Study on potential invasion threat area of Nicotiana glauca Graham based on the MaxEnt model

Nicotiana glauca Graham (N. glauca) is an agricultural weed, environmental weed, and noxious weed, posing a significant threat to ecosystems and agricultural systems. To provide a basis for the early warning of N. glauca, the existing geographical distribution data and environmental variables of N. glauca were used to predict the potential invasion threat area under historical (1970-2000) and future (2061-2080) climate conditions through MaxEnt and ArcGIS in this study. The results showed that the isothermality (bio3), the max temperature of warmest month (bio5), the mean temperature of wettest quarter (bio8), and the mean diurnal range (bio2) were the key bioclimatic variables affecting the growth of N. glauca. The potential invasion threat area of N. glauca under historical climate conditions was mainly distributed in the central and southern parts of North America, the vast majority of South America, the northern coastal areas and the central and southern parts of Africa, the western and southern parts of Europe, the central and southern parts of Asia, and the vast majority of Oceania, among which the high-threat areas were mainly located in the southern regions of each land. Among the four scenarios of future climate, the centroid of the invasion threat area shifted southeastward and northeastward, and the total area of the invasion threat area was larger than that under historical climate conditions, suggesting the arduousness of the task of preventing the invasion of N. glauca. The results of this study provided valuable information and theoretical references for the early warning of N. glauca.