About Me

My photo
Canberra-based naturalist, conservationist, educator since 1980. I’m passionate about the natural world (especially the southern hemisphere), and trying to understand it and to share such understandings. To that aim I’ve written several books (most recently 'Birds in Their Habitats' and 'Australian Bird Names; origins and meanings'), run tours all over Australia, and for the last decade to South America, done a lot of ABC radio work, chaired a government environmental advisory committee and taught many adult education classes – and of course presented this blog, since 2012. I am the recipient of the Australian Natural History Medallion, the Australian Plants Award and most recently a Medal of the Order of Australia for ‘services to conservation and the environment’. I live happily in suburban Duffy with my partner Louise surrounded by a dense native garden and lots of birds.

Wednesday, 25 March 2015

Tierra del Fuego; the national park at the end of the world

Until recently, all I knew of Ushuaia, on Argentinian Tierra del Fuego, was that it claimed to be the world's southern-most city, and that it is the jump-off point for most of the Antarctic cruises. (I'm now convinced that their claim is justified; Chilean Puerto Williams, just across the Beagle Channel on Isla Navarino, is indeed just further south, but with only 2000 inhabitants can hardly claim to be a city; Ushuaia, with 60,000 people, certainly is.) 

Recently however I was going to be 'in the area' (really!) and decided we should extend our Patagonian trip to see what was there. It was one of the best decisions I've made. The town itself, facing the Beagle Channel, is a real surprise and a worthwhile destination in its own right, but you don't read these posts to hear about towns; just out of town is the world's southern-most national park, Parque Nacional Tierra del Fuego and we spent a delightful day there.
Ushaia is at the end of the red arrow and Tierra del Fuego National Park is immediately to the west,
bounded to the south by the Beagle Channel and the west by the Chilean border.
Don't think this means it is tiny however - the whole island covers 4.8 million hectares,
and the park is 60,000 hectares, extending inland (north) for 60 kilometres.

In a day we saw nowhere near the whole of the park - indeed you need to be prepared to do some serious mountain hiking for that - but we absorbed some beautiful Nothofagus (southern beech) forest, alongside the lovely Beagle Channel.
Zarathiegui Bay, Beagle Channel, above and below.
The channel separates the main island of Tierra del Fuego (the 'Isla Grande')
from the many smaller islands immediately to the south.
It runs 240km from the west (where it is entirely in Chile) to the east, where it forms the boundary between
Chile and Argentina - see map above. It was named for the survey vessel commanded by Robert FitzRoy (after the suicide of Captain Pringle Stokes) during the expedition of 1826 to 1830.
(It was on the follow-up survey, beginning the following year, that Charles Darwin joined him.)

Wind-shaped Magellanic Beech Nothofagus betuloides, on the shores of the channel.
Across the channel the mighty Andes emerge from the sea to extend for 7000 kilometres to the north.
The beginning - or end, depending on your perspective - of the Andes, across the Beagle Channel
from Tierra del Fuego National Park.
The old beech forests are superb; with a growing season of perhaps only a few weeks a year, they are venerable indeed. 
Looking through the Magellanic Beech to the Beagle Channel and the Andes beyond.
This is a very beautiful place (and no, it's not always sunny!)
The understorey is quite open; here there are mosses, ferns and saplings of Canelo (see below).
In these Gondwanan relics, you could easily be in Tasmania or New Zealand - and of course
they once all formed part of the same temperate rainforests.

Old beeches growing over mossy boulders.

Ancient beech bases, draped in mosses, with Fishbone Ferns Blechnum penna-marina
and Canelo seedlings.
Canelo or Winter's Bark Drimys winteri, of the very old Gondwanan family Winteraceae -
it is often described as close to being the oldest living flowering plant family.
The Australian native peppers Tasmannia are very closely related, and indeed until recently
were included in the same genus.
Until relatively recent times when citrus was identified as a source of Vitamin C to combat scurvy,
ships rounding the Horn would take on loads of Canelo bark as an antidote. The first to do so was
John Winter, captain of the Elizabeth, accompanying Francis Drake in the Golden Hind in 1577 - hence the
scientific name and English common name. (But how he knew, I can't imagine.)

Clearings such as this one can be carpeted with orchids in summer.

Dog Orchid Codonorchis lessonii, above and below.
This is a very common Patagonian orchid, supposedly named for its scent, though I've not noticed it!

Beech Orange Fungus, or Pan de Indio (Indian Bread) Cyttaria harioti.
Darwin collected these and when Joseph Hooker of Kew Gardens recognised them as being very similar to
beech fungi from New Zealand and Australia, they began to postulate a former great southern continent.
As the Spanish name suggests they were indeed eaten, in considerable quantities, by indigenous
Patagonians, who also brewed an alcoholic beverage from them. 
I've tried the fungi (though not, sadly, the beverage) and it's not too bad.
The fungus uses a chemical to form the massive gall in which the fungus lives and feeds,
and from which it produces the spore bodies (the 'oranges') in summer.

Holly-leafed Barberry Berberis ilicifolia Family Berberidaceae, is one of many barberries found in Patagonia.
The berries of many are used for jams and liqueurs.
Rainberry Rubus geoides, Family Rosaceae.
Birds are fairly prominent in the forests and on the channel.
The Southern Giant Petrels Macronectes giganteus in Zarathiegui Bay, above and below, were as
numerous as I've ever seen them anywhere.

The South American 'geese' that dominate many Patagonian landscapes are actually closer to the shelducks.
These Ashy-headed Geese Chloephaga poliocephala are among the most striking of them.
Two old passerine groups, the sub-oscines, dominate in South America, though are barely known elsewhere in the world; representatives of both the funariids (oven birds) and tyrant flycatchers are present in Tierra del Fuego National Park.
Dark-bellied Cinclodes Cinclodes patagonicus, a common funariid.

Tufted Tit-tyrant Anairetes parulus, a tyrant flycatcher which, unlike the cinclodes,
is found along the entire 7000km of western South America.
Mammals are certainly present, though not readily encountered. One species however, the North American Beaver, has become a serious problem since being introduced in the 1940s to try to start a fur trade. Numbers in Tierra del Fuego have been estimated at tens of thousands, and huge areas of native forest are under threat as trees fail to recover from being felled (the local species tend not to coppice), and are drowned by raised water levels from beaver dams. Control measures have begun, but it's a huge job.
Beaver lodge (no longer occupied) with drowned trees, Tierra del Fuego National Park.
But we need to end on a happier note, and this magnificent weevil seems appropriate for the role.
Weevil, Lago Roca. We were told that local people had regarded it as sacred, but I can't find any information on that.

Yes, I know it's a long way to the end of the world, but it's worth it! And if you find yourself in the vicinity of Ushuaia, do drop into Tierra del Fuego National Park too - it'll be well worth your while.


Wednesday, 18 March 2015

Some Acacia Curiosities; wattle they think of next?

Acacias are fundamental to Australian landscapes, though we sometimes forget here that they are equally characteristic of many African ones. 
Mulga Acacia aneura woodland, Chambers Pillar, central Australia.
Acacia woodland, Murchison Falls NP, Uganda.
The minor tensions generated between Australian and African botanists by our tendency to think of acacias as 'ours' came to a head in 2003 with a proposal from a couple of Australian botanists to change the type specimen of Acacia from an African one to an Australian one. This was breathtakingly cheeky, with very little precedent, and was based on two factors. The first was the growing acceptance that Acacia as traditionally used for plants across Africa, Australia and America (and a few other places) was an artificial genus, comprising at least five distinct genera. The second is the fact that the majority of Acacias are Australian (some 1000 of the 1300 known species) which would have involved a massive task in changing names here. After consideration by subcommittees the proposal to change the rules in this case was ratified by the International Botanical Congress in Vienna in 2005, but challenged on procedural grounds. After another sometimes bitter six years the original decision was upheld at the next Congress in Melbourne in 2011.

However for some it didn't actually end there, with a number of influential botanists preferring to go on using Acacia in its broad sense and ignoring the Congress rulings. I don't share the sense of triumphalism some in Australia were displaying after the decision, and have sympathy with these bolshie botanists - if we can change the rules for one circumstance, we can do it whenever it seems convenient in the future. I can't help but think this might come back to bite us one day.

For the record, African acacias are now either Vachellia or Senegalia. Both these genera are also significant in South America, along with smaller genera Acaciella and Mariosousa. A few species of Vachellia and Senegalia also occur in tropical Australia. Had the normal rules been followed, the rest of Australian acacias would now be Racosperma.

Anyway, what I really wanted to talk about was the way Acacia foliage in Australia has evolved so differently in Australia from elsewhere (and for now for simplicity I'm going to continue to refer to Acacia in the older broader sense but to avoid controversy I'll use lower-case acacia as a group name!). In both Africa and America acacias are typified by divided - pinnate - leaves.
acacias in northern Cameroon (above)
and near Machu Picchu (Peru) below.

Many Australian acacia species - though a definite minority - also have compound leaves, with foliage ranging from having just a few pinnae (leaflets) to scores.
Acacia spectabilis Goobang NP, central New South Wales
Acacia elata, coastal New South Wales

Acacia deanei Goobang NP, central New South Wales.
Most of these leafy acacias live in moister parts of Australia; an advantage of compound leaves is that they confer a larger surface area which enables higher levels of photosynthesis, but the trade-off is in greater water loss.

Accordingly a very large number of Australian acacias, especially in drier situations, have done away with their leaves altogether, at least as adult plants. However, it's of course not that simple - if you're a plant you need leaves to photosynthesise, and there's no using conserving water if you can't function. So the compromise solution has been the evolution of phyllodes in Australian acacias (phyllodes are not unique to acacias, but they are probably most dominant there). A phyllode is a petiole - a leaf stalk - which has shed its leaf, flattened out and taken chlorophyll on board to take over the photosynthetic role. In acacias the phyllodes tend to hang down or stand stiffly erect to minimise exposure to the sun, and are tough and leathery (like a eucalypt leaf) to minimise water loss. Here is a small sample of the numerous phyllode types that Australian acacias display.
Acacia anceps Eyre Peninsula, South Australia

Acacia floribunda, south coast New South Wales

Acacia hakeoides Goobang NP central New South Wales

Acacia inaequalitaria Kata Tjuta NP, central Australia
Acacia monticola Ormiston Pound, west MacDonnell Ranges, central Australia

Acacia pycnantha Canberra.
This is Australia's floral emblem, Golden Wattle

Acacia retivenea Bladensberg NP, tropical central Queensland

Acacia spondylophylla Ormiston Pound, west MacDonnell Ranges, central Australia
Acacia triptera Goonoo NP central western New South Wales
The hard spiky phyllodes on this last species, known as Spurwing Wattle, raise another interesting difference between Australian and other acacias; you'll note the Cameroonian and Peruvian species above both sport savage thorns (though they're less obvious in the Peruvian photo). Here are a couple more examples.
northern Cameroon

Acacia (Vachellia) rorudiana, Santa Cruz, Galápagos
Thorns, botanically, are modified pointed branches, complete with their own vascular system, which cannot be removed without tearing the wood; Australian acacias don't have them. It seems equally odd that they either never evolved them in the face of the large browsing herbivores which inhabited Australia until relatively recently while most of their relatives elsewhere did, or that they all lost them at some point in the past. Neither makes much sense to me. 

However there a number of spiky Australian acacias, most of which rely, like the Spurwing Wattle above, on toughened sharp phyllodes.
Acacia genistifolia Canberra
Acacia tetragonophylla south-west Queensland.
This is known as Dead Finish, the logic being that if it dies of drought, there's no hope for anything else.
Other plant parts also provide protection however for some species.
Acacia paradoxa Canberra.
In this one - Kangaroo Thorn - the spikes are stipules, growing from the base of the petiole.
Acacia spinescens Lincoln NP South Australia.
Here the branches themselves are spike-tipped. (Technically I suppose they could thus be thorns,
but that usually refers to smaller branches growing off the main ones.)
And there's another thing...
Acacia mearnsii Canberra.
Note the glands along the branch.
Such glands are common in African species, where they attract aggressive ants which defend the plant. In Australia however this does not seem to be the case, though you can find some websites which should know better asserting that it is - they have simply used African data. The Australian glands do exude small amounts of nectar (which acacia flowers do not) which attract a range of insects, including ants but not for the most part insect-hunting ants which would protect the plant. A lovely mystery to be solved...

And we could go on, but before I instead wrap up for today, let's return briefly to phyllodes. I've been asked, quite reasonably, how I know they aren't actually leaves? Well, there are doubtless some physiological reasons, but the best answer is "because we can see it happening".
Acacia rubida Redstem Wattle, Canberra.
Many acacias begin life with true divided leaves - perhaps because maximising photosynthesis is the top priority in the early establishment phase - then switch to phyllodes, water conservation being the long-haul imperative. In Redstem Wattle it is particularly evident. At the bottom of this sapling are the juvenile leaves, at the top are pure phyllodes. But halfway up, look carefully at the phyllode on the right of the stem. The compound leaf is still growing from the end of petiole, which is flattening and becoming a phyllode beginning from the base. On the bottom left petiole the process is just beginning.

The wonderful wattles - like everything else, there's much more to them than immediately meets the eye.


Wednesday, 11 March 2015

Mount Field, a Tasmanian Treasure

Back in 1885, just 13 years after Yellowstone National Park in the USA became the world's first national park, and only six years after Royal National Park in Sydney became Australia's first and the world's second, Russell Falls Reserve, 60 kilometres north-west of Hobart, was also declared (under the Waste Lands Act 1863!). The concern was primarily for protection of the scenery, as a basis for passive recreation. The 120 hectare reserve included both Russell and Horseshoe Falls at the foot of the mountain.
Russell Falls, set in wet forest and surrounded by Tree Ferns and with a
Blackwood Wattle Acacia melanoxylon growing in the stream.

Horseshoe Falls, near to Russell Falls and on the same walking track.
People visit the falls and forests for recreation now, as colonial Tasmanians did in the 19th century.

For those unfamiliar with Australia's geography, Tasmania is the island state off
the south-east coast, separated from the mainland by Bass Strait.
Mount Field is here indicated by the end of the red arrow.
In 1916 Mount Field and Freycinet Peninsula on the east coast were simultaneously declared the first national parks in Tasmania under the new Scenery Preservation Act. The mount - and subsequently park - were named for the wonderfully monickered Barron Field (very Dickenesque!) who came to Australia to take up a post as judge of the Supreme Court of New South Wales. He is better known however as the author of the 12 page best-seller First Fruits of Australian Poetry, though one might reasonably think some of the fruits to have been significantly over-ripe. As far as I can tell he never went to Tasmania.

The change in vegetation from near sea level at the entrance station to 1000 metres higher at Lake Dobson is dramatic. At the base the wet eucalypt forest is dominated by huge Eucalyptus regnans (Swamp Gum in Tasmania, Mountain Ash across the strait in Victoria) and E. obliqua, Messmate Stringybark. Swamp Gum (when in Rome...) is known as the world's tallest flowering plant and second only to Coastal Redwood Sequoia sempervirens of California; the tallest known specimen, from Victoria, was 132 metres high. The ones on Mount Field aren't of that stature, but are ancient and massive.

Swamp Gums over Tree Ferns, Mount Field

Massive base of ancient Swamp Gum
Swamp Gum 79 metres tall, Mount Field.
These forests drip, as evidenced by the height of the trees and the understorey.
Soft Tree Ferns Dicksonia antarctica and mosses, both of lineages far older than the eucalypts'.
Further up the mountain are temperate rainforests, though the eucalypts, especially the Messmate Stringybarks, penetrate their lower levels.
Messmate Stringybark base, growing in Sassafras (Atherosperma moschatum), family Atherospermataceae,
of old Gondwanan stock.
Messmate is of historic interest, as the first eucalypt to be scientifically described, having been collected
at Adventure Bay in Tasmania on James Cook's third expedition in 1777.
The specimens were lodged at Kew Gardens where they were studied by French botanist
Charles Louis L'Heritier de Brutelle.
A feature of the Tasmanian rainforests is the presence of pines of old Gondwanan families.
Celery-top Pine Phyllocladus aspleniifolius, Family Podocarpaceae, Mount Field.

Underfoot in the rainforest, mosses become even more dominant.
Mosses, Mount Field rainforests, above and below.

Then near the top of the mountain are sub-alpine woodlands, dominated by the endemic Tasmanian Snow Gum Eucalyptus coccifera.

Old Tasmanian Snow Gums, Wombat Moor, Mount Field.
 I love the name Wombat Moor! The understorey to these snow gums is the evocatively - and utterly inaccurately! - named Pineapple Grass, actually a lily Astelia alpina Family Asteliaceae.
Pineapple Grass under Snow Gums, Wombat Moor.
Outside of these Snow Gum stands, the moor is largely treeless (as a moor should be!)
Wombat Moor, Mount Field.
The start of the long walk to Lake Belcher passes through here.

Nearby however is a much shorter walk, and to my mind the loveliest in the park. The Pandani Grove walk passes through woodland around delightful little Lake Dobson; on these sheltered slopes the trees grow thickly and there is a rich understorey. The Pandani reference is to a big heath Richea pandanifolia, called Pandanus in Tasmania, though totally unrelated to the true pandanus of the tropics. Here are some highlights of this walk.

Pandanus growing in White Peppermint Eucalyptus pulchella woodland, Lake Dobson.
Pandanus in a rainforest pocket of Myrtle Beech Nothofagus cunninghamii, Lake Dobson.

Tasmanian Snow Gums, Mount Dobson.
New bark, above, and by the lake below.

Old Pencil Pine Athrotaxis cupressioides Family Cupressaceae, on the shore, Lake Dobson.

Pandanus buds, Lake Dobson.

Another heath, Trochocarpa thymifolia, Lake Dobson

And another,  Cyathodes petiolaris.
All three of these heaths are Tasmanian endemiics.

Yet another Tasmanian endemic, Lomatis polymorpha, family Proteaceae.
This high level of endemism is typical of islands, and it is certainly true of Tasmania, yet another reason to visit.

You can make an easy day trip from Hobart to Mount Field - as we did on this occasion - or better still you can camp on site. Whatever you decide, your Tassie trip will be deficient if you don't spend at least a few hours there.