Anybody who knows my work knows I have a great love for the organic grass roots arboricultural projects, that lead into quality arboricultural articles, and into further projects and education to be shared.
Following a request from AA to contribute with feature articles, I see this as an opportunity and this article, my last technical report based feature – heralds the birth of my working as a Conservation Arborist in support of the growing global Ecovillage movement. A movement that I see as the start of a golden age in promoting arboriculture as we start to move away from tree processing into tree culture or Arboriculture.
Now that I am living in an Ecovillage personally, I see the Ecovillage movement as being a catalyst for conservation arboriculture; from a business perspective, with myself at the helm of the Naturaculture Network, I am using this report and project as an educational opportunity for Australian Arboriculture – this is to be discussed in Part 2.
Having recently completed the following professional arboricultural report for Crystal Waters Ecovillage – Crystal Waters Community Trees Report – ‘The Trees on the Green’ – published October 7, 2019, I am running this technical report as a prelude to Part 2 which will also be published in a national Australian Ecovillage community publication. This is an edited version of the original report which can be seen at https:// bit.ly/33qSELo
My goal is to seed Arboricultural values in the global Ecovillage movement which places tree and land care higher in their valuing process than most private or government organisations (bar perhaps Botanic Gardens) that I have experienced. I invite the AA readership to come on this journey with me. In part 2 we will be studying an iconic and ancient community Fig tree as part of the feature article.
Crystal Waters Community Trees Report – The Trees on the Green Following a request from the Landscape Sub Committee for the Crystal Waters Co-op I accepted an unpaid commission to draft this report on the avenue of trees that make up the heart of the Crystal Waters communal area known as the Green.
This report is principally a study on the five main trees that make up the avenue and are of key amenity interest subject to the greatest congregation of people. The report discusses the status of the trees as well as a management plan to integrate new trees over a 40 year window moving forward.
Background – Cassian in the Crystal Waters community
I first came to Crystal Waters in 2009 as a tree inspector working the Energex VTA Program (I helped found the program), when proactively assessing trees likely to fail on to the Electrical High Voltage Network (2007-12 Tin Can Bay to Central West Brisbane).
I returned in 2017 and became a resident where I lived at a number of properties with a number of hosts.
Though I have been moving around the world since then, I regard Crystal Waters as a home and am now part of the growing community passionate about sustainable living. In the long term I wish to invest in CW with a view of keeping a home base. As a qualified professional consulting arborist (30+ years in vegetation management), educator and writer I have been working in S.E. Qld, as a qualified contracting arborist since 1991 and consultant since 2003 (I am currently at Diploma level – Australian Qualifications Framework – Level 5 since 2009 – upgraded to current training package in 2017).
I am a founder member of the Queensland Arboricultural Association (1994+), member, past committee member (1995-98) and past Technical Officer (2014).
There are a total of nine established trees – made up of the Genera Albizia, Tipuana, Grevillea and Jacaranda that make up the treed avenue bisected by the brick pathway known as Bricabrack Lane. The pathway is 83m long by 3m wide, the treed avenue is roughly 110m by 25m.
This is adjacent to a stand of Paulownia trees at the southern end that adjoin the plant nursery area, the Paulowinia trees are in reasonable order following my cleaning them out (dead wood removal) last year (with the ground support of Hayley Buchanan).
The communal hall, deck and cafe is located on the eastern side of the avenue. The gathering of visitors to the Crystal Waters Green is substantially increased on market days (first weekend each month) with a steady flow of locals and visitors attending the Flower pot Cafe, bakery (eastern/western sides of the avenue) and other events. At the northern end of the avenue is the car park and entrance to the Green, another area of focused people gathering.
The reason I have selected the five trees highlighted in Fig. 2 as my key focus is because this is the greatest people traffic area, these trees are the oldest, are the most vulnerable to visitors, with T1, T4 and T5 posing the greatest long term risk to visitors. This is primarily due to stress caused by people pressure (note – all trees are stressed due to decades of soil compaction and biological desertification).
This report is for the CW community, though I have tried to keep it brief – I also intend for it to be published as a Conservation Arboriculture article in The Australian Arbor Age for professional arborists. This report will also be read by professional allied stakeholders (I intend to involve to help fund the avenue’s restoration – the Naturaculture Network), as well as being a future article for other national and global Ecovillages. The content is for both unschooled and professional tree people.
To enable a comprehensive understanding of my recommendations I aim to run an educational power-point presentation (subject to CO-OP approval) on the report to the CW community and will be open to questions to assist this process.
I am in a position to finance the tree restoration process by running a series of workshops (in a similar capacity to Steve Cran’s Permaculture CAP project), hence my interest in drafting this report with a view to project managing this as a Naturaculture project.
Evidence of Genus, Species, Health, Dimensions and Crown Structure – T1 Genus and species.
In the original report is a detailed record on Trees 1-5, in this version the report is briefly summarised.
T1, T3 and T4 – Albizia spp, until flowering time I am unable to get a positive identification on this rare tree (rare in Australia). My own study backed by feedback suggests that this tree is an African species, possibly Albizia amara or Albizia adianthifolia yellow flowered spp), having not seen this tree outside of Crystal waters or in flower, I await flowering time for identification. I am however familiar with this Genus and a number of the local Genera in the family – Fabaceae (Albizia, Caesalpinia, Delonix, Tipuana). The CW trees and African species studied by me online fit the description of being a dominant canopy tree in dry African/Indian deciduous woodland (similar conditions in S.E. Queensland).
T2 – The Rosewood or the Pride of Bolivia – Tipuana tipu from South America is a popular amenity tree with global significance. This tree is regarded as a weed species in Australia and belongs to the same family as the T1 – Fabaceae (https://en.wikipedia.org/wiki/Tipuana).
Discussions with the community indicate that the Avenue was planted in the late ‘80s/early ‘90s placing them at approximately 35-40 years old (since drafting this report leading Permacultural trainer Robin Clayfield confirmed she planted the trees).
When we consider the time frame taken to create the tree cover of Bricabrac Lane avenue it is in all out interests to keep these trees alive and stable for as long as is practically possible. From my perspective with modification to the site the trees lifespans can be extended in the order of decades. I am less concerned with the Tipuana trees long term (they tend to die before they shed crown structure – so when it comes to safety we get plenty of notice) because of their robustness – as I am the Albizia trees which are known to shed live limbs when stressed.
To this effect I will be recommending site improvements to all trees, but the treatment of the Albizia trees are first in the order of priority.
The long term management of the trees require community consideration, with the trees themselves being given the space to make improvement (by giving them friable soil surface area they can better interface with) – this means sacrificing a reasonable percentage of area within the trees root zones for soil restoration. A sustainable management and action plan is in my opinion very necessary to reduce risk, stress on the trees and sustain this very valuable community asset. From what I can see with the Green we have plenty of space that we can share with the trees.
Tree Constraints/ Site Limitations
The constraints that are causing these trees to be in decline need to be understood and recognised by all concerned to enable the reasoning necessary to create change. Personally I would rather see a gradual process that supports the benefits the trees are currently providing extending into another 40 years, rather than a time lag where following tree removal and a greater deserted landscape it takes another 40 years to establish new trees to achieve what we have now. It is normal in most reactive tree management situations (based on a lack of value to be realised in retention over removal and processing) that an avenue such as this be felled then replanted as soon as trees shows symptoms of age.
Imagine if we humans were ‘felled’ as sick 25 year olds rather than be nourished to live out our full lifespans?
Because of non-sustainable tree-management practices trees rarely make it to maturity (the first ⅓ of their lifespans) before the onset of early old age and their removal.
The Constraints On The Trees/Site Are As Follows:
- Lack of soil oxygen due to Soil Compaction due to decades (pre and post planting) of People Pressure from vehicles, machinery, hooved animals (bullock timber trains, dairy cows) and site visitors (multitudes of feet)
- Below ground Biological Desertification due to decades of compaction, loss of leaf litter and lawn competition
- A lack of soil water holding capacity after rainfall, compacted biologically desertified soils (soils low in fungi do not hold water for long) and lawn grasses have significantly greater impacts in times of drought. Wood embrittlement due to drought stress is a factor in major limb failure
- Limited budget for tree maintenance or removal (from my perspective this is also a benefit – detrimental over-pruning is a common issue where budgets exist)
- Reduced tree health due to site constraints, the Albizia trees (more particularly) now with advancing signs of decline
- Expected time frame for another major limb failure – within five years
- Due to overshadowing/space there are limited options for the successful establishment of replacement trees (replacement planting sites between the existing avenue trees is right within access routes and market stalls), in this case the establishment of Figs is the best practise option
- ‘Tree time over Human time’ – because human life spans are so short and the processes that make up tree time are much longer – few of us have the understanding to accommodate full tree life expectancy
As stated based on the stress that the trees are under – they are in a stage in their growth cycle where due to the limits imposed upon them they are becoming old before their time. However I see these trees at a switching point in their vitality – whereby (based on stored energy) they can make a comeback (optimise their bodies) with help.
Opportunity for Crystal Waters
Most amenity trees in the urban environment are recoverable, but not so under the reactive land and vegetation management system that is common to most private and public land holders in the world. Proactive tree management means addressing the needs of trees before they go into decline, before they fail or die.
Crystal Waters (as a potential global hub for sustainability) has a great opportunity with these trees, by initiating and being part of a proactive project concerning this Green community hub, Crystal Waters could well be the first Eco-village in the world to save a treed avenue into posterity (this rarely happens in the mainstream globally outside of historical trees in Botanical Gardens).
Discussion and Recommendations Background – Trees and Risk Considering the major limb failure last year (T4), risk needs to be another motivating factor for change, though with my overall recommendations in the long term I am confident that risk can be managed to an acceptable level. In support of the trees it needs to be stated that apart from the 2018 limb failure on T4 in the last 30+ years these trees have no history of recorded risk/ hazard (bar one recent trip hazard incident from a raised brick). Assuming no action is taken considering risk, human occupancy of the site (the number of hours people are under the trees) and the likelihood of a limb failing and falling on a person – I suspect that the trees are barely on the threshold of risk. Based on the current established target level of risk – being 1 in 10,000 or less (Ref: systems of assessing Tree Risk – VALID – Tree Risk-Benefit Assessment and Management and QTRA – Quantified Tree Risk Assessment). Of course with no action taken the trees will continue to decline from people pressure with the likelihood of tree failure escalating and therefore risk of harm.
I intend to organise a workshop to enable an independent risk assessment to be carried out as part of the project management plan
I have for the trees (this I aim to host as a workshop to help raise revenue) should my proposal be accepted by the Co-op.
The steps listed in section 4.0 will collectively reduce risk likelihood well below the risk matrix that professional consulting arborists like myself follow.
People Exclusion Zones – PEZ – reducing targets (on people) whilst reducing people pressure (on trees)
To facilitate the recovery of these trees we need to give a significant amount of space back to them. This means reducing people pressure – people access/congregation (and therefore soil compaction) within the trees root zones (from the trees trunk to the trees driplines) by making designated areas no go zones – PEZ – for people and then making those zones soil restoration areas.
With the goal to make the soil’s friable, to improve on soil health and therefore tree health.
The Bricabrac lane treed avenue roughly measures 110m by 25m (including an extra 15m² to encompass T5) that is an overall area a little under 3000 m².
Currently this whole area is used by people and subject to people pressure, the community need to agree on how much space they are willing to give back to the trees. The brick lane itself takes up approximately 300m², the trees trunks/non treatable structural root zones a further 36m² (4m per tree *9 trees = 36m²). Less the non treatable areas that leaves 2639m² for potential treatment.
Allowing for monthly market stall space is the crux of the issue that will fuel resistance to giving the trees room to breath (as discussed for long term health oxygen in the root zones of woody plants is essential).
If the community is not willing to facilitate space for the trees it will not be viable to make the needed improvements to support the restoration of the trees health. Out of the overall 2639m² of space that the trees need to improve we need to return at least ⅔ of this area to being a healthy friable biologically active soil, that’s 1800 square metres. This area to be comprised of gardens decking or cellular confinement systems. Within this area where people access and market stalls are paramount – we need raised walkways as beneath this zone it is critical that soil friability is improved and sustained.
The community needs to very carefully consider the benefits the trees give versus the costs the trees pose. Which is the greater cost to lose the current avenue and start again from scratch?
This means paying for the trees to be felled and processed, with stumps ground (a cost of up to $10,000 for the three Albizia trees alone), to then carry out soil restoration and treatment with new trees planted followed by 30-40 years of growing time to achieve the current green tunnel that is Bricabrac lane.
The alternative is to retain the current trees but give them the growing space necessary to facilitate the health improvements needed. To do this without great financial cost will mean sacrificing a number of market pitches, if the community are not willing to make that sacrifice then the only solution is to establish raised timber decks or to establish cellular confinement systems over the root zones designated to be restored (this is cheaper than decking though involves changes to the ground surface and financial cost).
Most amenity trees in the urban environment are recoverable, but not so under the reactive land and vegetation management system that is current to most private and public land holders in the world. Proactive tree management means addressing the needs of trees before they go into decline, before they get sufficiently stressed that they fail or die.
As proposed Crystal Waters has a great opportunity with these trees, by initiating and being part of a restoration project concerning the Green Avenue, with being the first Eco-village in the world to do so. As well as project manage such an event I am willing to also draft an article on such a project to share globally. To be true this is my main drive for being in service to the trees and the community, though with my history of project management this project would be in the top 10.
Though for me to be in a position to project manage these trees firstly my vision needs to be understood, then deliberation can arrive at an agreed plan. I am in a position to raise funds for the restoration of the trees by running workshops to cover the cost of materials, labour and arboricultural expertise, though regardless of how this is funded or how the project is designed without gifting the trees a minimum of 1800m² in space then the project is unlikely to achieve success. That advice relates to the replacement trees too, as the existing trees have utilised most of the available resources within the soil.
Soil Inoculation, Nutrient Bed and Plant System establishment (within the Exclusion zones)
Trees as woody plants obtain their nutrition via microbiological association in the trees nutrient absorbing interface known as the rhizosphere – this is literally the ‘stomach lining’ of the tree/soil. The nutrient cycle essential to tree longevity is a natural synthesis that can not be replicated by mankind (people can only sustainably work with the cycle), the rizosphere is retarded/ damaged by fertilizers, herbicides, pesticides, soil compaction and desertification.
The most sustainable strategy for facilitating optimal tree health involves the use of organic cold processed humus.
This is not available in landscape yards, nor from tree processing contractors, the products available from Bunnings are not biologically active (are not a true compost, the microbiology in humus with a very limited shelf life can only be sustainably handled over short time periods). The humus that I use/have access to is farmed sustainably largely from green vegetation (a by-product of tree prunings and removals).
As well as vertically and horizontally inoculating (Soil Inoculation) as a means to decompact soils, I construct Nutrient Beds to house the biologically active medium necessary to (naturally open soils up), to provide nutrition as well as protect the integrity of the inoculated soil medium.
The Nutrient Beds are then capped with a vegative layer – by establishing a Plant System (plant component of an ecosystem) comprised of companion plants that form closed canopies further proofing the system as well as creating high value amenity gardens for site beautification.
The establishment of such systems are self regulating and maintaining as long as people keep off the system. The combined effect of soil inoculation, establishing nutrient beds and plant systems significantly reduces drought stress by holding moisture in the soil. The periodic Irrigation of the plant system helps drought proof trees, hydrated sapwood helps to prevent major limb failure even with the presence of wood decay fungi.
Cellular Confinement Systems
The purpose of cellular confinement systems (in our context) is to enable access to restored tree root zones without recompacting soils. Such a system is laid out over geofabric and is made up of a cellular matting filled with angular gravel, another similar load bearing system supports lawn grasses.
In those areas where the community is unable to sacrifice market stall areas as space for trees – cellular confinement is the greatest option, though timber decking is another.
Maypole rigging for the Flamboyant trees (T1 and T4) and propping of lower limb T1 As well as tree health a sustainable management plan must also include risk management.
My main concern is major limb failure, as discussed this relates to the Albizia trees, because of their body language, their stress symptoms and because T4 has already had one major limb failure I am inclined to recommend establishing a fall arrest system to help mitigate further limb failure. This can be seen akin to training wheels for human toddlers. Though the trees are highly stressed young adults – whilst their vitality improves a back-up system brings us a step closer to being well under the acceptable tree risk threshold. Mechanically speaking the trees have recently been demonstrating their prowess to dealing with major wind load – this is evidenced by my study of the trees in response to the heavy August/ September winds.
Generally speaking, where possible, I recommend pruning of trees via volume reduction as a means to reduce limb failure likelihood, however I believe that any pruning on the Flamboyant trees will accelerate their health decline (wounding into heartwood enables oxygen ingress and an acceleration of wood decay, particularly on stressed trees) therefore as a means to help mitigate failure whilst their health levels improve (and therefore their mechanical capacity) I recommend the Maypole rigging system.
This involves setting up fall arrest from a timber pole (power poles are ideal), which is established in close proximity to a trees trunk (not too close to cause damage) yet established to be as central to a trees crown as possible. With fall arrest running from the upper pole to selected crown structure (to be ascertained by me) as a means to arrest structure likely to fail.
I also recommend (in association with our resident builder) to create and install a prop for the lowest limb on T1.
Structurally speaking, I see the retention (without pruning) of this limb as being paramount to the trees overall mechanical capacity to dampen wind load. Propping the limb is likely to buy the tree decades of sustained functionality. Based on experience the removal of this limb is likely to cause upper crown failure in wind events (removal of this limb will also cause major wounding/oxygen ingress) with photosynthate loss and subsequent decay undermining its adjacent trunk – this will seriously mechanically compromise the trees upper crown to deal with wind load.
I recommend removing the line covered flags, setting a pole to attach them to, because of the status of this tree we need to discourage climbing of this tree by our children, that means keeping the adults out too. By the time we have set up the exclusion zones (PEZ) for this tree, we will only have people walking under her, so further reducing risk (and people pressure).
Because of the stress the Albizia trees are already under it is possible that another limb failure may occur post treatment works (the trees will need integration time – up to five years), the goal in the meantime is to mitigate risk through establishing exclusion zones backed with the fall arrest system (Maypole Rigs) discussed.
With regard T5 (no Maypole planned for this tree) I recommend sustaining this trees integrity/reducing risk through establishing an exclusion zone and light pruning.
Parent And Child Trees
I see the installation of native Ficus species (Child trees) to engulf host trees (Parent trees) as being the best means to maximise space, whilst utilising the established woody trunks/root plates of the existing trees and compartmentalising them. The restoration of the current treed sites as part of the health management of the existing trees will also facilitate the optimal future health of the replacement Fig trees. By growing Figs on the avenue trees this saves using space between the avenue trees for tree replacements.
The natural precedent of Fig trees growing on and engulfing host trees is a phenomenon that is classic to S.E. Queensland (and the tropics) and is a best practise means to replace local veteran trees with new ones. This strategy is brilliant for stabilising veteran trees (such as the avenue trees) whilst providing an established body for the Fig tree to grow on, as well as being an excellent way to grow a native tree over one listed as a weed species. With consideration of local trees to grow as child trees I recommend two species – Ficus obliqua (Evergreen) the Small leaved Fig and F. virens (deciduous) the white Fig.
As a means to assist the engulfment of the replacement Fig trees I recommend the utilisation of Coir (coconut fibre) tubing, this enables the acceleration of the establishment process as well as help target the root system of the establishing Fig tree/ soil/root area. I recommend installing three Figs per tree (F. virens on the Albizia trees), and three Figs (F. obliqua on the Tipuana
trees). Each tree to have 3 Coir tubes per tree linking the Figs to ground, each tube to be split and filled with leaf litter/humus to accelerate the process. I recommend that the figs be installed low enough to the ground to be irrigated (hosed) once per month during establishment phase.
Key site modifications (Ref: T1 and T3) needed to reduce risk and reduce stress loads on trees
To help accommodate the needed site improvements around T1 I strongly recommend the relocation of the trampoline and potentially the swing set, at least to the edge of the trees canopy. As well as it being important to reduce people pressure within this trees root zone with the long term in mind we also need to reduce people’s exposure to potential risk from this tree. I see the need for T1 to be an exclusion zone for most if not all of its dripline (bar Bricabrack lane as an access route).
Likewise with regard T3 the fire pit needs relocating to beyond the trees canopy. In the long term the constant radiation of the soil/ soils microbiology will significantly reduce the lifespan of this tree.
At the heart of Crystal Waters there is a treed avenue (Ref: T1-T5) in need of human support if the avenue is to have a sustainable future.
This report is a result of a request from Ally Bing of the Crystal Waters Landscape community sub group for professional arboricultural advice.
This report has been drafted as a professional document though is free of charge, it specifically covers five of the main avenue trees but relates to the whole avenue of Bricabrack lane. Personally I elected to take on this work as I see a great opportunity to be in service to the Avenue trees, the community, as well as to cocreate a precedent for Ecovillages globally to take on proactive tree care projects.
For these trees to be integrated into a replacement canopy moving forward action needs to be taken now. The course that
I recommend is for the Committee, the Co-op and the community to discuss and agree on an action plan, a plan that reflects the needs of the trees and the community, that values and integrates the two. It’s my job as an experienced Project Manager interested in championing this cause to help the community see what I see as a long term management plan, to then mediate the steps to bring that into reality. I will assist this process through running a 40 minute presentation with a question and answer session, I suggest doing so via the community Eco-centre.
The management steps I am to initiate to enable a successful outcome are as follows
- To achieve the support of the CW Landscape Committee, Markets managers, Co-operative and community, this will involve careful discussion, demonstration and negotiation to achieve the objective of giving the trees sufficient space to better interact with their soil environment, to therefore be able to improve their health and biomechanical status
- To share this report with the Stakeholders I have a history with, with a means to gauge the kind of support I can attract for the trees (this was already acted on with the relevant parties at the time of completing the 1st draft of this report)
- To plan the engineering components, particularly in association with the Maypoles rigs and prop (T1 and T4)
- To Price The Associated Costs Necessary To Gauge Project Cost And Management
- With the aim to cover the associated costs through running a number of workshops (to the Australian arboricultural profession and allied professions concerned with tree management) I will ascertain a budget as a means to allocate funds to pay for the works. The number of workshops and trees I aim to service per operational step will feature in an Operations Plan (to be developed)
- To gauge from the Co-operative what is willing to be given in support of this proposed project, i.e. use of the Eco-centre and CW accommodation to help keep workshop costs down and to build revenue for the proposed restoration project.
The practical steps I recommend to follow to enable a successful outcome.
- In association with the Landscape Committee to map out the areas for People Exclusion Zones, Vertical Inoculation, Nutrient Beds, Plant Systems and Cellular Confinement Systems (for market pads and people access walkways
- Working with the Landscape Committee to relocate the trampoline, swings and fire pit
- To establish an order of trees to be treated based on priority and workshop funding, to then treat each tree in succession (Maypole Rig, Nutrient Bed, Plant System, Cellular Confinement System, tree pruning and Fig tree planting)
- To establish a maintenance plan
- To discuss with the Committee news of any intended development projects that are likely to impact on any of the trees discussed in the report
To help establish a benchmark for Eco Villages globally with a proactive tree management project such as this, I intend to further develop this report as an arboricultural article and an article for the Ecovillage community Australia wide. Should I gain approval to project manage this proposed project subject to funding, I aim to record and promote the restoration process in a series of future articles.