Recreating the Country blog
Paddock trees in decline
Phillip Adams is the ABC presenter of Late Night Live and an Ozzie legend. When I get the chance I listen to Phillip, hoping to absorb some of his remarkable understanding of world affairs. I’m disappointed to report that my hope is usually in vain.
Though my ears did prick up recently when he was introducing English author James Canton. His book ‘‘The Oak Papers’ follows the extraordinary life story of an 800 year old Honeywood Oak tree at ‘Marks Hall Estate’ in Coggeshall, Essex. (Australia has a River Red Gum of the same vintage. See image on left - Bilston's tree)
In his introduction Phillip reports that his own experience with ancient trees has been very disappointing. Many of the century old native trees on his ‘Elmswood’ property died during the millennial drought. Unfortunately Phillip’s experience isn’t unique and reflects a pattern of ancient tree decline and loss throughout Australia.
I think we all should be concerned that 2% of our old trees are dying each year. Of greater concern is they are not being replaced. This was the disturbing finding of an extensive 1,000,000 ha study of old paddock trees in the SE of Australia by ANU researcher Dr Joern Fischer in 2009. This worrying trend has not improved in the last eleven years and is actually accelerating.
A city the size of Melbourne lost every year
Putting this 2% annual death rate into a human context. If we estimate 5 old trees/ha in Joern Fischer’s study area each with 30 hollows/tree. The overall annual loss is a staggering 100,000 trees with 3,000,000 hollows lost annually as the dead trees collapse. In human terms this is a city the size of Melbourne lost every year.
Ecologists describe old paddock trees as ‘keystone features’ in our rural landscapes. Their loss translates into the loss of the many dependent insect and animal species living in and around the old trees. Particularly the wildlife that need tree hollows. Click here to Paddock trees - part 1. Their beauty and their bounty for more on this topic
Clearing on our watch ...and is it legal?
Paddock trees and standing dead trees are still being cleared for plantation establishment, firewood collection and paddock management purposes. They are part of a large study that reported;
'Deforestation in Australia: How does your state (or territory) compare'?
This article vividly reveals the clearing done between 2010 - 2018 in each state. For example Victoria cleared the equivelant of a 1-kilometre-wide piece of land extending from Hobart to Brisbane. NSW cleared an area equivalent to a 1-kilometre wide strip extending 7,000 km from Perth to Cairns via Brisbane - depressing isn't it. Read on for an inspiring story.
Please note: A planning permit is usually required to remove, destroy or lop native vegetation in Australian states and territories.
If you're thinking about cutting down an old paddock tree please consider the many benefits it provides to you and the broader community.
Click here to Paddock Trees - part 1. Their beauty and their bounty.
Paddock Trees - part 2. Their economic benefits on farms
Click here to read more about removal of vegetation regulations in Victoria
This link will take you to the draft national plan to protect paddock trees
One farmer’s vision - a 100 year plan
In our early years in the nursery we were fortunate to befriend a couple who had been planting trees for shelter on their farm since the early 1950’s. John and Janice Morrison were pioneers in the industry and enthusiastic about the conservation benefits of planting several thousand trees and shrubs each year.
John had another tree planting strategy that was both remarkable and inspiring. It was a plan that would take his family over 100 years to complete.
He had divided his 4,000 acre property roughly into ten areas of 10% or 400 acres. His plan was to take 10% out of production for 10 years. This meant no grazing and no cropping. During this ten year period the family would plant well-spaced paddock trees to provide shade and wind shelter. After ten years another 400 ha would be set aside, while the first area was put back into production.
There were clear advantages to this radical plan. It allowed the Morrison family to plant paddock trees very cheaply and conveniently, because there were no large and expensive stock proof tree-guards required. It also allowed easy access to the young trees for care and maintenance.
Natural regeneration – what a bonus!
A significant added bonus to this forward thinking plan was the existing century old paddock trees on the property started to regenerate. It was amazing to see the hundreds of River Red Gums germinating beyond the tree canopies beside the mature ‘mother’ trees. These trees quickly reached five meters tall in 3 – 5 years. This meant that they needed no stock protection beyond this time, though they had another 5 years to 7 years to strengthen with John’s ten year plan.
Click this link to read about funding to protect paddock trees
Changing management practices
Old paddock trees produce a lot of seed every year. River Red Gums for example produce on average 500 viable seeds per gram (about half a teaspoon). This seed is dispersed into the surrounding landscape in autumn where it lies in wait for the first soaking spring rains. Every old paddock tree literally produces millions of fertile seed that potentially could grow into another paddock giant. These seeds are ready, willing and able. Our challenge is to provide them with the opportunity.
The traditional farming practice of continuous grazing doesn’t allow paddock trees to regenerate. Permitting stock to have general access to paddocks for long periods results in intense grazing of everything green include tree seedlings.
I have surveyed areas around mature eucalypts and have found young trees with sizeable stems nibbled off to just 5cm tall. I have also witnessed the extraordinary transformation of these young trees when stock is removed for as little as 12 months. They quickly grow to heights over 3 meters because of their well-established roots.
Resting paddocks for periods of 12 months is often enough time for seeds to germinate and for young trees to emerge.
How can we help emerging trees establish before grazing pressure is returned?
High Intensity Rotational Grazing
In High Intensity Rotational Grazing stocking numbers are dramatically increased and animals are moved frequently. In this system stocking rates for cattle can increase by more than 500 times and at this number they may need to be moved daily. This technique can result in enhanced soil health and improved pasture condition if it is done well. Click here to read more about High Intensity Grazing from the 'Noble Research Institute', Oklahoma
I have seen this system used on a 300ha farm at Healsville divided into 0.5ha plots with mobile electric fencing. The farmer dramatically increased his soil fertility and pasture health. In this example the cattle were followed by chooks for egg production.
Increasing the natural regeneration of paddock trees
Dr. Joern Fischer from the Australian National University recommends this grazing method to increase the regeneration of paddock trees. He observed a fourfold increase in natural regeneration where sheep were grazed intensely in small paddocks for a few days and moved on.
The grazed paddocks were then rested for three or more months. Three months rest in spring is enough time for seeds to germinate. Small trees can then be guarded or temporarily fenced-off until they establish. Fischer observed trees regenerated best in soils with low fertility and recommended that fertiliser be phased out to improve the success of tree regeneration.
Isolated paddock trees
Paddock trees located a long way from boundaries can be temporarily ring-fenced for 2 – 5 years until regenerating seedlings are big enough to tolerate stock grazing, browsing and rubbing. This is a relatively cheap method because large numbers of young trees are protected. Trees within the fenced area may need to be individually guarded to protect them from rabbits and hares.
Ringlock, cable-tied to star pickets should be adequate to keep out stock for short periods. This can be quickly and conveniently moved to another site by cutting the plastic cable ties and lifting the star pickets.
Fencing well beyond the old trees is important because seedlings won’t germinate under the tree canopy because of allelopathy. This is a natural process used by plants to reduce competition. Mature trees drop growth inhibitors with their leaves to protect their own growing space and to prevent overcrowding.
Cheap and effective stock proof tree guards
Individual tree guards can be expensive unless waste products like used rabbit netting, old wooden pallets or 44 gallon drums are used.
Peter and Julie Waldron from western Victoria were part of the Potter Farms project, funded in the mid -1980s by the Ian Potter Foundation. Peter guarded his newly planted River Red Gum paddock trees with used 44 gallon drums. When the trees reached the top of the drum he added a large old tractor tyre. The tyres were much wider than the drums and prevented his cross-bred sheep from browsing on the young trees.
A very convenient and cheap tree guard, advocated by Rowan Reid, Australia’s agroforestry guru, is a ‘vine-guard’ cable-tied to a 2m length of flexible 16mm plastic conduit. This guard bends when stock push against it, but it springs upright when it’s released. Seedlings quickly grow to the top of the guard and they’re able to move in the wind which encourages strong root development.
Paddock trees near boundary fences or on waterways
Paddock trees growing near boundaries and creeks can be fenced into windbreaks and biodiversity plantings. This allows the old trees to be protected permanently and enhances biodiversity plantings immeasurably. The hollows and other habitat provided by the old trees gives new plantations a maturity that would normally take hundreds of years to achieve.
Important note: Tall understorey and canopy trees planted close to an old tree will compete for moisture and light and will likely shorten it's life
Adding only shrubs or native grasses and herbs around paddock trees both under and beyond the tree canopy is recommended. This encourages insect eating small birds that will help keep the old trees healthy. This strategy allows the old trees to naturally regenerate amongst the shrubs and grassland flora.
Including some nitrogen fixing shrub species enriches the soil around an old tree. Examples of nitrogen fixing native shrubs and ground cover genera are Acacia, Dillwynia, Eutaxia, Glycine, Pultenaea, Hardenbergia, Kennedia, Indigofera, Daviesia, Platylobium and Desmodium. (Cut and paste the genus names into google for species descriptions and images – they are so beautiful!)
Cropping paddocks can be planted with paddock trees at very low cost and for a huge gain locally and nationally
Restoring paddock trees across rural areas is as simple as planting a seed. If every hectare of open paddock in Australia had 5 to 10 scattered shade trees, our climate and our living environment would improve immeasurably.
Millions of tonnes of carbon would be sequestered every year and the quantity of carbon being taken from the atmosphere would increase exponentially as the trees grew toward maturity.
See Paddock trees parts 1 & 2 to appreciate of the benefits.
A cropping paddock is the perfect place to start planting because the biggest threats to new trees have been removed - grazing and browsing animals. Cropping for a period of 2 – 3 years is enough time to cheaply and painlessly fully establish paddock trees without the need of tree guards.
Enhancing germination ... at a glance
What could go wrong? - farming practices that weaken old trees
When paddock trees become stressed for a long period their branches drop leaves and become bare. Often they will shoot again from further down the trunk but the dead limbs from an earlier dieback event are still visible.
When Dr. John Walmsley, who became famous for wearing a hat and cloak made from cat skins, established 'Warrawong' the first of his Earth Sanctuaries' in 1969, he wanted Australians to protect and value native wildlife. In the year 2000 when he floated Earth Sanctuaries Limited (ETL) he proposed putting a price on all wildlife protected in his eleven sanctuaries. For example, a threatened eastern quoll was valued at $1,250, a rare pademelon came to $2,500 and an endangered bilby was worth $5,000. ETL then valued all the wildlife in its care at $3,800,000
Following John Walmsley's example, what value would you put on a century+ old paddock tree. You could pay $50 for a three year old eucalyptus tree to plant in your garden. What price would you put on 300 year old eucalypt with hollows. $50 x 100 = $5,000 is very conservative. Using this conservative figure, the 100,000 trees lost each year in Joern Fischer's study area would then be valued at a staggering $5,000,000. This is just a single pixel on a computer screen or a fragment of Australia's overall paddock tree loss through clearing and poor management each year.
Though how can we put a value on something so irreplaceable, so priceless? Its futile to quantify in dollars the extraordinary and unacceptable losses to Australia's heritage that we are witnessing in our lifetimes.
Yet all is not lost if we put our hearts and minds to protecting these irreplaceable national treasures. I'm hopefull that we will see the current pattern of losses turned around in the next decade. The nations State governments are beginning to choose a better path toward meeting the climate-change challenge. It could be argued that the nations health depends on paddock trees being restablished across our broad and timeless landscapes. This will be a remarkable achievement but entirely necessary to support the many and varied ecologies to which these trees are unquestionably the 'keystones' feature.
You may have missed;
Paddock trees - part 1. Their beauty and their bounty
Paddock trees - part 2. Their economic benefits on farms
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
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.