Ailanthus altissima

Ailanthus altissima

• Family: Simaroubaceae

• (sim-a-roo-bA-C-A)

• Native to: China

Common Name

Ailanthus altissima

Common Name

Tree Of Heaven

Ailanthus altissima

AKA

Ailanthus

Chinese Sumac

ECOLOGICAL IMPACTS:• Uses lots of

water• Increases

soil pH• Decreases

C/N ratio• Changes

habitats – converts native vegetation stands, particularly riparian habitat

Affected Areas - N America

Source: USDA

Invasive Status in Europe

National Register of Big Trees

• Location: Westmoreland, VA • Circumference: 244” • Height: 55 feet• Spread: 48 feet• Points: 311• Year Nominated: 2009• Nominator/s: • Carmean, Williamson, Wilson, VA

Plant ID

• Leaves

compound 18-24'' long with 13-25 leaflets arranged alternately on stem, lanceolate, 3-5'' long with 2-4 teeth near

base. • Twigs

reddish-brown with a distinctive leaf scar

Ailanthus altissima

FLOWERS• Panicles, 8-16'' long,

yellowish-green, mid-June• Dioecious (male and

female flowers on separate plants

• A fragrance that “could chase people out of the garden” gives it its derisive nicknames of "ghetto palm" and "stink tree".

Fruits• Samara,

furrowed winged seed cluster

• seeds not very

nutritious for (and therefore not very attractive to) animals

•A. altissima is a "classic weed" species (Stobel, 1991)

INVASIVE ADVANTAGE:

Allelopathy

• can suppress competition from other plants (particularly natives) with allelopathic chemicals

• Its leaves are toxic to over 40 native species of plants.

Resource Availability

• modifies nutrient cycle; leaves decompose at much faster rates than native species

Competition

• Can grow up to 1m per year, out-competing native seedlings.

• Has the ability to quickly colonize disturbed areas.

• Very fast growing, dense canopy shades out native species.

Escape from Biotic Constraints

• in China it had 30 natural predators, here, not so much.

• Here, no large animals eat it, it is unpalatable to herbivores.

• Reportedly NOT A host of Asian Long-horned Beetle (ALB)

Habitat:

• Highly adaptable and pollution tolerant, grows in the poorest of soils, in full sun to partial shade.

• It does not grow well is full shade or in flooded conditions.

• Ailanthus can overwinter in northern climates, and is resistant to both frost and drought, giving it a clear competitive edge over native species.

Spread • Reproduces sexually and

vegetatively. • Prolific seeder; One study

reports that an individual tree can produce as many as 325,000 seeds per year.

• Seeds are wind dispersed easily, often taking advantage of the wind-tunnel effect of roadways. Seeds can hang out on tree all winter.

• Germinate with as little as 3% light cue.

• The plant also spreads by aggressive suckers, or runners. Re-sprouts vigorously from cut stumps.

Because of these attributes, Pennsylvania state botanists have dubbed A. altissima

Tree of Hell

NON-CHEMICAL CONTROLS:

Integrated Vegetation Management (IVM)

manual

cultural

biological

CULTURAL

• Prohibition• CT – invasive –

banned• MA – prohibited• NH – prohibited

invasive species• VT – Class B noxious

Weed

CULTURAL

• Remove as much Tree of Heaven (ToH) without disturbing other vegetation, to slow down regrowth of ToH

• Competitive ground cover to retard re-growth (eg crownvetch)

• “Any method must be diligently and continuously pursued to eradicate this invasive weed. For the occasional stubborn individual tree, the Division of Forestry recommends flame-throwers and bulldozers as a means of permanent removal. Burning doesn’t work unless you get the whole root, which generally is not the case.”

MECHANICAL• Young seedlings may be pulled or dug up, preferably when soil is

moist. Care must be taken to remove the entire plant including all roots and fragments, as these will almost certainly regrow.

• Cutting alone is usually counter-productive because Ailanthus responds by producing large numbers of stump sprouts and root suckers. However, for small infestations, repeated cutting of sprouts over time can exhaust the plants reserves and may be successful if continued for many years or where heavy shade exists.

• If possible, the initial cutting should be in early summer in order to impact the tree when its root reserves are lowest. A Subsequent cutting late in the season removes stores to support it in winter. Mow new shoots from cut trees regularly for several years to gradually weaken root systems. Cutting large seed producing female trees would at least temporarily reduce spread by this method.

BIOLOGICAL• Natural control methods are limited. The tree of heaven

is preyed upon by very few insects due to the chemicals in its wood and bark.

• The fungus Verticillium albo-antrum kills A. altissima, but unfortunately the fungus spores remain in the area of the dead tree and will kill many species of native trees that might germinate in the infected location.

• Several fungal pathogens are being investigated as potential biological controls for ailanthus. Two of these, Verticillium dahliae and Fusarium oxysporum, have been isolated from dead and dying ailanthus trees in New York and in southern and western Virginia. A disease affecting ailanthus in PA was studied using inoculations in the lab and on canopy field trees; the agent was identified to be Verticillium albo-atrumand.

CHEMICAL CONTROL

• Gets fully 2/3 of any research article‘s publication space allotment for control measures.

• The most effective method of ailanthus control seems to be through the use of herbicides, which may be applied as a foliar spray (to the leaves), basal bark, cut stump, or hack and squirt treatment.

• Keep in mind that it is relatively easy to kill the above ground portion of ailanthus trees, you need to kill or seriously damage the root system to prevent or limit stump sprouting and root suckering.

• Always be extremely careful with herbicide applications in the vicinity of valuable ornamental shrubs and trees.

SOURCES / REFERENCES• Isolation and characterization of seed germination inhibitors from ailanthus

altissima, Lisa McFarland, Univ Maine Orono MS Chemistry Thesis, 1996• VT Exotic Invasive Species Fact Sheet Series VT Fish & Wildlife• Dept of Environmental Protection, VT, Invasive Plant Information Sheet

Ailanthus altissima• Schall, M.J. and D.D. Davis. 2009. Verticillium wilt of Ailanthus altissima:

susceptibility of associated tree species. Plant Disease 93:1158-1162. • Managing Tree of Heaven on Roadsides Penn State Dept of Horticulture

Fact Sheet• Jil M. Swearingen, National Park Service, Center for Urban Ecology,

Washington, DC• Powerpoint presentation, Univ of Nevada, Reno • Texasinvasives.org• Alien Invasive Species of VA – VA Dept of Conservation & Recreation• Pacific Island Ecosystems at Risk (PIER)