Trees and Bees
oak
Death of an Oak
This beautiful old oak tree was struck by lightning last September. Within 2 days, it had completely wilted and showed no signs of life. Sudden death due to lightning is uncommon in trees, especially after the end of the growing season. Several experts recommended leaving the tree until spring to see if it showed any signs of recovery. Sadly, the tree did not leaf out this spring. Because the tree is in a public park next to a popular basketball court, it had to be removed promptly. The photos below show the tree before and after death and the process of removing it. We have collected a section of the trunk and will use it to determine the tree’s age.
Before it was hit by lightning, this was a remarkably vigorous tree with no signs of death or decline. Within days after being struck, the leaves had wilted, twigs were dead and the fungus Biscogniauxia atropunctata had popped out on the major branches. Biscogniauxia is an endophytic fungus, living quietly within the bark of healthy trees and fruiting rapidly when the tree is stressed.
The tree before being hit by lightning.
The tree after felling
Section of the tree for ring counting
The tree three days after it was struck by lightning
Slicing the tree to count rings
The gray material is the fungus Biscognauxia atropunctata
Flowers, Pollen and Allergies
Is that tree causing your allergies? That pretty tree with the white flowers? That pine tree covering your car in green film? Nope. It’s the trees you don’t see that are getting you.
This is the height of allergy season. You can feel it in your sinuses and see it on your car windows. Huge amounts of pollen are flying through the air, seeking out female flowers with which to mate. There are many misconceptions about pollen, tree flowers and allergies.
In my experience, many people are confused about what trees cause allergies. The beautiful showy flowers of spring trees like black locust or flowering crab are not the cause of allergies. These flowers are designed to attract insects, hummingbirds and other pollinating animals. They do not toss their pollen into the air, but wait for animals to carry pollen from tree to tree.
It is the tree flowers we don’t notice that are the culprits. Oak, Osage-orange, hickory, and lots of other trees produce long male flowers called catkins that drop huge amounts of pollen into the air. You may not notice the flowers, but your respiratory system does.
Pine, spruce and other conifers don’t produce flowers, but they do toss huge amounts of pollen into the air. However, their pollen is so large that few people have problems with conifer allergies.
So, if you have to curse at a flower this spring, don’t pick on the pretty ones.
Oak stories for 2014
Here is a New Year’s reading list for all our quercophile (oak-loving) friends. These are articles at Venerable Trees published or revised in 2014.
Stories and News:
- Riparian oak, a hybrid oak in the Bluegrass
- The Old Schoolhouse Oak in the news again
- The Old Schoolhouse Oak Has Babies
- Friday Tree – The Oak Conundrum
- A magnificent bur oak
- Even Llamas Love Bur Oaks
- Why are young bur oak leaves hairy?
- chinkapin oak, Quercus muehlenbergii
- The Trees of Horse Country
- October Tour of Large Bluegrass Trees
- A Visit to Runnymede Farm
- Tree are Popping
- A most puzzling tree
Species Narratives:
Picture Galleries:
- Venerable Trees (all these galleries include photographs of oaks)
- Oaks and Related Trees
- Range and Importance Value Maps (including some oaks)
Friday Tree – The Oak Conundrum
The Friday Tree for this week is an introduction to several articles about oaks coming up next week at Venerable Trees. Oaks form the foundation of the forests of eastern North America. In abundance, size, diversity and usefulness, no other eastern tree comes close. There are fifty oak species in eastern North America, and oaks are dominant species in nearly 70% of eastern forests.
Oaks can be a real challenge to identify. See if you can identify this week’s Friday Tree to species. Make a comment in the comment box below (scroll all the way down) or on our Facebook page, and tell us why you think you are correct in your answer. We will reveal the tree’s identity, and have a lot more to say about oaks next week.
A most puzzling tree
Shumard oak, Quercus shumardii, is a puzzling tree. It is not abundant anywhere in its large range. It is easily confused with other red oaks, and it probably hybridizes with them. In the Bluegrass, Shumard oak is common, but highly variable. Here is a slide show of Shumard oaks in the Bluegrass.