Campus trees on the mend after ring-barking

The three camphor trees along Stanley Road on middle campus that were stripped of their bark in December last year are responding well to treatment after arborist and conservation forester Riaan van Zyl applied "tree paste" to the stems.

Some trees are "girdled" for the bark's medicinal value, some because they are alien and deemed to be a "biological blot on the landscape".

But Van Zyl's "medicine" is doing the trick for the woody trio on middle campus.

"We've applied a tree paste made of vermiculture, extract of equisetum, stinging nettle, compost tea, and clay," he said. "This prevents or reduces the potential for pathological infections and promotes the trees' vitality."

The initial harvesting last year was done in a particularly severe manner, says Van Zyl.

"In most places more than 50% of the stems' circumference was stripped of bark."

Because of their macro-porous nature, camphor trees (Cinnamomum camphora) are able to maintain vitality and sap flow, and by retaining sap flow they maintain life in their older year rings, he adds.

"When tree bark is mechanically damaged and loosened from the live wood, there are two main concerns: infection by pathogens, and loss of vitality due to disturbed sap flow," he explained.

"By its nature the bark will try to cover the tree stem again and form new growth to facilitate this. Should there be some live meristematic tissue – cambium – it should differentiate into wound wood and bark. In time this re-growth, together with the re-growth from the bark edges remaining, will re-form the cylinder of protective bark around the stem."

(Members of the campus community are encouraged to report any ring-barking incidents or suspicious activity to Campus Protection Services at Burnage on ext 2222.)

Story by Helen Swingler. Image supplied.