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Emerald ash borer discovered in Kentucky

Bad news for Kentucky's ash trees

The emerald ash borer (EAB) has been found in two Kentucky counties. One of the infestations was found in a residential area of Jessamine County (in the Lexington, KY area), and the other infestation site was found in a wooded area of Shelby County (in the Louisville, KY area),

It was probably inevitable that this insect would be brought into Kentucky, but I am very sorry to hear that it has arrived.

A news report about the discovery of the emerald ash borers suggests two important ways that Kentuckians can help limit the spread of the tree-killing insect:

Kentuckians are asked to avoid transporting firewood, even within the state, and to not buy out-of-state firewood. Firewood could include infected ash wood.

People with ash trees are asked to inspect them. Signs that the insect is present include death of the upper tree canopy, sprouts growing from roots and the trunk, loose bark, signs of woodpecker activity and D-shaped holes in the truck. [sic]

Source: "Insect endangers Ky. ash trees" by Andy Mead, published in the May 26, 2009, Lexington Herald-Leader.

If you think you have an EAB infestation, call the EAB Hotline at 1-866-322-4512, or the state entomologist, (859) 257-5838. (These are the telephone numbers provided in the above-cited Lexington Herald-Leader article.)

More information about the EAB is available online at the Emerald Ash Borer information website or at the UK Entomology Emerald Ash Borer Page. Also check out the previous Tree Notes articles under the label "Emerald ash borer".

Credit: Kentucky maps from Wikipedia

Natural shape of the pin oak

Don't try to change the pin oak's shape by pruning.

The pin oak (Quercus palustris) has a characteristic shape. It has a long central trunk. Its upper branches always lift to the sky. Its middle branches extend more or less horizontally from the trunk. Its lowest branches always droop toward the ground.

The pin oak's shape is usually described as pyramidal or sometimes as conical. The unique angles of its branching and the presence of many pins --short stubs on the trunk -- are reliable clues to its identification.

A pin oak tree will do its best to maintain the characteristic shape of its species. If its lower branches are removed, the next branches that are lowest on the trunk will gradually begin drooping toward the ground.  For this reason, pin oaks are not very good for planting along narrow streets or in parking lots.

I hate to see a pin oak that's been deformed by excessive pruning in an effort to keep its lower branches from drooping into human zones. Here's an example of what I'm talking about -- a much abused pin oak that grows in a field of asphalt near the Bradford Square Mall in Hopkinsville, KY.

Why don't landscapers think about the size and shape and spread a tree will have in maturity when they plant it? Thinking ahead would be so much better than spending years fighting the natural tendencies of a tree. Just my opinion.

Photo of pin oak in winter provided by Robert Underwood.

Ten invasive non-native trees of the South

Alien trees that threaten southern ecosystems

The USDA Forest Service Southern Regional Task Force for the Assessment of Nonnative Invasive Species has compiled a list of invaders that they believe to be a very grave threat to forest and grassland ecosystems of the South. This "High Priority" list includes 121 non-native, invasive species -- and 10 of them are trees.

On the list:

1. Tree of heaven, ailanthus -- Ailanthus altissima
2. Silktree, mimosa -- Albizia julibrissin
3. Russian olive -- Elaeagnus angustifolia
4. Chinaberry tree -- Melia azedarach
5. White mulberry -- Morus alba
6. Paulownia, princess tree, royal empress -- Paulownia tomentosa
7. Octopus tree, schefflera (in southern Florida) -- Schefflera actinophylla
8. Brazilian peppertree (in Florida and southern Texas) -- Schinus terebinthifolius
9. Saltcedar -- Tamarix ramosissima
10. Tallowtree, Chinese tallowtree -- Triadica sebifera

Eight of these trees also appear on the Invasive Plants of the Eastern United States list at invasive.org.

According to the Executive Order on Invasive Species signed by President Clinton in 1999, an alien (non-native) species is invasive when its "introduction does or is likely to cause economic or environmental harm or harm to human health."

May 22 is The International Day for Biological Diversity, and the theme is "Invasive Alien Species". A booklet, Invasive Alien Species: A Threat to Biodiversity (pdf) can be downloaded. In observation of the day, I've written this post to help increase awareness of some invasive trees that are (or may become) a big problem in the southern United States.

Buzzard Tree

Dead tree a preferred perch for raptors

I've been watching this old oak tree for years. It stands by itself on a hilltop along a highway I travel frequently. The weather has been hard on it in recent winters. It has lost several branches, and I'm not sure it's going to leaf out this year.

Today, when I passed by the old oak on my way home from work, several buzzards were resting in its upper branches. From the top of the tree on top of the hill, they have an unobstructed view for miles around. The lack of leaves is a plus.

I an still hoping that the tree will eventually get some leaves this year. But if it has died, I hope the landowner will leave it standing for the birds. Raptors (birds of prey), such as the turkey buzzards in the photo, enjoy perching on dead trees, and the location of this one is perfect for them.

Other users of dead trees

Cavity nesters who need dead trees include woodpeckers, bluebirds, nuthatches, chickadees, house wrens, tree swallows, screech owls and more. Birds that build nests in the branches of dead trees include eagles.

Other wildlife, such as squirrels, deer mice, weasels, raccoons, and bats, use hollows in dead trees for shelter.  In fact, the Natural Resources Conservation Service states that dead trees provide homes for more than 400 types of birds, mammals, and amphibians.

Related post: Woodman, spare that (dead) tree

This article is my contribution to the 100th Festival of I and the Bird which will be published on May 14, 2009, on the Nature Blog Network's blog.

How to identify common tree leaves

Leaf shapes and characteristics of five common types of trees

In human families, the members often resemble each other. Trees are much the same. When you learn the general appearance of one tree's leaf, you can often recognize its relatives.  You can say, "That leaf looks like a willow," just as you might say, "That boy looks like a Johnson."

And keep in mind that there are always exceptions -- some leaves don't look exactly like their relatives in every detail.

Here are some generalizations that will help you recognize five common tree families:

Maples

Long-stalked, toothed, broad leaves, shaped somewhat like a hand with the fingers spread ("palmate lobes").

Left: Sugar maple
Right: Red maple

Willows

Long, slender leaves, arranged alternately on long thin branches. The trees are usually found in wet areas.

Left:  Black willow

Right: Pussy willow

Poplars

Broad, shiny leaves with a heart shape, toothed edge, and bright green color. Long slender stems allow the leaves to dance in a breeze.

Left: (Bigtooth aspen)

Right: (Plains cottonwood)

Image credit for Plains cottonwood: USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. Vol. 1: 591.

Oaks

Oak leaves vary greatly in shape from one species to the next. Even a single oak tree may show a lot of variation in leaf shape! Some species of oaks have bristles at the ends of the leaf lobes; some do not. However, one thing that can be said about most oak leaves is that they are leathery in texture. Also, many of them are a little lighter and duller in color on the underside. Look on the ground under the tree for evidence of acorns.

Left: Pin oak

Right: Bur oak

Elms

Elms usually have oval leaves up to 3 inches in length, pointed on one end, with a sawtooth edge and a short stem. The veins are V-shaped and regularly spaced, almost like a feather, and the leaves are rough on the underside. The bottom of the leaf is usually uneven or unequal where it joins the stem.

Left: American elm

Right: Winged elm