Ailanthus altissima - Tree of Heaven

Drawing of Foliage and Seeds of Ailanthus altissimaAilanthus altissima is native to Asia, and began its journey west by being introduced to Europe in 1751 by a French Jesuit preist who brought it from Nanking, China to England.  The first known specimen was brought into the United States a few decades later by William Hamilton, who planted this species in Philadelphia (Shah 1997).  People admired the beautiful foliage of these fast-growing trees, and for over a century have been planting it as an ornamental, although the males of the species often emit a foul-smelling odor.

The first records of this species in Massachusetts, as presented on the map below, are in part based on occurrences of cultivated individuals.  Even though these individuals did not occur naturally, their records are important, since is these plants that were the first vectors that allowed A. altissima to expand its range.  It is curious that as recently as 1996 (see Weatherbee) there is still no record for this species in Berkshire County.  A possible explanation for this may be lack of suitable habitat (disturbed urban areas) for the plants to grow.  Also, although the first published record found for Suffolk County is 1978, it is almost certain that A. altissima was present in the Boston area prior to the twentieth century, since this plant was often planted along sidewalks in the major East Coast cities of the United States (Shah 1997).

One of the problems with A. altissima is that female trees produce large quantities of wind-dispersed seeds, and these seeds can germinate in a wide variety of disturbed habitats, including urban and suburban areas and along railroad tracks.  This species is known to have a tolerance for polluted environments (Shah 1997) which explains its success along roadsides and other highly disturbed habitats.

A. altissima is considered an "Invasive" species by some.  But in reality most of the habitats it invades are places where not many other species can grow.  Its only fault may be decreasing the biodiversity of urban weeds; the other species it outcompetes are often non-native themselves.  And we are all to blame for this, since the recent success of this species is due in part to the alteration of the landscape by humans.

Occurrences of Ailanthus altissima over time
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