Leaves

I’ve always loved leaves. When I was young, I viewed the leaf covered forest floor as if it were covered with treasure. I couldn’t wait to dig in and see what I could discover. I regularly told my parents that I was making a leaf collection for school, just so I could get permission to explore the woods. To make it a truthful story, I always turned my collections over to my elementary school teachers. The confused teachers would usually explain that I could better use my time by working on the assigned lessons, instead of trying for extra credit with a never ending series of leaf collections. A little show of confusion and fear usually earned me the extra credit despite the teacher’s initial reaction.

What you find on the woodland floor is not always a true representation of the species mix on that site. At first glance the Blue Jay Barrens woods would appear to be primarily oaks. This is just an illusion created by the fact that the oaks are usually the last to drop their leaves, so they cover everything that has fallen before.

In some ways, collecting leaves was somewhat pointless. Many species of trees cannot be identified solely from the leaf. Oaks are a good example. Depth of sinuses, number of lobes, shape and length of points are all variable. A single tree can exhibit leaves of such varied shapes that you might mistake each shape for a different species. To make a positive ID, the leaves must still be attached to the tree so you can also view the buds and twigs.

Even if you can’t be sure of the oak identification, you can make some accurate generalizations. Round lobe tips indicate species in the white oak group and pointed lobe tips designate red oak group. A large number of similar leaves usually indicate that the source is close by. Leaves can be carried long distances by the wind, so a few scattered leaves of one type could mean that they have been blown in from some other area.

I spend a lot of time sifting through the leaves. You may not be sure of your identification from just a single leaf, but you may suspect the presence of a particular tree based on the evidence. I’ve found several interesting species by first finding their leaves in the fall and then searching for the tree the next summer. The leaves can suggest possibilities and identifying a possibility is typically the first step towards discovering the reality.

Acorn Status

2010 was an exceptional year for acorn production in Southern Ohio and much of the Eastern United States. Many people within a couple miles of Blue Jay Barrens reported acorns nearly covering the ground in their oak woods. Unfortunately, Blue Jay Barrens’ oaks failed to join the majority and produced a 2010 acorn crop that was slightly below normal. I headed into one of the most concentrated stands of mixed oaks to officially assess the 2011 acorn crop.

I did find acorns and they were in numbers that I consider to be about average. At least there were several meat filled acorns scattered about. When I checked last year, the only acorns I could find were either buggy or rotting. For a short while the supply should outpace the demand.

The number of empty acorn caps on the ground was too low to suggest that animals had already cleaned up a huge crop. Many of the caps were fresh and clean, indicating that they had just recently fallen.

Pieces of seed coat sitting on top of the fallen leaves were the most abundant evidence of acorns. Some of these pieces were newly exposed, as evidenced by the bright fuzzy lining.

This looks like the work of a mouse. I used to have a pet Peromyscus named Mousie and this is exactly how he would deal with an acorn. I’m surprised the mouse didn’t hide the nut away somewhere safe. Maybe it became a meal before it had finished eating.

There are still a few acorns left in the trees, but not enough to make this more than an average year. I guess average is pretty good. There should be enough food to maintain animal populations near their current level, so there won’t be any radical population swings one way or the other. It’s out of my control anyway. I just watch and see what happens.

Field Going to Oaks

Not all of my management units are large. This place is no more than a clearing among the trees. Many years ago, I removed some cedars in an attempt to let in sunlight, so I could evaluate the possibility of this growing into a quality prairie opening. Before my intervention, it was well on its way to becoming a cedar thicket. Cedar thickets provide a lot of interesting life forms, but Blue Jay Barrens has no shortage of cedar thickets and I was hoping for something a little bit more uncommon.

Several years of ample sunlight resulted in a profusion of deciduous tree seedlings, with a high number of oak species. Oak are declining in many areas and I began to contemplate managing this site toward becoming a stand of mixed oak. I’ve now decided that managing for oaks may be the best choice.

Despite many years of sunlight, very few prairie species have developed. Those that did were species that were already abundant in large open fields. Quality oak trees seem a much better alternative than a small, isolated prairie of low species diversity.

Oaks that were freed from crowding by my earlier cedar clearing efforts have now gained some considerable height. Now that I’m managing for oak, I’m well pleased with the progress these trees have made.

One hundred feet away is the seed source for all of these small oaks. A cluster of about 30 large oaks dominate the crown of a low hill. Soil conditions in the clearing are identical to those enjoyed by the mature oaks, so their seedlings should prosper.

The total area of cedar thicket surrounding the clearing is about one-half acre. Several small oak saplings are trying to maintain themselves in shade beneath the cedar tops. Gradual removal of the cedars should allow the oaks to gain strength and begin to increase in size.

These cedars have suffered greatly from heavy ice and snow loads. If left in place they would eventually fall. There’s never been any doubt that the cedars would be cleared. The question has been how I would try to direct the plant growth that would result from the cedar’s absence.

Other cedars have lost their tops. Large broken tree tops are quite heavy. I’ve seen them fall from the tree like giant spears and stab their jagged ends into the ground. It’s quite shocking to find what looks like a twenty foot tall dead tree where nothing was growing the day before. I use a rope and pulley arrangement to bring down the tree top before I fell the tree. I would hate to be the recipient of one of those falling spears.

So, this opening is now destined to become an oak woods. Management won’t be much different than that required for a prairie. I’ll cut cedars and remove other woody growth. The main difference will be that I’ll leave the oaks and do what I can to insure their survival. It’ll be another 15 or 20 years before the trees become so thick that sun loving plants begin to dwindle. If a rare prairie species shows itself in that time, I’ll just have to change my management goals and start removing the oaks. It’s good to have a definite goal in mind, so I can be more confident in my management decisions for the site.

Chewed Oak Leaves

When I first saw these leaves, I thought they had been hard hit by some herbivorous insects. Closer examination made me think the leaves may have been distorted by some infection or weather related phenomenon. The margins of the leaf appear to be healthy. Could the leaves have been eaten at an early developmental stage and then healed as they matured?

The leaves belong to a small oak on the edge of one of the prairie openings. Not all of the leaves are like those above, but I couldn’t find a single leaf on the tree that hadn’t been damaged in some way. Being on the edge of two different habitat types increases the range of insect species that might come into contact with and find edible, this little oak.

Some leaf clusters suffered just minor damage. This tree bears all of the indicators of being Quercus bushii, a hybrid between the Blackjack Oak, Quercus marilandica and the Black Oak, Quercus velutina. Perhaps, instead of hybrid vigor, this individual received enhanced taste as a result of the cross.

The feeding pattern on this leaf makes me more certain that the damage to the first leaf was indeed feeding damage. Until a better theory comes along, I’m going to say that the feeding was done on young leaves and the leaves partially healed as they grew.

I wish I could have seen this tree early in the year, but it’s impossible for me to get around and see everything in all seasons. I’ve noticed that the majority of things I notice while I’m walking are within ten feet of me. I’ve walked through this particular prairie opening many times this year, but if I was more than ten feet from the tree, I probably wouldn’t have noticed anything peculiar about the leaf shape. This is another one of those things that I’ll put on my list to watch out for next year. Maybe I’ll find the answer then.

Oaks Lose Leaves

The combination of wind, rain, wind, snow and wind has resulted in the loss of leaves from most of the unsheltered oaks. Normally during this time of year, you can see the oaks still holding a large percentage of their leaves. Cedars partially protected this oak, but the top was exposed to the wind.

These leaves are still hanging tight and it takes a pretty good tug to make them come loose. I don’t know where the benefit lies in keeping the dead leaves on the tree.

The big cedar on the left blocked some of the wind from the neighboring oak, but the wind managed to nearly denude the upper half of the tree. I know a person that does winter tree identification by picking up a leaf from beneath the tree. I failed to convince him of the absurdity of the idea that tree leaves fell straight down. He couldn’t quite get my point.

This little tree has suffered several setbacks through the years. The wind has removed the burden of having to maintain any growth on the mostly dead tree. Maybe the roots are healthy enough to send up a strong, new shoot.

This section of the woods is primarily oaks. Strong west winds, going from left to right through this shot, have taken most of the leaves except for a small patch on the right side. This may benefit some of the early spring wildflowers that end up wearing a cap of spring falling oak leaves.

Oak Island

Blue Jay Barrens doesn’t have enough water to make an island in the traditional sense. The islands I have here are ecosystems or patches of vegetation effectively isolated within the landscape. My oak island is a patch barely 40 feet across that contains an incredible diversity of oak species. The island is surrounded by prairie on one side and Eastern Red Cedars on the other. There’s even an eroded bank that acts as the shore of the island.

One thing that makes this island particularly significant is the presence of the only specimen of Post Oak, Quercus stellata, that I have found at Blue Jay Barrens. Post Oak is one of Ohio’s uncommon species and it would really be nice to have more than the one tree.

The Post Oak I do have isn’t even a prime specimen. The bulk of the tree is a horizontal branch that grows out over the eroded bank. The tree appears to be healthy, but horizontal growth like this is usually destined to failure. I’ve searched this tree every year for acorns and have yet to find the first one.

Growing beside the Post Oak is a Blackjack Oak, Quercus marilandica, another uncommon species. There is a general similarity in leaf shape here. If you look closely, you’ll see that the main veins of the leaf end at a bristle tip extending from the leaf margin. This puts the Blackjack Oak in the red oak group instead of the white oak group with the Post Oak. Oak leaves can be highly variable in shape, even when they occur on the same tree. This leaf is not the typical shape for a Blackjack Oak and more resembles the leaf of Bush’s Oak, which is a hybrid between the Blackjack Oak and a Black Oak. Checking twig, bud and bark characteristics suggest to me that this is in fact a Blackjack Oak. Of course, I’m often high susceptible to the powers of suggestion. Especially when I’m the one making the suggestion. These oaks deserve a more detailed study.

Several other oaks have inserted themselves into the mix. Here is White Oak, Quercus alba.

Shingle Oak, Quercus imbricaria, is common at Blue Jay Barrens.

Another common species is Chinquapin Oak, Quercus muehlenbergia.

These oaks are growing in a tangled mess with some large cedars. I’d love to remove the cedars and allow the oaks to grow without competition, but cedar removal would create several problems. The oaks are growing through the cedar branches, so there is no way to remove the cedars without damaging the oaks. If the cedars could be safely removed, the oaks would probably not stand on their own. Oaks often become dependent on surrounding trees for support. When that support is removed, the oaks bow over and side branches begin to compete to be the new leader. The result is a misshapen tree with little chance of long term survival. The management decision here is to leave the island alone.