To What Extent do Non-native Shrubs Support Higher Trophic Levels?
Abstract
Invasive species threaten ecosystems and economies. Globally, biological invasions are estimated to have cost over $2.1 trillion since 1970. In Eastern North American woodlands, invasive plants are rapidly displacing natives. This is concerning, because invasive plants may not support the diverse and abundant arthropod communities essential to ecosystem function. Despite the conceptual understanding of invasive shrubs’ potential to transform forest communities, scant research has focused on the effect of invasive plants on higher trophic levels here in Ohio. To address this gap, I examined the diversity and abundance of arthropod communities, caterpillar performance, and caterpillar predation on two invasive shrubs, Amur honeysuckle (Lonicera maackii) and border privet (Ligustrum obtusifolium), relative to native counterparts. Lo. maackii supported a depauperate community; however, Li. obtusifolium hosted a surprisingly robust community. Nevertheless, both invasives proved poor hosts for caterpillars and were less preferred by foraging insectivores.
