PD, I'm out of my depth in all things botanical. Twice in one page! The person who would have been able to help is my wife, Jen, who is now in dementia care.
There are three related genera of trees,
Angophora,
Corymbia and
Eucalyptus, which are commonly referred to as 'eucalypts' or, when it is appropriate, 'gum trees'.
Many of the eucalypts shed their old bark, exposing the new bright green or orange bark – bet that's the wrong botanical term! The new bark in the second tree below was actually green a few weeks before the photo was taken.
Eucalypts are also branch-shedders extraordinaire. The first photo below is shows where a major limb has broken off at the tree's trunk: this is commonplace, not exceptional.
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Late January
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Early November (2009!)
Areas of 'bush' like this are major fire hazards because of the debris and the flammable oils both in the leaves and exuded from them. Fortunately for SE Queensland, the hottest time of year – right now! – is usually the wettest. For Melbourne (VIC), Adelaide (SA) and Perth (WA), summers are dry: fire danger!
And one more thing: these trees are prone to falling over, as some in the photos are 'thinking of doing'!