Then call a "tree surgeon" quick.
The decaying parts of trees are caused by destructive fungi. The damage is manifested by cavities, holes or rotten parts on the trunk, stems, branches, and roots.
"Saving damaged trees has been one of the concerns of the Department of Environment and Natural Resources-Ecosystems Research and Development Bureau (DENR-ERDB)," said ERDB director Dr. Agustin Piñol.
The Los Baños, Laguna-based ERDB has research specialists who are adept at saving decaying trees, Piñol said.
One of them is ERDB pathologist and "tree surgeon" Marcelina Pacho, who said, "Tree surgery is the answer to decays, especially when the damage is extensive."
Decays in trees, according to Pacho, start as mere injuries or cuts caused by insects, animals, cars, people or other causal organisms.
The injury becomes the entry point for fungus spores that germinate and ramify in the cells and tissues through time. The damage, as it becomes bigger and bigger, affects the flow of nutrients within the tree.
If not controlled, it can cause the tree to die. Likewise, a decaying tree is hazardous to lives and property.
Pacho said the tree repair procedure is similar to dental work and requires knowledge and expertise.
To prevent further damage, the rotten portion of the tree should be removed and the cavity cleaned. Antiseptics and healing aids must be applied. If the cavity is shallow, it is usually left unfilled but must be shellacked and waterproofed.
Pacho emphasized that if the cavity is weak and might cause the tree to fall down, braces and fillings are used.
"We usually use cement mixtures but boulders or Styrofoam can also serve as fillers," she said, adding though that Styrofoam might melt during the summer.
A number of trees in the country have been saved because of tree surgery, the ERDB said. Most of them are in parks, churchyards and private lands.
"We have been asked to conduct tree surgery on those trees because they have historical or sentimental values according to the requesting groups and individuals," Pacho said.
Some of the trees that the ERDB has saved through surgery are the century-old raintree (acacia) in front of the St. Francis of Assisi parish church in Sariaya, Quezon; a century-old siar tree in front of the Immaculate Concepcion Parish Basilica Minore Cathedral in Malolos City (Bulacan); a 30-year-old narra tree inside the Pasonanca Park in Zamboanga City; and an acacia mangium near the Western Mindanao Agricultural Research Center in Ipil, Zamboanga Sibugay.