Recreating the Country blog
Dear reader, this blog is divided into two parts which can be read separately:
A modern Landcare fable
In 1989 Prime Minister Bob Hawke was on his way to launch ‘a decade of Landcare’ in country Victoria. As he was being driven down a quiet country lane, he spotted an old woman in the middle of a paddock planting a tree. He lent forward and asked his driver to stop the car,
“give me a minute can you Bill?”
Bill couldn’t believe his eyes as he watched the Prime Minster of Australia climb the wire fence in his pressed suit and polished shoes. He walked across the grassy paddock toward the old woman with a string of confused reporters in tow. He called back to the reporters,
“Ahhh, could you people give us a bit of privacy”
From a distance, the huddle of reporters could just make out the conversation;
“Gooday darlen”, said Hawke, “looks like you could do with some help”.
He put out is hand and said “Bob’s my name”.
The old women looked up with a curious smile.
“Pleased to meet you Bob, Una’s my name.
I can see you’re dressed for the occasion Bob”.
She handed him the shovel and said’
“I suppose you know what this is for?”
Bob gave her a big pearly grin and took the shovel.
“Where do you want the hole Una?”
As he pushed the shovel into the soil he said,
“Una, do you mind if I ask your age”?
Una, “I’m 87 today”.
She paused as she considered,
“I’ve planted a River Red Gum on my birthday since I had my first baby nearly seventy years ago”.
“I’m impressed Una” said Bob.
“Then why aren’t your children and grandchildren out here helping”?
“They’re busy planting a thousand trees in the next paddock along the creek”, Una said.
“Though, this is something I like to do myself, while I think about the year that’s just passed.
She then said with conviction,
“I think planting a tree is the best thing a person can do for the land and for the environment”
Bob thought for a moment and said,
“You’re an inspiring woman Una and I can see you have a lot more years left in you, but I doubt you’ll ever see your grandchildren climb the tree you’re planting today”
Una, “Bob don’t you know the old Greek proverb”.
Bob, “Can’t say that I do”.
Una stood tall and looked directly at Bob, "A society grows great when old men plant trees in whose shade they know they shall never sit".
And I could add Bob” said Una with a gentle smile,
“a society grows even greater when both men and women plant trees that they will never see mature”.
Bob considered for a moment and said mischievously,
“Have you got another tree in that bucket Una? I think we’d better plant two”.
The fable ends here but Una's story continues at the end of the blog... and it has a twist that you might not see coming.
Paddock trees - benefits in a gum nut-shell:
Benefits to stock and crops
After the study John came up with a radical 100 year plan that would enable him to plant paddock trees on the rest of his farm. The plan would also allow the existing old trees to regenerate naturally.
You can read about how John did this in 'Paddock Trees part 3 - restoring paddock trees and fostering the next generation' - see image at left. (to be published in November)
Entomologist Dr Ian Smith from Ecologian supported John's findings at a recent Landcare presentation. He confirmed that scattered paddock trees provide better general wind shelter than shelter-belt plantations. This is because there is no turbulence or increase in wind velocities downwind beyond the protection zone of tree belts. On windy days paddock trees provide a more even and less turbulent reduction in wind throughout a protected paddock.
Shelter belts planted across a farm at regular intervals of 100 - 200 meters, combined with scattered paddocks trees between the shelter belts, will provide the most wind protection in paddocks for stock and crops.
Studies show that sheep produce more wool and cows increase milk production by up to 20% in sheltered paddocks. New lambs are more likely to thrive in environments protected from the wind with 20% less mortality.
How wind dehydrates plants?
Plants maintain humidity over the surface of their leaves through their stomata. Strong winds remove this moist layer, drying the leaf surface. Plants try to replace this lost moisture which the winds remove again creating a leaf drying cycle. This dehydrates plants putting them under stress and usually causing them to wilt
Paddock trees create a cooler microclimate and can reduce the radiant heat on hot days by more than 50%. This shade also benefits the farmers working around their property.
Benefits to the land
Soil on farms is a precious commodity that forms at an estimated rate of 10mm/1000 years in Australia’s southern states. It makes sense to protect this valuable asset, yet we lose tonnes each year through wind and water erosion.
It’s estimated that the world loses more than 24 billion tonnes of fertile soil to erosion every year. In Australia dust storms carrying soil have become more common in dry years. Older Australians will remember February 8th 1983 when ‘the Mallee came to Melbourne’ and an estimated 140 million kg of topsoil was carried away in a dust storm that threw Melbourne into total darkness in the middle of the day.
I recall a visit to a farm in Deans Marsh, Victoria in the mid 1980’s. The owner told the story of how his grandfather cleared a paddock of trees and shrubs for cropping. He then scalped a line through the paddock to create a shallow drain.
Two generations later this shallow drain had become deep and wide enough to hide a two story house. Tonnes of precious soil had been washed down the Yan Yan Gurt Creek into Bass Strait.
To prevent further soil loss the grandson was replanting trees and shrubs on the Creek and throughout the farm.
Maintaining paddock trees, allowing the old trees to regenerate and planting scattered trees in bare paddocks is a strategy that would help address this significant and damaging annual loss of soil
Paddock trees have deep roots that search the subsoil and the deeper bedrock for minerals. Through osmosis and ion exchange mechanisms they absorb these minerals concentrating them in their leaves. These minerals are added to the soil around the tree when the leaves fall and decompose.
Carbon from this leaf litter is also incorporated into the soil by insects like Springtails, (Class Collembola). These little insects are often seen in your garden leaping about when a log/rock is lifted uncovering their home. They are specialists in breaking down hard woody material into soil enriching and moisture holding humus.
Soil fertility is also enriched by birds, marsupials and insects living in paddock trees. The nutrient rich animal droppings are vital to the health and survival of these isolated trees because they often grow in poorer soils low in nitrogen and phosphorus.
Use this link to read more about paddock trees and birds and how they have built a mutually beneficial relationship
Salt (sodium chloride or table salt) rising from the water table to the surface is called ‘dryland salinity’ and kills most plants. Farms with severe dryland salinity can look like deserts.
Also high levels of sodium in soil changes its structure making it very erodible. Deep gullies can develop overnight after heavy rain.
Dryland salinity devastated many farms in the 1980’s and 1990’s and became a focus for Landcare in its early years.
Dryland salinity explainer
Big trees are nature’s water pumps, taking most of their water deep down at the water table. One mature tree can drink 500 – 1000 L of water/day & in one day 1000 mature trees can empty an Olympic sized swimming pool.
When millions of big trees are removed from the landscape, pumping from water-tables stops and the ‘Olympic pools’ deep underground (called groundwater) overflow and the water level rises to the surface. Often this water is naturally quite salty and it's made saltier at the surface by evaporation. These high levels of salt brought to the soil surface cause dryland salinity and are toxic to most plants.
The simple solution to dryland salinity is trees. Keeping existing paddock trees healthy, allowing them to regenerate. Planting trees back onto the broader landscape is also an accepted strategy that will start to reverse dryland salinity in as little as five years.
To read more about dryland salinity click here for a CSIRO article 'Dealing with Dryland Salinity'
How biodiversity benefits farm production
Compared to areas without trees, even a small increase in numbers to 5 trees/ha in an agricultural landscape significantly increases the numbers of bats and birds present. The presence of a single tree can double the number of bird species.
Paddock trees are also stepping-stones for animal movement between patches of native bush making it possible for wildlife to access the diversity of foods and habitats that they need to 'make a living'.
Interestingly studies show that one x 100 year old tree produces a lot more nectar and pollen than two x 50 year old trees. So the food produced by old trees increases significantly as they mature, providing proportionally more pest control benefits.
Increase bird and micro-bat numbers reduces pest insect species.
Owls live in tree hollows and eat mice and rats, insectivorous birds like the Pardalote, Welcome Swallow and homey-eaters fly kilometres from their home trees searching for insects. Many of these are pests that damage grain crops as well as trees producing fruit and nuts.
Magpies perched on old paddock trees have been recorded feeding on snails and slugs in vineyards. They also scare grape-eating birds like Starlings and Blackbirds reducing damage to bunches
Ecologist Dr Rebecca Peisley from Charles Sturt University found that insect damage to apple orchards, vineyards and crops was reduced when sites were close to native vegetation. She also found raptors that control rabbits preferred paddocks with large paddock trees.
Micro bats that live in hollows and fissures in paddock trees can consume 500 insects in an hour and half their body weight in insects every night. They also make a significant dint in mosquito populations.
Parasitic wasps are attracted to paddock trees to feed on nectar and pollen. They lay their eggs on leaf-eating caterpillars keeping their numbers in check. They are critical to maintaining the insect balance on urban landscapes.
Hugging a tree also improves our wellbeing. Click and scroll to the end to read about 'the science of tree hugging'
They are also a convenient source of firewood and craft wood that would be valued on farms. A practice of take one & leave one is the policy that we adopted on our rural property. This provides for both personal needs and the needs of wildlife.
Because older trees produce consistently more nectar and pollen, honey products from paddock trees could be a valuable supplement to a farm income and the farm pantry. Feral bees will evict native fauna from tree hollows but well managed hives would pose little or no threat to native fauna.
Video on paddock trees
The Fenner School of Environment and Society at the Australian National University has posted this 9.5 minute earthy video on the values of Scattered Trees on farms. Click here to watch.
....Una's story continues here;
A parallel universe – imagine the perfect world
Una watched the reporters trailing behind as Bob walked briskly toward his waiting car. She smiled as she thought of the geese in her orchard honking excitedly at feeding time.
The animated gaggle of reporters talked amongst themselves, occasionally looking back to Una and nodding their heads in her direction as a sign of respect.
Una chuckled, she was well aware of who Bob was but she hadn’t let on.
She decided that she liked him and his ambitious plan to plant one billion trees. Her son Malcolm wouldn’t believe her story, or maybe he would when he saw the newspaper headlines the next day.
Click here to visit this inspiring site and enjoy the beauty of magnificent old trees.
Paddock Trees - part 3. 'Restoring paddock trees and fostering the next generation' (to be published November 2020). Explores how we can protect paddock trees and restore them on our rural landscapes
Paddock Trees - part 1. 'Their beauty and their bounty'. Explores the amazing benefits to the environment that old paddock trees provide.
Click here to read part 1 in this series
Blackwood, Acacia melanoxylon
Riparian Wattles – think black, think silver and think swamp.
Victoria’s waterways are great places to visit. Whether they are wide flowing rivers or small dry creek beds they are exhilarating to explore.
Here are some snapshots of my own memories of walks along river/creek banks;
The edges of our creeks and rivers are where you will find plants that are unique to moist environments. These are plants that have adapted to wet feet during times of flooding and to extreme dry seasons a few months later. They deserve our admiration because they somehow thrive in spite of these dramatic climate contrasts.
Three remarkable riparian wattles
There are three remarkable wattles that grow on waterways that I regularly visited on seed collecting expeditions and they’re easy to remember - think black, think silver and think swamp.
The Blackwood and the Silver Wattle, Acacia dealbata are often found sharing a river bank. You can see them together at Morrisons on the Moorabool River 7km north of Meredith in central Victoria. In this deep and mysterious valley they grow on the river flat and provide the understorey and tall shrub layers under a canopy of River Red Gums.
The Swamp Wattle, Acacia retinodes forms a low shrub layer under River Red Gums at the very pretty Pitfield’s reserve on the Woady Yallock River, 15km NW of Rokewood.
These wattles illustrate how nature builds structural layering into vegetation, a critically important strategy to maximise safe habitat for wildlife. Click here and scroll down to read about structural layering in vegetation
The tallest of this trio is the Blackwood, Acacia melanoxylon;
Commonly pronounced melon-ox-a-lon
It’s all Greek – melas = black; xylon = wood.
Literally it translates as ‘black wood’ and it describes the deep brown/black colour of the heart wood of mature trees. The outer layer of the heartwood is called the xylem. This is where water is carried from the roots, up the trunk to the leaves. Tall trees like the taller Blackwoods have a long way to lift water from their roots to nourish the leaves and new growth.
Some Human context
The adaptable Blackwood
The Blackwood has a very wide distribution from northern Queensland right down the east coast to Tasmania. It also occurs naturally in the Mt Lofty region of SA.
It is a hardy, dense, strong, long lived wattle that makes an excellent fire retarding windbreak on farms. Its best suited to moist soils and damp gullies.
Choosing the right provenance for your planting is important because they vary greatly in drought tolerance and size, from forest giants to bushy tall shrubs (see below). Ideally choose Blackwoods indigenous to the planting site as they will be well adapted to the local climate and soil.
Blackwood’s are well known for producing a hard, dense timber for making beautiful furniture, benchtops, cupboard doors and veneers. It is described as one of the world's finest furniture timbers.
The timber most suitable for cabinetry is usually harvested from Blackwood’s growing in higher rainfall areas where the trees grow tall and straight. In the wet forests of the Otway Ranges and Tasmania, Blackwood’s live well over 150 years and can grow into 30m tall forest giants.
In lower rainfall well drained soils and moist gullies, Blackwood’s may live up to 100 years and are a much smaller tree (10m – 12m). They have closer growth rings and are prized for making personalised furniture. Blackwood’s growing in low rainfall dry woodland areas along waterways grow to a similar size and age. The Morrison's Blackwoods described above fit into this category.
This medium sized form is ideal as a street tree because it is strong, dense, shady and long lived. It has the added advantage of needing very little maintenance.
There are also smaller Blackwood’s that have adapted to the heavy soils and exposure to the climate extremes of the basalt plains. These trees have a hard life, live up to 25 years and reach 5 – 7m tall. They’re gnarly wood is prized for craft work.
Wood-workers take care
Blackwood saw-dust is a recognised lung, eye and skin irritant. I met a cabinet maker near Portland who had a small shed full of dried and numbered Blackwood planks that he was keen to sell. He had harvested the logs himself from trees that had been cut down under powerlines on a nearby roadside. The logs had been slabbed and were ready for use in his workshop. Sadly he found that the saw-dust from the Blackwood irritated his normally healthy lungs causing asthma, even when he worked with a dust extractor.
The perfect paddock tree - the benefit of clumps
The hardiness and longevity of the Blackwood makes it an ideal paddock tree. It also hosts nitrogen-fixing Rhizobium bacteria (like all wattles) that improve soil fertility. This benefits surrounding trees, crops and native grasslands. Its tough bark is resistant to damage from stock and the trees provide excellent shade.
To hasten the development of significant habitat for wildlife as well as excellent shelter for stock, plant new paddock trees in groups of five with a spacing of 3 – 5 metres between each tree.
Group planting like this multiplies and accelerates the ecological services these new paddock trees provide. The tree clump will have many of the benefits of a single 50 – 75 year old mature tree in only 10 – 15 years.
When these Blackwood's mature beyond 15 years some can be thinned for their valuable timber to make room for the remaining trees to develop a more robust form.
The Blackwood’s pale yellow to white flowers grow in clusters and appear from September – November in the southern states and November – March in Queensland.
In south-east Queensland the Blackwood supports many native butterfly larvae - the tailed emperor, silky hairstreak, imperial hairstreak, stencilled hairstreak and large grass-yellow butterflies.
Its dense foliage also provides shelter for many birds. It offers protected nesting areas and produces copious quantities of seed.
This seed is popular food for Cockatoos, Rosellas, Wattlebirds, various honeyeaters, King Parrot and the Bronzewing Pidgeon.
Ants also harvest Blackwood seed for the oil rich aril and take the seeds underground where they will remain viable for centuries
Small birds like the Grey Fantail and Superb Fairy Wren glean insects from Blackwood leaves.
The glands at the base of the Blackwood leaves (phyllodes) produce a sugary sap during flowering that attracts a variety of birds including silvereyes, honeyeaters, treecreepers, spinebills and thornbills. This entices them to the tree to help with pollination.
Sugar Gliders also harvest the nourishing protein rich sap by wounding the trunk to encourage it to bleed. The Gliders defend the Blackwoods within their territory from other families of Sugar Gliders.
Sugar Gliders also feed on the sap of Black Wattle, Acacia mearnsii, Silver Wattle and Lightwood, Acacia implexa
Blackwood has a rich history of use by indigenous Australians;
The bark of the Blackwood is soaked in hot water to produce an analgesic solution. This will ease pain when rubbed into sore muscles or used to bathe painful rheumatic joints.
The leaves have been used as a natural soap. Take some fresh leaves, add a little water and rub hands together vigorously until the foam forming saponins are released. These natural chemicals will clean your hands.
Blackwood twigs and bark were used to stun fish, making them easy to catch.
The thick sap from the trunk was used as an adhesive to join pieces of Blackwood to craft strong weapons and tools. These include spear-throwers, boomerangs, clubs and shields. The inner bark was used to make a strong string.
Caution – Cleaning Blackwood seed creates a fine dust that is very irritating to the lungs.
Like other wattles, Blackwoods are easy to gerninate from seed using the boiled water treatment described at the end of the ‘Black Wattle’ story.
The seed is very distinctive as it is encircled by an orange aril. It is also very convenient to collect as it often hangs on trees for months with the seed-pods fully open as if advertising its availability.
Refer to a section at the end of 'Acacias' for a simple method of inoculating wattle seedlings for more vigorous and healthy trees.
Removing the aril
I have found that Blackwood seed is easier to treat and to sow if the aril is removed.
After the seed is separated from the pods most of the arils will still be attached. To remove them, wearing leather gloves and a dust mask, rub the seeds vigorously between your hands until most of the arils are dislodged. Winnow the seed pouring it from bucket to bucket in a light breeze. The lighter arils will blow to the side leaving the cleaned seeds ready to package in a Zip-lock bag.
Remember to record the species name, collected location and the date of collection on the bag for future reference. Other valuable information to record; tree size, soil type, drainage, exposure and the number of plants in the seed collection sample as a guide to its genetic diversity.
Paddock trees: benefits on farms
Silver Wattle, A. dealbata
Stephen Murphy is qualified in Geology and Environmental Management and has been a nurseryman and a designer of natural landscapes for over 30 years. He loves the bush, supports Landcare and is a volunteer helping to conserve local reserves.