Citation

Wang HH, Wonkka CL, Grant WE, Rogers WE. AoB Plants 2016; ePub(ePub): ePub.

Affiliation

Department of Ecosystem Science and Management, Texas A&M University, College Station, Texas 77843, USA.

Copyright

(Copyright © 2016, Annals of Botany Company, Publisher Oxford University Press)

DOI

10.1093/aobpla/plw012

PMID

26903488

Abstract

Non-native plant invasions and changing management activities have dramatically altered the structure and composition of forests worldwide. Invasive shrubs and fire suppression have led to increased densification and biomass accumulation in forest ecosystems of the southeastern United States. Notably, Chinese and European privets are rapid growing, shade tolerant shrubs which number among the most aggressive invasive species in these forests. Privet encroachment has caused losses of native diversity, alteration of ecosystem processes, and changes in community structure. The latter has become manifest through decreases in fine herbaceous fuels concurrent with increases in coarse woody fuels in forest understories. These alterations in fuel structure will potentially lead to less frequent, but more severe forest fires, which threaten important forest resources during extreme weather conditions. Drawing on extensive datasets compiled by the U. S. Forest Service, we integrated statistical forecasting and analytical techniques within a spatially-explicit, agent-based, simulation framework to predict potential range expansion of Chinese and European privet (Ligustrum sinense and Ligustrum vulgare) and the associated increase in crown fire risk over the next two decades in forestlands of Mississippi and Alabama. Our results indicate that probability of invasion is positively associated with elevation, adjacency (within 300m) to water bodies, mean daily maximum temperature, site productivity, and private land ownership, and is negatively associated with slope, stand age, artificial regeneration, distance to the nearest road, and fire disturbance. Our projections suggest the total area invaded will increase from 1.36 to ≈31.39 percent of all forestlands in Mississippi and Alabama (≈7 million hectares) and the annual frequency of crown fires in these forestlands will approximately double within the next two decades. Such time series projections of annual range expansions and crown fire frequency should provide land managers and restoration practitioners with an invasion chronology upon which to base proactive management plans.

Language: en