typical C₄ woody plants. The assimilation shoots of H. ammodendron has a large number of crystal-containing cells， while the assimilation shoots of C. mongolicum has many mucilage cells. The inorganic carbon sequestration capacity of deserts in an arid region has not been for a properly explained. By analyzing the soil inorganic carbon density and their storage in gravel desert （gobi）， sand desert， and silt desert， Su Peixi et al. proposed the concept of soil carbon assimilation for the first time in 2018， and three stages of soil carbon assimilation were given to explain the phenomenon of soil inorganic carbon sequestration. Compared with the plant carbon assimilation， soil carbon assimilation is the major pathway of carbon sequestration in desert. Finally， we prospected the research direction of desert C₄ woody plants and soil carbon assimilation， and discussed the possible contributions to China's carbon neutral goal before 2060.

Key words: kranz anatomy, C₄ plant, woody plant, soil carbon assimilation, inorganic carbon sequestration