News [ 13 items ]
Plastic Free JulyPlastic Free July (PFJ) aims to raise awareness of the amount of unneeded plastic in our lives by encouraging people to eliminate the use of single-use plastic during July each year.
Single-use includes plastic shopping bags, plastic cups, straws, plastic packaging. Basically anything that is intended only to be used once and then sent to landfill. If refusing ALL single use plastic sounds too daunting this time, try the TOP 4 challenge (straws, plastic bags, plastic bottles & coffee cups).
Attempt to consume no single-use plastic during July
Remember it's not going to be easy! It is a challenge, not a competition!
Collect any unavoidable single use plastic you buy and share with us at the end of July
It is up to you how long you participate, we encourage you to do it for a month, but you might prefer just a day or week!
Australians send 1 million tonnes of plastic waste to landfill each year. Lets try and decrease that amount!
To go into the draw for 2 free raffle baskets containing lots of items to make going plastic free so easy, contact NNRC on 8558 3644, or put your name down when you drop in.
YACCA LILLAYACCA (Youth and Community in Conservation Action) is an environmental youth group set up to educate high school aged students about their local environment. YACCA Willunga was set up in the late stages of 2013 and has been running successfully, with the number of members, aged 11-16, skyrocketing. These members attend different schools and come from different environmental backgrounds.
Some of the environmental activities the Willunga group have participated in include planting days with Trees for Life and NRM, surveys along the Aldinga Reef with Reef Watch, water and macro-invertebrate testing along the perennial creeks in Willunga, trapping nights at Tatachilla Lutheran College and much more.
YACCA LILLA (Yankalilla) is hoping to run monthly after-school sessions using a similar format, with a partnership established between Normanville Natural Resource Centre, the Yankalilla Library, the Community Services team from Council and Corey Jackson, Coast, Estuary & Marine Officer for the Southern Fleurieu Peninsula.
YACCA LILLA will be staring at 4.00 pm on Wednesday 2nd August at the Yankalilla Community Centre.
At this initial meeting we will be having a visit from Radicool Reptiles where kids will be able to interact with some amazing wildlife.
Refreshments will be available and its all FREE!
For more info please call the NNR centre on 8558 3644.
Geology WalkIt was an excellent excursion on Saturday 12th April when 40 enthusiastic people ventured out to learn more about the fascinating rocks around our local area.
The Southern Fleurieu has a rock record extending back at least 1600 million years. So we started at Myponga Beach with an energetic scramble over some huge rocks to view interbeds of limestone and mudstone from the Sellick Hill Formation and then on to Carrickalinga Heads for a more leisurely stroll down to the beach to view the sandstone from the Carrickalinga Head Formation.
After a picnic in Bungala Park we headed to Little Gorge where we viewed gneiss and schist from the Barossa Complex and glacial tillite composed of conglomerate and sandstone from the Sturt Tillite.
Wirrina was another scramble of some boulders to see sandstone from Aldgate Sandstone, glacial tillite composed of conglomerate and sandstone from Sturt tillite and black mudstone from Tapley Hill Formation.
It was then time for a nice relaxing cup of coffee or tea and some delicious scones at Leonard's Mill which gave us time to digest some of the information swirling around in our brains.
The day concluded at Second Valley to view black mudstone from Tapley Hill Formation and limestone from Brighton Limestone.
Thank you to Dr Pierre Kruse for organising theevent and putting together a very interesting power point presentation which is available below.
Download the Slide Show Presentation
FREE HOME ENERGY AUDITInterested in finding out how you can reduce your energy consumption? Want to know how much your appliances cost to run? The Normanville Natural Resource Centre can assist you. The centre has two trained Home Energy Auditors who are available to visit your home to help you understand and reduce your energy consumption.
This is a free service available to all Yankalilla District Council residents. If you live outside this area a small fee is required to cover travelling expenses. The Home Audit takes between 1-2 hours depending on the size of your house and you are given energy saving recommendations at the completion of the audit.
Jules lives with her husband and two sons. Since having an Energy Audit her bills have gone down from $500 to $400 a quarter. "I was really surprised about how much the air con costs to run" it just eats up money! Before having the audit done, on hot days Jules would set the air con on the lowest temp to stop the inside of the house heating up. The auditor explained if we set the air con to an ordinary temperature, around 25C, it would save us a lot. Jules now makes good use of their ceiling fans and finds they do a great job.
Other cost cutting areas Jules has targeted include drying the clothes outside instead of using the tumble dryer and not leaving the beer fridge on all the time, just turning it on when needed e.g. for a BBQ. Another cost saver is not leaving appliances on stand-by. We also used to leave all our appliances on stand-by, it's just laziness really, using the remote. Now we try to turn them off at the switch as much as possible.
An Energy Audit can also raise awareness of how to select the most energy efficient appliances when replacing your old electrical ones and why choose water efficient shower heads. Please contact the centre to arrange a FREE audit.
All you need to know about snakes and more!
BATSIt was past midnight when my carriage turned into the gates of Castle Dracula. No lights shone from its windows. A tall old man, dressed from head to foot in black met me at the door.
And so began the Jonathon Harken diary of his visit to Castle Dracula, the gothic horror novel published by Bram Stoker in 1897, the story centred about the Transylvanian nobleman and sorcerer who claimed descendent from Attila the Hun.
This also marked the modern eras story-telling of vampires and their readiness to sink fangs into any available neck! The shape-shifting naughty nocturnal neck nibbler of the night strikes again! Curiously before publication woman's fashion dictated coverage from foot to chin with the neck totally encased. After publication, a total reversal with the neck fully exposed. Is there a message here?
The name bat is from the Middle English backe , borrowed from the Old Swedish natbakka, night bat, in turn taken from the Old Norse lethrblaka with the literal meaning of leather flapper.
In many western cultures bats are a symbol of the night, synonymous with vampires, and invoke a sense of fear and dread derived from the association with black magic and witchcraft. However this is not universal as in both Poland and Macedonia they are considered symbols of luck. Similarly in many of the Arab lands and China where they are considered symbols of longevity and happiness. Unfortunately with the largely Western negative view these critters have ended up with a much undeserved reputation. This has been somewhat reversed in recent years with the rise of the dynamic duo of Batman and Robin taking on all the villains of Gotham City, and as good always does, triumphing against the evil doers.
Bats like ourselves are mammals and they belong to the Order Chiroptera which has an ancient lineage. They are found world wide and comprise over 1240 individual species, which is approximately 20% of all the mammal species. In numbers they are the most numerous of mammals on the earth but still they go generally unnoticed amongst us. Within the mammals they are the only members capable of sustained flight and as a consequence are found world wide, except for the Arctic, Antarctica and a handful of remote islands in the Pacific Ocean. Along with the pterosaurs and birds, bats are the only known vertebrates to achieve powered flight.
They are broadly classified into two suborders, Megachiroptera (megabats) and Microchiroptera (microbats). As the name implies the megabats are large with a wing span of up to 1.5m and weigh 1.2 kg. In comparison the microbats are small and range down a wingspan of 15cm and weighing 2.5 gm. They are generally 'furry' but the microbats lack underfur. Whereas birds fly by flapping the entire forearm, bats in contrast only move the greatly extended thin and flexible 'finger' bones. This flexibility is achieved by a lack of calcium in the cartilage of the fingers allowing for a great amount of bending without fracturing. The wings stretched between the foreleg and hindleg digits is a very thin membrane of skin and although easily damaged it has the property of rapid healing. This thin naked membrane is the secret of the bats high manoeuvrability and precision in high speed flight which is far superior to that in the birds.
Some bats are solitary but most are social roosting in colonies which may number in the millions of individuals. It is not uncommon for bats to migrate over considerable distances to semi-hibernate in dens during winter when food supplies are limited. Both groups are considered to share a common ancestor although considered to have been a small nocturnal insectivore, happily hanging from the underside of branches and when necessary, took to the air exhibiting elemental gliding. The origin of this proto-bat is still the subject of an ongoing debate and remains unresolved despite employing DNA investigations of today's bats.
The bones of both groups are delicate and are rarely preserved in the fossil record. The oldest known remains were found in the USA during 2004 and are dated at 52.5 million years, placing it in the early Eocene time. An even older single tooth believed from a microbat was found in South America and dated to the late Cretaceous Period (prior to 66.5 million years ago). Luckily the vampire members do not get the blame for the dinosaur extinction at the end of the Cretaceous!
Broadly the Megabats are fruit or nectar eaters, while the microbats which comprise 70% of bats, are insect eaters, although there is some cross over. The large megabats are out and about around twilight but just hang out with their mates during the day in any handy tree. It is generally these we see and take notice of. Food is located by smell and well developed eyesight. The microbats in contrast are exclusively creatures of the night with a somewhat poor vision and rely upon echolocation for navigation and finding their prey in total darkness.
The fossil remains from the USA reveal the ear modifications for echolocation were not present indicating that this was an evolutionary development exclusive to the microbats. These bats generate an ultra sounds and the returning echo is interpreted by the brain as a detailed image of the environment allowing the bats to navigate, locate, chase and catch fast moving prey on the wing. Although barely audible to the human ear the intensity of the generated sound is measured at 130 decibels, making it one of the most intense airborne sounds in the animal kingdom. Cunningly muscles in the middle ear contract during signal generation thereby ensuring that they do not deafen themselves. A down side of this brilliantly evolved bio-technology is the system fails in rain due to interference.
The 'calls' are specific for different species, and once recorded and analysed they can be distinguished and identified similar to songs from different bird species. With the rise of robotics in the last few years there is currently considerable interest and research in the field of echolocation.
A major advantage of hunting at night is to avoid competition with birds and take exclusive advantage of the myriad of insects that emerge only at night. In the warmer months they are voracious insect eaters and can eat half to three quarters of their own weight in insects per night, considerably more than insect-eating birds. The microbats have evolved to take full advantage of this night time niche and research reveals some bats consuming up to 600 mosquitoes per hour. The ultimate 'mozzie zapper' for that barbecue! With such a track record they can truly be considered as Cheetahs of the night sky. And like their Mega cousins they simply cannot resist hanging out with their mates in some dark recess during daylight hours.
And on the subject of vampires, yes there are vampire bats which feed on blood and as such are unique amongst the mammals as the only ones that are classed as parasites. But relax there are only three species and among them is the Hairy-legged Vampire Bat (true) and this feeds on the blood of birds. A handful of bats are actually carnivores, this includes the Ghost bat in Australia which feed on other bats and another which is a predator of small birds.
As mammals they give birth to live young which are nourished with milk. Generally a single and furless pup is born in spring to early summer. Mum dutifully carries junior about for up to a week before the weight training becomes problematic at which time it is left at a roost site while mum is out feeding, returning to provide milk. It takes two to three months for the pup to become fully furred, a competent flyer, and take leave of mum. Bats normally live five to ten years, but may live up to 30 years.
Recent research in the vicinity of wind turbines has observed a significantly higher death rate of bats as compared to birds. The cause is currently unknown although it has been proposed that the rapid change in air pressure in the vicinity of the revolving blades may rupture the delicate lung membranes.
In Australia there are 90 species of bat of which 75 are the small insect eating microbats and overall they comprise 25% of all native mammal species. Locally within the Mount Lofty Ranges area 95% of the vegetation has been cleared since European settlement. Recent research has identified twelve species of microbat ranging in weight from 5gm to 60gm. Many species forage within different sectors of the forest structure thereby reducing competition amongst themselves. The clearing presents a double problem for the local micro bats. Apart from the loss of roosting places, particularly in tree hollows there has been the loss of safe foraging areas within a closed forest environment as opposed to open forests. Despite the potential problem of being classed as homeless they have adapted surprisingly well to our constructions including roof cavities and readily take up residence. The average feeding radius from the roost is 15km but may fly up to 50km in search of food. Whereas insect feeding birds will frequently not visit out to a single paddock tree many bats in contrast will visit and make full use of it.
The unrecognised presence of bats is highlighted by Dr. Lindy Lumsden, an Environmental Scientist from Victoria and president of the Australasian Bat Society. Several years ago Dr. Lumsden carried out field work on property in Northern Victoria and within a patch of remnant vegetation. The local landowner had lived there for 80 years and never seen a bat. Next morning he was presented with 50 bats of seven different species. Currently farmers in Australia and overseas spend a fortune on pesticides in an effort to control pests. Perhaps we should be giving more attention and consideration to our unseen ally. Bats are highly beneficial in most farming areas and more than likely play an unrecognised critical role significantly reduced insect numbers.
Although under pressure, in general the microbat population is faring better than some other mammals and birds. One species, the lesser long-eared bat, because of its slow ground-hugging flight unfortunately falls victim to both domestic and feral cats.
They are significantly impacted by poisoning, particularly from the organochlorine and organophosphate pesticides, however currently there is a lack of information on pesticide accumulation.
Bats are very dependant upon trees, the population size being restricted by the availability of roosting sites. These are in high demand with competition from possums, birds and feral bees. Adding to the problem, a bat does not use just one site, but rather multiple sites, and this is further compounded by some picky species requiring specific height above the ground, entrance and cavity size, and proximity to water.
Bats can be encouraged by;
Retaining remnant vegetation
Replanting vegetation, especially around crops in a rural setting
Erecting bat boxes
In tropical and subtropical areas bats have an important function as both pollinators of flowers and dispersal of fruit seeds. Small bats eat a range of insects including mosquitoes which are becoming a human health problem here in Australia as they extend their range southwards with global warming.
With the constant and increasing competition between ourselves and the crop pests (diamond back moths, coddling moths, locusts, aphids, thrips to just a few), coupled with the increasing demand for greener food products, an increased positive association between us and bats would seem a very sensible and appropriate solution given their beneficial affects around a variety of crops including orchards, vines and broad acre crops.
Do you remember "Millie"?
If not cast your mind back to the 2000 Olympic Games in Sydney. Millie the Echidna was our national mascot and in that brief time became known world-wide. It was a very appropriate choice given that the Echidna is the most widespread of the Australian native mammals. But even with all this attention there is still a veil of mystery with not much known about them.
Echidnas are commonly known as spiny anteaters and although resembling porcupines and hedgehogs from the northern hemisphere they are distinctly different. The similarities are the result of convergence; a process whereby two different organisms exploit the same environment and because of the adaptations evolve to look similar.
The scientific name is a mouthful; tachyglossus aculeatus. The name Echidna is derived from the Greek ekhis 'the mother of all monsters' half woman, half snake and mother to most of the Greek mythological monsters.
Echidnas grow to 50 cm long, 2.5-7 kg in weight. They have a distinctive elongated snout which doubles as both mouth and nose, a long tongue, which as the common name implies, is excellent for catching its staple diet of termites and ants. Nostrils are located at the end of the snout together with 400 or so electro-receptors to aid in food detection. The mouth is toothless and they have an excellent sense of smell. Characteristically they are covered in spines which are modified hairs, and these are progressively shed and replaced similar to our own hair. The spines are surrounded by fur, short on the mainland but more obvious in colder Tasmania where the fur may almost hide the spines. From the distance it has a distinctive awkward and somewhat clumsy gait which is more reptilian-like due to the shared feature of the legs at the sides of the body instead of beneath as in the marsupials and placentals mammals. Uniquely they have backward-facing rear feet which aids in the escape strategy by digging straight down into the soil and presenting any potential predator with a face full of spines. This digging ability served them well during the devastating Victorian bush fires. While tree stumps were still glowing and smoke drifting emergency workers reported Echidnas out and about, essentially unharmed accept for some melted spines.
Although still considered by many as primitive they have a large brain case and do in fact have the same level of intelligence as a cat. They are long-lived reaching 40 years or more.
The Echidna belongs to a small group known as monotremes, which together with the marsupials and placentals are classified as members of the Class Mammalia. The ancestor of these three, a proto-mammal, arose at approximately the same time as the dinosaurs, approx 245 million years ago, and were dispersed across the then united supercontinent of Gondwanaland. This land mass was the southern of the two supercontinents (the northern being Laurasia) and comprised todays Antarctica, South America, Africa, Madagascar, Australia, the Arabian plate and India. The progressive breakup of Gondwanaland commenced approximately 150 million years continuing until approximately 55-60 million years when the last two, Australia and Antarctica separated. It was shortly after the initiation of the breakup, 140 million years that the monotremes diverged from the main proto-mammal line. Later at 100 million years the marsupials also diverged from this main line.
The Echidna itself is currently believed to have split from a platypus-like water-foraging ancestor 19-48 million years ago and returned to the land. Since this family split, the platypus has survived essentially unchanged, a true aussie battler, a real survivor, but that is a story for another day.
The fossil jaw of one on these ancestors dated to 110 million years has been found at Lightning Ridge in NSW and is currently the oldest known remains.
The lore of Australia's First Nation People has another explanation on the origin.
Back in the Dreamtime, Echidna, like many other of the animals and birds of today, had a human form. Echidna was an old man who transgressed the law and aroused the anger of the elders. As punishment he was surrounded and speared multiple times so his back bristled with a mass of embedded spears, and his arms and legs broken. His wife Nunkito was so distressed at the news that she gashed her head with her digging stick until the blood flowed freely and stained her body. Later Nunkito was transformed into a robin and the red breast is an echo of that distant event. Old man Echidna although badly wounded had survived and crawled into a hollow log where he remained until all his wounds had healed. His arms and legs were now badly distorted explaining his now seemingly clumsy gait. Hands and feet were transformed into strong powerful claws. Despite the efforts of both himself and wife Nunkito, the spears could not be pulled from his body and today we see him out and about still bearing the mark of his punishment.
The monotremes are a unique group. Like their relatives the marsupials and placentals they are characteristically warm-blooded. All three provide their young with milk, but unlike the others the monotremes lay eggs. When the Scottish Naturalist William Caldwell announced this to the British Academy in London during 1884 it caused an uproar. This reptile/bird like trait is even the more intriguing given that the X sex chromosome is similar to that of the birds. On this basis some researchers propose that the ancestors of the synapsid lineage leading to the mammals and the sauropsid lineage leading to the reptiles and birds diverged some 315 million years ago.
Today the monotremes survive only in Australia and New Guinea. The iconic Platypus is found only in Australia. The long-beaked Echidna is restricted to New Guinea, while the Short-beaked Echidna is found in Australia and with a limited range in New Guinea.
Within Australia the Echidna is widespread, found from the mountain peaks, forests, grasslands to deserts. Solitary for most of the year they forage over a home range of 9-190 hectares (20-456 acres) which may overlap with a number of other individuals. Work on Kangaroo Island reveals a range of 40-150 hectares (88-330 acres). They are selective feeders and rotate through the home range foraging for up to 18 hours per day, travelling 1-2 km and excavating up to 1000 digs. In the process they contribute to soil aeration, the spread of mycorrhiza, nutrient mixing and seed germination. The Australian Short-beaked dines on ants and termites while the New Guinea Long-beaked seek out a wide variety of invertebrates including grubs, beetles, nematodes, invertebrate eggs, earthworms, insect larvae together with the ants and termites.
For the Australian Short-beaked the powerful claws come into their own, particularly to rip into ant and termite nests exposing the galleries of eggs. Here the long sticky worm-like tongue is ideally suited to the task of food gathering.
Given the opportunity Echidnas show a preference for a dense under story which provides not only protection but a warm dry area in winter and cool in summer. Caves, logs and rabbit burrows can be used as home.
As mentioned they have a large brain case with intelligence comparable to a cat. The neocortex in the brain is the site of higher mental functions and comprises 43% of the brain mass in the Echidna. On Kangaroo Island some have been observed foraging around the base of tidally inundated sea cliffs and display what can only be interpreted as an environmental awareness of tidal movements by regularly departing before they are cut off by the rising waters.
As an echo of their platypus cousin, they appear to be confident swimmers. Similar to the platypus the males have spurs on the rear legs but are non-poisonous. Within the eyes, cone structures are absent indicating no colour vision but they do have an excellent sense of smell. They are also capable of vocalisation with soft grunting sounds.
Echidnas are solitary by nature, do not fight or defend territory and basically ignore other individuals they encounter. However come spring and the females waft forth a pheromone courtship invitation. A number of males take up the invitation and form echidna courtship trains with a female in the lead followed by commonly two to six males. These trains may persist for one to six weeks during which time males can loose 25% of their body weight. Trains of a dozen individuals have been reported. Research by Peggy Rismiller on Kangaroo Island indicates that females only breed at 3-7 year intervals. After mating the males are observed to congregate for what could only be described as a post breeding blues bash!
Meantime after a gestation period of about 23 days the female lays a single egg directly into the 'pouch' where it remains for an incubation period of 10-11 days. The pouch itself it not a permanent pocket and milk is secreted through a number of non-localised mammary glands along the elongate edge of the 'pouch'. The young puggle, as they are called, is carried, and provided milk for 50-60 days at which time it has grown too big, not to mention the emerging spines!
Mother stashes the puggle away in a nursery burrow. However it is still totally dependant upon the mother for subsistence she will return every 5-6 days for a period of a couple of hours during which time the puggle can ingest up to 40% of its own weight in one sitting. As the mother leaves she blocks and conceals the entrance to thwart predators. This cycle is repeated for the next seven months until junior is weaned and ready to leave home. Field work on Kangaroo Island revealed one such individual fitted with a radio tracking collar travelled 40 km before settling down.
Despite all its strangeness the Echidna has been a real survivor. Its success has been put down to a controlled birth rate thereby preventing overpopulating and consequently not competing amongst themselves for the food resources. With their colour and shape they blend into the surroundings and are a master of camouflage. In fact they are not uncommon in urban areas but rarely seen.
With their intimidating appearance the adults present a prickly problem to any predator with thoughts of a quick a-la-carte meal. The adults and more particularly the highly vulnerable burrow young have a number of natural predators including goannas, quolls (native cats), Tasmanian devils, dingos and large snakes. Imported predators have a significant impact and include dogs, cats, foxes and feral pigs. Research work on Kangaroo Island reports a 20% loss of both burrow young and adults to cats.
Additional to this predation the Echidna Watch Program reports that 20% of all sightings are road kills. Although not endangered as yet the pressure is mounting with expanding development.
JUMPING JACKSA man in his 40's was cutting wood in the bush when he told his companions he had been stung by a jumping jack ant (Myrmecia pilosula). Suspecting an allergic reaction, he took 2 antihistamine tablets. His companions left him alone for 15-20 minutes only to find him dead on their return. He was alleged to have died from anaphylaxis resulting from the sting of the ant.
The sting of this species of ant, is responsible for more anaphylactic shock (severe allergic reaction) than any other Australian insect. More commonly know as jumper ant, jack jumper, jumping jack or hopper ants it has been coined these names due to is jumping action when aggravated, which is very easy to do.
Jumping jacks are on average 10mm-12mm long and are highly aggressive and fearless. They are black bodied with bright yellow mandibles (nippers), antennae and lower part of the legs. Excellent vision make them efficient lone hunters often straying long distances from the nest. Although carnivorous, there have been reports that the worker ants eat nectar and collect insects for the developing larvae.
These jumping jack ants are uniquely Australian although a rare species has been found in New Caledonia. Nests are not easy to find and are commonly a small hole in dry ground, about the size of a ten cent piece. They are sometimes found under rocks with their eggs being visible at the surface. The ants prefer to make their nests in dry open eucalypt woodlands but have adapted to make their homes in walls, cracks in concrete, rockeries, dry dirt and dry grassy areas.
Common reaction to jumping jack stings involves, burning, itching and redness at the site followed by local swelling with blister formation. Itching of the site can last for a week or more. An icepack and "stingose" can ease these symptoms. Other symptoms may include fever, elevated heart rate and a decrease in blood pressure. Symptoms will vary from individual to individual. In severe sting cases, anaphylactic shock can develop requiring immediate medical attention. Some signs of anaphylaxis are swelling, in particular the mouth and throat, breathing difficulties, chest tightness, nausea and confusion. There has been a link between some types of medication, e.g. blood pressure medication, increasing the chances of anaphylaxis when stung by a jumping jack.
It"s always best to live with our fellow critters, but in cases where yourself or a family member could be sensitive to this ants venom, it may be advisable to consult a qualified pest control operator in your region. These ants are a huge problem in Tasmania prompting considerable research into venom studies and allergy immunotherapy. If you suspect you are sensitive to insect venom, you can arrange with your doctor to have a blood allergy test performed from "Southpath Laboratories" Flinders Medical Centre, Bedford Park, SA 5042.
Once meeting these ants you will not forget them especially if have been stung. If you have found these ants in your garden or house, could you please contact the Normanville Natural Resource Centre 8558 3644. An informal study is currently being performed on these ants and knowing their distribution is valuable, particularly in the Normanville, Yankalilla and Carrickalinga areas.
SNAKES and SPIDERS FIRST AID WORKSHOPThe NNRC held a First Aid Workshop presented by David Hamilton from St. Johns, the topic was snake and spider bites and what to do if you get bitten. In both cases if the casualty is young or old get medical attention asap.
Snake and Spider Bites
Building Soil Carbon Workshop (Report of Workshop held)18th November 2010 Victor Harbor
Presented by Tim Marshall of T M Organics and Deputy Chair of the Organic Federation of Australia (OFA).
The project is supported by funding from the Department of Agriculture, Fisheries and Forestry of the Australian Government.
The workshop modules covered:
- Climate Change background
- Vegetation management
- Monitoring business and marketing
- Water management
The critical part of Tim's presentation was a relatively recent established fact that soil carbon in agricultural areas throughout the world, including Australia, have drastically declined with intensive agriculture. The situation has deteriorated more by the loss of topsoil as a result of wind and water erosion including slope instability following deforestation.
In Australia the pre-settlement soil carbon content was stabilized at 5% and this has now fallen to 1-2%. The lost carbon has been released into the atmosphere as carbon dioxide, CO2. According to Dr. Christine Jones, one of Australia's leading experts on carbon sequestration, "every tonne of carbon lost from the soil adds 3.67 tonnes of carbon dioxide to the atmosphere"
Exasperating the problem of atmospheric carbon dioxide are the results from a long term (50 years) research program of the University of Illinios which found that the use of synthetic nitrogen fertilizer lowered the soil carbon. Although the finger is almost invariably pointed at the burning of fossil fuels as the culprit for the rising of the atmospheric carbon dioxide content, the "poor" management practices relating to soil carbon are a very major contributor.
Decline and deficit of soil carbon can be turned around simply by the addition of plant material. The carbon in all plant material is derived directly from atmospheric carbon dioxide. The use of green plant material (rich in starch) provides a quick hit and result. This material is unfortunately quickly broken down by bacteria and the carbon release back to the atmosphere as part of a short term cycle. The dry material is better as this provides food for the soil fungi as part of the long term cycle.
With the correct approach and management encouraging and utilizing the micro-organisms in the soil the carbon is bound in a variety of organic humic acids as part of humus and as such is immobilized for several thousands of years. The critical part is to then maintain those conditions to preserve the humus otherwise it will be lost back to the atmosphere as carbon dioxide.
Apart from sequestrating the carbon from the atmosphere humus has a number of other attributes significant for soil fertility.
The first is water retention. A soil with 5% soil carbon can hold 2½ X more than a soil with only 2% soil carbon. Apart from storing water and aiding in the "drought proofing" of plants, it significantly reduces run off and potential water erosion.
The second , nutrition:
Humus can store 90 - 95% of the soil nitrogen
15 - 80% of the soil phosphorus
15 - 20% of the soil sulphur
In addition to these a variety of essential plant trace elements are also stored and are likewise available to plants.
As part of the management to preserve the humus the style of soil tillage is a critical factor. A technique which opens and aerates the soil needs to be employed, rather than one which inverts and destroys the soil structure.
The realisation of importance soil carbon is not new as very recent work indicates. Researcher Per Stenborg from the University of Gothenburgh in Sweden working on an pre-Columbian archaeological project in the Santerarem area of Brazil (Amazon) regularly came across very fertile soil surrounded by otherwise infertile land.
These were not natural soils but had been created by the pre-Columbian Indians. Carbon had been added to the soil to enhance its productivity in order to support the agricultural based communities, which according to early 16th century Spanish explorers, flourished and were numerous. A significant amount of the carbon, some as charcoal, still remains in the soil to this day.
The State of Australia's BirdsThe State of Australia's Birds reports are overviews of the status of Australia's birds, the threats they face and the conservation actions taken.
To see the reports go to the Birds Australia website
E-wasteE-waste has been growing three times faster than any other type of waste. In 2007-08, 16.8 million televisions, computers and computer products reached the end of their life with 84 per cent sent to landfill. Only ten percent were recycled; nine per cent of these were computers and one per cent televisions. If Australia was to continue without any form of collection and recycling scheme, approximately 44 million televisions and computers would be discarded in 2028.
A national product stewarship legislation and accompanying e-waste regulations has been developed. This includes a TV and computer recycling program which is free at the point of disposal. Hopefully this will divert TVs from landfill and illegal dumping. This program has been implemented in 2013.
To find your location go to the TechCollect website
For more information go to the National Television and Computer Recycling Scheme website
Did a turtle die for your tuna?Tuna stocks have been decimated worldwide. Supermarkets play a key role in the oceans crisis by selling us overfished tuna. Destructive fishing used for canned tuna also kills sharks, turtles and juvenile tuna. Australians can buy a sustainable canned tuna brand, go to Greenpeace's canned tuna guide website to check out tuna brand rates. You can also send an email to Australian tuna brands and tell them to use sustainable and equitably-caught tuna.