THE CORBY PLOTS, Corby Logging Area, Imbil State Forest.
On the range between Mt Traverse and Mt Borumba, in Imbil State Forest, six experimental forest plots were planted in 1961. They are called the Corby Plots being on the edge of the Corby Logging Area. Since being planted these plots have never been thinned, though they were closely planted. But they have been protected from fire.
There are 6 plots each planted with a different species:
native Eucalyptus cloeziana (Gympie messmate),
native Araucaria cunninghamii (hoop pine),
exotic Pinus patula (Mexican weeping pine);
exotic Pinus caribaea (Caribbean Pine);
Eucalyptus pilularis (blackbutt)
Eucalyptus grandis (flooded gum).
This view into the plot of Pinus caribaea shows that all trees have survived but a few have grown to a large girth, whilst the majority are limited by the close planting and lack of thinning. The same could be said of the Hoop pine plot, except that the growth is more uniform in that plot.
An under-storey has developed in each plot and is composed of a diversity of local rainforest and wet sclerophyll species.
Today, these 6 plots, each about 30M x 120M are part of the plantation leases of Forest Plantations Queensland. They are embedded into an area of native forests that have high conservation value, located on the upper steep slopes of the Coonoon Gibber Creek catchment in the Yabba Valley.