Response of NonNative Invasive Plants to Large Scale Wind Damage

Abstract

Non-native invasive plant species pose a serious threat to forest ecosystems around the world. Forest edges are associated with non-native invasive plants and forest interiors are often regarded as more resistant to invasion. The objective of this study was to determine if a large-scale wind disturbance facilitated the invasion of forest interiors by non-native invasive plant species. The northern portion of LaRue Pine Hills — Otter Pond Research Natural Area in the Shawnee National Forest of southern Illinois, was severely damaged by high winds during a powerful storm event on 8 May 2009. In the summer of 2011, 53 permanent research plots, as well as 20 additional plots located along roads that form the boundaries of the study site, were surveyed for the presence of 20 non-native invasive plant species. Only three of 53 interior plots (5.6%) contained invasive plant species (Lonicera japonica Lonicera maackii, and Rosa multiflora). Sixteen of 20 road plots contained a non-native invasive species (80%), and six species were identified (Dioscorea oppositifolia, Lactuca serriola, Lonicera maackii, Microstegium vimineum, Rosa multiflora, and Sorghum halepense). These findings indicate that wind damage does not appear to have facilitated invasion of forest interiors in the first two years following the storm. The spatial distribution of non-native invasive plants in the study area fits the pattern of other studies conducted in southern Illinois with non-native invasive plants associated primarily with forest edges and diminishing in the forest interior despite the apparent opportunity for establishment following the wind disturbance.