Your decision on its future
The tree has a relatively large fungal bracket of Ganoderma resinaceum at the base, this fresh fungal fruiting body is growing above last season’s fruiting body.
Although the tree is suffering from a fungal infection, it poses a broadly acceptable risk and work is not required from a health and safety point of view.
Ganoderma resinaceum on oaks affects the roots and root plate, almost only ever below ground. This is a white rot which selectively removes lignin from the wood. At advanced stages of decay, the infected wood becomes increasingly softer and loses its stiffness but not toughness. Finally, the decayed wood breaks right down, giving a soft spongy consistency.
The presence of last year’s bracket and the relatively large size indicate that the oak tree T1 has had the infection for a number of years. The tree is small in stature not exposed to high winds, being protected by adjacent buildings and the bus shelter.
The wounds on the exposed roots all round the tree, caused by lawnmower blades, are the most likely entry point for the fungi. Healthy trees with no wounds are very rarely infected with parasitic fungi.
The whole root plate is raised, giving presence to the exposed roots, exposed roots being unusual in the species. This suggests there may be some object or obstruction under the tree preventing the normal colonisation of the rooting area available. Perhaps the previous trees stump / root plate is still in place or the soil below the planted tree is compacted prohibiting root ingress. Whatever the reason for the defective footplate growth habit, the actual infection would appear to be a cause of strimmer/mower damage to surface roots and then fungal infection.
The tree may compartmentalise the fungi, using its own defence mechanisms and grow into a mature oak. However, there will always be the issue and concern of the reduced rooting zone and the weakness caused by the infection until the tree is able to fully compartmentalises the fungi and produce stabilising reaction wood. To give the tree the best chance of surviving for the longest possible time, kill the grass and mulch around the tree, at least the whole area under the crown. This will remove the competition from grass for nutrients and water. Apply a granular fertiliser onto the roots to feed the tree (ask at the garden centre for the best one, NPK slow release).
Thinking of the future, consider planting a replacement tree now, I suggest the area to the west of the bench may be appropriate dependant on underground services. Plant the tree and ensure soil amelioration is undertaken, use of mycorrhizal fungi to help establishment. Ensure that the nursery planting and aftercare guide is adhered to. When or if the oak T1 begins to struggle, the new tree can then become the successor.
Ideford Parish Council would like to get the views of all residents as to the future of the oak tree. Please submit comments before Thursday 11th February 2021.
Please email your comments to Mrs Juliette Thompson – the Parish Clerk email@example.com or call on 07731 145077 / 07427 145320
Post your comments at the mailbox of Stapley Cottage
Or speak to any of the Parish Councillors