A Conceptual Model of Bell Miner Associated Dieback
Tony Hastings, October 2010.
Science Centre at Manna Park, PO Box 130 Merimbula NSW 2548. This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Charles Sturt University, School of Environmental Sciences
Abstract
The Bell Miner, Manorina melanophrys, is a small bird that maintains exclusive territories, farms lerp-producing insects, mostly Psyllids, which in turn can cause canopy defoliation and death of Eucalyptus trees. The process is known as “Bell Miner Associated Dieback” (BMAD). The resultant sparse canopy favours other species, such as rainforest lianas and ground ferns. The altered forest structure has corresponding habitat values, possibly favouring ground-dwelling mammals. With these changes in habitat resulting from Bell Miner colonisation, it is appropriate to call them ecosystem engineers.
Typically rainforest species are fire sensitive and proliferate in the absence of fire. The disturbance of fire exterminates these species and regenerates fire adapted species, mostly eucalypts and acacias. Bell Miner colonisation can reduce eucalypt lifespan from centuries to just decades. This speedy elimination accelerates the transition to rainforest species.
In this literature review, models of ecosystem engineering and vegetation succession are applied to BMAD. The resulting model provides an understanding of the process useful to determine critical elements that may be managed.