Potentially suitable geographical area for Colletotrichum acutatum under current and future climatic scenarios based on optimized MaxEnt model

Global climate warming has led to changes in the suitable habitats for fungi. <i>Colletotrichum acutatum</i>, a common fungus causing anthracnose disease, is widely distributed in southern China. Currently, research on the relationship between <i>C. acutatum</i> and environmental warming was limited. In this study, MaxEnt and ArcGIS software were used to predict the suitable habitats of <i>C. acutatum</i> under current and future climate conditions based on its occurrence records and environmental factors. The optimal MaxEnt model parameters were set as feature combination (FC) = lp and regularization multiplier (RM) = 2.6. Bio15, Bio12, Bio09, and Bio19 were identified as the main environmental factors influencing the distribution of <i>C. acutatum</i>. Under current climate conditions, <i>C. acutatum</i> was distributed across all continents globally, except Antarctica. In China, <i>C. acutatum</i> was primarily distributed south of the Qinling-Huaihe Line, with a total suitable area of 259.52 × 10⁴ km². Under future climate conditions, the potential suitable habitat area for <i>C. acutatum</i> was expected to increase and spread towards inland China. The results of this study provided timely risk assessment for the distribution and spread of <i>C. acutatum</i> in China and offer scientific guidance for monitoring and timely controlled of its distribution areas.