As we begin a new year working with ancient trees, we want to pay our respects to one of the most important ancient oak trees in Lexington. We were able to carefully preserve the tree during development, and today it is thriving. Here is a photographic tribute to the Old Schoolhouse Oak. I hope it has many more years, perhaps centuries, to look forward to. If you wish to visit the tree, here is a map.
I have lived in and near Lexington for about 35 years. As a careful observer of trees, I have always been amazed at the number of very large trees. This became the subject of my first book, Venerable Trees – History, Biology and Conservation in the Bluegrass. Since 2005, we have been working with landowners and others to conserve our ancient trees and to provide opportunities for them to successfully reproduce. As part of that work, we have been using GPS and GIS to map and record the condition of as many trees as possible.
Sadly, the population of big, old trees in our community is continuing to decline. While construction, lightning, age and disease are major causes of their decline, I think there is a more fundamental problem: we do not sufficiently value our great trees to ensure their survival.
We are planning a walking and bus tour of some of the Great Trees of Lexington in an effort to bring more attention to their plight, and to create a community-wide effort to do more to preserve our natural heritage. The tour is scheduled for Saturday, September 16 from 8:30 am to 1 pm. We will begin our exploration at West 6th Brewing, travel by bus to as many sites as time allows, and return to West 6th for an informal discussion of ancient tree conservation. Each participant will receive a map of known large trees in Lexington.
Attendance is limited to 30 people. We hope you will join us. Register here and we will send you more information.
Today, the Venerable Trees staff worked with Beard House Media to get our first drone inspection of a huge bur oak. It is very difficult to estimate the volume of a big tree, or to inspect it for potential problems. Aerial or satellite photos often lack detail. Today, our friend Jeremiah Oschwald from Beard House Media flew his Phantom 4 Quadcopter over the big bur oak at the Peninsula on Squires Road. This cite has been approved for development, but we are protecting this magnificent bur oak and the surrounding trees.
We plan to begin using drones to carefully inspect large trees and also to begin creating 3D models of trees. One of our goals is to be able to estimate the amount of carbon stored in the huge trees. Large trees are very important for carbon sequestration, one of the solutions to the problem of climate change. We will tell you more about this soon.
For now, we hope you enjoy this wonderful aerial photo of this huge tree. Scroll down for more information about our drone use.
Drone photo of a bur oak. Photo by Jeremiah Oschwald
Small drones have become much more useful as more automation is built into them. The Phantom 4 drone used by Beard House Media is capable of autonomous flight. Jeremiah programmed a grid into the drone’s software. Once it took off, it flew directly to the grid, pausing at set locations along the grid to take a photo. The photo here is stitched together from multiple drone photos.
This video clip shows the drone hovering over the big bur oak, then moving and pausing again.
Those who have read my book or heard my presentations know that one of our major concerns about the future of our rare and ancient woodland pastures is the failure of trees to reproduce. With trees succumbing to age, lightning and poor management, the population of ancient trees is declining. While we are constantly on the lookout for young trees, they are quite rare. As anyone can readily see, if death rate > birth rate, the future of our trees is grim.
On January 1, we had the opportunity to explore woodland pastures and a large woodland in Bourbon County, thanks to the hospitality of Jim and Kellye Pikul. We wandered their property and several adjacent properties in search of woodland pasture trees, especially bur, chinkapin, and Shumard oak as well as kingnut and blue ash.
What we found was astonishing and a revelation. All over the area were huge old venerable trees, including a 72″ diameter bur oak. There were exceptionally large bur, chinkapin, and Shumard oaks and blue ash, with a few kingnuts. There were also many immense sugarberry trees (Celtis laevigata). Sugarberry is primarily a bottomland tree in western Kentucky and the south. It is found on upland limestone sites but has apparently not previously been reported in Bourbon County.
The most astonishing part of our ramble was the very large number of young trees of all the woodland pasture species. This indicates that there is the potential on this site for a self-sustaining woodland pasture. We found young trees mixed with very large trees in three sites. In the large woodland, most of the younger trees were chinkapin oaks, bur oaks, a few Shumard oaks, many kingnuts and blue ash. These trees ranged from pole-size saplings to mature overstory trees. The woodland is now choked with honeysuckle and wintercreeper, so it is likely that further natural regeneration will not occur.
There is a huge amount to learn from this site, and it is worthy of close scrutiny. If we can learn why this site is reproducing well, we may be able to facilitate natural regeneration in other woodland pastures. We hope to work with landowners and with interested volunteers to learn more about this site, and to work on improving management, especially of the woodland which is badly in need of thinning and invasive species control.
Followers of our website will hear a lot more about this very exciting site in months to come. We will schedule a Field Course there as soon as possible.
A deep green autumn is rare in Kentucky. By this time of year, our trees usually look forlorn and bedraggled. Dry summers, high temperatures, insects and diseases all take their toll. Not in 2015, though. Our frequent rainfall and cool temperatures have allowed many trees to maintain lush green leaves and to continue growing. Some trees are still producing new shoot growth.
Leaves are a bit like tissue paper, designed for use for only a short time and then discarded. From the time a leaf is formed, a tree invests a limited amount of resources into maintaining it. Shade, drought, insects and fungi all take their toll, so by August, a lot of trees look pretty sad and pale. This is especially true in the Bluegrass and Nashville Basin, where our karst topography leads to water stress even in modest droughts.
The last three years (2013-2015) have been different. Tree growth has extended well into the fall. Today, the first day of meteorological autumn, sees many trees still growing, and leaves of some trees staying dark green.
2015 is even more exceptional. I have rarely seen trees still growing in September, but some of our bur oaks, even some very old trees, are still producing new flushes of growth.
See what the trees in your neighborhood are doing.
Today, we are launching a new project “Great Trees of the Bluegrass” to locate and identify important trees in our region. We have a new Facebook Group: Great Trees of the Bluegrass for you to contribute your own observations, and we are also creating a new web-based identification and mapping tool for your use. The purpose of this project is to identify, map and evaluate the important trees of the Bluegrass and to tell their stories. We will later be extending this to the Nashville Basin.
The criteria for listing Great Trees of the Bluegrass are: 1) the tree should be native to the Bluegrass; 2) the tree must be publicly available – either on public property or accessible to the public; 3) the tree must be old and large – we will start with a minimum of 100 inches circumference (32 inches diameter). Of course, we don’t know how old most of these trees are, but we can recognize the very old ones that are likely to predate the establishment of Lexington in 1779.
To get us started, here are 10 of Great Trees of the Bluegrass. Each tree will eventually have its own page. For now, the link will show you a larger version of the photograph.
The Ingleside Oak on Harrodsburg Road near Red Mile
The Ingleside Oak
The St. Joe’s Oak
The St. Joe’s Oak
The Henry Clay Basswood
American basswood (National Champion), Lexington Cemetery
A couple of weeks ago, we told you about a magnificent, ancient bur oak that was suddenly defoliated overnight. We said that it would recover quickly and that we would update you. With 10 days of mild weather, the tree has leafed out very quickly. Most trees maintain large reserves of starch and protein in their stems, and they can quickly mobilize the stored material to make new leaves. Here are a couple of before and after pictures. The upper picture is the tree on May 21, right after it was defoliated. The lower picture is the same tree on May 31, showing how quickly the tree has leafed out. We still haven’t found the culprit, but this old tree does not seem to have suffered from early spring defoliation.
The Kirklevington Oak on May 21. There are very few leaves on the tree after defoliiation the night beforeThe same tree on May 31, 10 days after defoliation. Notice the new leaves growing quickly.
You may recognize the bur oak in this page from previous photos. It is a magnificent, ancient bur oak in Kirklevington Park. I visit it often. Last week I was looking at the tree in the late afternoon and noticed a few leaf fragments on the ground. The next morning, I came back and saw that the tree had been totally defoliated overnight, stripped of nearly every leaf. After a few days, it began to refoliate – to produce a new crown of leaves. Spring defoliation is very common, but is not very harmful to hardwood trees.
None of the nearby bur oaks were defoliated. Two Shumard oaks had lost a little bit of foliage. It was like a special forces strike on a single tree. Remarkably, the defoliating insects were completely gone by morning, not a sign of them. I don’t know what they were.
We’ll add more pictures as recovery continues.
Click pictures to enlarge or for a slide show.
The old bur oak stripped of its leaves overnight.
Closest bur oak to the old tree, with no defoliation.
Bur oak the day after it was defoliated.
The old bur oak stripped of its leaves
New flush of growth after defoliation
The bur oak after defoliation, with new leaves beginning to grow.
New leaves growing on the old bur oak
Crown of the bur oak beginning to leaf out a week after defoliation.
For the last 10 days, I have watched an amazing phenomenon that I have never seen before. Oaks are wind pollinated. Occasionally we see insects visiting, but only casually. However, one bur oak that I keep an eye on has been abuzz with activity. Every day while the male flowers were open, there was a constant movement of bees. I saw several species, but only one was large enough to photograph readily. This large bee, about half the size of a honeybee, was abundant and working hard, with full pollen baskets.
What do you think? Have you ever seen this before? Comment below (Facebook) with your observations
A few other observation: The bees were not working other nearby bur oaks. There were lots of other trees and shrubs nearby with showier flowers but they were not as heavily visited and did not have the same bees.
And now the big question – are these bees robbing pollen, or are they actually pollinating this bur oak?Bees on male bur oak flowersBees on male bur oak flowersBees on male bur oak flowersBees on male bur oak flowers
The Venerable Trees of the Kentucky Bluegrass are extraordinarily long-lived. This past weekend, we lost one of the largest and oldest bur oaks in the region. The tree, at the corner of Versailles Road and Man O’War Boulevard on a farm, fell to the south. The death of this tree was most unusual. It was a huge and vigorously growing tree, and it simply fell over. Here is a preliminary analysis of what might have caused this tree to fall over.
Although this tree was ancient, it is rare for Bluegrass trees to simply fall over. More commonly, trees decline slowly after lightning strikes, or following soil compaction and mower damage. Of course, the most common cause of death is the bulldozer – development has decreased the population of bur oaks in Fayette County by over 90% in only 60 years.
I examined this tree as did Master Arborist Dave Leonard, and there are some clues to why this tree fell over. The conclusions are mine, but Dave pointed out several features of significance.
The most important clue is the exceptional weather just before the tree fell (weather data from a station <1 mile from the tree):
From April 2 to 3, we had 6.40 inches of rain, including 5.17 inches in 24 hours, a record;
Sustained winds from April 2 to 5 were 16 to 36 mph, with gusts of 47 mph on April 2 and 36 mph on April 3 from N and WNW;
There were no tornadoes in the region, and no known microbursts. However, there is no nearby official Doppler radar and we cannot rule out a microburst.
The condition of the tree:
This is an exceptionally large tree, 15.96 ft circumference 10.5 feet above ground (it wasn’t possible to get a tape under the tree at 4.5 ft.) and tall, >92 ft.
The tree was growing vigorously and rapidly, which is common in our ancient trees. Lateral branches averaged 9 inches new growth in 2014.
The tree had a pronounced lean to the south. Such leans are common in ancient bur oaks in the Bluegrass.
The tree is remarkably sound. Although there does appear to be some heart rot, there are few signs of extensive decay. We will know more when we dissect the tree.
Structural roots (the major woody roots) on the north side of the tree are large and sound, with no decay. However, they broke off at 3-15 ft from the stem.
There was evidence of surface structural root damage on the south side of the tree from long-term mower damage. We can’t yet see deeper structural roots on the north side because the stem is in the way. This is important because in heavy wind, these roots would experience strong compression.
My tentative conclusion is that the tree fell because 1) surface structural roots on the south side were heavily decayed due to long-term mower injuries; 2) the soil was saturated from prolonged heavy rainfall; 3) wind gusts from the north compressed roots on the south side, and the remaining south side roots were not sufficient to absorb all the compressive force; 4) as the compressed roots on the south side failed, the weight of the tree exerted enough tension on roots on the north side that these roots failed, even though they were not decayed. We cannot, however, rule out a microburst that produced an intense force on the north side of the tree, compounded by the weakening of soil structure by heavy rain.
This is a preliminary analysis, and we will learn more as we dissect the tree.
Ancient bur oak that fell in unusual weather.Uplifted root systemBase of the tree with moderate decay . Note the pooled water in the pit.Mower damaged (A) and undamaged (B) surface structural rootsMajor structural roots (starred) on the north side
Finding left-behind trees can be the start of an urban adventure. As our woodland pastures were developed into urban areas, most of the trees of woodland pastures were cut down. A few remained, usually as single trees in a parking lot or front yard. Here’s where the adventure comes in: when we find a single tree and take some time wandering around, we often find more.
A bur oak behind the Ingleside Oak
So it is with the Ingleside Oak on S. Broadway in Lexington. I have known this tree for many years, but only recently took the opportunity to wander the neighborhood near the tree. The search was rewarded, as we found about a dozen trees representing the original woodland pasture trees of Ingleside Manor.
Clusters of trees are found in other areas as well. In Ecton Park are two old blue ash trees, but the neighborhood around the park has over a dozen trees in front and back yards.
Old oak in an abandoned lot behind the Ingleside Oak
The next time you find a Left-Behind Tree, we hope you’ll take the time to look around for others. And be sure to tell us about them.
The Veteran Oak in Lexington is one of the most iconic trees in the city. A magnificent bur oak, it lies along a popular walking path on the south side of town. The Veteran Oak is a left-behind, the only ancient tree in a young riparian (stream-side) forest. Most of the ancient left-behind trees are on dry uplands, like the Old Schoolhouse Tree. The Veteran’s Park Oak is on a stream bank and benefits from high soil moisture and intermittent flooding.
The tree is in excellent condition. It has a few dead branches and lost its top at some time. This is normal for very old trees, and the dead branches and hollows provide habitat for a wide range of animals and fungi. Young trees around the old oak are beginning to grow into its canopy. Sometime soon, in the next few years, we will need to thin the trees around the Veteran’s Park Oak to give its lower crown more sunlight. This technique of removing smaller trees to concentrate growth on larger trees is called ‘thinning from below’, also sometimes called ‘haloing’, though I prefer the former term. The path that goes by the tree on the creek side is causing some soil compaction, and should be closed.
Here is a photograph of the entire tree. This is a composite of 36 individual photos stitched together.
Tom Eblen has a fine article in today’s Lexington Herald-Leader about the Old Schoolhouse Oak and the commitment of Ball Homes to preserve the tree in a new housing development. By my count, this is the 14th Herald Leader article about this splendid tree
Bur oak in the Bluegrass reproduces only rarely. Although it is a prolific seed producer, there is very little suitable habitat for young bur oak trees.
While inspecting our preservation work on the Old Schoolhouse Oak with Tom Eblen of the Herald-Leader, we noticed several vigorous young bur oak seedlings. These trees are just outside the tree protection zone, and we have marked them to keep. They will eventually become shade trees to add to this new development – we may leave them in place or transplant them to a suitable location.
Click on the pictures for a gallery of images of the Old Schoolhouse Oak.
Runnymede Farm in Bourbon County is the oldest continuously-operated thoroughbred farm in Kentucky. Founded in 1867 by Colonel Ezekiel Clay, it is today operated by his grandson, Catesby W. Clay, and great-grandson Brutus J. Clay III. As you might expect for such a long-running family farm, the Clay family has taken great care of their land, including many venerable trees. Runnymede is most famous for its horses, and has played a key role in the foundation of the thoroughbred industry. We, of course, were attracted to Runnymede for its venerable trees.
Brutus Clay, the President and fourth generation farmer of Runnymede, was kind enough to show us around the farm on a cool, very foggy day. The manor house, built originally by Gov. James Garrard, is surrounded by a grove on enormous, ancient blue ash and bur oak trees. The common practice at that time was to build manor houses in the middle of groves of old trees, creating
Brutus J. Clay III, President of Runnymede Farm with Tim Diachun, Operations Manager of Venerable Trees
the instant appearance of an old English manor. Such is the case here – the trees are much older than the house. The blue ash trees are exceptionally large and tall – among the largest we have seen, though we will have to wait until another day to measure them. One blue ash is especially prominent because it appears never to have been struck by lightning and is very tall.
A nearby farm, also in the Clay family, has a number of ancient trees including a very fine bur oak standing in the middle of a pasture. Typical of most ancient bur oaks, it lost its top to lightning, but has built a vigorous new crown. This year, the old tree has a very large crop of acorns, and we plan to collect some for our nursery project.
Ancient bur oak in a paddock near Runnymede Farm
Although our focus is usually on trees, one of the buildings on Runnymede farm caught our attention. Cooper’s Run Baptist Church was originally built in 1787, and completed in 1790. That original log structure was quickly outgrown, and the congregation built a new structure of cut limestone blocks beginning in 1801. Services were held in the limestone church from early 1803 to 1816, when the congregation needed a larger building. The church became part of the Gov. Garrard’s property and today is a barn at Runnymede. Brutus Clay likes to puzzle visitors by noting that the church was built in Virginia and only later found itself in Kentucky. Of course, the church didn’t move, the states did – in 1803, Bourbon County was part of Virginia.
Cooper’s Run Baptist Church, 1803
There are several farms in the Bluegrass that are still operated by the original families that began farming them in the 18th or 19th centuries, and many of these farms have magnificent woodland pastures of venerable trees. It is the long-term land stewardship of the Clay family that has helped maintain the verdant landscape of the Bluegrass.
A magnificent bur oak growing in a pasture in Woodford County, KY has lessons for us about managing old trees. Our Chief Scout, Jason DeBold, found this tree.
The tree is a huge old bur oak that lost its top a long time ago, probably to lightning. Like many old trees, this tree has completely recovered by building a new crown. This process, sometimes called retrenchment, is very common in old in the Bluegrass. The tree now resembles many of the ancient European oaks.
This tree has some important lessons for our management of venerable trees. Lightning strikes are very common in trees in woodland pastures but are rarely fatal. Left to their own devices, lightning struck trees can rebuild a new crown and can live a very long life. The second lesson is that crowns are not permanent structures in old trees – they are easily replaced.
Venerable bur oak in a farm fieldBroken top of the old bur oakLigntning scar in the old bur oak
Young bur oak leaves are densely hairy. Why? Scroll down past picture to read more…
Young leaves of bur oak, Quercus macrocarps with dense hairs.
Why are the young leaves of so many trees hairy? Here are some possible benefits to hairiness in leaves. There is no reason to think that only one of these explanations is correct. Many organs, tissues and processes in plants serve multiple functions.
Development. Leaves develop tightly packaged in a bud. Hairs develop very early, as soon as the leaf starts to develop from a few cells. Hairs may serve to separate layers of cells and keep them from fusing together. Leaves without hairs tend to be folded differently than hairless leaves. We’ll say more about this in a future post.
Defense. Hairs can be a significant defense against small herbivores. Mites, beetles and other creatures trying to eat the tasty young leaves are deterred by the hairs. The hairs provide a mechanical barrier to small herbivores, who have to get past the hairs to get at the nutritious leaf tissue. The hairs in oaks are also chock full of nasty chemicals like phenolic compounds that taste bad and are toxic. An herbivore that tries to eat its way through the hairs to get to the good stuff may get a nasty surprise.
Protection from sunlight. Leaves are well protected against sunburn from UV radiation by their thick epidermis that contains UV-absorbing chemicals. Young leaves do not yet have a thick epidermis: a thick epidermis would prevent the young leaf from expanding. Hair cells that contain lots of phenolic chemicals absorb UV radiation protect the developing leaf from UV damage while still alowing growth the continue.
Reducing water loss. Hairy leaves are more common in desert plants than in plants of very moist habitats. Hairs reduce the rate of transpiration by creating a thicker boundary layer – a layer of unstirred air over a leaf where diffusion slows the rate of gas exchange – over the leaf. For bur oak, this is especially important early in development when the epidermis and stomata are not yet able to fully regulate water loss.
I’m sure readers can come up with other explanations for the hairiness of leaves, but these are the most common explanations, supported by some experimental evidence.
As the leaf matures and grows, the hairs become more widely spread and wear off. Once the epidermis is fully developed, the hairs are unimportant and gradually wear off, especially from the upper surface of the leaf.