Dean Nicolle

Two big issues with the new BOM site, for anyone working in the field:

The 'Current Observations' table, where you could see and compare current observations (wind gusts, temps etc) across the state, is no more.

Rain radar maps are dumbed-down so it is difficult to locate on-ground locations.

The new BOM site is a shemozzle. Dumbed-down information and impossible to find actual weather data. A massive step backwards for such an important service.

Currency Creek Arboretum open days for 2026 are now scheduled!

The world's most diverse collection of eucalypts is only open to the public twice a year, at our biannual open days. Details here: www.dn.com.au/Currency_Cre...

We're all set up and ready to go for the arboretum open days THIS WEEKEND! Come and see the world's most diverse collection of eucalypts, with over 800 species growing on the one site.

About an hour's drive south of Adelaide in SA. Open day details here: www.dn.com.au/Currency_Cre...

Ocean heat was off the charts, and Australia bore the brunt For the past year, Australia's oceans have been hotter than ever before. The impacts are being felt all across the nation — as far away from the coast as you can get.

www.abc.net.au/news/2025-10...

1. Eucalyptus conferruminata subsp. 'Cape Arid' (Cape Arid marlock)
2. E. dolichorhyncha (long-budded fuchsia gum)
3. E. diversifolia subsp. hesperia (Wylie Scarp mallee)
4. E. rhodantha (rose mallee)

You can also find out more about the arboretum here: www.dn.com.au/Currency_Cre...

Less than 2 weeks until our arboretum open days! Here's a few of the eucalypts flowering at the moment.

These free open days only occur biannually. Currency Creek Arboretum is about an hour's drive south of Adelaide in SA. Open details here: www.dn.com.au/Currency_Cre...

Carnivorous plants are always pretty cool, and we are lucky enough to have large populations of four different sundew (Drosera) species at the arboretum.

D. whittakeri (Whittaker's sundew)
D. glanduligera (scarlet sundew)
D. auriculata (tall sundew)
D. macrantha subsp. planchonii (climbing sundew)

Forest rail trail grows from artist and tree scientist's seedling deal A unique partnership between an artist and a botanist has resulted in an old rail corridor in South Australia becoming an eucalypt forest.

A unique partnership between an artist and a botanist has resulted in an old rail corridor in South Australia becoming an eucalypt forest.

"Perth had its wettest winter in 30 years. Why aren't its dams full?" An insightful and alarming news article by the ABC:

www.abc.net.au/news/2025-09...

A great initiative by Ian Roberts, showcasing many of the eucalypt species he has planted around Blyth.

Unfortunately I can’t be there for the opening (I’ll be many thousands of kilometers away on that date) but it should be a wonderful day for all that make it.

Behind blooming paddocks sit communities worn down by 'green drought' Rain has returned to farming regions in South Australia. But the drought is not over  — it just looks like it.

Southern Australia’s green drought:

www.abc.net.au/news/2025-07...

Discover the wildlife that call eucalypt hollows home in this stunning poster series by Paula Peeters! 🌳 Now featuring 4 ecosystems, incl. the new WA Wheatbelt Woodland. Explore + order here: paperbarkwriter.com/12967-2
#LoveAGum #TreeHollowThursday

The buds/flowers/fruits begin on a thin twig, but as the branch gets thicker over time (due to secondary growth), the wood envelops the peduncles (the group stalk of the buds/fruits). This can happen relatively quickly (a year or two) in fast-growing plants.

dnicolle's Profile Botanist, arborist and ecologist, specialising in the eucalypts (genus *Eucalyptus*, but see note below). Creator/curator of *Currency Creek Arboretum* in South Australia. Published numerous peer-revi...

You’ll find me there:

www.inaturalist.org/people/dnico...

Caught a flock to 20-odd yellow-tailed black cockatoos shredding the large woody fruits of Eucalyptus youngiana and the branches of drooping she-oaks at the arboretum.

They certainly are efficient at shredding fruits and branches in search of seeds and grubs!

Eucalyptus rhodantha (rose mallee) at Currency Creek Arboretum today.

The operculum (bud cap) is here shedding to reveal the stamens (the pink, thread-like structures which form the colourful part of most eucalypt flowers) and the anthers (the tiny, pale yellow 'dots' which produce pollen).

This year's spring open days at Currency Creek Arboretum will be on Sat 11 & Sun 12 October 2025.

Learn about the research we are doing in the most diverse collection of eucalypts on the planet (over 800 species!) Free entry and tours. Open Day details here: www.dn.com.au/Currency_Cre...

The genus problem – Eucalyptus as a model system for minimising taxonomic disruption The ongoing reclassification of higher plant genera (their division, combining and recircumscription) is the cause of extensive modifications to binomials. Many genus reclassifications have been far ...

Haha… well you’ve got me started! Lemon-scented gum has now been placed back into Eucalyptus by some (including me) in response to some other taxonomists splitting it into a new genus, Blakella, in 2024.

Further reading: onlinelibrary.wiley.com/doi/full/10....

The euc flowers are Eucalyptus leucoxylon, known as yellow gum in Victoria and South Australian blue gum in SA.

A well-developed root-plate and lignotuber in a planted spotted gum (Eucalyptus maculata) in Adelaide.

Sure, the tree has displaced the concrete kerb, but it is well worth it to have such a large, structurally-sound tree providing so much shade, cooling, wildlife and amenity to this streetscape.

Not that I’m aware. There’s so much drought dieback in southern SA at the moment though, so someone might be measuring this somewhere?

Following on from my earlier post, here are a few more sites, this time from east of Adelaide (Murray Bridge, Monarto, Callington), showing the impacts of the 'green drought'.

And these are all considered to be relatively drought tolerant species - mallee box, sheoaks, Callitris, olive trees...

Depressing pics of remnant pink gum & SA blue gum woodland on the Fleurieu Peninsula in South Australia.

This 'green drought' is caused by record low rainfall followed by some winter rain. Here we are seeing vegetation change in progress, caused by rapid climate change.

The green drought: June rainfall has come too late to offer relief to farmers in southern Australia The winter crop growing season requires three days of steady rain – but many inland parts of southern Australia did not receive an autumn break this year

www.theguardian.com/australia-ne...

Unusually vibrant bark in Eucalyptus maculata (spotted gum) at Currency Creek Arboretum.

Known as 'ginger syndrome', it is caused by the bark overheating and desiccating from severe drought stress. It will be interesting to see if these trees recover or continue to deteriorate after some rain.

Eucalyptus crebra (narrow-leaved red ironbark) in the Warrumbungles of central NSW.

Eucalyptus camaldulensis subsp. camaldulensis, characterised by its distinctly-beaked bud caps, in which the caps have concave sides. This is the common 'Murray-Darling basin' subspecies of river red gum, and thus is sometimes known as Murray red gum. It occur thoughout the Murray-Darling drainage basin in NSW, Qld, Vic and SA, and extends westwards to Kangaroo Island and Eyre Peninsula in SA.

Eucalyptus camaldulensis subsp. arida, characterised by its more rounded bud caps, in which the caps have convex sides. It also sometimes has pruinose (waxy-white) branchlets, as seen in this pic. This is the inland subspecies of river red gum, and thus is sometimes known as the Centralian river red gum. It has a scattered distribution along larger ephemeral watercourses in north-western NSW, western Qld, northern SA, southern NT and westwards to the west coast in WA.

Eucalyptus camaldulensis subsp. acuta, characterised by its long-conical caps, in which the caps have straight sides. This is the north-eastern subspecies of river red gum, scattered through Qld and extending into northern NSW, where its distribution is poorly understood. Our fieldwork is helping to resolve the status and distribution of this subspecies in NSW.

Just back from three weeks of eucalypt fieldwork in NSW. The state has 3 subspecies of river red gum (E. camaldulensis), which differ from one another most notably in the bud shape.

🔲⬛⬛ subsp. camaldulensis
⬛🔲⬛ subsp. arida
⬛⬛🔲 subsp. acuta

6, 9, 12 and 18 month rainfall deciles for South Australia. Lots of red across southern SA for whatever time-length you pick.

Rainfall maps offer ominous insight where Australia's climate is headed As South Australia and Victoria continue to face drought and unseasonable heat, there has been a notable absence of major rain systems. So, what's going on?

Why it's currently so dry across southern SA and western Vic, and the long-term prognosis for similar conditions:

www.abc.net.au/news/2025-05...