Wednesday, August 10, 2011

Forest Redgum

Eucalyptus tereticornis
This is another common local eucalypt, a beautiful tree whose leaves are among the top favourites with koalas.

Our local redgums are coming into bud now, and showing why they are called “tereticornis”. Terete is a word used in botany to describe things which are cylindrical or slightly tapering, and “cornis” means a horn. You can see that the bud-cap - the “calyptus” which gives Eucalyptus their name, is shaped like a straight little horn.
As the flowers mature, they will push off this cap with their many stamens, and attract many insects, including honeybees with their copious nectar.
Redgums can grow to be very big trees, with trunks up to 2m in diameter (though trees of this size would be hundreds of years old). They respond well to coppicing, which is a good way to manage them if they are being grown to be harvested for their good quality firewood.
If you see Eucalyptus overseas, they are quite likely to be this easy-to- grow species. It is a common subject for forestry plantations, grown for its heavy, red construction timber, and for firewood. It is not always appreciated, however. Like other Eucalyptus species, it has a tendency to become an environmental weed when grown away from its natural predators - and a fast-growing woody weed which can support devastating bushfires is an unwelcome immigrant.
We Australians are aware of the second reason why gumtrees are unpopular overseas. Eucalyptus’ ability to out-compete other tree species by taking the lion’s share of available water, especially in the upper layers of the soil, is familiar to us. Our native dry rainforest species are deep-rooted, so can co-exist, but tree species from our wetter rainforest have shallower roots. Like many introduced garden species, they feel the pinch if asked to share their soil with gumtrees.

While this is much-needed koala habitat tree is well worth growing, it is best kept for large properties, parks, and highway planting.

No comments: