The concept of ground substrate and its physical structure & mineral element composition constrain mechanisms on vegetation

The ground substrate is a new concept in the field of natural resources proposed by Chinese scientists in 2020 (Ministry of Natural Resources, 2020). It is the basic material that supports and nurtures various natural resources such as soil, forests, grasslands, wetlands, and water. The layer of ground substrate is the most active geological space for the exchange of substances and energy such as water, heat, salt, gas, carbon, etc. It is also serving as a bridge link between the land cover layer and the underground resource layer. The proposal on concept of ground substrate has clarified new directions and goals for geological survey to support ecological civilization construction and natural resource management, has great significance.

In different climate zones such as humid, semi humid, semi-arid, and arid in China, there are significant differences in the material composition, genetic types, and characteristic physicochemical properties of ground substrates, which call ground substrate heterogeneity by us. In recent years, based on multiple ground substrate surveys and research projects, some important conclusions has been gained. The first is we revealed the constraint mechanisms of the physical structure, mineral element composition, and chemical properties of ground substrates on the types, NDVI, NPP of vegetation ecology in the key ecological functional areas in northern China and hilly mountainous areas in southern China. The second is the determination of the bottom boundary of the ground substrate layer requires comprehensive consideration of five factors: they are depth of the underground variable temperate zone, the roots depth of crop and vegetation, the depth of the surface karst development zone, the thickness of the weathering crust, and the burial depth of the groundwater level. It is generally believed that the depth of the ground substrate layer is less than 20 meters. The third is the key constraint layer of ground substrate (rock and soil layers that have important control and influence on vegetation and crop growth, water and salt storage and transport, etc.) is a special layer that should be given special attention in ground substrate filed survey.

More detailed about the scientific connotation and theoretical framework of ground substrate, please see the published paper(Hao Aibing, Yin Zhiqiang*, Li Hongyu, Lu Qinyuan, Peng Ling, Shao Hai, Jiang Qida, Zhao Xiaofeng, Liu Jiufeng, Pang Jumei, Yang Ke, Chen Peng, Kong Fanpeng, Hou Hongxin, Lu Min. 2024. The scientific connotation and theoretical framework of ground substrate. Acta Geologica Sinica. 98(11):3225-3237)