Biodiversity of canopy invertebrates along a latitudinal gradient

Project name:	Biodiversity of canopy invertebrates along a latitudinal gradient
Year started:	2001
Project number:	WRA074
Primary investigator:	Dick Bashford
Other investigator(s):	Andrew Muirhead, Peter Lillywhite, Simon Grove
Enquiries:	warra.enquiries@forestrytas.com.au
Organisation(s):	Forestry Tasmania, Museum of Victoria
Project type:	Professional
Project status:	Completed

Array of collecting funnels being hoisted into position beneath the fogger, October 2001.

Image: Simon Grove

Project summary:

Warra is a core site in the Asian Forest Ecosystems section of the International Biodiversity Observation Year (IBOY) program, and is a satellite site for further IBOY projects. Warra is the southernmost site in a latitudinal transect running from Japan to Tasmania involved in a study examining the diversity of insects inhabiting the forest canopy.

There was a considerable difference in the insect counts between the upper and lower canopy catches, with the lower canopy harbouring many more insects. Beetles and bugs were numerically dominant. Beetle assemblage composition was clearly related to tree species. Within E.obliqua, assemblage composition differed more among trees than between the upper and lower canopies of individual trees. Subsequently, the bark-dwelling invertebrates of the same trees have been sampled using knockdown insecticide. The findings from this project will feed into other projects investigating the relationships between biodiversity and tree structural complexity at Warra.

Methodology:

Canopy insects have been sampled by fogging the tree canopy with the insecticide Bioresmethrin using a motorised backpack fogger. Following insecticide application, the fogger was removed and a 10 m² catcher array placed in the canopy under the treated foliage. The catcher was left in place for at least one hour. Insects falling into the collectors were washed into collecting bottles at the base of each collector using an ethanol spray. Four Eucalyptus obliqua trees were sampled, as well as two Nothofagus cunninghamii and one Acacia melanoxylon.

Fogging was done in October 2001 and again in February 2002. Collected insects were sorted to order, with beetles being further separated to morpho species.

Datasets:

None available.

Publications:

Bashford, R. & Boutin, L. (2002). The spider fauna utilising Eucalyptus obliqua at the Warra LTER site in Southern Tasmania. The Tasmanian Naturalist 124: 70-76.

Bashford, R., Taylor, R., Driessen, M., Doran, N. & Richardson, A. (2001). Research on invertebrate assemblages at the Warra LTER Site.Tasforests 13: 109-118.

Powledge, F. (2002). A look back at the International Biodiversity Observation Year. BioScience 52: 1070-1079.