Megumi Aisu is currently a graduate student at the University of Alaska Anchorage, working with the Landscape Ecology program to develop a statewide model of invasive plant distribution using GIS. Contact information is available on her staff page.
Non-native plants are rapidly filling the empty niches in interior Alaska (Figure 1 and 2). Potential ecological threats of non-native plant invasion include changing the nutrients and moisture in soil, encroachment of rare plants, reduction of native species density, and changing the pollination pattern.
Although several studies have been conducted to predict the distribution and potential impacts of non-native plants in Alaska, a comprehensive model that predicts ecological impacts of all non-native plant species that are already observed in Alaska based on all three factors that potentially affect non-native plant distribution (climate, habitat condition, and anthropogenic infrastructure) has not been made.
The objective of this study is to identify (1) which factor or combination of factors among 10 climate, 2 habitat, and 5 anthropogenic variables makes the landscape ecologically vulnerable to plant invasion in interior Alaska, and (2) where the areas are that are most at risk for plant invasion currently and in the future (2020s and 2060s).
These objectives were addressed by constructing a decision tree (CART model) that classifies a multitude of climate, habitat, and anthropogenic variables based on how they interact with the current non-native plant distribution (Figure 3). The model suggested that anthropogenic land use is the single, most influential factor, making the eastern Alaska more vulnerable to the plant invasion (Figure 4).