Quantitative assessment of vegetation suitability in China based on carbon-water balance

Abstract

Driven by climate change and ecological restoration, the contradiction between rising vegetation water consumption and declining terrestrial water availability becomes more apparent in non-humid regions in China, putting significant strain on the stability of water balance pattern. Thus, evaluating scientifically the suitability of plant coverage and types from the standpoint water balance is crucial to preserve or construct a relatively stable pattern of “carbon-water balance”, while which has not been investigated thoroughly. Here the study quantified the appropriate vegetation coverage of forest, shrubland and grassland, and identified unsuitable vegetation types over China in 2018 under 2 constraints of water balance (land-atmosphere water balance and terrestrial water storage stability). The findings revealed that, majority of China was across a stable state of "carbon-water balance" in 2018, but there was still a space to lower plant coverage in about 345,052 km2 (14.87%) of China with the declines mostly falling within 0.3, in 8.94% of which vegetation types were unsustainable; vegetation adjustment is advised to be prioritized in the locations (final hotspot regions, accounting for 7.43% of vegetation area of China) with water deficit, descending terrestrial water storage and the artificial vegetation areas. This study proposed a new quantitative assessment method for vegetation suitability aiming at “carbon-water balance” and provided scientific basis and practical value for maintaining the balance between the vegetation restoration and sustainable utilization of water resources.