Invasion by Eucalyptus megacornuta of an Urban Bushland in Southwestern Australia1

Abstract

Eucalypts have been planted extensively beyond their natural range but few of these plantings have become invasive. The Kings Park bushland in Western Australia is an example of a native bushland in which a few nonlocal eucalypt species (Warted Yate, sugar gum, and lemon-scented gum) were introduced as ornamentals and have since spread into the bushland. Although the population expansion was obvious, little was known about the factors influencing this pattern, making management options unclear. The study objective was to investigate the factors facilitating the invasion of Kings Park by Warted Yate. The study has shown that ecological characteristics that may be facilitating the Warted Yate invasion in Kings Park include mass recruitment of seedlings subsequent to fire, high seedling survival rates, high levels of serotinous seed storage, and a high germination rate. It seems that this species has a high resilience in a fire-prone environment. However, it appears that Warted Yate is not as invasive as sugar gum. The Kings Park situation highlights the risks associated with planting introduced eucalypts at the interface between native and managed systems.Nomenclature: Corymbia citriodora; Eucalyptus cladocalyx; Warted Yate, Eucalyptus megacornuta.Additional index words: Ecological study of invasive eucalypts, restricted natural distribution.