White ash trees face environmental threats

The white ash (Fraxinus americanna) is a fast-growing, long-lived tree that prefers deep, rich, somewhat moist soils.

It has tight, ridged bark and a compound leaf containing seven to 10 leaflets. The ash family is one of the few trees that have opposite leaf and branch structure. White ash produces a winged seed samara that is transported by the wind; these light seeds can blow up to 1,000 feet from the mother tree.

In Frederick County you often find ash growing out in the open, in old fields, young forest communities or in mixed forest associations in the mountainous areas growing alongside tulip poplar, red oak, white oak, hickory, black birch and maples. Under ideal conditions white ash can live a long time and grow to a large size. Old-growth ash can live up to 300 years and grow to 120 feet tall with a nearly 6-foot diameter.

Until recent times, ash was thought to be pest-free. That has changed dramatically with the onset of the emerald ash borer and ash decline. Ash decline is a complex disease that showed up in the mountainous regions of northwest Frederick County and surrounding areas about 10 years ago and is slowly killing many of the ash trees found there.

Diseased ash trees will display a thinning leaf canopy, which will eventually spread throughout the tree. The wood of the tree will have brown stains throughout the outer sap wood.

Emerald ash borer is an insect that bores into and kills ash trees. This insect pest has the potential to drastically reduce ash throughout the country. The first onslaught of this insect was noticed near Detroit in 2002 and has now spread throughout Michigan, Iowa, Kentucky, Ohio, Indiana and Pennsylvania, with localized populations found in West Virginia, Virginia, Maryland and other states.

So far, no signs of this insect have been found in Frederick County. In Michigan and Ohio, tens of millions of ash trees have died from this destructive insect.

Ash wood is light, strong, pliable and very shock-resistant. For these reasons, white ash has historically been the premier wood for baseball bats, with most being made from the lumber found in Pennsylvania and New York.

In 2001, professional baseball player Barry Bonds began using a maple bat and set the major league record for home runs with 73. Following that season, maple bats grew in popularity.

Maple is harder than ash so the baseball flies off a maple bat at a greater speed. Ash, on the other hand, has a bit more give and flexibility, which results in the springboard effect. It is believed that balls will fly a greater distance with an ash bat, and that an ash bat has a larger sweet spot than its maple counterpart.

Another difference is that maple splits apart, losing large pieces when it breaks, whereas ash bats splinter, rarely in large pieces. Most professional baseball leagues have banned "soft" maple bats that are made from red or silver maple, because they are considered unsafe. Maple bats made from "hard" sugar maple do not have the severe breakage problems as bats made from soft maple.

Black locusts

The abundant rain and cooler weather have provided us with some beautiful and extended blooms this spring. The tail end of the dogwoods is still evident and the native azalea and black locust are now coming into bloom.

Black locust (Robinia pseudoacacia) are found in abundance along roads or any area that receives full sunlight. The trees have a large, white compound flower that has a pleasing aroma.

The locust is a medium-sized tree that often grows in disturbed areas or in abandoned fields that are reforesting by natural means. The black locust belongs to a group known as pioneer or early successional trees, because they are the first individuals to colonize old fields. Locust trees grow quickly and do not live very long compared with other trees. Pioneer species establish the initial forest canopy, then give way to longer lived, larger-growing trees in a process known as forest succession.

Black locust can grow on a number of sites, especially very acidic soils. For this reason, locusts are often used in land reclamation projects. The locust tree is a nitrogen fixer so it can take nitrogen out of the air and deposit it in the soil, making it more fertile.

Locust wood is very hard and rot-resistant; it is often used for outdoor fence posts and makes excellent firewood. Locust honey is also prized for its sweet taste. The locust leaf is fed upon by locust leaf miner in late July or August. This feeding activity turns the leaf brown, which gives the tree a sickly appearance. Despite the appearance, the damage does not harm the hardy locust tree.

Article by FCFCDB

Nature Notes for 5/22/2011