Plant-Soil Carbon Storage in Dynamic Succession of Ecological Restoration in National Grassland Natural Park

Ecological restoration has a positive impact on global climate change. How plant-soil stores carbon in degraded grassland ecological restoration requires long-term monitoring and support. To reveal the dynamics of plant-soil carbon storage in the succession process of ecological restoration, compare the effects of artificial interference and natural restoration, and determine the impact of climate change and biodiversity on vegetation soil carbon storage, we conducted a study in National Grassland Natural Park, which is located on the southern foot of the Yinshan Mountains in Hohhot, Inner Mongolia, China. Based on long restoration chronosequences (2012-2022), using a space-for-time substitution approach and one-way ANOVA tests, Pearson correlation and structural equation modeling were used to investigate the interactions among these various factors. The results indicated that the carbon storage of aboveground vegetation first increased, and then, decreased with time. The underground root carbon storage and soil carbon storage at 0-10 cm and 20-30 cm first increased, then decreased, and finally, stabilized. The highest soil carbon storage (0-30 cm) was 102.11 t/ha in 2013, which accounted for 96.61% of the total organic carbon storage. The Shannon-Wiener index, individual number of species, and surface root carbon storage (0-10 cm) significantly increased the carbon storage of surface soil (0-10 cm) (p < 0.05). Compared to natural restoration, artificial restoration over seven years decreased soil carbon storage at 0-30 cm and underground root carbon storage at 0-10 cm (p < 0.05). Consequently, combining artificial restoration with natural restoration can help in establishing a more stable ecosystem faster and in increasing the carbon storage of the ecosystem. It is an effective management measure to promote grassland restoration in arid areas. Also, climate (MAT, MAP) change was closely correlated with plant-soil carbon storage.