Wednesday, 30 January 2008

Ochre Archives Newsletter - Issue No. 8

Welcome to the eighth edition of ‘Ochre Archives’, our farm newsletter.

Feedback on Ochre Archives No. 7

Elizabeth Flann advised that she is having some success in establishing False Sarsaparilla (hardenbergia violacea) as both climber and ground cover in her new indigenous garden at Chelsea (Vic.). Elizabeth has several dillwynia growing as they make a hardy and attractive feature in a small garden. A friend of Elizabeth’s has even used them successfully to create a Japanese style garden and they look very effective among the rocks and stone sculptures. We have also managed to successfully transplant a seedling from the Middle Hill Paddock to under the mailbox out the front of the farm.

Tein let us know that early settlers used Sweet Sarsaparilla (Smilax glyciphylla) rather than False Sarsaparilla for tea making as the former is truly sarsaparilla-flavoured (very sweet and strong when nibbled). False Sarsaparilla has similarly coloured and shaped leaves. Both are weak twiners and occur in the same ecosystem type, however, the difference is that the Sweet Sarsaparilla has three main veins.

Derek from Quirindi has found that what we thought were native bees are in fact a type of hoverfly. He made the identification discovery by chance after finding what he suspected were their larvae all through their barley crop feeding on aphids.

Findings from recent trips to the farm
Trees and Shrubs

Mikla Lewis tells us the mistletoe in this photo is the common Box Mistletoe (Amyema miquelii), probably so-called because it grows on Eucalypts and especially Black Box, according to Plants of WNSW. It's also called drooping or stalked mistletoe and has a lovely red flower. We have only found one Mistletoe plant on Ochre Arch to date, and have been told by an environmental scientist that large numbers in concentrated areas can signify that the ecosystem is out of balance.

Our attention was drawn to the fact that the Silky Oak (Grevillea Robusta) tree near the house was flowering by the distinctive call of a Blue-faced Honeyeater.

Silky Oak is a native of NSW and Queensland and is now grown as a popular ornamental tree all over the world. The tree requires full sun for maximum flower development and is the largest of the Grevilleas reaching 30m tall in native areas. The timber is strong and silken in texture and used in cabinet making and craftwork.

To date we’ve located over 20 Angular (AKA Propeller Bush) Hop-bush (Dodonaea truncatiales) plants, two of which are fully mature at around 3 metres in height. The commonly used name is derived from the shape of the flowers – similar to the four pronged wooden propellers as you may be able to see in the photograph.

Last week we found a Deane’s Wattle (Acacia deanei) tree not far from Ochre Arch. It’s the first wattle we’ve come across on the place.

Many of the native plant species are seeding presently, and the ants are very actively creating mini-storage dumps, like the one you can see in this photograph.


We’ve come across 3 new bird species on Ochre Arch since the last newsletter:
• Australian Hobby or Little Falcon (Falco longipennis). These are almost exclusive on-the-wing hunters and in the stoop, a Hobby may reach speeds of well over 100km/h. Large females have been recorded taking Galahs, though their main prey species are smaller than this. The Australian Hobby in the accompanying photo sat curiously watching us for well over half an hour as we were using the chainsaw to cut into sections a large tree that had fallen across a boundary fence.

• Emu (Dromaius novaehollandiae). Our neighbours to our east re-introduced Emu to their property many years ago and over time the numbers have grown. It’s not unusual for us to come across an Emu on our place and we enjoy watching their antics. The Emu is the world's third largest bird, after the Ostrich and the Cassowary. The nest of an Emu can be up to 1.5 metres wide.
• Black Falcon (Falco subniger). These impressive avian predator birds are uncommon and their main stronghold and breeding region is thought to be SE Queensland and NW Victoria. After breeding the birds migrate and disperse across most of eastern Australia and north-west across the Northern Territory to the Kimberley WA.
Our bird species tally currently stands at 68.

The Crested Pigeons that nest in our shed have just produced more offspring. Mikla tells us “They nest anywhere and anytime and make good 'fodder' for raptors, which is just as well because they are one of the 'increaser' species.”

Grasses and Forbs
The rains through November, December and January, coupled with an absence of stock have resulted in Ochre Arch having a reasonable cover of vegetation. Here’s a photo taken in the Spring Paddock. The primary pasture species you can see is Hairy Panic (Panicum effusum).

The taller couple of plants visible in the foreground of the photo you can see are Redgrass (Bothriochloa macra)

There was a colourful cover of native Yellow Burr-daisy (Calotis lappulacea) during late spring across the southern end of the Forgotten Paddock. You can see one of the plants in flower in the accompanying photo.

Here’s a photo of a single Small Grass Burr (Tragus Australianus) taken near the front gate. The species colonizes on bare ground.

On a recent return to the farm we were confronted out at the verandah by what is arguably an Australian wildlife conservationists ‘enemy number one’. This natural killer was incredibly quiet, and we are not sure whether this was due to having been dumped or purely to temperament and lack of previous contact with humans.

Rock Formations
The aspect of the rock formation in this photograph that captured our attention was not so much the shape but the realisation that with little more than a light shower of rain it creates a small but valuable temporary water point for fauna in its vicinity.

During one of our walks we came across the granite rock formation you can see here – a circular pattern with a centre hole.

A friend of ours near Quirindi, John P., is studying geology so we emailed him a copy of the photo seeking comment. His much appreciated response reads: “The rock photo is indeed interesting, raising some questions that cannot be answered from the photograph 'per se'. The regular hexagonal / polygonal cross-section reminds of magma cooling joints (hot rock shrinks) that form normal to the gravitational flow. However, such are typical of low-viscosity flows (eg. mafic ('black') basalt) and not of highly viscous rhyolitic or crystalline felsic ('white') granitic material. And one would expect to see a whole lot of such surrounding the rock in the photograph. That is, one wouldn't get just one column (hence, "columnar jointing") by itself.

The rock in the photo may come from the cooling of expelled late / residual melt mush (eg. aplite; material high in volatiles and/or silicate incompatible elements), but again, one would expect such low viscosity expressions to result in many cooling joints. Late melt rocks are generally found at the top of the oblong / ellipsoid plutons. (Here I am still assuming that the rock is essentially granitic in composition
- this may not be so. A sample is needed).

Another unusual feature is the hole in the middle. If not made by aboriginals, it might evidence material / mineralogy vulnerable to weathering on the Earth's surface. Further, the rock might be one large feldspar crystal (unlikely).”

We’ve yet to send John a sample or search for similar formations in the surrounds. If the formation was made by Aborigines it would be neat to know what the purpose was.

Community Working Together
In late October a local bloke (ex-farmer) delivered some materials to us. Just before reaching Ochre Arch he’d noticed some smoke rising from a creek on a neighbours place, only a few hundred metres from our boundary. On investigation he and Phillip realised that no one else was aware of the fire so contact was made with the neighbours, including the local fire Captain. Within 10 minutes or so there were 20 local farmers on hand, all working on putting out the fire. We were all very fortunate in that the conditions were such that the total area burned was contained to only a couple of hectares. A few learnings included:
• Two of the golden rules in fire fighting are ‘Don’t panic’ and ‘Try to be useful’
• The Bureau of Meteorology tracks EVERY lightning strike in Australia. A lighting strike caused this local fire.
• The Membership Application process to be become a volunteer with the NSW Rural Fire Service is somewhat arduous, but we’ve come through OK.

Out of curiosity
We are thinking of scoping setting up a structure enabling others to take equity in the stock we manage on Ochre Arch, with the returns being a share of the profits. One of the motivations is enabling the creation of stronger linkages to the land for those who might not have such an opportunity. If this sounds like something that might be of interest to you please let us know.

In Closing
Once again, feedback is most welcome, via email to

Kind regards… Phillip & Jan Diprose

Link to Ochre Archives - Issue No. 7

Saturday, 12 January 2008

Correlation between Rainfall and Elevation

Six months or so ago I analysed the data from the three climate monitoring sites closest to and surrounding Ochre Arch. These locations are Forbes, Quandialla and Grenfell. One observation was that the mean annual rainfall at Grenfell (elevation of 410 metres above sea level) was 602 mm whilst Forbes (elevation 240 metres) was 503 mm and Quandialla (elevation 250 metres) was 521 mm. Given that the elevation at various points on Ochre Arch increases by approximately 100 metres (from 315 metres near the house to 415 metres at Lookout Rock) it struck me that there was a reasonable prospect that the rainfall on our place is greater at the highest point and that the order of magnitude would be around 20 %. We now have rain gauges near both the house and Lookout Rock and we are finding that we consistently measure 20 % more rain near Lookout Rock – especially in instances where the rainfall in the area is general rather than narrow storms and such like.

Following on from my previous post looking at temperature and elevation I decided to use the climate data from the locations in and around the landholder sites to see what the correlation was between annual rainfall and elevation.

In the accompanying graph you can see the results. The vertical axis represents both elevation in metres above sea level and mean annual rainfall in millimetres. The horizontal axis shows each of the locations – sorted by ascending elevation from left to right.

Whilst it would not be appropriate to conclude that what occurs in these locations could be expected to be experienced in locations in all regions the graph does show rainfall continuing to increase with elevation increase. At lower elevations the annual rainfall is a much higher multiple of elevation (roughly 3 times) whilst at the higher elevations the rainfall is a much lower multiple (roughly 1 to 1 at Crookwell). This suggests that the trend is likely to reverse at a certain point and a quick look at the data Guyra (elevation 1332 metres, annual rainfall 926 metres) tends to confirm this – although Guyra is in a totally different region.

Friday, 11 January 2008

Correlation between Temperature and Elevation

A mate of mine (David McL.) told me not so long ago that as a rule of thumb, all other things being equal, the temperature at different locations falls by 1 degree Celsius for every 100 metre increase in elevation. Thus a place that was 100 metres above sea level could be expected to be 8 degrees hotter than a place that was 900 metres above sea level.

I decided to put this concept to the test using real historical figures sourced from the Climate Online Data produced by the Bureau of Meteorology. The locations I selected are all on reasonably similar latitudes and are in or adjacent to the various local districts where (most of) the landholders live who are currently participating in a project I have underway in conjunction with the Lachlan Catchment Management Authority and Lachlan Landcare Network.

The approach I took was basically:
1. Source the climate data from the Bureau of Meteorology website for each location
2. Divide the elevation of each location by 100 to derive a temperature adjustment figure. Thus the adjustment figure for Ivanhoe at 85 metres above sea level is 0.85 (degrees C) and the figure for Frogmore given it is 500 metres above sea level is 5 (degrees C).
3. Add the respective adjustment figures to various temperatures (types) for each location to derive an ‘adjusted temperature’ figure. Adding the adjustment figure to the actual temperature in this way is in effect theoretically determining what the temperature would be at sea level – as a common denominator.
4. Analysing the results for various temperature types (such as maximum temperature, mean maximum temperature, mean minimum temperature, and lowest temperature) to test the hypothesis that the temperature falls by 1 degree C for every 100 metre increase in elevation.

My conclusion from the above analysis is that there is a very strong correlation supporting the hypothesis when using data for the mean maximum temperature. The correlation in the data was not nearly as good for the temperature types: maximum temperature, mean minimum temperature, and lowest temperature.

The accompanying graph shows the annual mean maximum temperatures (degrees C) for each of the locations I selected (line at the top of the blue shaded area) together with adjusted mean maximum temperatures (top line of the graph). The maroon shading represents the amount of the adjustment that was applied in degrees C. The vertical axis is temperature in degrees C and the horizontal axis shows each of the locations I selected. The numerical figure at the end of the name of each location is the elevation above sea level. As I’ve said previously the elevation figures were divided by 100 to derive the temperature adjustment figure. For graphing purposes I sorted the locations left to right in order of ascending elevation.

The key points from the graph are:
1. As the elevation increases the actual annual mean maximum temperatures decline (line above the blue shading)
2. The amount of the decline in temperature as the elevation increases is in fact roughly equal to 1 degree C for every 100 metres. This is graphically demonstrated by the fact that the top line figure in the graph is virtually straight and level from left to right – across all elevations.

POST SCRIPT: After completing this post I sent a link to another mate, John F. who happens to work at the Bureau of Meteorology. He subsequently sent me a link to an article that explains some of the science behind the temperature change impact. Here is a link:

Thursday, 10 January 2008

Energy Consumption by Person / Vehicle Type

During the past couple of months I’ve come across some figures on energy output and consumption that I thought were worth sharing. Here goes …

Human V Oil / Coal Based Energy
The amount of energy in a litre of fuel is roughly equivalent to the amount of energy used by one man working 8 hours a day for 3.3 days.

Freighting Cargo
A litre of fuel will power the transport of 450 kg cargo over the following distances:
170 km by rail via freight train
17 km by road via freight truck
0.4 km by air via plane

My data source for the ‘Human Energy’ figure is David Marsh from a talk he gave at last year’s Carbon Farming Expo and Conference at Mudgee. The ‘Freighting Cargo’ numbers are from Fred Hays at the Center for Sustainable Resources in the USA. I’ve converted their figures as appropriate from gallons, miles and pounds to metric. (NB: One gallon in the USA equals 3.8 litres). Obviously there are a whole bunch of assumptions behind all of the figures. Whilst I’m sure one could spend plenty of time debating the specific magnitude of each calculation I doubt there would be much room for debating the overall fuel use rankings.

I don't have any figures on the amount of fuel required to transport goods via sea, however one suggestion that I read recently seems to have significant potential - using technology to set sails on cargo ships to leverage wind at appropriate times.

Fuel Consumption in Sydney each Tuesday
Fuel prices in Sydney and Melbourne vary of a weekly cycle, with Tuesday being the cheapest given consumers need to purchase is less. Prices are increased by the fuel outlet owners before and over the weekends to catch those consumers who need to top-up before going on non-work related trips and visits. The total fuel demand every Tuesday in Sydney is in the vicinity of 11 M litres, which approximates to the amount of liquid that would be held in 11 Olympic size swimming pools. On days other than Tuesday demand is around 5 M litres.
Given that the total population of Australia is now around 22 M this means that every Tuesday the fuel volume sold is roughly 0.5 litre for EVERY man woman and child in this entire country. Reflecting back on the amount of energy contained in each litre of fuel mentioned at the start of this post the amount of energy contained in the fuel sold in Sydney each Tuesday equates to the amount of energy that would be expended by almost 320,000,000 men doing manual work for one hour.