Tree Watch
The Elm Avenue
What’s happening in the Elm Avenue? Recently the Council have arranged to undertake maintenance work s on the Elms. This involves trimming some of the dead branches and generally cleaning up the lines of the tree. The Council will also be engaging an arborist to assess the elms health. As they are quite old trees they need to be monitored and assessed to keep them in good health. FoCP have requested a copy of the arborist’s report to gain an understanding of the condition of these trees. It is important to consider how these old trees will be replaced and the FoCP will continue to be involved in discussions with the Council regarding issues of this nature in the Park.
Cork Oaks
In September, FoCP reported to Council that the three cork oaks in the park were looking very sick. Council responded by putting a possum barrier on one tree and having an assessment of all three trees. The assessment is reproduced below. We hope this action will be effective.
As per our discussion I have looked into this further and I still feel that my initial diagnosis of water logging of the soil is the most likely cause. Quercus suber naturally occur within the open forests of Spain and Portugal and prefer siliceous soils, in Australian terms a very sandy loam that is deeply drained and well aerated. They are also a species that is very susceptible to waterlogging which exhibits itself in symptoms that are similar in fashion to a plant that is under stress from lack of water. This consists of leaves with dried, curled tips and margins and even de-foliation and thinning of the crown. I feel that the aeration works are the best option, and the trees should not be mulched. These trees have also had years of drought that they have adapted to over an extended period of time but the recent rains have occurred in a very short time span limiting the trees ability to adapt.
In response to the below email I would assume that the term "Blight" is referring to a pathological attack on the trees. This has also been investigated with consideration being given to Pythium spiculum, Phytophthora cinnamomi. Botryosphaeria corticola and Lithocarpus densiflora were ruled out due to the lack of canker wounding that would be seen on the stems or trunks of the trees. Phytophthora is not species specific and as such if it was prevalent within this section of the reserve then there would be many plants effected. It also exhibits itself via large dead patches within the crown, not even defoliation as is evidenced within these trees. Pythium spiculum is not noted within Australia and exhibits a different pattern of leaf margin dieback to what is being seen here. Also if it was prevalent I would expect all three trees to be showing similar symptoms.
Whilst possum browsing is not the major issue within these trees, the tree that has been banded was showing signs that the healthy leaves were beginning to be browsed. The rate of recovery of these trees will be governed by the amount of healthy foliage present. As the trees have many buds on the branches that will soon shoot the band was installed as a preventative measure as possum attack on weakened trees compounds the already present issues and often inhibits recovery. The second tree showing poor health is being monitored but banding of this tree is harder as it is in close proximity to overhead wires which gives easy access to possums. When banding trees these limbs are normally removed to prevent access, but I am currently unwilling to complete this work on an unhealthy tree as it also leads to increased stress.
North-east corner of Caulfield Park
In the past two years, with the removal of the cypresses that used to dominate this section of the park, and the erection of the ugly water tanks, this section of the park has become quite bleak and barren . The final blow came when a eucalypt shed one of its branches on the pumping station during a recent storm and the whole tree was removed. FoCP approached the Council about this state of affairs.
In response, most of trees listed below have been planted for screening near the tanks and pumping station.
In response, most of trees listed below have been planted for screening near the tanks and pumping station.
- 2 Angophra costata
- 3 Waterhousea floribunda 'Whisper'
- 5 Callitris rhomboidea
- 4 Elaeocarpus reticulatus
