Kudzu invasion and its influential factors in the southeastern United States

As an invasive plant species with wide ecological tolerance and fast infestation, kudzu has posed persistent challenges to the ecosystem and economy in the southeastern United States. However, current studies on kudzu mapping and invasive mechanisms are inadequate to unveil the characteristics of kudzu’s spatiotemporal dynamics. In this study, we investigate kudzu distribution and its influential factors based on continuous Sentinel-2 satellite images and a multi-temporal mapping strategy. The study was conducted in Knox County, Tennessee, a representative region highly impacted by kudzu in the southeastern United States. Our results revealed a steady increase in the kudzu invasion area from 2020 to 2022, with a phenology of a growth season from May to September (peak in August) and a rapid defoliation in the fall. We found precipitation is not a limiting factor for kudzu growth, while temperature has strong correlations with kudzu growth, exhibiting seasonal variations in this humid subtropical region. Human activities play an important role in kudzu distribution with a sharp decrease in kudzu density away from road networks, residential clusters, and the edges of urban forests. These findings provide valuable insights into the complex nature of the kudzu invasion in Knox County, as well as other similar areas in the southeastern United States. The observed unique growth patterns of kudzu and its interactions with various environmental factors in this study are also of importance for future initiatives related to mapping the distribution and devising strategies for the prevention and control of kudzu invasion.