White Ash tree

White Ash tree

The White Ash tree, or Fraxinus americana, is a type of ash tree that is native to eastern and central North America.

Description

White ash trees grow between 60 to 100 feet tall on average, with a 2 to 3 foot trunk diameter. It is the largest of the ash trees found in North America. The leaves are opposite, and have between 5 and 9 leaflets. The bark ranges in color from yellow-brown to light grey and has deep furrows.

White Ash leaves

Distribution

The White ash tree is found only in the central and eastern parts of North America, ranging as far north as Nova Scotia, south into northern Florida, and west into the upper areas of Texas and parts of Iowa. Habitats include floodplain woodlands, upland woodlands, shaded gravelly seeps, high riverbanks, limestone glades, and in city parks.

Ecological Importance

White Ash hosts many species of insects, which feed on parts of the tree. At least 280 arthropods rely on White Ash trees as a source of food and shelter. Additionally, White Ash trees provide habitat and food for many vertebrates, such as squirrels, deer, various birds, and mice. Ash trees also play an important role in nutrient and water cycling in forests.

Threats

Due to the accidental introduction of the Emerald Ash Borer, ash trees have seen a significant decrease in population, and this has led to many adverse ecological effects. Widespread ash mortality severely alters forest habitats and dynamics. This causes loss of habitat and food for many organisms, including 44 species of arthropods that feed exclusively on ash trees.

Additionally, loss of ash trees, and therefore an increase in sunlight on forest floors, may cause an increase in the spread of invasive species, such as honeysuckle, multiflora rose, and autumn olive.

Widespread ash mortality also can alter soil pH, mineral concentrations, and soil moisture levels, affecting nutrient and water availability for nearby trees and other organisms living in the soil.

Emerald Ash Borer