Oak vs Honeysuckle

After removing an Autumn Olive shrub and its attending Japanese Honeysuckle, I found a nice young Shingle Oak struggling with its own honeysuckle infestation.  Growing conditions definitely improved for the oak when the Autumn Olive came down.  Now it needs freedom from the honeysuckle.

Japanese Honeysuckle is a perennial vine that uses woody plants as support for its vertical growth.  The spiraling growth habit allows it to climb even a limbless tree trunk.  The vine will climb into the treetop and exploit this position in the sun by extending its leafy twigs above the oak leaves.

The Japanese Honeysuckle Vine bears no aerial roots, so the plant must maintain its connection to the soil.  Multiple vines are usually found at the base of any affected tree.

Vines travel along the ground until they reach a vertical structure.  At each node along the vine, roots penetrate the soil and additional vines are produced.  In this way the vines can effectively carpet the ground and all surrounding vegetation.  The end result is a solid stand of Japanese Honeysuckle.

Both the supporting tree and the entwining vine continue to increase their size.  The vine becomes an unyielding collar around which the tree spreads as it grows.  The entrapped vine physically weakens the trunk and cuts off the movement of plant nutrients.  Eventually the tree top, too weakened to support the mass of vines, will fall.

I removed the vines from the tree, but the tree may not be able to heal itself.  This could easily develop into a weak place that will break later in the tree’s life.

The tree is now honeysuckle free.  I’ll monitor its progress to see how it reacts to its newfound freedom.  If the top looks like it’s beginning to fail, I may cut the tree off at the ground and let it regrow.  Oaks are very good about producing healthy stump sprouts and in a good location could easily be back up to 12 or 15 feet in just a few years.  That may be a better long term option for this tree.

Ants Still up a Tree

A Shingle Oak is not supposed to turn brown in the middle of August. I’ve been watching this tree grow for 25 years and even during the worst of our droughts it has never turned brown this early in the year. A sight like this tells me that something is wrong.

There are very few branches low enough to be easily examined, but these showed the same pattern of dead leaf clusters as the rest of the tree. This is the tree that attracted so many ants in early July. The ants have not changed their behavior and are still pouring up and down the tree trunk. They’ve got to be responding to something and I’ve got to believe that it has something to do with the mysterious dead spots.

I could find no leaves in the intermediate stages between brightly healthy and dead. Perhaps the catastrophic event has passed and the tree is no longer at risk. That’s possible, but the presence of the ants kept me searching.

Then I found some mottled brown nodules growing on a stem. Galls had developed in response to insect eggs laid on the oak stem. Inside each gall would be a developing larva, safely contained within the growth produced by the oak. But galls on an oak are a common occurrence. I think it would be hard to find an oak tree that didn’t have at least a few galls. I continued my search.

An ant tending a gall. This ant would not be so protective if it was not getting something of value from the gall. Certain Cynipid Wasp larvae produce galls that ooze a sweet liquid. The ants stay on duty collecting the sweet substance and in so doing, protect the gall from predators. It’s hard to believe that a few galls could cause a massive leaf die-off on the tree.

Well, there turned out to be more than a few galls. Gall villages were scattered along every branch. This amount of gall activity could certainly hurt the tree. It would also explain the thousands of ants traveling up and down the tree trunk. It’s also possible that the ants are inadvertently responsible for the clusters of dead leaves scattered across the tree. Cynipid Wasp galls don’t normally reach this density because they are destroyed by a parasitic wasp species that lays its eggs inside the gall. The parasite consumes the Cynipid larvae which reduces the stress on the tree. The ants are such good protectors that the parasitic wasp can’t get close to the gall, so the Cynipid numbers grow out of control.

Many dead stems can be found on the ground around the tree. These dead sections don’t show any signs of galls. Maybe galls located further down the stem effectively girdled the branch and caused the tip to die. I’ll just have to keep watching and see what develops. I’m sure the tree will be able to recover next year, but I don’t know if it can survive too many consecutive seasons of this kind of stress.

Trees in a Clearing

I always enjoy running across a Beech tree. Across the entire property I’ve probably encountered fewer than a dozen specimens. This is a small example of the species, but it still displays a handsome collection of leaves beginning to show their autumn colors.

I found the Beech growing in this small opening in the cedars. The hole in the canopy isn’t more than 20 feet in diameter and wouldn’t take more than a couple of good trees to fill it. I wonder what the chances are that the Beech could win against its competitors and claim a position in the canopy.

The primary competition for sunlight is going to come from various oaks. This species can be particularly difficult to accurately identify. Although the various characters predominately point to Blackjack Oak, Quercus marilandica; this is a species that crosses to produce a number of different hybrids. Someday I’ll have to spend time studying the different trees to see if I can identify what types of crosses are growing here. Regardless of the parentage, these are rapidly growing trees that would have no trouble overtopping the Beech.

Fragrant Sumac, Rhus aromatica, is a shrub that will not hinder the growth of the Beech. Maximum height of this shrub is usually around ten feet. The branches tend to lean as they grow, so most of the specimens are more sprawling than upright. As an understory species it often supports itself on the branches of taller trees and works its way upward in this manner.

Chinquapin Oak, Quercus muehlenbergii, seedlings can be found just about anywhere at Blue Jay Barrens. This species doesn’t seem to put on the rapid growth of most other oak species. Instead of racing toward the sunlight, Chinquapin Oak progresses slowly and seems to get left behind as stunted specimens in the understory.

Shingle Oak, Quercus imbricaria, is another fast growing oak species. The oaks already have a head start on the Beech and will probably end up shading it as they move to fill the available space. It’ll be a few years before a clear winner will be decided and it’s hard to predict the outcome with any real certainty. The competition should be interesting to watch.