The Ailanthus Girdling Project - Spring 2014

Ailanthus (Ailanthus altissima) also known as tree of heaven occurs in several parts of Caumsett State Park along woodland edges and forest openings. As a fast-growing tree and a prolific seeder, Ailanthus can take over relatively sunny sites, replacing native plants. Able to grow under adverse conditions Ailanthus also produces a poisonous “ailanthene” in bark and leaves that helps limit competition posing a threat to Caumsett’s forest communities.

Downed native trees resulting from Super Storm Sandy produced open areas within Caumsett’s forest thereby creating potential sites for Ailanthus to establish itself. This situation combined with existing infestions of Ailanthus in the park spurred the eradication program into action. If cut Ailanthus responds by producing sprouts. Therefore a plan to employ girdling or belting was explored to avoid sprout re-growth. Vincent Simeone, a NYS Parks horticultural professional and Robert O’Brien, the NYS Parks Invasive Species Specialist, advised on a plan to girdle the trees. Girdling involves removing about a 2 inch wide band of bark around the tree trunk, using tools such a chisel. This process prevents the transport of carbohydrates above where the bark is stripped. Without carbohydrates, the tree slowly dies.

Simple tools such as this chisel is easy for volunteers to use and inexpensive to purchase. Safety glasses and gloves were also wore by volunteers.

In order to test the effectiveness of this technique a test site was established. All girdled trees were numbered. Data including circumference, sex (male/female) and percent of circumference girdled was recorded.

On March 22, 2014 eight volunteers met at Caumsett State Park Preserve to participate in the Park’s pilot project to eradicate Ailanthus.

ABOVE AND TO THE RIGHT: The group removed a 2″ strip of bark from the trunks of 75 invasive male and female Ailanthus trees.

Above Ailanthus trees were girdled for a second time during the summer of 2014.

Dead Ailanthus trees along woodland edge in test site. Summer of 2015

This female Ailanthus tree located in an open sunny area within the test site continued to live during the 2015 summer despite being girdled twice.


A report describing the preliminary findings of the test site and the Excel spread sheet describing each tree are available below:

Spread Sheet | Report