Arbor Week Activity

Trees matter! Collectively they add beauty to our urban landscapes, compliment architecture, screen unsightly views, provide privacy and contribute to a landscapes character and sense of place.

Tree management in all open spaces is important, and this is especially the case for schools. Correct planning and specification, correct planting, ensuring they establish and implementing good pruning practices combine to ensure a safer tree population. Tree selection is primarily about The right tree for the right space.

Appropriate site assessment and tree selection can have the following benefits.

• Reduce conflict between tree roots and adjacent infrastructure/buildings
• Reduce the incidence of pest and disease outbreaks by selecting resistant varieties of trees and better species diversity
• Increase plant performance by attributing species to particular site conditions
• Utilise drought tolerant plants to cope better with climatic changes
• Increased tree longevity so that tree benefits exceed the costs – the benefit of an urban tree is directly proportional to its crown size or volume and longevity in the landscape
• Reduced maintenance costs – pruning requirements can be reduced by selecting tree size and form (shape of the canopy/crown) to best suit the location
• Attractive school grounds that reinforce the pervading landscape and architectural character
• Reduced environmental demand – trees that have drought tolerance and are less reliant on irrigation or fertiliser in order to perform well.

With all these things in mind Logical Tree Management is offering a school the chance to win a FREE customised tree planting program. This is a great opportunity for your school to benefit from quality tree advice and to address any concerns about existing trees on your school site. After an initial consultation, our team will supply the trees and even do the planting for you.

To be in the running for this ‘Arbor Week’ activity complete this very simple statement… “We need trees because…..”  

Take the step to create your schools’ own urban forest and enhance the lives of your school community. To enter please fill in the entry form.

Fri 23 March 2012, Melbourne

What is Tree Biomechanics? And why should I care?

Tree Biomechanics is the mechanical study of trees. Trees are structures and must obey physical laws just like buildings and bridges. A basic understanding of how physical laws apply to trees and arboricultural practice is critical to improving one’s arboricultural knowledge.

This one-day workshop will review basic physical principles like force, movement, stress, and strain, to see how they apply to cabling, climbing, pruning, rigging, and tree risk assessment.

Dr. Kane has conducted research projects in all of these areas and will present his data to highlight practical considerations for working arborists.

testimonial…

…we had the pleasure of hosting Prof Brian Kane in Singapore in 2011. He spoke at our annual Arboriculture Seminar and also conducted a one-day standalone seminar… What is Tree Biomechanics?.. His workshop was very well received, with lots of practitioners giving a thumbs up …for making a not so easy topic easily understood. He is a fantastic speaker…

Kay, Centre for Urban Greenery and Ecologogy, Singapore

Fri 23 March 2011
Jika International
551 Heidelberg Rd
Fairfield Victoria

Melbourne’s City Square has been transformed with a magical forest maze of lush trees, nutcracker soldiers, an interactive story book, giant presents and of course the traditional nativity scene.

In consultation with the City of Melbourne, Tree Logic placed up to 20 large, living Hoop Pines in a forest maze with a centrepiece Christmas tree displaying an impressive show of lights and decorations. Christmas Square comes alive between the hours of 9.30 and 11pm each night in December.

And in the early hours of the morning, Tree Logic’s gnome (aka Peter Frank) can be seen tending to the trees… watering and ensuring the Hoop Pines are at their best for the parade of daily visitors experiencing the wonders of Melbourne’s new ‘Christmas Square’.

Read the article published in Herald Sun.

City of Melbourne mentions the trees also

The Separation Tree is a large River Red Gum (Eucalyptus camaldulensis) located at the Royal Botanical Gardens, Melbourne. On November 15 1850, the citizens of Melbourne gathered there to celebrate the news that Victoria had separated from NSW, giving the tree it’s great historical significance.

In August 2010, the Separation Tree was vandalised in an overnight attack when someone effectively ringbarked it, using an object which was likely to be an axe or machete to carve a forty cm strip around the circumference of the trunk which is approximately 3.8 metres.

Arborists at the Royal Botanical Gardens were uncertain about the tree’s survival and have done everything possible to ensure that the tree has every chance. Arborists used a techinique of patch grafting which involved reconnecting sections of vandalised bark that had been removed to encourage a reconnection of the trees tissues that transport nutrients and water to enable natural callous tissue to gradually enclose the wound.

Shade cloth was applied over the damaged area to retain moisture and protect the wound.  Water management has been closely observed and soil moisture sensing equipment installed to monitor long term health. Regular drip irrigation is occurring to 5m out beyond the canopy line and a bi-monthly program of sub-surface drenching is being applied with a pressurised soil probe.

In addition to these efforts, Tree Logic was commissioned to carry out a sucrose drenching treatment to add carbohydrates to the existing sub-surface layer.  The treatment involved a sub-surface injection of a Sucrose and Raffinose solution via a pressurised soil probe. Six (6) litres of solution was injected into each square metre of available soil within the drip line of the tree.
Carbohydrates are required by plants for the initiation of new roots. Generally these carbohydrates are generated through the process of photosynthesis. By providing sucrose at specific rates in and around the root zone of the plant, the carbohydrates required for growth are immediately available for use thus limiting the plants reliance on the crown to provide these assimilates.

In addition, carbohydrates such as sucrose affect the plants sugar sensing-systems and initiate changes in gene expression and subsequently plant growth resulting in the repression of the photosynthetic genes, decreased rates of net photosynthesis and carbon remobilisation in favour of enhanced root development (Percival, 2005). Carbohydrates are also known to stimulate beneficial soil microbial and fungal rhizosphere that assist in plant nutrient uptake.

Under the constant watch of arborists, we watch and wait to see if this 400 year old historical beauty will survive.

REFERENCE
Percival, G.C. (2005). The Influence of Carbohydrates on Root Vigour of Urban Trees, Proceedings for the 9th International Society of Arboriculture – Australian Chapter National Conference

Relocating a 1st World War Memorial

Tree Logic was commissioned to relocate a small 3.5m Lone Pine as part of the Camberwell Civic Centre refurbishment. The Lone Pine was planted as a living memorial to Australian and New Zealand soldiers who fought in Gallipoli. The tradition began when seeds from a solitary Turkish Pine tree (Pinus brutia) located at the war site in Turkey were brought back to Australia and original Lone Pines were grown.

The relocation of the Lone Pine was required at short notice and the new season spring growth had begun. At this time of year the risk of transplant injury to established trees is at its greatest. To overcome a lack of preparation time, a large rootball measuring 2.8m in diameter was dug to preserve as much root mass as possible to avoid potential transplant injury.

A novel lifting technique was applied. The tree was excavated, lifted and carried out using a steel frame constructed around the base of the tree. Steel pipe inserted across the frame and beneath the rootball formed a cradle underneath, which was then bound to the frame and lifted.  The final weight of the tree and frame was around 7.5 tonne.

Despite weather delays the Lone Pine eventually found its new home just 15 metres away from where it was originally planted.

Most Australian Christmas traditions have predominately derived from our British heritage, as well as European influences and later the American commercial influences. The tradition of the Christmas tree in Australia has its roots in Victorian England when Queen Victoria and her German Prince, Albert, popularized its use in England during the mid nineteenth century.  The fashion quickly spread throughout the colonies and the Christmas tree has since become an integral element of Australian Christmas celebrations.

The tradition of the Christmas tree has pagan ritual origins.  Originally, evergreen trees were symbols of life and fertility among some European cultures.  They were used in ceremonies and festivals during the winter solstice.  This symbol was merged with the celebration of Christmas leading to the tree’s Christian beginnings.

Some traditions (wrongly) credit St Boniface an 8th century a monk from Crediton, Devonshire and two common versions of the legend persist. In one, St Boniface is said to have used a triangular sprig of Fir tree to symbolize the holy trinity to unbelievers whom subsequently adopted the fir tree as a Christian symbol.  The other popular version is that St Boniface cut down the legendary Donar Oak (also known as Thor’s Oak) sacred to the local pagan Germanic peoples.  This version again divides with some versions believing St Boniface planted a fir tree there, but the most common idea is that a fir tree grew spontaneously in the oak’s place.

The custom of erecting and decorating a Christmas tree can be historically traced to 16th century Livonia (present-day Estonia and Latvia) and 16th century Northern Germany.  Though the Christmas tree custom spread through Germany, the tradition did not become widespread throughout Europe until 19th Century.  In England the first Christmas tree was erected by the Georgian royal Queen Charlotte in Windsor Lodge in 1800.

In Europe, the original and still most common tree used is the Norway Spruce (Picea abies).  Other popular choices include Silver Fir (Abies alba), Nordmann Fir (Abies nordmanniana), Noble Fir (Abies procera), Serbian Spruce (Picea omorika), Scots Pine (Pinus sylvestris), and Swiss Pine (Pinus cembra). In Australia, the Monterey Pine (Pinus radiata), a species originating in California, and grown in South-eastern Australia, is the most widely used tree.  Available as a cut tree, it is a common sight throughout the country in the lead up to Christmas eve.

Artificial trees were introduced in the mid 20th century and brought the best of kitsch to Christmas, while “environmentally friendly” living Christmas trees became commercially available during the 1980’s.  The most popular choice being Australian native Norfolk Island Pine (Araucaria heterophylla) Norway Spruce (Picea abies) and the Dwarf White Spruce (Picea glauca ‘Conica’).

Just as the BBQ prawn is replacing the roast turkey on Christmas day and the Easter Bilby the Easter Bunny, it would seem a natural progression to draw upon local flora for Christmas decorations.  In fact Australian flora has appeared as Christmas decoration since the mid 19th Century with several Australian native plants becoming associated with Christmas.  It was refreshing for the Europeans settlers who were used to celebrating Christmas during the bleak winter dormancy to be surrounded by colourful summer wildflowers.  Due to their flowering period coinciding with the Christmas season such plants are referred to as ‘Christmas plants’.  The association with Christmas is usually reflected in the local ‘common names’.  Some examples include: Christmas Bells (Blandfordia grandiflora, B.nobilis), NSW Christmas Bush (Ceratopetalum gummiferum), Victorian Christmas Bush (Prostanthera lasianthos), Tasmanian and South Australian Christmas Bush (Bursaria spinosa), Christmas Orchid (Calanthe triplicate), and Christmas Tree (Nuytsia floribunda).  Even tree fern fronds (probably Dicksonia antarctica) were popular as Christmas decorations in 19th Century Australia.

Norfolk Island Pine (Araucaria heterophylla)

Australia has several indigenous conifers, other than previously mentioned include: Bunya Pine (Araucaria bidwilii), Hoop Pine (Araucaria cunninghamii), Norfolk Island Pine (Araucaria heterophylla), Huon Pine (Lagarostrobos franklinii), Cheshunt Pine (Diselma archeri), Kauri Pine (Agathis robusta), Celery-top Pine (Phyllocladus aspleniifolius), King Billy Pine (Athrotaxis selaginoides), Pencil pine (Athrotaxis cupressoides), and Cypress Pines (Callitris spp.). Of this group, few have a form or growth rate that readily lends itself as a substitute to the Norway Spruce or Monterey Pine. Norfolk Island and Hoop Pines however are exceptions with their fast growth rate and regular form created by whorled of branching.

Although we admit to not having the same fashion influence as Queen Victoria, it will be interesting to test the acceptance of native conifers during Australian festive seasons in the future.

Logical Tree Management was recently commissioned by Mal’s Environmental & Ecological Services to assist in the rescue and relocation of fauna from 88 trees including Conifers and Sydney Blue Gums.  The trees were being removed to make way for a new development in Wantirna South.

The trees were between 30 and 50 years old and were too immature for hollow formation but after further inspection five Common Ringtail Possum dreys were discovered. Two females and her three young were removed from dreys, placed into two nesting boxes and taken by the LTM climbers to Llewellyn Park Reserve where they were safely relocated to mature Swamp Gums. Llewellyn Park Reserve was chosen for the wildlife relocation as it was close to the site and contained high quality habitat that would suit the ringtail possums.

Introduction

Malcolm Legg from Mal’s Environmental & Ecological Services was commissioned by Michael Tracy of Logical Tree Management to rescue and relocate fauna from 88 trees including conifers and Sydney Blue Gums before removal. The fauna rescue and relocation was conducted on the 17th and 18th of October 2011.

Study Site

The site is situated on the corners of High Street and Stud Road Wantirna South (Melways reference number 72 J3) and was the former Nu-brick property which has been bought and is currently being turned into a housing estate by Mirvac Home Builders (Vic) Pty Ltd. The trees marked for removal reside along the north-western boundaries and include Conifers, and Sydney Blue Gum. The trees are between 30 and 50 years old and were planted by the former property owners. No indigenous trees were present. All trees were too immature for hollow formation but after initial site inspection on the 10-10-11 Common Ringtail Possum dreys and bird nests were noted to be present within the trees.

Methods

All trees were examined for wildlife with the use of a large cherry picker and equipment used included gloves, noose, net on a pole, hessian sacks and nesting boxes for possums.

Discussion

During tree examination five Common Ringtail Possum dreys were found of which only two were occupied by possums. Two females and three young were removed from the dreys. They were placed in two nesting boxes and taken to Llewellyn Park Reserve approximately 1km (refer to map 1) away and placed in two Swamp Gums by one of Logical Tree Management tree climbers. All possums that were detected at the capture site were caught and no injuries occurred.

Six Australian Magpie and 3 Little Wattlebird nests were also located within the trees marked for removal but all were old and no babies or eggs were present.
Llewellyn Park Reserve was chosen for wildlife relocation as it was close to the site and contained high quality habitat that would suit the ringtail possums. The habitat within this reserve along Blind Creek is at a much higher quality than from their original site. James Rose (Team Leader of Bushland Management) from the City of Knox permitted such a relocation within their municipality.

Mal’s Environmental & Ecological Services
ABN 70 165 787 370
PO Box 247
Shoreham 3916
Ph 03 59 863 448
M 0438 898 325
E malcolmlegg@bigpond.com

Xanthogaleruca luteola

Spring is not the only thing in the air this time of year.  For those owners of Elm trees, spring also brings with it the reemergence of the Elm Leaf Beetle.  Elm Leaf Beetle has been in Victoria for over two decades and is now a widespread and serious pest for owners and managers of susceptible Elm trees.

Both the larvae and adults feed on foliage causing the leaves to desiccate, turn brown and fall to the ground.  Severe foliage browning and defoliation results in a loss of amenity and more importantly if left unchecked, repeated seasonal defoliation can have serious consequences on tree health and implications for tree longevity, rendering affected specimens susceptible to other environmental stresses.

In addition, the beetle can be an indoor, household nuisance in autumn and spring for households and buildings in close proximity to trees infested with the pest.  The adult beetles are inadvertent invaders.  In autumn, adult beetles overwinter by hiding in cracks and crevices and may enter houses and other buildings to hide, emerging again in spring.

European Elms are susceptible to attack. The most common types of European elms found throughout Victoria include the English Elm (Ulmus procera), Dutch Elm (U. x hollandica), Golden Wych Elm (U. glabra ‘Lutescens’), Variegated Elm (Ulmus minor ‘Variegata’) and Weeping Elm (U. glabra ‘Pendula’), are susceptible to the beetle.  Asian Elms such as the Chinese Elm (Ulmus parvifolia) and the closely related Zelkova (Zelkova serrata) are relatively resistant to Elm leaf beetle.  The Hackberry (Celtis spp.), also closely related to the Elm is not known to be susceptible.

Elm Leaf Beetle can be readily controlled through the use of insecticides.  Tree Logic’s Horticultural Services uses low toxicity insecticides applied through soil or trunk injection techniques to provide effective control for up to two seasons.

More info and booking form…

It never rains but it pours

River Red Gum (Eucalyptus camaldulensis) experiencing extended inundation

Trees have evolved to occupy a wide range of environmental niches and while a minority of species have adapted to succeed in sporadically or permanently flooded areas most are not well equipped to deal with waterlogged soils.

Different species and individual trees have developed a range of flood tolerance levels but it is difficult to predict how long a tree can tolerate waterlogged soils. In part, the duration and timing of the water-logging event, the complexity of the soil as well as individual tree characteristics all affect the outcome for the tree.

Waterlogged or saturated soils are those where the voids between the soil particles are entirely filled with water and occur when water enters soil faster than it can drain away under gravity.  The duration of a water-logging event is influenced by the rate of water input and the rate of outflow or drainage. Topography will influence lateral flow; however soil structure and texture is critical in influencing vertical drainage.

Soil is made up of solid material, accounting for around 40-60% of the soil by volume, and the spaces between or pores. Soil texture determines pore size, while soil structure influences the inter connectivity of the pores. The ease with which water passes from pore to pore is referred to as hydraulic conductivity.  Small pore size and poor connectivity, such as occurs in clay soils, will drain slower than sandy soils which although having lower porosity than clay soils have larger pores that are efficient in the movement of water and air.

The immediate effect of waterlogging is to significantly reduce the movement of oxygen from the atmosphere to the soil and the root surface where it is used for respiration.   A lack of oxygen is the principle cause of injury to roots and other parts of the tree.  Oxygen depletion in waterlogged soils occurs rapidly.  The maximum amount of dissolved oxygen in still water is a little over 3% of that in a similar volume of air.   Available oxygen is quickly used by respiring roots and aerobic microorganisms creating an oxygen depleted or anaerobic environment.

Oxygen deprived or anaerobic soils lead to the production and accumulation of, gases such as carbon dioxide, ethylene, methane, hydrogen, nitrogen, sulfur and cyanogenic compounds, some of which are toxic to trees influencing plant growth and function.  The soil ecology is altered as anaerobic soil organisms replace aerobic organisms.  Soil pH becomes increasingly acidic influencing nutrient availability.  Anaerobic organisms, primarily bacteria alter soil chemistry and cause de-nitrification and reductions in manganese, iron and sulfur.

Waterlogging can be fatal to trees. Mature, well-established trees are generally more tolerant of waterlogging than senescent trees or seedlings of the same species.  Healthy trees are generally able to withstand periods of waterlogging better than trees that were already under stress. Waterlogging during periods of growth tends to be more harmful than during period of plant dormancy.

Signs of waterlogging include the yellowing or paleness and mottling of older leaves.  Growth is stunted and internodal extension may cease.  Wilting of young shoots and leaves may occur and brittle green leaves present.  Premature senescence and abscission of leaves (older leaves first) can occur. Fibrous root death occurs and the death of small ephemeral woody roots may follow.  The dead roots become blackened and the bark may peel away.  Prolonged waterlogging can result in root decay rendering trees susceptible to wind-throw.  Notably the anaerobic decay of organic material including dead roots in waterlogged soil creates a characteristic sour sulfurous smell.

Waterlogging alters the biochemical functioning of trees, impairing defense mechanisms and increasing the potential for trees to succumb to attack from opportunistic pests and diseases. Soil-borne fungal diseases that tolerate low soil oxygen levels include Phytophthora spp. and Pythium spp.

Following periods of extended waterlogging, tree management should aim to enhance tree vigor whilst avoiding further stress. The addition of a light dose of nitrogen, potassium and phosphorous can assist, though the addition of micronutrients should generally be avoided.  Pruning that removes live foliage or foliage-bearing branches should be avoided to conserve the trees energy supplies and photosynthetic potential and capacity.  Mulching may encourage the return of aerobic micro and macro soil organisms improving nutrient cycling.

Knowing your site conditions and if the area may be prone to periodic inundation or extended waterlogged, will allow appropriate plant selection to suit the location.  Some ornamental Australian native tree species tolerant of temporary inundation include some of the Bottlebrush (Callistemon viminalis, C. ‘Harkness’ and C. ‘Kings Park Special’), Argyle Apple (Eucalyptus cinerea), Plunkett Mallee (Eucalyptus curtisii), Spotted Gum (Corymbia maculata), and Water Gum (Tristaniopsis laurina).  Some exotic trees include the River Birch (Betula nigra), Black Tupelo (Nyssa sylvatica), Dawn Redwood (Metasequoia glyptostroboides) and Callery Pear varieties (Pyrus calleryana var.).

Simple.  Elegant. Formal. Symmetrical. Broad descriptors for contemporary garden design. Effective. The role of small trees as structural components of the landscape has become more prolific as replacement for the larger tree canopy. However as previous newsletter articles have indicated, (Newsletter No. 21) the allocation of space for smaller trees in some developments has been insufficient. The domain of the smaller tree within landscape design has usually been that of the exotic deciduous landscape components that conform to a resilient formal approach of European design.

Emerging now as an equally effective landscape component are the smaller varieties of Eucalypts. The contrasts in foliage, texture and colour are noted design elements offering a unique contrast in form. They are great in conjunction with the exotics and provide broader design options for gardeners, designers and clients.

Eucalyptus leucoxylon ‘Eucky Dwarf’

A past criticism of smaller varieties has been a lack of trials with seed stock from provenance based, small form parent plants that revert back to ‘true’ size defeating the planting intent. But Austraflora’s Daniel Mansfield, amongst other propagators, has outlined a number of smaller Eucalypts that are available as good design options. Work within developing a seed bank as well as grafting for size, form and vigour has produced solid varieties including:

• Dwarf form of Eucalyptus leucoxylon ‘Eucky Dwarf’ offering abundance of red flowers.
• Eucalyptus mannifera ‘Little Spotty’ offering structural form and textured bark.
• Colourful Eucalyptus landsdowneana ssp. albopurpurea ‘Purple Patch’ offering yellow foliage and bright red stems within new growth with seasonal purple flowers.
• Dwarf forms of Eucalyptus pauciflora ‘Little Snowman’ with textured white bark.
• Dwarf Eucalyptus elata ‘Dry White’ with a squat clean straight trunk.
• West Australian derived Eucalyptus olivacea ‘Summer Scentsation’ with textured buds and flowers.
• Eucalyptus viridus ‘Winter Light’ upright form and massed cream flowers.
• Eucalyptus stellulata ‘Little Star’ small multi-stemmed structural form.

Colourful Eucalyptus landsdowneana ssp. albopurpurea ‘Purple Patch’