Eucalyptus Regnans - Conservation

Conservation

Great controversy surrounds the logging of old-growth Eucalyptus regnans in its natural range in both Victoria and Tasmania. Aside from its symbolic significance as the largest eucalypt of all, Eucalyptus regnans has value to conservationists in providing essential habitat to important birds and mammals (notably the Wedge tailed eagle, the Lyrebird and the endangered Victorian state animal emblem Leadbeater's possum). In a land of vast, arid plains and desert, the contrasting lush fertility of mountain-ash forest is particularly dear to nature lovers.

Although its status as a species is secure, old-growth forests of Eucalyptus regnans are particularly susceptible to destruction by forestry. For this reason stands of very old and very tall trees exist only in pockets. Very few such stands of trees fall within those areas that have been listed as National Park or World Heritage environments. Most lie within areas controlled by state forestry management authorities and their heritage value is balanced against the commercial value of harvesting and then planting fast-growing and more productive monoculture timber crops on these comparatively well-watered and fertile areas.

In Tasmania, of the 10,000 hectares of tall-eucalypt forest logged between 1996 an 2006, E. regnans made up more than 1,100 hectares. The trees continue to be logged, most notably by Gunns, a major forestry enterprise.

Political opposition to the logging of forests by the process known as clearfelling has grown very strong in recent years (particularly in the case of woodchipping), and the extent of future harvesting remains uncertain.

It has long been believed that while many species of eucalyptus successfully survived severe bushfires, forests of Eucalyptus regnans are highly susceptible to destruction by fire. While the process of recovery of most eucalyptus forests is rapid, so that trees that are devoid of leaves may be fully foliaged within two years, in the case of Eucalyptus regnans, the recovery of a forest after a severe fire might require the total regrowth from seed of the devastated area, taking perhaps 200 years or more.

It has been suggested that fire is necessary for the germination of Eucalyptus regnans, and that young Eucalyptus regnans trees flourish best where there is open space, allowing sunlight to penetrate. Prior to European intervention, indigenous land management practices involved controlled burning in order to maintain grassland. This resulted in cleared areas in forests, around the peripheries of which young trees could germinate and grow. It is probable that these indigenous practices were used within forests of Eucalyptus regnans. Cleared spaces also occur naturally in tall forests when an old tree falls, or dies and loses its foliage. These very tall trees do not survive independently of each other, as single trees are more subject to lightning strikes and wind damage.

The natural habitat of the Eucalyptus regnans is in general the areas of Australia with the highest and most reliable precipitation. These areas are less prone to catastrophic fires than other forested areas. Research has indicated that a stand of mountain ash in Victoria is actually a multi-age stand due to fire, having experienced seven fires since the 15th century, whereas, since European settlement, many of Australia's eucalyptus forests have suffered severe fires as often as every 20 years.

Studies conducted in the 20th by T. M. Cunningham and David H. Ashton suggest that the re-growth habit of Eucalyptus regnans requires open space, and an ash layer. For this reason clearfelling (as opposed to selective logging methods) are justified by the timber industry by claiming it is required for the successful germination and growth of seedlings, despite such intense burns not occurring naturally and the cleared land requiring reseeding from seed collected elsewhere. The clearfell process can lead to spectacular and uniform regrowth of commercially viable timber, if managed properly. Those who support clearfelling see it as an ideal method of land management but critics point to the impact of such activities on stream health, water yield of catchments, impacts on threatened forest fauna and flora, long term soil healthy and viability, and the loss of all biodiversity to the harvested area.

In addition to this, opponents of clearfelling point out that the forests survived for centuries without clearfelling and that it takes perhaps 300 years to replace a giant tree, commercially valuable only as woodchip, and therefore designated as "waste" by the harvesters. Opponents of clearfelling point out that the clearfell process was unavailable until the arrival of European settlers (indigenous people practised a mosaic burn system that kept the forest open but didn't remove large amounts of timber).

Half of Victoria's forested water catchment areas, which provides water requiring little treatment, are composed of E. regnans forest. Yields from these catchments fall significantly for 20 to 40 years after disturbance. These areas have an increased risk of bushfire due to smaller trees being more flammable, the risk increasing further with climate change.