NEW VIDEO ON YOU TUBE
“The big trees of the Bambra Agroforestry Farm”
The Big Trees of the Bambra Agroforestry Farm. Using the Master TreeGrower diameter tape Rowan shows us some of the largest high pruned tress on his farm. No tree is older than 28 years. Featuring Spotted Gum, Otway Messmate, Silky Oak, River Sheoak, Black Walnut, Poplar, Red Cedar, Redwood and English Oak.
NEW VIDEO ON YOU TUBE
“High pruning a Sydney Blue Gum”
High pruning a Sydney Blue Gum (Eucalyptus saligna) using ladder, harness and hand tools. Rowan takes us through his high pruning method step by step. Pruning to 8cm diameter and removing large branches (over 2.5cm). NOTE: Occupational Health and Safety rules vary from State to State. If you employ staff or work as a contractor the methods or equipment shown may not be acceptable. For example, a bicycle helmet may not be appropriate. Please refer to local legislation about working at heights.
24th August 2014
“Keep it simple stupid” “No brainer” “Absolutely”
I'm hearing these sayings a lot and wondering why they make me feel uncomfortable. Have knowledge, research, investigation and education suddenly become redundant? Are there really simple and absolute solutions to complex problems like climate change and sustainable land management? Are we, the audience, really too brainless and stupid to understand the complexity and uncertainty inherent in natural systems?
Of course simplicity has a good side. It was Einstein who said "everything should be made as simple as possible, but no simpler". Before him Leonardo Da Vinci wrote, "Simplicity is the ultimate sophistication". That these eminent philosophers felt the need to speak to the subject suggests that achieving simplicity is not simple, and certainly not something that can be easily taught to the stupid. There are no absolutes, we do need to use our brains.
Through observation and research Da Vinci demonstrated that it is possible to design elegant solutions to complex problems. By making something appear simple he wasn't dumbing down the engineering, he was highlighting its sophistication.
Well-designed farm tree plantings can look simple: After years of thinking carefully about his own needs and observing tree growth Andrew Stewart designed a 5-row shelterbelt system with three rows of tall trees interspersed with rows of understory shrubs. The pruned stems leave the electric fenceline clear whilst the shrubs are able to spread out providing habitat for small birds and filling the gaps to stop wind tunnels.
Multipurpose shelterbelt. Three rows of pruned timber trees with two rows of understorey
With this design outcome in mind Andrew started with a paired-planting pattern for the Spotted Gums: at each spot where he wanted one timber tree he planted two, about 75cm apart. As they grew he was able to cull the poorer individual and prune up the best. This almost guaranteed he got a well-formed tree at each spot and a regular spacing to block the wind. Note that he planted the middle row of timber trees at a slightly wider spacing to compensate for the different level of competition. The result is a simple yet sophisticated shelterbelt solution that reflects his needs and interests.
Visitors can 'see' that it works, its commonsense design that balances multiple objectives, risks and opportunity. It fits neatly into Andrew's farming system. It looks simple, but it is a simplicity that is borne out of sophistication. Another farmer might copy the design but just because it works on one farm doesn't mean it will be right for another.
That's the danger. Those that subscribe to the 'keep it simple' approach like to 'copy and paste'. They argue that not every farmer can be like Andrew and work through the design process to come up with their own solution. They think it is a 'no-brainer'; that if it works for Andrew then it is worth promoting to other farmers.
But the 'demonstration' that Andrew provides is not his pattern of planting or his mix of species. The demonstration that matters is the example he provides by showing how farmers can design agroforestry systems that 'fit' their farming and family systems. What a particular farmers comes up with hardly matters, as long as it is right for their particular situation.
Da Vinci was a master at making the sophisticated look simple. No doubt there were many who copied his ideas but then failed because the solution didn't match their problem. They couldn't see past the simplicity, they couldn't see the sophistication. They weren't inspired to learn and create their own solutions.
Across Australia and around the world most farm forestry and agroforestry extension programs have failed to capture the interest and enthusiasm of the farming community. I blame the experts who think that farmers were too stupid to understand, design and implement their own tree growing systems. They adhered to the KISS principle and made decisions about species selection, planting design and management without working with the farmers on their own farms.
It's time we rejected simple, embraced complexity and celebrated sophistication; in our world of tree growing it is the farmer groups that have done this that are growing whilst most are in decline.
Simple yet sophisticated pruning gauge
It was 30 years ago when I was working in New Zealand that I first used a pruning gauge. It was a wooden caliper that fitted over a point on the trunk below which I had to remove all the branches. A few years later the same research group started using a second smaller caliper to determine which of the large branches, above the pruned height, should be removed ensure they didn't affect wood quality or tree form.
Before heading over to Indonesia to work with smallholder teak growers I made up a gauge with two 'mouths': an 8 cm one for stem pruning and a 3cm one for identifying large branches above the pruned point. The farmers loved the tool and immediately made up copies. Was this an example of good or bad simplicity?
Of course I'd like to think it is the former. The questions it raises are obvious: Why 8 and 3 cm? Why not 10 and 4? In this respect it is a tool that invites discussion. Well, 'it depends'. Of course I have my reasons for picking 8 and 3 for teak but I was prepared for farmers to suggest otherwise and have the discussion. They could then make their own based on what they felt was appropriate for their situation. In that way I see it as a tool that hands over the power of design to the farmers. Simple, yet sophisticated.
Todd Mansfield of The Deep Living Project has just released a short video in which I try to explain how I use the gauge to guide my stem pruning for timber production. CLICK HERE TO VIEW
1st July 2014
Pruning has it's own risks but is still worth the cost
Whenever I meet another tree grower it seems we always start our conversation with a weather report. Right now on our farm it is cold and wet, but it is the wind that is causing me the most concern. Although June-July is our lambing time we don't seem to have problems with cold stress any more now that the farm is well treed. It is the trees themselves that are copping the brunt of the wind.
Early in winter, before the soils become waterlogged, the tree damage is limited to a few broken limbs. This doesn't usually affect the pruned sawlog unless a double leader splits out and tears down the trunk. Spotted Gum and Blackwood are notorious for this so I now try and correct double leaders early, even if they occur above the pruned section.
Now that we've had a few inches of winter rain the soils are starting to get waterlogged. This is when the winds can cause trees to topple over, completely uprooting them. My timber trees seem to be most susceptible about 2 or 3 years after I have finished the pruning. My first experience with this problem was about 20 years ago. I had finished pruning my best young Mountain Ash trees up to 6.5 metres, creating what my neighbours referred to as my 'lollypop farm', when the trouble started. Over the next two or three years the strong equinox winds and heavy spring rains left many of my best trees lying on the ground, wrenched over exposing half their root system.
I began searching for a reason, maybe even a solution. An experienced arborist suggested I'd planted J-rooted seedlings or used a poor planting technique that had twisted the roots making them unstable. A forester who was more familiar with dense unpruned plantations simply pointed out that the wider spacing and pruning must have opened the trees up to the wind. I dismissed both suggestions; my own observations didn't support either.
My approach to learning is to identify theories, based on my own or others' experience, observations and research, and then continually review them as I see and learn more. The key is to not become attached to any one explanation and to be willing to reject a strongly held theory in favour of a better one. In science, being prepared to change your mind is a strength, not a weakness.
That's when I met Ken James, an engineer who was working on tree stability at the University of Melbourne. Using sensitive instruments pinned to the tree trunk, Ken was able to measure the strain in the stem as the tree swayed in the wind. We would demonstrate this to our students by tying a long rope to a big solid tree in the university gardens and getting them to pull on it while Ken's data logger mapped the imperceptible movement of the lower trunk. Using data collected during windstorms Ken was able to show that the branches on a tree act as mass-dampener and thereby reduce the dynamic stress.
Apparently engineers position large tanks of water in skyscrapers to achieve the same outcome; when the building moves in the wind the delay in the movement of the water in the tank holds it back, then, when the building tries begins to swing back over its original position the water is working against it thereby dampening the speed and the extent of any movement. Because tree branches sway independently of the main stem they effectively do the same job. Therefore, a tree without branches, or one with a very high clean bole, exhibits greater movement in the stem and is therefore at much greater risk of snapping or toppling over than a tree with a deep green canopy.
By pruning all the branches off the lower stem I had reduced the mass dampening effect thus increasing the dynamic load on the main stem and the risk of the whole tree toppling over. Knowing this doesn't really help solve the problem but it does explain why most of my trees seem to grow out of the problem as they develop more large branches above the pruned section. I haven't really modified my pruning techniques but I do tend to prune more so I have a few in reserve, just in case. Some species are more susceptible than others which I why I now grow Californian Redwoods, Spotted Gum and Blackwood in my waterlogged soils rather than the southern eucalypts or pine.
Whatever the future climate, growing trees is an inherently risky venture. It always surprises me how confident many foresters are about their species choice and projected yields. How can they know the future? The only 'known' is that there are lots of 'unknowns'. I prefer to manage for risk by always have a fallback option; I plant for multiple purposes (conservation and profit) and plant a range of species across a range of sites. Then, if something goes wrong, it becomes a learning experience rather than a demoralising catastrophe.
This has been well demonstrated by the mass deaths of cypress (Cypressus macrocarpa) trees in farm shelterbelts across Western Victoria. Cypress is a great timber: light, nice colour, durable (above ground) and easy to dry. We are running a series of field days for farmers to help them understand the disease, clear the dead trees and replant. I've been taking my sawmill along and mill up a cypress log to encourage farmers to salvage the best logs. Unfortunately, because none of the trees were pruned, most of the dead cypress belts provide very little timber that is worth processing. A bit of thought in the early days would have saved thousands in the clean-up costs and may have even allowed the farmers to make a profit out of adversity.
Last Spring was particularly wet and windy at home and I lost a large Messmate tree that was planted by a friend and his young family more than 22 years ago. It was over 50 cm in diameter and pruned to 5.5 metres: a perfect sawlog. Had I not pruned it the whole tree would have been only good for firewood. As it was I was able to mill more than a cubic metre of clearwood from the butt log. A few minutes work back then makes a big difference today.
Whether it is wind, fire, disease or just old age, trees will eventually die. Pruning might seem expensive and timber production might not be your primary interest but if you do prune at least you have the option of salvaging something more than firewood.
By Rowan Reid Bambra Agroforestry Farm
Read Ken's PhD Thesis or Listen to him explain it (warning: contains heavy physics).
13th Feb 2014
The World Congress on Agroforestry, Delhi - 2014
It's big: more than one thousand delegates from eighty countries making it the largest ever agroforestry gathering. It's impossible to hear all the 200 presentations or meet everyone who might share my interests but I'm having a go. This is the third Congress, I attended the first in Florida (2004) but missed the second (Nairobi 2008). After all those years it's good to see some reflection: has agroforestry achieved what we thought it could for the poorest farmers across the world? The Answer: Well no, not really.
I was please to hear one of the keynote speakers say: “despite the 'silver-bullet' value of agroforestry models proposed by researchers there has not been widespread adoption - agroforestry has not created a movement.” Exactly. For too long researchers and extension agents have used their science to devise perfect models of trees, crops and stock that farmers don't want; expensive, inflexible and complex options that don't fit into farms. If the aim is to attract farmers to the idea of planting multipurpose trees on their farms then the professional have largely failed: Their options are 'ugly'. I then see the same researchers use their science and economics to defend their models; which just suggests that it must be the farmers who are wrong.
It's a case of the "emperor's got no clothes.” I'm pleased to see others question the approach. What they should be doing is using science to assist farmers design the agroforestry options that they need, that fit into their farms, for the reasons that are important to them. The Master TreeGrower program has never promoted recipes, we deplore the idea of best-bets and we have argued against using subsidies to pay farmers to accept less than perfect choices. Farmers don't need best-practice agroforestry, they need best-fit. That means they need to be engaged in the process, which get us back to the congress: there has been not one farmer (to my knowledge) presenting and I've heard of only two in the audience!
However, there is some excellent research, both physical and social, on display from all around the world. A lot of the researchers are women from developing countries that are passionate about using science to help their communities. The focus of much of the international research continues to be on ways in which tree growing can help the poorest, subsistence farmers. That's fair; trees can help the poor by providing firewood, fertiliser, food and fodder. But there is a risk. Dr Howard Sapiro is the Chief Agricultural Officer with Mars Inc (yes, the huge US Mars Bar company). He has been leading the research on farming systems for Cocoa (the chocolate tree) and made a point that is still ringing in my ears: He said that we need to be careful that we do not 'certify poverty' by using our science and markets to help the poor remain on unviable farms. He highlighted that farmers who were able to plant the improved genetic stock and manage it effectively (including in mixed agroforestry plantings) could increase their cocoa yields by 3 or 4 times. That's enough to lift them out of poverty and straight into prosperity.
But this change wasn't going to happen on the poorest farms where families were struggling to grow enough just to feed themselves. Only money can ensure that the poorest families are able to feed and educate their children. As well as stopping erosion, providing fuel and replenishing soil fertility, agroforestry must deliver money. Of course, it is worth helping the poorest farmers grow trees if it helps them survive but if agroforestry is to become mainstream and provide real development opportunities it will also be necessary to work with 'middle-class' farmers (in the same district) who are keen to learn, able to experiment and can help develop new industries that can provide regional employment and open up new market chains for the small growers.
I get the feeling that agroforestry research and development has reached a critical point. The right questions, the hard questions, are being asked and some of those involved are prepared to take a good-hard-look at what has been achieved and at what needs to change.
This afternoon I attended a great session on farmer-to-farmer extension. Of course, for me there was no surprises coming out of the research from Africa: farmers learn best from other farmers and it is the role of professionals to facilitate and support leading farmers and encourage them to share their experience and work with their neighbours. As we begin our national peer group mentoring project in Australia I'm pleased to report that the Australian Agroforestry Foundation is at the forefront of international thinking on agroforestry extension. I spoke about our approaches and their is interest in the Master TreeGrower and Peer Group Mentoring ideas from around the world. Maybe at the next world congress we'll see some Master TreeGrowers from Uganda, Indonesia and Australia on the stage standing beside researchers, policy makers, donors, investors and academics.
By Rowan Reid.