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I've been a Canberran since moving here from Adelaide on the first day of 1980. I now live in suburban Duffy with my partner Louise Maher, ABC 666 radio and on-line journalist. Among my early memories is following Sleepy Lizards (Shinglebacks) around the paddocks north of Adelaide, guarded by the faithful bull terrier. I have always been passionate about the natural world, trying to understand how it works, how the nature of Australia came to be, and sharing those understandings. My especial passions are birds, orchids and mammals. I am now a full-time naturalist, running bush tours, writing books etc, doing consultancies, presenting a regular radio slot on local ABC, chairing a government environment advisory committee and running adult education classes. I was awarded the Australian Plants Society Award in 2001 and the Australian Natural History Medallion in 2006, both for services to education and conservation. As part of my fascination with our Gondwanan origins I've been running tours to South America for the past few years.

Thursday, 23 June 2016

San Pedro de Atacama; an astonishing part of the world. Part 1, Deep Desert.

The far north of Chile is some 4,500km from the cold wet windy south - but in some ways it feels even further. The mighty Atacama Desert is unlike anywhere else on earth, though near to the sea it has similarities with the Namib of south-western Africa, centred on Namibia (which takes its name from the desert). Both have a cold current - the Humboldt in the case of the Atacama - hard on-shore, which doesn't give rise to moisture-bearing air masses. (On the west coast of Australia the desert also comes to the coast, but it isn't as arid and is vegetated.) What makes the Atacama unique however is the fact that it rises to over 4,500 metres above sea level (masl) across substantial areas in the Andes, though some people would technically exclude the arid Andean slopes from the definition of the desert. The Andes exacerbate the aridity by intercepting clouds moving west from the Atlantic across the Amazon basin.
A typical Atacama scene near San Pedro de Atacama.
There is no vegetation at all across vast expanses of the desert; in this area for instance the annual
rainfall is just 40mm, half of which is expected in January.
The three winter months (June to August) average exactly zero...
And there is something surreal about the backdrop of snowy peaks.
Most visitors are likely to fly into Calama on the Rio Loa, then drive the 100km south to San Pedro. Calama exists solely to support the world's largest copper mine, Chuquicamata, and unless you have business there, there is really no reason to linger. San Pedro is a much pleasanter town of some 5,000 people, built at 2400masl (a comfortable altitude for most people) on an oasis which is based on an aquifer originating in the high Andes and nearing the surface in the dry bed of the Rio Grande. It was inhabited at least 3000 years ago when it acted as a rest stop on the trading route to the highlands. It has been described as ‘the gringo gathering point of northern Chile’ and the main streets comprise mostly bars and souvenir shops - I am not surprised to find that I don't have any photos of it. However, we don't go there for its own sake, but as a base to explore the surrounding desert.
The arrow indicates the approximate position of San Pedro de Atacama,
at 2,400 metres above sea level on the Atacama Plateau.
The unvegetated expanses are hard to comprehend at first, even to someone like me who has spent quite a bit of time in deserts - I've always known that there are 'deserts and deserts', but I think you have to really experience the Atacama to appreciate the truth of that.

It seems extraordinary that people have been present in this harsh landscape for many centuries, but as mentioned above oases like San Pedro have long enabled trade routes to pass through the Atacama. And when the Inca Empire pushed south into Chile, their famed roads which took traders and messengers throughout the empire pushed even through the forbidding Atacama.
Inca Road, marked with rocks (for scores of kilometres) near San Pedro. There was no need to seal roads here
(unlike the amazing paved roads through the Andes, such as the Inca Track near Machu Picchu), but
they did need to be clearly defined. I muse on whether it would be worse to be an Inca runner here,
or in the high cold mountains.
The ever-present mountains are another remarkable aspect - and the Andes are still growing as the Nazca Plate (under the Pacific Ocean) shoves its way under the South American Plate, and the volcanoes are either potentially or actually still active. 

Sunrise through a haze of mist - it's hard to imagine there could be moisture in the air - from San Pedro.

Volcano Lascar.

Volcano Lascar from a different angle - with smoke wafting from the crater.
And in that last photo something different appears - vegetation, even trees! Tamarugo is a pea, Prosopis tamarugo, which remarkably can grow in the total absence of rain, relying on dew and deep tap roots into water tables.
Tamarugo - old tree (above) and close-up (below).


Partially excavated Tamarugo root, Pampa de Tamarugo NR (further north in Chile).
Various species of chenopods (or saltbushes) grow as an understorey to the Tamarugo, or on their own. 
Tamarugo woodland and chenopods, west of San Pedro.
As you might expect, wildlife isn't obvious, but it certainly exists, especially near settlements, which are associated with oases. 
Female Greenish Yellow-finch Sicalis olivascens, Socaire.
Yellow-finches are now understood to be tanagers; this species occurs in flocks in the Andes.

Great Thrush Turdus fuscater, another high country species, though this one is more often encountered
in wetter habitats. It is well-adapted to urban living.
Guanacos Lama guanicoe, above and below, west of San Pedro.
They are far less common than in past times, and nowhere near as abundant in the
north as they are in the far south. More on them here.
 

There is in fact one habitat in this part of the Atacama which hosts a wealth of wildlife, but that's the topic of next week's posting.

Most visitors come for the desert scenery, and a tour of the Valle de la Luna (the Valley of the Moon) is on everyone's itinerary - and for good reason! It compromises a huge amphitheatre with jagged rock formations, and vast areas of gleaming salt from a long-gone age when there were lakes here; now no rain has fallen here in the time of a European presence. Here are just a few of very many images that I could have offered you.

Close-up of the salt surface. It can be near-blinding in the full sun.

A typical scene from within the amphitheatre, looking out to the Andes beyond.

Salt-crusted rocks come in a variety of forms, from massive domes...

... to strange twisted remnants of outcrops. This one is known as Las Tres Marias.
A striking juxtaposition of red sand dune and salt field, which resonates with an Australian.

A panorama incorporating some of the above themes.
Many of these tours are timed to end at sunset, absorbed from an extensive lookout area along cliff tops looking out across the plains to the Andes through more than 180 degrees. These photos don't need explanations. They are offered in chronological order, taken over a period of 17 minutes.








The Atacama is a grand and magnificent adornment to the world, and the San Pedro area is as good an introduction to it as any. And next week I shall conclude this visit to it with a look at two very different and unexpected features - lakes!

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Wednesday, 15 June 2016

Eremophilas; the desert lovers

I am on record as being a passionate orchid-lover (even an orchiholic) but other groups of plants put up a pretty good case for my affections too. I love arid lands (which is as well for an Australian!) where there tend not to be orchids; here there is little doubt as to the subjects of my unashamed - or only a little bit ashamed - favouritism. 
Crimson Turkey Bush Eremophila latrobei, near Windorah, south-west Queensland.
Eremophila means 'desert lover' (what a wonderful name) and the great German-Australian botanist
Ferdinand von Mueller named this one for 1850s Victorian Lieutenant Governor Charles La Trobe.
This is slightly ironic as Victoria is the only mainland state where it doesn't grow!
Eremophila is a large genus of woody shrubs (and a few small trees) found solely in Australia; the only New Zealand species, the prostrate E. debilis, appears to have been introduced from eastern Australia. There are over 220 named species, with at least another 40 awaiting description. Some have small distributions, most live in remote areas. As I have suggested they are consummate arid land survivors, though they may be found in a variety of habitats, including sand dunes and stony ranges.
Rock Fuchsia Bush E. freelingii, near Alice Springs, central Australia.
Arthur Freeling was South Australian Surveyor-General through the 1850s, and
may have collected the specimen which von Mueller named.

Desert Fuchsia E. gilesii, east of Uluru, central Australia.
Named for the great 19th century desert explorer Ernest Giles, who collected the type specimen.

We have already noted a mix of common names for the group; these include Emu Bush (for the erroneous belief that emus avidly seek them out and are responsible for triggering their germination in their gut), Fuchsia Bush (for the general flower shape), Poverty Bush (for the harsh environments where they are found) and Turkey Bush (probably referring to bustards or 'plains turkeys' in the same general context as Emu Bush). Some (including E. latrobei, above) are toxic to stock and are sometimes referred to as Poison Bush.

Until recently Eremophila was included with Myoporum (and some smaller genera) in the family Myoporaceae; now that whole family has been subsumed into the rather inelegantly named family Scrophulariaceae.

The genus name was bestowed by the eminent Scottish botanist Robert Brown, who sailed with Mathew Flinders on the Investigator from 1801 to 1805. He described two species of Eremophila  from specimens he collected, but both were in the same publication and unusually he didn't nominate one of them as the type species (the 'reference species' by which all later plants included in the genus must be tested). I find it surprising that this situation has not bee retrospectively corrected; for instance if in the future it was decided that that the 'joint type specimens' actually belonged to different genera, there would be no way of determining which would remain Eremophila! The two were named by Brown (who had no way of knowing how many there actually were) very sensibly as E. alternifolia and E. oppositifolia, respectively with alternate and opposite leaves of course.

E. alternifolia (above) and E. oppositifolia (below),
both in Whyalla Conservation Park, South Australia.


The flowers are tubular with five petals, surrounded by a shorter tube of five sepals - this can readily be seen in the photo immediately above. However there are two basic flower types, determined by whether they are pollinated by birds or insects. Insect-attracting species tend to be blue or mauve, occasionally white, and with two petals above (often pointing backwards) and three below, protruding to form a landing platform. Their stamens are usually short and enclosed within the the tube.
Turpentine Bush E. clarkei, near Paynes Find, central Western Australia.
Von Mueller named it for one William Clarke who funded the Western Australian expedition which collected it,
but I can't tell you much more about him I'm afraid.
This is a classic insect-pollinated Eremophila.
Here are some more.
E. christopheri (the incorrect form christophori is also often met with), Olive Pink Botanic Gardens,
Alice Springs. It is endemic to the southern Northern Territory.
E. freelingii (above) and E. gilesii (below);
these are close-ups of the shrubs illustrated above.
 


E. rotundifolia, Coober Pedy, South Australia - this species is almost entirely
restricted to that state.

Scotia Bush E. scoparia, Nullarbor Plain.
This one is found right across dryland southern Australia.
E. willsii, Uluru NP, central Australia, where it grows on red sand dunes.
It was named for William Wills, second in command of the famously disastrous Burke and Wills expedition,
in the year after his death.
Bird-pollinated Eremophilas on the other hand are red, orange, yellow or even green, with four upper petals and one lower petal which is bent back out of the way to deny insects a platform. The stamens usually protrude beyond the tube to contact the face and forehead of the bird. Several of the previous photos illustrate this option, as do the following.
E. forrestii, Mount Magnet, central Western Australia.
Von Mueller named this one for the impressive John Forrest, late 19th century explorer and politician.
Tar Bush E. glabra, Shark Bay, Western Australia.
A very widespread and familiar species, found in every mainland state.
Berrigan, E. longifolia, Uluru NP.
Another ubiquitous species found across the continent; it grows into a small tree.
Spotted Emubush E. maculata, south-west Queensland.
This hugely variable species can be mauve, blue, orange, red or yellow, and with or without spots!

Kopi Poverty Bush E. miniata, Norseman, Western Australia.
Pixie Bush E. oldfieldii, Nallan Station, central Western Australia, east of Geraldton.
Yes another named by von Mueller, this one for Augustus Oldfield, a British-born professional plant collector.
Crimson Eremophila E. punicea, Nallan Station.
The reason for the misleading common name is unclear.
After fertilisation the flower tube drops off and the hitherto relatively inconspicuous sepals grow and develop bright colours to draw attention to the fruits which are mostly bird-distributed.
Burra E. fraseri, Nallan Station; the flower tube has fallen away and the sepals are now very obvious.
This is yet another of von Mueller's, honouring one Malcolm Fraser - not the 20th century prime minister,
but an 1870s Western Australian surveyor-general.
I hope you've enjoyed this brief introduction to these truly beautiful desert-lovers as much as I've enjoyed presenting it. Next time you're driving the outback, keep a special eye out for them.
Bignonia Emubush E. bignonifolia, Windorah, south-west Queensland.
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