|Circumstances:||broadly tailored, rising in all however moist soils, solar to mild shade|
|Seed Dispersal:||wind, but additionally water and tools|
|Seed Banking:||lower than 1 yr|
|Allelopathy:||Allelopathic to each softwood and hardwood tree species|
Ailanthus altissima (Tree of Heaven or Ailanthus) is a member of the quassia household, Simaroubaceae, native to northeast and central China, and Taiwan, however now presently an invasive weed all through a lot of the world. It’s a deciduous tree which grows quickly and might attain as much as 25 m tall, not often 35 m, with a trunk as much as 1 m diameter, not often 1.5 m diameter. The frequent title is a direct translation of the Indonesian title ailanto for a carefully associated species in the identical genus. Different frequent names embrace china sumac, copal tree, stinktree and ghetto palm.
The tree is often planted in closely polluted areas as it’s tolerant of each particulate and chemical pollution, in addition to saline soils. Outdoors these areas, it ought to by no means be planted because of its invasive nature.
The bark of the tree is easy and light-weight gray, whereas the stems are reddish or chestnut. Its massive, compound leaves are organized alternately on the stem, and might be 30–60 cm lengthy (often as much as 1 m lengthy on vigorous younger sprouts) and comprise 11-33 leaflets, often as much as 41 leaflets. Every leaflet has one to 3 tooth on either side, near the bottom. This helps distinguish it from sumacs (Rhus spp.).
The flowers are small, yellow-green to reddish, produced in late spring to mid summer time in panicles as much as 30 cm lengthy. It’s dioecious, with timber being both all male or all feminine. The seed is 5 mm diameter, encapsulated in a samara 4 cm lengthy and 1 cm broad; the samara is twisted, making it spin because it falls, helping wind dispersal. Feminine timber can produce greater than 300,000 seeds in a yr. All components of the tree produce an disagreeable odour, suggestive of rancid cashews, with male flowers having the strongest odor.
In total look, it’s considerably just like some species of sumac; Staghorn Sumac Rhus typhina might be distinguished by sumac’s crimson and barely furry stems, in addition to leaves which might be serrated, as an alternative of getting the bottom tooth of A. altissima. Easy Sumac Rhus glabra, additionally lacks the bottom tooth of A. altissima. Ailanthus additionally grows a lot taller than all sumac species. Seedlings of the Black walnut (Juglans nigra) may typically be mistaken for this plant, however their trunks are extra slender as a sapling.
Ailanthus is an opportunistic species, thriving in full solar and in disturbed areas. It does, nevertheless, exhibit some shade tolerance. It spreads aggressively each by seeds and vegetatively, by root sprouts. It may well resprout quickly after being lower. Ailanthus is among the many most tolerant of all tree species to air pollution, together with sulfur dioxide, and excessive soil acidity corresponding to that from acid mine drainage (as little as pH 4.1). It has been famous as drought-tolerant, storing water in its root system. It’s continuously discovered alongside highways and railroad tracks, in deserted tons in cities, on deserted mining websites, and in different areas the place few timber can survive. Alongside highways it typically varieties dense thickets during which few different tree species are current.
Ailanthus produces allelopathic chemical substances, which inhibit the expansion of different crops. Resistance in numerous plant species has been proven to extend with publicity; populations with out prior publicity to the chemical substances are most vulnerable to them. A number of crops are resistant to those chemical substances and kind associations with Ailanthus in areas the place it’s dominant, corresponding to alongside highways.
Folks have recommended many components to Ailanthus’ success at naturalising, together with the absence of bugs consuming the plant, lack of publicity of native crops to the Ailanthus’ allelopathy, and the widespread human disturbances which favour the tree. Regional variation has begun to point out all through its vary, with timber within the colder northern areas producing heavier seeds than these in hotter areas.
Tree of Heaven is a well-liked decorative tree in China, valued for its tolerance of adverse rising situations, and its makes use of in Chinese language conventional drugs. The bark is used to deal with dysentery and different bowel illnesses. A tincture of the root-bark has been used efficiently in cardiac palpitation, bronchial asthma and epilepsy. The leaves are additionally used to feed silkworms of the moth Samia cynthia, which produces silk that’s stronger and cheaper than mulberry silk, though with inferior gloss and texture. There are additionally information of the wooden from this tree being utilized in China. Below the synonymous title “A. glandulosa“, an extract of the bark is usually touted as an natural homeopathic treatment for numerous illnesses. Nonetheless, taken in massive doses, the bark extract is extremely poisonous.
It was first launched to Europe (France and England) by a French Jesuit priest getting back from Nanking in 1751. It was delivered to the US by William Hamilton, a gardener in Philadelphia in 1784 and shortly grew to become a favoured decorative tree in parks and gardens. By 1840, it was out there in lots of nurseries and was planted as a decorative. The tree arrived within the Western U.S. with the Chinese language immigrants who labored the gold mines in California. To at the present time many deserted mines have massive colonies of it.
Within the panorama these timber may cause issues due to their aggressive nature and weak branching habits. As a rule, they shouldn’t be planted exterior of their native vary, and feminine timber ought to be killed or saved lower to the bottom to forestall additional seed manufacturing. Male timber might be grown as a fast-replenishing postwood crop or hedge by coppicing on the floor each few years.
Tree-of-heaven has change into a problematic invasive species in lots of areas with heat temperate climates, particularly in North America, because of its aggressive unfold, vigorous progress and allelopathic chemical substances. It typically grows instantly up towards a constructing or construction, the place the roots can harm sewers and housing foundations. The timber develop quickly and produce many offspring of their root neighborhood. In addition they shed many small branches at common intervals. It’s an agricultural pest as properly. These undesirable qualities typically lead land and enterprise homeowners to eradicate the plant.
Many various strategies of management have been tried and one of the best contain prevention in addition to eradication. Technique of eradication might be bodily, thermal, managerial, organic, or chemical. A mix of those might be best, although they should be suitable. Bodily strategies are fascinating because of their excessive selectivity, however are very labour intensive and thus dearer. Hand-pulling is a extremely efficient option to take away younger seedlings earlier than the event of a faucet root, however thereafter it’s ineffective. Reducing and hand digging are choices for bigger timber, however the former will produce stump sprout which is able to must be managed later and the latter may be very time consuming and is barely sensible for small infestations. Girdling, the elimination of the cambial tissue with a hand axe or machete, is efficient for very massive timber, although re-sprouting typically happens. Thermal management, i.e. managed burning, can also be efficient at eradicating the seen portion of timber, however sprouts will happen shortly after. These strategies might be counter-productive if not carried out commonly. On their very own they’re best in locations with small infestations or in areas with pretty sturdy shade or competitors. The foundation programs will finally change into exhausted and die if mechanical or thermal management is completed completely and constantly, although this may occasionally take a number of years.
Managerial management isn’t efficient with controlling ailanthus as native timber can’t compete simply with the tree and it’s unpalatable to animals that would doubtlessly graze on it. Organic management, the usage of bugs or ailments, can also be not in use for ailanthus eradication. Chemical management, nevertheless, is kind of profitable, particularly when mixed with mechanical strategies. Foliar herbicide sprays are very efficient when crops are in full leaf, however are troublesome to make use of when fascinating crops are within the neighborhood. Additionally very massive timber might be out of attain. Herbicides for this use embrace the non-selective glyphosate, although care should be taken as it’s mildly poisonous to animals and particularly to aquatic life. Its commerce names embrace Accord and Roundup, although the latter incorporates different dangerous surfactants which can be extra poisonous than the herbicide itself. Triclopyr is another choice and is selective for woody crops, making it a more sensible choice for delicate areas. Additionally it is non-toxic to fish, although it may be poisonous to waterfowl. It’s bought underneath model names corresponding to Garlon. Foliar purposes of glyphosate have been proven to be barely more practical than triclopyr. Dicamba, imazapyr and metsulfuron methyl are additionally efficient, however haven’t been examined extensively with ailanthus.
Different chemical strategies for controlling ailanthus embrace a basal bark software of oil-soluble triclopyr in late winter or early spring. This technique requires no chopping, however is barely efficient on timber with a diameter of 15 cm (6 inches) or much less. For bigger timber, an efficient technique is to chop off strips of bark on the trunk in the course of the summer time and spray a 100% focus of triclopyr, solely about 1 or 2 ml per lower, inside a couple of minutes. The tree shouldn’t be lower all the way in which round in a hoop, however quite solely a hoop with three to six cm (1 to 2 inch) items of residing bark in between every lower. Reducing a full ring will kill the higher a part of the tree and trigger root suckers to sprout. Lastly, timber might be lower down and the stump handled with any of the above herbicides, although they should be utilized instantly after chopping. That is best in the course of the rising season.
- Mowing: As with most timber, mowing of seedlings is kind of efficient
- Girdling: Girdling is efficient for killing the tops, however the plant will resprout
- Coppicing: Coppicing of feminine timber is an efficient technique for stopping seed manufacturing. This must be finished pretty typically, because the resprouts shortly develop sturdy sufficient to start manufacturing
- Grinding: Sprouts from the outer root system are frequent, if potential the world ought to be mowed for not less than 1 yr after grinding.
- Pulling: Seedlings and saplings pull simply as a result of shallow root programs
- Flame: Managed brush fires will girdle on the floor.
- Systemic herbicides (artificial): Glyphosate is efficient each as a twig and as a stump remedy, however reapplications could also be vital.
- Biocontrols (microorganisms): Verticillium can kill the plant, however could be inappropriate as a biocontrol because of it is lengthy life within the soil.
- Biocontrols (animal): A number of insect species are being thought-about as biocontrols.
- Grazing: Goats will strip the bark, together with the bark of enormous timber. Cattle will eat the seedlings. Deer don’t present management.
- Disposal: All components might be composted, together with seeds, since they’ve a short-lived dormancy. The resinous sap might pose an issue for small chippers.
- Swearingen, Jil M.; Pannill, Phillip (2006). “Tree-of-heaven”. Plant Conservation Alliance’s Alien Plant Working Group. Nationwide Park Service. http://www.nps.gov/crops/alien/reality/aial1.htm. Retrieved 2007-06-05.
- Flora of Taiwan: Ailanthus altissima var. tanakai
- Heisey, R.M. (1990). Allelopathic and Herbicidal Results of Extracts from Tree of Heaven. Amer. J. Bot. 77 (5): 662-670.
- Hoshovsky, M. (1988). Aspect Stewardship Summary for Ailanthus altissima. The Nature Conservancy, Arlington, Virginia, USA.
- Lawrence, J. G., Colwell, A., & Sexton, O. J. (1991). The Ecological Affect of Allelopathy in Ailanthus altissima (Simaroubaceae). Amer. J. Bot. 78 (7): 948-958.
- Woodworker’s Web site Affiliation: Ailanthus altissima Wooden
- Introduction of Non-native crops to Massachusetts
- Nationwide Park Service reality sheet
- U.S. Forest Service Database entry on distribution and incidence
- U.S. Forest Service database web page with particulars on invasiveness and management