CONTROL OF THE UNDERSTOREY IN WET EUCALYPT FORESTS

Abstract

The dense understoreys found in forests in areas of high rainfall in Tasmania are described. Present practices of logging and burning for regeneration are causing increases in the area covered by understoreys of wet sclerophyll scrub at the expense of rain-forest understoreys. Rain-forest understoreys can produce wood in utilizable sizes, but most of the species in the wet sclerophyll scrub do not. It is considered that competition from dense understoreys could affect the survival and growth of eucalypts. Possible methods of controlling the density and species composition of the regenerating understoreys are discussed. The majority of the wet sclerophyll species sprout only very weakly after fire, but the seeds of these species retain their viability in the soil for long periods, making them difficult to control. Frequent burning will remove the understorey and replace it with a fern layer. Double burning causes some reduction in density and can alter species composition. Native animals reduce the density and change the species composition by browsing. Further research into the effects of dense understoreys is recommended, and it is suggested that studies on the ecology of the species concerned could lead to practicable methods of controlling the understorey. at least in terms of its species composition.