Ian Williams, the Southwark tree officer for parks has issued an emergency tree felling notice for a sycamore in Dog Kennel Hill Open Space. The large tree sits next to the much-used ramp that goes down into the Sainsburys car park. On close inspection it turns out that the tree had extensive Kretzschmaria deusta fungus at the base. This fungus looks relatively inconsequential but is a very significant causer of sudden fracture of the trunk.
The tree was felled yesterday with the temporary closure of the path to the supermarket. We asked for any non-diseased wood to be left in the park but in fact most of it had the fungus in it and so had to be removed.
Stephen Govier writes:
” Brittle Cinder (Kretzschmaria deusta ) is a fungus considered to be one of the most dangerous to trees as it attacks the root system as well as the heartwood. Trees commonly affected are beech, sycamore and lime although it may occur on any species. It is parasitic on the roots and lower trunks of living hardwood and continues to consume the timber once its host has died.
Kretzschmaria deusta is dangerous for two main reasons. Firstly it attacks live trees. It decays the base of the tree, attacking the heartwood. This can often make the extent of decay within the tree difficult or impossible to identify. It can potentially cause stem failure without warning, particularly if the fruiting body has not been identified.
The second reason Kretzschmaria deusta is particular dangerous is because the fruiting body is difficult to spot. It is not an obvious fungal bracket. It instead grows first a white layer at the base of the tree when juvenile, then transforming into a black layer when mature. It can often look like a thin tar covering at the base of the tree. As the fruiting body only grows at the base of the tree, it can often be hidden by long grass, weeds or other plants within a dense understorey. This is one reason you may see experienced tree consultants kicking undergrowth away from the base of trees when carrying out an inspection.
As Kretzschmaria deusta can cause tree failure without warning, infected trees are often condemned as soon as the fungus has been identified, particularly if the tree is in a high risk location such as at a roadside or adjacent to a building. There is no cure for the infection and it can continue living on dead tree stumps after the rest of the tree has been removed. This makes controlling the disease difficult and we must instead be vigilant to spot infection before serious harm is caused.”
A pdf of the location of the tree has been supplied by the Council.
Here’s a pic of the tree trunk post felling