River Red Gums

Echuca Moama Flora

River Red Gums (Eucalyptus camaldulensis) as their common name suggests, are associated with water, particularly river water, while 'Red' refers to the deep red colour of the timber. River Red Gum forests are the most widely distributed forest type in Victoria. Most of Victoria’s Red Gum forests occur along the channels and flood plains of inland waterways, principally the Ovens, Goulburn and Murray Rivers.

The largest areas are Barmah Forest and Gunbower Island, both on the Murray River. In a well watered forest the trees grow up to 45 metres tall with long, twisted trunks. In more open forest and woodland, the trees are often shorter, with thick twisted trunks and large branches. River Red Gum forests often occur in ‘pure stands’ (ie River Red Gum is the only tree species in the forest), especially on land that is frequently flooded. On slightly higher ground with less flooding, Red Gum can occur with Black, Grey or Yellow Box, with the latter three species often being more common than Red Gum.

River Red Gum forests are open with very little shrub understorey because of the frequent flooding. They have a very different micro-climate to the denser forests such as ash and rainforest. There is a much greater penetration of the sun’s rays to the forest floor than in other forest types. Therefore River Red Gum forests are normally lighter and warmer than others. The low tree density and absence of shrubs allows wind to blow through the forest to a greater extent than in denser forests, this in turn reduces humidity.

The understorey is dominated by grasses, sedges and rushes, with Moira Grass being the most common. The limited volume of vegetation growth in River Red Gum forest compared to some other forest types means that there is little litter on the forest floor. The River Red Gum trees do shed bark, leaves and branches, but much of this can be washed away by floods.

River Red Gum forests generally occur within an elevation range from 20 to 700 metres. However, landforms tend to be flat, reflecting the association between River Red Gum forests and river plains. River Red Gum forests are versatile in the types of soil on which they grow. They occur in soils ranging from well drained sandy soils to poorly drained clays.

However, River Red Gum forests tend to occur mostly on deep, heavy alluvial soils. The River Red Gum forest and associated wetlands provide a range of distinctive habitat which support an array of wildlife. The forests provide excellent breeding and feeding grounds for birds. These include heron, ibis, cormorants and spoonbills. Grey Kangaroos, Yellow-footed Antechinus, Sugar Gliders, Eastern Water Rats and echidna are some native mammals found there. The creeks and rivers of these forests support populations of Murray Cod, Golden Perch and the introduced Redfin and European Carp.

River Red Gum forests provide important habitat for a number of rare and threatened species including Carpet Pythons, Turquoise Parrots and Squirrel Gliders. For many thousands of years, Aboriginal tribes utilised a range of resources from River Red Gum forests including fish, shellfish, crustaceans, small mammals, water fowl and a variety of plant species. Plants also supplied materials for fish nets, spears and other devices for capturing and preparing food. River Red Gum bark was used to construct shelters, canoes and shields.

Today, it is possible to see relics of the Aboriginal lifestyle, particularly of the Yorta Yorta tribe, including middens, oven mounds, scarred trees and fish weirs. River Red Gum was also a popular resource used by the early European settlers. By the 1860s heavy cutting of these forests had commenced. The durability of the timber and its resistance to termites made it a popular timber for railway sleepers, wharves and mine shafts. The timber was also used to fuel river boats. 

A River Red Gum forest can produce 250 million seeds per hectare per year. If the seeds fall and germinate in cool, wet weather before the floods the seedlings will become submerged and die. Most seeds fall in spring and summer as the floods are receding. Ideal conditions for germination occur if the flood waters recede in spring, allowing sufficient time for seeds to germinate and grow prior to the hot, dry conditions of summer. The main obstacle to natural regeneration is ants and other insects which make off with most, and sometimes all of the seeds.

The natural flow and flood patterns of the Murray River catchment have been changed by the storage of water during winter and spring and its release in summer and autumn to meet irrigation demands.

Consequently the frequency of minor flooding in winter has been reduced. This has meant less vigorous growth and regeneration of River Red Gum. These changes to water regulation can lead to poor tree health and growth rates as well as altering the types of plants found on the forest floor. Like most eucalypts, River Red Gums have in-built survival mechanisms. If the seedling or young tree is damaged, seedlings develop a swelling near the foot of the stem from which new shoots can grow. After long droughts of many months or even years, seedlings shed most of their leaves to preserve moisture, growing new shoots as soon as the rain or floods come again.

The introduction of water regulation for crop irrigation has also changed the timing, extent and duration of flooding. Detailed plans are drawn up to control water flow so that the wetlands and river red gums remain healthy.

On the Murray River the flow of water into the forest is carefully controlled by ‘regulators’, special gates that can be opened and closed at will on to both the Victorian and New South Wales sides of the river.

Timber Production River Red Gum is a popular wood for sculpture, wood turning and decorative work because of its fine grain and dark colour. It is a strong, durable termite resistant timber which makes it sought after for a variety of uses, from railway sleepers, bridge and wharf piles to outdoor furniture, garden mulch and high-grade charcoal. River Red Gum burls are used for wood turning and carving.