Analysis of the Spatiotemporal Evolution of the Net Primary Productivity of Glycyrrhiza uralensis Fisch. and Its Influencing Factors from 2014- 2022

Glycyrrhiza uralensis Fisch. is widely used in medicine for its roots and rhizomes, and it plays a significant role in enhancing the regional ecological environment. In this study, firstly, based on the spectral characteristics of G. uralensis distribution areas under the G. uralensis Vegetation Index (GUVI) feature set of major feature types and G. uralensis in different years from 2014 to 2022, the G. uralensis distribution areas were identified and extracted using the Random Forest. Moreover, we estimated the Net Primary Productivity (NPP) of G. uralensis in Dengkou County using an improved version of the Carnegie-Ames-Stanford Approach (CASA) and investigated its spatio-temporal evolution characteristics. Additionally, with the assistance of GeoDetector, we systematically analyzed the relationship between the NPP of G. uralensis and 71 environmental factors from 2014 to 2022. The study findings indicated that the distribution area of G. uralensis fluctuated significantly over the years. Initially, its distribution was predominantly concentrated in the northeastern part of Dengkou County, but later it expanded to the southwestern region as well. Although the annual mean NPP of G. uralensis from 2014 to 2022 showed a fluctuating downward trend, it still accounted for a high proportion in the regions with high annual mean NPP within Dengkou County, which implies that G. uralensis has a strong carbon sequestration capacity. Furthermore, the GeoDetector analysis revealed that the impacts of various environmental factors on the spatial distribution of G. uralensis NPP in Dengkou County involve complex interaction relationships. This study offers valuable perspectives on the potential of G. uralensis as a key species for ecological restoration, desert management, sustainable utilization of medicinal plant resources, and carbon sequestration in (semi)arid regions. It also underscores the possibility of achieving a win-win situation for ecological conservation and economic development.