Two dead Norfolk Island pine trees will be removed from Granite Island to make the area safe for the public.
National Parks and Wildlife Service SA Fleurieu District Ranger Paul Unsworth, said the trees, believed to be more than 100 years old, have died from a combination of old age, termites and drought.
He said they and another three Norfolk Island pines had been showing signs of deteriorating health for several years, with rangers trying to save them by watering them during dry periods.
“When one of the pines blew over in a storm last July, there was evidence of termite attack, with a subsequent arborist inspection showing termites were also present in the remaining trees.
“National Park rangers arranged for the trees to be treated and also increased watering and fertilising, as well as aerating the soil.
“Unfortunately, however, two of the trees have died and are a risk to public safety.
“We would have loved to have kept these old trees alive and we are still working on the remaining trees to give them the best chance of survival, but unfortunately we are dealing with very old trees and there are no guarantees of success,” Mr Unsworth said.
“Norfolk Island Pines can live for 150 years in ideal environmental conditions. We have a photo of this area which we believe is from 1915. The pines are several metres tall, so to have them last this long in the shallow Granite Island soils is perhaps more than we might have expected.”
Mr Unsworth said the southern side of the island was being planted with vegetation similar to what would have been there prior to it being cleared.
“However, given the north shore area has more of a heritage feel as part of the old Port Victor and links to Victor Harbor township, we will keep this theme going and will replace the Norfolk Island pines with new ones.”
In the coming months, a part-time ranger will be employed by National Parks and Wildlife Service SA to improve the presentation of the lawns and gardens on Granite Island.