Europe, W. Asia
"Based on regional floras, invasive plant publications, and websites, English ivy is most invasive in the Pacific Northwest...
English ivy seed is dispersed by birds. In North America, birds that distribute English ivy seed included European starling, cedar waxwing, American robin, Steller's jay, mockingbird, and house sparrow. Snow and Snow provide a list of birds that may act as potential dispersers of English ivy seed in the United Kingdom (see Importance to Wildlife and Livestock). After digesting the fruit, birds may regurgitate English ivy seed one at a time. One literature review suggested that English ivy seed is deposited in bird droppings as well as regurgitated; however, a seed germination study found no evidence that English ivy seed is defecated by birds. Researchers in the Netherlands speculated that English ivy has an 80% chance of being dispersed to a forest if there is a seed source 3 feet (1 m) or less away, but at 3,000 feet (1,000 m) away, the probability decreases to nearly 0%...
Once English ivy begins to ascend a tree, its photosynthetic capacity increases due to increased light, which facilitates a transition to the adult growth phase...
One review from the United Kingdom suggested that English ivy grows most "vigorously" in shaded, moist sites on heavy, fertile soils [97]. However, on Potomac Island in Washington, DC, English ivy's biomass increased with increased light in upland sites...
In the Pacific Northwest, sites dominated by English ivy have lower diversity of mammals, birds, and amphibians compared to uninvaded sites, and appear to be good habitat only for rats. In California, English ivy is unused by most herbivores except nonnative rats. In South Carolina, the leaves of English ivy were important forage for white-tailed deer during the summer. In various parts of its European range, English ivy fruit is eaten by numerous native birds including blackcap, European robin, thrushes, and European starling. Wood pigeons are the only know predator of English ivy seed. English ivy foliage is subject to extremely low rates of herbivory in Great Britain." [1]
"Brought to North America by colonial settlers, English ivy was first documented in North America in Virginia around 1800. Since then English ivy has been widely cultivated as an ornamental, although its cultivation in Hawaii did not begin until the early 1900. In many places where it is planted, English ivy escapes cultivation to varying degrees and invades and persists in wildlands...
The America Ivy League was formed to promote the propagation and use of English ivy in landscaping and indoor gardening. It is occasionally recommended for landscaping to reduce fire hazard in seasonally dry areas (see Fuels). Historically, English ivy was used as a topical agent for its antifungal and antimicrobial properties." [1]
"In Denmark, farm animals including cattle, domestic sheep, geese, and peafowl eat the juvenile form of English ivy...
English ivy is sold as an ornamental plant by nurseries in the United States. It is widely planted in landscapes because of its evergreen foliage and dependability as a year-round ground cover. English ivy is planted for erosion control in parts of the United States and Serbia." [1]
[1] Waggy, Melissa A. 2010. Hedera helix. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: https://www.fs.fed.us /database/feis/plants/vine/hedhel/all.html [2020, July 9].
