Tom Kimmerer
Scientist, Author, Conservation Photographer
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Shillito Park-2734-Edit

News Callery pear, invasive species, News, Reforest the Bluegrass, Urban forestry

Our most successful tree?

Tom Kimmerer

April 14, 2014
Callery pear (white flowers) in a detention basin, Pyrus calleryana

Reforest the Bluegrass is one of the oldest and most successful community forestry programs in the US. Every year in April, thousands of volunteers turn out to plant trees from the Kentucky Division of Forestry nursery. The purpose of the program is to establish forests along riparian zones to protect water quality. There is no question that this program has benefited Lexington, Kentucky, and it has spawned similar efforts throughout the state.

Over the last several years, I have been looking at older Reforest the Bluegrass sites around Fayette County. Last year, I was joined by students from the Natural Resource and Environmental Science program at the University of Kentucky. In the course of our surveys, we found that most species that are being planted during Reforest the Bluegrass events are doing well.

At some sites, though, there is one tree that is more successful than the others, and it is one that nobody plants. The tree is callery pear, Pyrus calleryana, better known by its cultivar names Bradford pear and Aristocrat pear. All the white-flowering trees in the picture above are callery pears established from seeds brought in by birds.

These ornamental pear trees (with inedible fruit) are very popular among developers, who have planted callery pear in nearly every new housing project in the city, until it was finally banned. Although no longer permitted as a street tree, there are still thousands in the city and they are readily available to homeowners at local nurseries and big box stores. Technically, these trees in this picture are neither Bradford nor Aristocrat pears, because those are cultivars that have to be grown from cuttings. These trees are the progeny of those cultivars that are genetically distinct from the parents.

The fruits are dispersed by birds, and the tree has become established throughout the region. The picture at the top of this page is just one example of the great success of this tree: every white-flowered tree in the picture is a callery pear.

Is this a problem? Well, probably not. There is no evidence that this tree is displacing more desirable native trees. It certainly is providing shade and soil stability to the riparian areas that we are trying to protect. As the native trees, both the ones planted in Reforest the Bluegrass and volunteers, get taller, they will eventually shade out the callery pears and they will die.

Callery pear is an important lesson in unintended consequences. The horticulture industry gave no thought at all to the invasiveness of the tree, and it was planted everywhere. It should come as no surprise that it is very successful in disturbed sites all over the Bluegrass.

Callery pear, Pyrus calleryana planted in a shopping center parking lot.
Callery pear, Pyrus calleryana planted in a shopping center parking lot.
Bleeding sap in sugar maple

News News, sap, tree physiology, Tree structure, water relations

Sap flow in spring

Tom Kimmerer

April 3, 2014
Bleeding sap in sugar maple
Sap flow in a freshly cut sugar maple, Acer saccharum.

Have you noticed any cut branches lately?  Freshly pruned or broken branches at this time of year often ‘bleed’ sap, and that sap may taste very sweet.

Just before trees leaf out, they convert a large amount of starch to sugar.  The high concentration of sugar in the xylem sap causes a flow of water from the soil into the tree by osmosis.  As water flows into the tree down an energy gradient, a positive pressure develops within the tree.  If you cut into the wood, sap will come out because of the pressure.  This is the only time of the year (except in certain diseases) that trees have a positive internal pressure.  It is also the only time of the year that cutting into the tree will cause ‘bleeding’ of sap (again, in the absence of disease).

The picture shows a sugar maple tree in Lexington, Kentucky that was pruned a few days ago.  Notice the drop of water at the base of the cut.  This branch was bleeding at a rate of about 5 ml/minute.  The sap was noticeably sweet to the taste.  This is not always the case as the sugar concentration varies quite a bit. This branch has been bleeding sap for about 5 days.  It is harmless to the tree, since the volume of sap involved is quite small.  Some older texts suggest that it is harmful to prune when sap is bleeding, but I don’t think there is any evidence for this.

This bleeding is the basis of the maple syrup industry.  There have been several online discussions lately about making syrup from other species, such as hickory, walnut and birch.  Not all trees develop a high enough sap pressure to bleed.

For the maple syrup industry, this is make-or-break time. The window of opportunity for gathering maple sap is very small, but the reward is sweet. There is even a song to sing while gathering sap:

Oh, bubble, bubble, bubble goes the syrup in the pan.
Making sweeter music try to top it if you can.
See the golden billows; watch their ebb and flow.
Sweetest joys indeed we sugar makers know.

Maple syrup production is usually a northern industry, centered in the northeastern states and provinces.  There is a good reason for this:  the highest sap pressure and the longest duration takes place where soils are cold, nights are cold and days are warm.  The further south you go, the shorter the sap flow season.  Climate change  threatens to dramatically reduce maple syrup production.   The top maple syrup producers in 2010 were:

Province of Quebec, Canada: 7, 989,000 gallons harvested.

State of Vermont, USA: 890,000 gallons harvested.

Province of Ontario, Canada: 400,000 gallons harvested. *

State of New York, USA: 312,000 gallons harvested.

State of Maine, USA: 310,000 gallons harvested.

Province of New Brunswick, Canada: 300,000 gallons harvested.*

State of Wisconsin, USA: 117,000 gallons harvested.

State of New Hampshire, USA: 87,000 gallons harvested.

State of Michigan, USA: 82, 000 gallons harvested.

State of Ohio, USA: 65,000 gallons harvested.

State of Pennsylvania, USA: 54,000 gallons harvested.

State of Massachusetts, USA: 29,000 gallons harvested.

Province of Nova Scotia, Canada: 22, 000 gallons harvested. *

State of Connecticut, USA: 9,000 gallons harvested.

Source: Maple Syrup World

Ghetto palm in Lexington

News News, Urban

The Ghetto Palm?

Tom Kimmerer

April 2, 2014

Scroll down below slideshow for the story

[soliloquy id=”1586″]

Tree-of-heaven, Ailanthus altissima, is a very common tree in large eastern cities. A native of Asia, Ailanthus was introduced as an ornamental and quickly escaped cultivation.  It has a remarkable ability to grow successfully in cracks in sidewalks, abandoned lots, even from the gutters of old buildings.

Ailanthus is called tree-of-heaven not because it is heavenly, but because it is taller than many urban trees, seeming to reach for the skies.  The Latin name, A. altissima,  also refers to this – altissima means ‘tallest’.   Of course, the tree is far from heavenly – it stinks, and has bad habits like root and stump sprouting.  After a few years of popularity as an ornamental in the 19th century, it is today almost never planted.  It is banned in many cities, though far too late.

Ailanthus is so abundant in cities today, and so aggressive at growing where no other tree can become established, that it is a good indicator of the ‘bad parts’ of town – the older, run-down parts of a city are where this tree finds its niche today.  And that has led to its other name “ghetto palm”.  I had known it by that name as a kid growing up in Baltimore, but had forgotten about it until recently, when I overheard someone talk about getting rid of a ghetto palm.

This is a vivid name for the tree, certainly more appropriate than tree-of-heaven.  Young trees, with a tuft of huge leaves at the top, do bear some resemblance to palms.  But the question is whether this term is offensive or racist?  If so, we need to find another term that is equally evocative of its position in our cities.   Comments (using the Facebook link) are welcome.

 

Spring 2014-8788

News flowers, News, reproduction, sex, Tree Biology, Tree Sex, witchhazel

Winter Sex: The Puzzling Case of Witchhazel

Tom Kimmerer

March 30, 2014

This is part of our ongoing series on tree sex.  

Witchhazel is one of the most beautiful shrubs or small trees in forests throughout the temperate zone.  It is easy to overlook in the summer, mixed in with lots of other shrubs and trees along creek banks and moist lower slopes of forests.

It is in the late fall and early winter that witchhazel stands out from its neighbors, and reveals its strange habits: witchhazel  flowers in the winter.  American witchhazel, Hamamelis virginiana, grows in eastern North America and flowers in late fall and early winter.  Vernal witchhazel, also called Ozark witchhazel, is found from Missouri to Texas and flowers in late winter or early spring (vernal means ‘spring’).  There are many ornamental witchazels, including the hybrid shown here, Hamamelis x intermedia ‘Arnold’s Promise’.  Whatever their habitat or geographic origin, all of the witchhazels flower when other trees are still snoozing through the winter.

This would not be so odd, except that these are obviously insect-pollinated flowers.  The long, bright-yellow petals, the presence of nectar producing a sweet smell and the stamens (pollen-bearing male bits) that are right next to the nectar source are all indicators of an insect pollinated flower.

For a long time, it was a mystery how a winter-flowering plant would get pollinated.  A  witchhazel that happens to flower on a slightly warm spring when honeybees are making their first flights in desperate search of food might get lucky.  That is not a reliable way to reproduce.

It was the renowned  naturalist Bernd Heinrich who realized that there was a group of owlet moths (family Noctuidae) called winter moths that are active on cold nights.  These moths have a remarkable ability to heat themselves by using energy to shiver, raising their body temperatures by as much as 50 degrees in order to fly in search of food.  It is a group of these moths that pollinate witch hazels.  The moths that pollinate witchhazel are several species of Eupsilia known as sallows.

It would be easy to conclude that this is a case of coevolution – both organisms having evolved to depend on one another.  This is probably not the case – Heinrich observed that these moths mostly feed on bleeding sap from injured trees.  So, the tree is dependent on the moth, but the moth is probably not dependent on the tree.

So the next time you see a witchhazel in flower, remember that it is waiting for a shivering moth.

References:

Heinrich, Bernd. 1987a. “Thermoregulation by Winter-Flying Endothermic Moths.” Journal of Experimental Biology 127 (1): 313–32.
———. 1987b. “Thermoregulation in Winter Moths.” Sci. Am 277: 73–83.
———. 1998. The Trees in My Forest. Reprint. Harper Perennial.

 

 

 

 

 

Spring 2014-8788

Hamamelis virginiana-5518

Trees on Chandler Farm

News News, Tree Sex

More Tree Sex at Under Main

Tom Kimmerer

March 29, 2014

The nice people at Under Main worked with me to put together a tree sex video and story.  See the whole thing at Under Main, or go straight to the YouTube video.  More to come!

 

 

Male and female catkins of black alder

News News, Tree Sex

Tree Sex Part 3

Tom Kimmerer

March 22, 2014

Black alder flowersSome trees are pollinated entirely by wind.  Many wind-pollinated hardwood trees make complex slender compound flower structures called catkins.

Later this spring, we will see catkins in all our oak trees, mulberries, walnuts and chestnuts, and further north on true poplars. Now, in early spring, you will notice catkins on alders, willows and birches.

Male catkins are large and long, getting longer as they expose their flowers to the wind. The female catkins are much smaller, often hardly noticed.  The female catkins are not open to receive pollen when the male flowers are releasing it – this ensures that the female flowers are not covered in pollen from the same tree.

This tree is European black alder, Alnus glutinosa.  Although not native to North America, it was introduced as an ornamental and has become naturalized throughout the east.

Click the video to see wind stirring the catkins, releasing pollen into the breeze. The catkins are very flexible. In even a modest wind, the catkins shake, releasing the light pollen into the wind.

Spring2014-8748

News News, Tree Sex

Tree Sex, Part 2

Tom Kimmerer

March 21, 2014

Many early spring trees are pollinated both by wind and insects.  For insects, these early spring trees can be critically important.  At a time when few plants are flowering, bees and other insects rely on trees for pollen.  Most early spring trees produce little or no nectar, and are much more important as a pollen resource than for the raw material for honey.  In early spring, honey bees and native bees are in deed of protein to start building up the population of worker bees in the hive.

This is not a native tree, but an ornamental witchhazel, Hamamelis x intermedia  ‘Arnold’s Promise’.  Its showy flowers are rare this early in spring, but it is adapted for pollination by moths, not bees.  Bees probably get relatively little reward except for a bit of pollen.

NatBridgeSpring-2060

News climate change, flowering, News, spring, Tree Sex

Flowering schedules in alpine flowers are changing

Tom Kimmerer

March 18, 2014

A 39-year record of wildflower blooming in the Rocky Mountains  shows that climate change has altered the timing of blooming for most species in an alpine meadow.  (Link is to University of Maryland press release. Original paper published in PNAS).

Virginia bluebell, Mertensia virginica, Daniel Boone National Forest

The blooming season now runs from late April to late September instead of late May to early September. The response to climate change is complicated: some plants flower earlier, others for a longer time.

The complex changes in flowering times are producing what ecologists call “no-analog” communities that are not closely related to existing communities.  In the case of the meadow flowers, hummingbirds can no longer rely on a huge spring peak in blooming when rearing their young. Instead, the same number of blossoms are spread out over a longer period of time.  This reduces the amount of nectar available each day.

Phenology is the study of the scheduling of events in an organisms life. Long-term plant phenology studies are pretty rare. David Inouye, a distinguished conservation biologist at the University of Maryland, started this project in 1974 because of his interest in nectar sources for hummingbirds and bumble bees. He has continued this project every year since, along with his students and post-docs.

This study is important for several reasons:

  • It shows the value of very long-term studies.  Long-term research is hard to sustain and even harder to fund.  Yet without long-term studies like this, we would detect only the most severe and catastrophic effects of climate change.
  • It shows that the impacts of climate change are complex, with each species responding differently, and with relationships among species changing radically.
  • It demonstrates the importance of studying mountain habitats, where the effects of climate change on the lives of plants and animals can already be seen.
Spring 2014-8776-Edit

News News, Tree Sex

Tree Sex

Tom Kimmerer

March 16, 2014

It’s Spring and time for trees to start their amazing sexual displays.  Tree flowers are often small and subtle, but will reward your close attention.  This is a  silver maple flower with the female parts fully expressed – the stigma is a sticky surface ready to receive pollen from another tree.  The male parts in this flower are present but not fully developed – the anthers are short and not open.    Stay tuned for more photos, videos and stories over the next couple of weeks.

Pinus ponderosa-9450

News News

Mistletoe Part 2

Tom Kimmerer

February 22, 2014

We talked about the mistletoes of the Bluegrass a while ago.  There are actually two broad groups of mistletoes in North America, the true mistletoes, which are found on hardwoods, and the dwarf mistletoes, which are only found on conifers.  We only have true mistletoe in the Bluegrass.  True mistletoe is fairly easy on its host plant – it only gets water and mineral nutrients.  Dwarf mistletoe is a serious parasite that meets all its needs by stealing from its host plant.  This slideshow shows the difference between true and dwarf mistletoe.  (See Part 1, about true mistletoe, here)

[soliloquy id=”1298″]

 

 

 

 

 

 

 

 

 

 

 

 

Site of first building in Lexington, a blockhouse built from a bur oak.

News News

The City Built from Bur Oak

Tom Kimmerer

February 22, 2014

 

There are few cities for which we can say exactly what trees built the city, but we can for the city where I live. Lexington, KY, was founded in 1775, but the first permanent structures were not built until 1779.  On April 17, 1779, Josiah Collins and others cut down a huge bur oak. From that tree, they built a blockhouse – basically a windowless cabin with portholes from which to shoot if defense from Indians was needed (it wasn’t), surrounded by a stockade fence.  The blockhouse is long gone, and today there is only a brass plaque memorializing the original location at Vine and Mill Streets.  Soon after, Josiah Collins helped build the first houses.  These were simple one-room squared log cabins with log ‘puncheon’ floors.  Remarkably, one of those cabins, built for James Patterson, still exists on the campus of Transylvania University.  (story continues below slideshow)

[soliloquy id=”1248″]

Although this cabin got its start near what is now Rupp Arena, it has wandered around quite a bit.  When Patterson become prosperous enough, he built a mansion and the cabin became slave quarters. Later, it was a tool shed.  When Patterson moved to Dayton, OH, he took the cabin with him, perhaps for sentimental reasons.  Later, his property became part of a Dayton city park,  When Dayton tired of maintaining the cabin, it was offered to Lexington.  In 1939, the cabin returned to Lexington and resides today on the Transylvania University campus, a mile from its original location.

The cabin has been rebuilt several times.  A few of the original cants (squared logs) that made up the original cabin may still be part of the structure, but we can’t be sure.  The cant shown in the picture is one of two oak logs that I think could be original.

Woodland Pasture in Woodford County

Classes and Workshops

Venerable Trees of Woodford County March 12, 6:00pm

Tom Kimmerer

February 10, 2014

Tom Kimmerer, Chief Scientist at Venerable Trees, will be giving a presentation “Venerable Trees of  Woodford County”  on Wednesday, March 12 beginning at 6:00 pm.  The presentation will be at Versailles Presbyterian Church, 130 North Main Street, Versailles KY (Map). Scroll down for more information.

Woodland Pasture in Woodford County

Woodford County is home to woodland pastures of open-grown, old trees shading grass and clover.  These woodland pastures have been in existence for hundreds, or perhaps thousands, of years. This presentation will emphasize the Venerable Trees in Woodford County, provide an explanation of their origins, and discuss the future of  the Bluegrass landscape.  The discussion will be especially interesting to rural land owners and farm managers. There will be ample time for discussion.

There will be a light supper at 6:00  before the presentation.  The cost for supper is $6.00. If you are planning to attend, please send an email to info at venerabletrees.org so we can tell the church how many people to prepare for.  If you want to skip the meal, please arrive at 6:45.

Trees on Chandler Farm

News mistletoe, News

Mistletoe

Tom Kimmerer

December 15, 2013

It’s the season not only to bring trees and other greens indoors, but also to kiss under the mistletoe.  The origins of this tradition are ancient,  rooted in Celtic and Old Germanic traditions.  In Europe, mistletoe is mostly found in oaks, and was thought to be found only in lightning-struck oaks.  So mistletoe was imbued with the power of lightning and therefore with sexual potency.  Or so goes the story. There is a simpler explanation.  In the winter when all the hardwood trees are  bare,  mistletoe remains green, a harbinger of spring.  We take holly, fir, mistletoe and other trees into our houses to remind us that winter will not last forever.   In Kentucky, mistletoe is found most often on walnut trees, though over 100 other hardwood trees can be hosts. Throughout the Bluegrass, the many walnuts are decorated with mistletoe.  It occurrence is patchy, with many walnut groves bearing no mistletoe.  Our mistletoe is Phoradendron leucarpum.  It is a mildly toxic plant (probably only the berries).  Although European mistletoe (Viscum spp.) has some medicinal and possibly anti-cancer properties, there is no known medicinal use of Phoradendron. Mistletoe is a hemi-parasite (partial parasite).  It is a green plant capable of supporting itself by photosynthesis.  It is anchored by haustoria (specialized roots) into the xylem of its host tree, not the phloem.  Mistletoe is able to obtain whatever is in the xylem sap of the host tree – mostly water and mineral nutrients, but also plant hormones such as cytokinins, which are produced in the tree roots.   In addition, any organic carbon in the xylem sap, such as sugar transported in the spring, is available to the mistletoe.  According to <a “href=”http://link.springer.com/article/10.1007/BF00318279″ target=”_blank”>some research, mistletoe may get a lot of its carbohydrates from the xylem sap of the host plant rather than from photosynthesis.  Mistletoes generally transpire much more water per centimeter of leaf area than the host plant, and this may help them compete with their host plant. Generally, we consider mistletoe to be harmless at low densities.  However, when a tree canopy is heavily loaded with mistletoe, its form is affected and sometimes its growth slows. The relationship between mistletoe and its host plant has not been studied much, and is probably a lot more complicated than we currently know.[envira-gallery id=”3288″]

Picture of American basswood, Tilia americana

News Classes and Workshops, News

Field Course: Venerable Trees of the Lexington Cemetery, November 23, 2013

Tom Kimmerer

November 9, 2013

What:  A tour of Lexington Cemetery to look at Venerable Trees.

Picture of American basswood, Tilia americana
National co-champion American basswood, Tilia americana, next to Henry Clay monument, Lexington Cemetery.

Instructors:  Tom Kimmerer, PhD, Chief Scientist at Venerable Trees Inc.

Special Guest:  Miles Penn, Horticulturist of Lexington Cemetery

When:  Saturday, November 23, 10 am to noon, Lexington Cemetery, Lexington, KY  (map).

We will meet just inside the cemetery entrance and will walk the grounds to look at the trees we believe to be older than the cemetery. Parking space is limited, and carpooling is a good idea. Bring your cameras and a raincoat.   In the event of severe weather, we will reschedule the event.  Please check the Venerable Trees website for last-minute updates.

This field course is free, but registration is required.  The course will be limited to the first 25 registered participants.

Register by sending an email to info@venerabletrees.org.  Provide your name, the number of people in your party, and the age of children, if any.  You will receive a registration confirmation.  Please do not attend the course if you have not received a confirmation.

Note:  This course is suitable for attentive children 10 and over accompanied by an adult (1 child per adult).  Younger children may not find the course to their liking.  We plan on doing a children’s course in the Spring.

 

Picture of sugar maple leaves in fall colors

News autumn, color, News, Photography, Photography

Don’t make candy trees

Tom Kimmerer

October 17, 2013

Autumn provides a huge opportunity for the photographer, whether amateur or professional.  The skies vary from shades of grey to brilliant blue, damp weather often makes color more vivid, and the incredible colors of autumn leaves are irresistible.  I will discuss fall colors from a tree’s point of view in a later post.  First I want to address the challenge of getting fall color right.

For many photographers, there is such a temptation to over-saturate colors that many otherwise excellent photos look like they contain artificial colors.  These over-saturated colors may be eye-popping, but they are 1) inaccurate, and 2) detract from the overall photograph.

Here are couple of examples of a properly exposed and oversaturated images of sugar maple and red maple. In each case, the upper image was from a carefully calibrated workflow (see below). The lower picture was oversaturated and represents what you often see on the web and in prints.

Picture of sugar maple leaves in fall colors
Sugar maple, Acer saccharum

How do you get the colors right? The most important piece of hardware is your eye. If it looks like candy, or something you would not encounter in nature, it probably is oversaturated. For the more advanced photographer, there are several things you can do. As a technical photographer, I work in a carefully color-managed work flow. I shoot in Camera Raw so I don’t have to worry about the camera’s white balance. I calibrate my camera frequently with an Xrite Color Checker Passport (see picture). Use of the color calibrator is especially critical in autumn, and I take at least one Xrite Color Checker Passport picture on each shoot, sometimes several if the light changes. I color calibrate my NEC and laptop monitors with XRite calibrators. I present my online pictures at Smugmug and print with Bay Photo. They consistently offer excellent color control. To be sure, I print my own calibration pictures with each batch of photos I order. I have never had to return a batch of Smugmug/Bay Photo because of poor color balance. Note that I have no commercial relationship with any of these companies except as a customer. I’m sure there are other products and services that provide good color management, but I am satisfied with what I get from these vendors and have no reason to experiment.

picture of Color Checker Passport
Xrite Color Checker Passport

The one area where no photographer has control is for images published to the web. Most people keep their monitors turned up very bright, and most web browsers are not color-space aware. However, more recent monitors have gotten a lot more consistent, and this seems to be less of a problem than it used to be.

Ultimately, it is up to the sensibility of the photographer to get things right, and only the photographer can judge what is right in his or her eyes. As a champion of trees, I think we should try to accurately reflect what they look like in nature.

Whatever you decide about autumn colors, the most important thing is this: get out there and shoot!

kingnut, Carya laciniosa

News Bluegrass, News, Venerable Trees

Herald-Leader Article

Tom Kimmerer

October 5, 2013

Tom Eblen, a fine reporter for the Lexington Herald-Leader, has written a really good article about our work at Venerable Trees.

Tom Eblen: Effort takes root to protect Central Kentucky’s most majestic old trees

Blue ash, Fraxinus quadrangulata

News News

Equine Photographer – Just for fun

Tom Kimmerer

October 5, 2013

This is just for fun.  While out photographing trees, my equipment was taken over by some beautiful mares and one of them, Violet Lady, figured out how to work the shutter.

Picture of chinkapin oak.

News News, Quercus michauxii, tree growth, video

Best Year to be a Tree Part 3

Tom Kimmerer

September 28, 2013

Here is a video continuation of our series on tree growth in 2013.  Best viewed at full screen

bur oak seedling, Quercus macrocarpa

News News, precipitation, shoot growth, tree growth

The best year to be a tree, Part 2

Tom Kimmerer

September 24, 2013

shoot growth in bur oak.
Second flush of growth in the wet growing seasong of 2013. Bur oak, Quercus macrocarpa

Part 1 described the unusual shoot growth pattern of trees this year.  Here we discuss why this happened.

Everyone realizes that this was an usual summer in eastern North America.  We had a mild summer and a remarkable amount of precipitation.  This graph (click for full size) is from the NOAA Climate At A Glance dataset .  It precipitation over the growing season (May to August) compared with the long-term average.  For the entire eastern US, the graph shows the complete absence of drought east of the Mississippi. In fact, it shows the reverse: the green colors show the areas that are above long-term averages in precipitation.  We don’t have comparable graphics for Canada, but precipitation data shows no areas of drought in eastern Canada this year.  Most of the east was above to well-above long term precipitation averages for the growing season so far (map is for May to August).

And the precipitation was evenly spread – every month was above average for most areas except in the upper Midwest, where August was dry.

As we said, a very good year to be a tree.  Just to note how unusual this is, I could not find comparable data for any prior year.

Lexington KY Precipitation
Lexington precipitation, 2013 and 2014 as departure from 1900-2000 average. Both years were very wet during the growing season
bur oak, Quercus macrocarpa, leaves in summer

News autumn, leaves, News, Temperate Forests, tree growth

The best year to be a tree, Part 1

Tom Kimmerer

September 23, 2013

Now that the Autumnal Equinox has arrived, it is a good time to look back on this year in the Lives of Trees.   For Eastern North America, this has been a great year to be a tree.  Temperatures were mild to moderate for most of the growing season, soil moisture was adequate to above average, rainfall was well spaced.  Although I have only been looking carefully at trees for a fraction of the lifetime of the average tree, I don’t remember a better growing season.

What have you seen this summer?  Have you noticed young leaves on trees in your neighborhood in mid to late summer?  Here in Kentucky, even though autumn is upon us, some trees still bear those very young tender leaves.

Have a look at these trees, and scroll down for more details

[soliloquy id=”1101″]

What we are seeing in these pictures is late-season growth.  You may think that trees grow all summer long, but that is almost never the case.  Trees are extremely risk-averse.  Young leaves are vulnerable to frost, drought, insects and diseases that do not much bother mature leaves.  Most trees in eastern North America open their buds in the spring, produce a quick flush of growth and then quickly stop.  In a good year, a bud may form in May or June, the tree will rest for a while and then growth will resume.  This creates a second flush of growth, as you can see in the young leaves in the pictures.

In a rare and exceptional year, you may see 3 flushes of growth.  This is the first year that I have ever seen a third flush of growth on trees throughout the region.  There are some slow-growing trees, such as bur oak, for which it is rare to see a second flush, let alone a third.

In the next part, I’ll explain some of the interesting details of this growth pattern.

 

 

whiskey-5821

News Barrels, Bourbon, News

The Barrel

Tom Kimmerer

September 11, 2013

Since The Bourbon Review is our launch sponsor (Thanks!), here is a short piece about the bourbon barrel.

Barrels of bourbon
Newly filled bourbon barrels at Woodford Reserve.

By law, Bourbon has to be aged in new oak barrels.  What kind of wood is used?  Any white oak wood will work, but red oak will not.

In Kentucky, white oak, Quercus alba,  is used almost exclusively because of the large volume of wood available.  Other white oaks, including bur oak, Q. macrocarpa, chinkapin oak, Q. muehlenbergii, swamp white oak, Q. bicolor, swamp chestnut oak, Q. michauxii, chestnut oak, Q. montana, and post oak, Q. stellata, can also be used. Most sawmills no longer distinguish between white oak species, so each of these species may contribute a bit of wood to the barrel business.

What’s wrong with red oak?   If you filled a red oak barrel with white dog, it would leak out in hours!  All oaks have very large pores, called vessels, that carry water up the tree when it is alive.  In red oak, those pores remain open. White oak pores are closed off by the tree with tyloses, effectively making the wood waterproof.

In the early days of Kentucky, barrels were used for storing all sorts of materials, including dry materials like corn meal and sugar.  These dry materials were stored in red oak barrels, which would breathe and keep the contents from spoiling.  Liquids such as whiskey were stored in white oak barrels.

In those days, if you wanted to order a barrel, you had to specify “tight cooperage” for liquids or “slack cooperage” for solids.  The slack cooperage industry is long gone, but the tight cooperage industry thrives in Kentucky today.

 

Picture of blue ash tree

News chinkapin oak, Classes, Classes and Workshops, News, Quercus muehlenbergii, Workshops

Don’t Miss the Workshop!

Tom Kimmerer

September 2, 2013
Picture of a dead chinkapin oak
Dead chinkapin oak, Quercus muehlenbergii.

 

When:  Saturday, October 12, 2013

Where: Floracliff State Nature Preserve and locations in Fayette and Scott Counties

The workshop is filling up and can only accommodate 20 people.  Read more about the Workshop, and call Floracliff to register.   Please note that clicking Going on our Facebook page does not register you for the workshop – you have to call Floracliff.

Horse farm with venerable trees

News News, People, Trees

Remembering Moosewood Bill Harlow

Tom Kimmerer

March 21, 2013

Cross-posted at Native Tree Society.
Many of us are familiar with the books by William Harlow, including the classic Textbook of Dendrology (Harlow and Harrar), Fruit Key and Twig Key and other forestry books. This reminiscence is sparked by several pictures from one of Harlow’s books posted on Facebook by Chris Budesa.

When I was an undergrad at Syracuse (1972-1975), Harlow had already retired as Professor of Forestry. He was renowned as a dendrology teacher although by academic training he was a wood technologist. Ed Ketchledge studied dendrology with Harlow; I studied dendrology with Ketchledge, and I taught dendrology for 18 years at Kentucky. So Harlow is my academic grandfather.

Harlow was still very much a presence on the Syracuse campus, and I had many opportunities to talk with him. He knew my love of the Adirondacks, particularly of tramping around Five Ponds when I was at Cranberry Lake. He shared with me many stories of weekend adventures dating back to the late 1920s when he was a student. The great conservationist Bob Marshall was also one of those who tramped around Cranberry Lake on weekends while at summer camp.

Harlow was known throughout upstate New York and the Adirondacks as Moosewood Bill. He was widely admired for his woods lore and worked with boy scouts and other groups on getting around in the woods. Among his many books was “Ways of the Woods: A Guide to the Skills and Spirit of the Woodland Experience” and “Songs of the Forester.”

One day, I was wearing my usual outfit – Pendleton shirt, khakis and hiking boots. He drew me aside and berated me for wearing Vibram-soled hiking boots. “Do you have any idea what those damned things do to the soil and the roots?” he asked me. “You want to tear apart the soil, you wear those. You might as well go out with a bulldozer.” Then he hiked up his pant leg and showed me his boots: 16″ high Bean’s Boots, the classic wetlands boot of the northeast. He extolled the virtues of Bean’s boots with their soft rubber sole with chain tread, as he lectured me about proper care of the woods. Of course, I had a pair of Bean’s boots, still have the same pair because they are immortal.

And that was the story Moosewood told me. You see, every time you wear out the bottoms of your Bean’s boots, you just send them back to LL Bean. They clean up the leather and stitch on new rubber bottoms. Moosewood had worn nothing but 16″ Bean’s boots his whole career, sending them back every year or two for new bottoms. One day, after he had sent off the boots for yet another repair, he got a letter from Bean’s. It seems that Moosewood’s boots were the oldest Bean’s boots still in service. Bean’s very generously offered him a new pair so they could put the old ones in their museum. Moosewood very politely responded “please repair these boots as requested. You may have them when I’m dead.” Although he lived for many years after that, I have always assumed that Bean’s eventually received Moosewood’s boots when he no longer needed them.

And today, whenever I lace up my Bean’s boots, which are a mere 12″ high, I remember Moosewood. My boots are now about 43 years old, but I have a long way to go before mine retire.

Like many foresters, I keep Harlow and Harrar, Fruit Key and Twig Key and other books by Bill Harlow on my shelf and use them often.

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Tom Kimmerer