The development of even-aged stands of Eucalyptus regnans F. Muell. in central Victoria

During the intensely competitive early decades, the height growth of Eucalyptus regnans is very rapid and the reduction of stem density most pronounced. The resultant large component of suppressed trees from this period is mostly eliminated before the spar stage at 40 years. At this stage height growth diminishes although diameter growth is sustained. In addition, the crown cover is a maximum and light penetration is a minimum. The canopy cover increases with increasing angle from the zenith, and in winter the light interception by deep mature crowns is considerable. On warm, dry north-western slopes, pole stage stands are shorter and denser than those on moister, cooler south-eastern slopes. By the spar stage such stands are differentiated by stature only. The thinning out of dense even-aged understoreys of Pomaderris aspera is inversely proportional to the density of the overstorey of E. regnans. The thinning out of E. regnans from the pole stage is independent of the type of understorey. The most intense competition between E. regnans and P. aspera is likely to occur in the first decade when the root systems of the two species are of similar form.