Contribution of ecological and socioeconomic factors to the presence and abundance of invasive tree species in Mississippi, USA.
Invasive tree species cause increasing damage to the environment and local economies. Previous studies have seldom treated the presence and abundance of invasive species as different phenomena. Using Classification and Regression Trees (CART) analysis, important driving factors affecting the presence and abundance of invasive tree species in Mississippi were identified. These selected factors were spatially analyzed using a spatial lag model at the county level. The empirical results from the spatial lag model showed that: (1) the presence of invasive tree species was more likely at lower elevations, private ownerships, and in counties with higher per capita annual income; and (2) the abundance of invasive tree species was related to stand age, and elevation. The odds ratio revealed that the presence was most affected by per capita mean annual income. This result might reflect impacts from intensified urban development and alteration of the landscape. As revealed by the coefficients, the abundance was most strongly affected by stand age. Thus, management prescriptions designed to monitor and control invasions should target young private forestlands at low elevations in counties with higher per capita mean annual income.