Native and Invasive Woody Species Differentially Respond to Forest Edges and Forest Successional Age

Forest fragmentation can promote non-native plant invasions by increasing invasive plant seed dispersal and resource availability along edges. These effects can vary based on forest age and may be influenced by differences in traits of native and invasive plant species. To determine how native versus invasive plant species respond to forest edges and forest successional age, we experimentally evaluated germination, survival, and growth of three native and three invasive woody plant species in eastern USA forests. Across all species, increasing distance from the edge resulted in more germination and less seedling growth, but had no effect on seedling survival. Generally, seedling growth was greater in younger forests and invasive species outperformed native species; however, there were significant species-specific differences in performance. For example, among native species, spicebush had poor growth performance but high survival, while redbud had low germination but high growth performance and survival. By contrast, the invasive privet and autumn olive produced more biomass with high relative growth rates, and autumn olive had exceptionally high germination but the lowest survival. Overall, our results suggest that while there are some general characteristics of invasive species, species-specific traits may better inform management strategies and improve predictions about biological invasions along forest edges