The Ash tree is one of the most important riparian plants in North America. Worldwide there are over sixty species of trees in the genus Fraxinus. In Eastern North America; however, three are common . . . or where—the Green, White, and Black Ash. In the Shenandoah Valley of Virginia, Green Ash is one of the most prolific trees along streams, river bottoms, and wetlands. Unfortunately, Ash trees are disappearing from the American landscape as we know it. The culprit is the non-native Emerald Ash Borer and is the reason all three species are critically endangered.

A young, healthy Green Ash in Swoope, Virginia at the intersection of Trimbles Mill Road and Boy Scout Lane. Photo by R. Whitescarver 7/19

These trees thrive near water and are tolerant of many harsh urban environments such as road salt and traffic. They have been extensively planted along urban streets in America and also abroad.

Green Ash distribution in North America. Photo from Wikipedia.

Ecosystem Restoration

Ash trees are special because of its ability to restore natural systems. Its roots stabilize stream banks, its leaves feed both aquatic and terrestrial ecosystems and its branches provide shade and nesting sites for many animals.

Ash leaves are a critical food source for American frogs. The growth performance of Amphibian larvae is better with a diet of Green Ash leaves than with Red Maple leaves according to research published in Freshwater Biology. Red Maple is filling in the void left by the disappearance of Green Ash. Populations of many animals that perform best from Green Ash nourishment will be affected.

Growth Performance of Some Aquatic Insects Best With Ash Leaves

Both White and Green Ash leaves are some of the most nutritious and important foods for leaf-cutting and shredding aquatic insects. For example, two species of Mayflies studied in White Clay Creek in Pennsylvania grew best on a diet of White Ash leaves. Some Craneflies and Stoneflies also showed better growth performance on White Ash leaves than on other species of tree leaves studied, according to Dr. Bern Sweeney‘s research published by the Academy of Natural Sciences.

Green Ash is a Pioneer Tree

When we fenced the cows out of the Middle River on our farm, Mother Nature planted Green Ash trees by the hundreds in the buffer area between the pasture and river.

Healthy Green Ash tree with seeds. The seeds are dispersed by gravity, wind, and water. Photo by R. Whitescarver.

The trees were so thick I had to thin them out. We call this tree a pioneer tree because it can populate an area on its own; you don’t have to plant them as long as there are source trees nearby.

The Wood is Unique and has Quite a History

Leo Fender introduced the Telecaster electric guitar in 1951. Made from the wood from both White and Green Ash, this guitar broke the barriers in rock, country, and blues music. When you hear the sweet-talking guitar sounds from Keith Richards, Elvis Presley, Eric Clapton, B.B. King and Buck Owens it’s probably from a Fender Telecaster.

The Fender Telecaster electric guitar debuted in 1951 and was made from the wood of Ash. Photo from the Fender website.

Ash wood has some special qualities. For guitars, it is soft enough to work easily and has large open pores that according to the Fender website “makes it remarkably resonant and sweet-sounding, with clearly chiming highs, defined midrange, and strong low end.”

Preferred Wood For Baseball Bats

Ash wood has another special quality. When hit with a baseball it compresses and sends the ball away with a “trampoline effect.” That’s why many of the famous Louisville Slugger baseball bats are made from Ash wood. White Ash is preferred but Green Ash is often marketed as White Ash.

This Louisville Slugger is made from the wood from Ash trees, many from Green Ash which is often marketed as White Ash.

This wood is also popular in flooring, millwork, boxes, crates, baskets, and tool handles.

Emerald Ash Borer Discovered in Michigan in 2002

First discovered in Michigan in 2002, the Emerald Ash Borer has caused the destruction of almost all Black Ash trees and is moving south rapidly, destroying all Ash trees in its path.

Adult Emerald Ash Borer, photo from the Arbor Day Foundation website.

Several years ago I noticed some of our Green Ash trees dying. Later, I learned that the Virginia Department of Forestry was no longer recommending planting Green Ash along streams. Too bad, Green Ash was one of my “go-to” trees along hundreds of miles of streamside buffers when we fenced cattle out of streams during my tenure at USDA. It was a first-string player in our journey to restore the streams that feed the Chesapeake Bay. It’s one of the fastest-growing riparian trees and is one of the first trees to emerge out of a tree shelter. But no more. The Emerald Ash Borer is killing them.

How the Borer Kills the Tree

The Emerald Ash Borer adult lays her eggs in the crevices of the bark.

Emerald ash borer damage. The larvae eat the vascular system of the tree.

When the egg hatches the larvae bore into the cambium layer of the tree and consume the tree’s vascular system thus cutting off the tree’s ability to transport nutrients and water.

Dead mature Green Ash trees along Trimbles Mill road in Swoope, Virginia. Photo by R. Whitescarver, 7/19.

I Lament Its Demise

In a single lifetime, Ash trees will be gone from the landscape as we know it. Like the American Chestnut, once the greatest tree in America whose population has been minimized by a foreign fungus, and the Eastern Hemlock, being killed by the Adelgid Aphid, the Ash’s demise comes from an invasive, foreign species.

I feel a sense of hopelessness in our never-ending struggle with invasive species. Has invasiveness joined so many other anthropogenic vectors on the Malthusian “J” curve? Human population, atmospheric CO2 concentration, extreme weather events, algae blooms . . . invasiveness, it feels like exponential growth to me.

We cannot give up. Like the Musk Thistle population on our farm, we have it under control. And, like the American Chestnut tree, there are dedicated scientists, foresters, and volunteers that keep planting seeds of hope.

Hope For a Remnant Population

We have hope that a remnant population can be sustained by using systemic insecticide treatments, biological controls and selecting for trees with high tannin content. Ash species with high tannin content are resistant to the borer.

Diversity is the Key For Sustainability

The lesson in all this, is that a diversity of native trees is paramount for forest and stream health—isn’t that true for just about everything? I’ll end with a quote from one of my ecology heroes, Dr. Bern Sweeney, Distinguished Research Scientist at the Stroud Water Research Center.  The destruction caused by the Emerald Ash Borer “is a wake-up call that we ought to value each and every species in our forest and avoid any and all carelessness that might lead to the demise of any given species.  For the loss of each species in a forest is analogous to death by a thousand cuts for the ecosystem.”

The Answer—Plant More Trees

Rachael Vannetta, Celeste Horton, and Laura Yates love planting trees.