Sunday, August 9, 2009

Something I’ve Pondered – Revisited

The July 26 posting led to a number of contributions I thought I’d share with you. I was aware of other species that acted like a chameleon but because of my love affair with the Madrone, I just restricted my thoughts to it.



Persimmon (Diospyros texana). Phototgraph taken by Scott Gardner.



Scott Gardner sent this specimen of the Persimmon (Diospyros texana) from the Browning Ranch three miles east of Johnson City. There weren’t any Persimmon here on the ranch forty years ago, until in my plan to have every species in Blanco County represented, I introduced some. Local old timers who were here to observe our restoration work thought it was a foolish thing to do, as once again on abused ranch land, Persimmons can become a problem and many considered it worse than cedar – me and the deer enjoy the delicious black fruit. It’s the seeds passing through the deer where the seeds become fully fertilized that spread the Persimmon, but this happens on mostly overgrazed land. This is wonderful landscaping plant except don’t plant it near a sidewalk or driveway as it can blacken your car, sidewalk and the soles of your shoes.



From no reply – comment:

“The only other hypothesis I’ve heard about the peeling of the bark was about solar heat. If the Madrone peels the darker red in the summer, could it be cooler for it to survive with its lighter colored bark and then go back to the darker red when the climate turns colder? This hypothesis, however, wouldn’t make sense if you posed the question to the Persimmon or even Crape Myrtle. Leave it to JDavid to always ask the good questions!!”


From another reader - How about this?

“David – It is logical that the Madrone tree sheds its bark in order to grow larger. On the other hand, maybe God gave the tree this ability so that it could have its “15 minutes of fame” and look beautiful! I shouldn’t really anthropomorphize, but you did call a tree “she” in your blog!”


In a newsletter from Friends of Friedrich Wilderness Park sent to me by Paul Cox of the San Antonio Botanical Center. This was written by Park Naturalist Wendy Cooley:


Why Does Texas Persimmon Bark Peel?


“Not too long ago a group of volunteers at Crownridge Canyon Natural Areas asked the question: Why does Texas Persimmon bark peel? Once I started doing research, I found that numerous trees shed their bark, like the Texas Madrone and the American Sycamore. One explanation is that these trees have thin brittle bark that cannot expand to accommodate new growth. The exfoliation and peeling of bark is a result of the tree growing and maturing. Trees with thicker bark, like live oaks, have bark that is generally able to expand and thus does not typically shed off in chunks. Shedding of bark is normal when it exposes new bark and not bare wood. When shedding bark exposes bare wood, then this could be a symptom of a larger problem (MSU-Extension 1999). There are many other explanations that have been hypothesized for why trees shed their bark. One that is relevant to our area includes a protective strategy against fungi, mosses, parasites, epiphytes, and lichens from inhabiting the trunks and limbs of trees. Another explanation deals only with trees in the floodplain. Trees with thick bark have a water conservation advantage and cannot transpire water as easily as thin barked trees. Thin barked trees allow for increased transpiration through their trunk (Still and Watt 2004). One final explanation involves photosynthesis in the trunks and branches of deciduous trees. This is particularly true for Sycamores where the exposed, new, and sometimes green woody parts can increase photosynthesis and thus increase growth (Still and Watt 2004). It is evident that Texas Persimmon bark sheds and exfoliates as a result of the growth occurring under the thin bark and that there are other trees that shed their bark as well for this same reason. However, the Texas Persimmon may have developed thin exfoliating bark as a protective strategy to shed its trunks and branches of epiphytes such as ball moss as well as lichens and other potential pests. Nature holds a world of wonder and as more and more naturalists come together to work and explore the Natural Areas more great questions are sure to come up.”




Birch bark (Betula papyrifera). Photograph taken by J. David.


In our quest for information or knowledge, it’s funny how researching something or networking leads you to something not thought of before. Just before posting this update on exfoliating trees, I was showing some friends through my house and explaining some fact or history of items you could say were decorations, but mostly just things picked up on the ranch or, in some cases, acquired from places we traveled to and served as somewhat of a museum of memories. Lo and behold, here on the stone window seat is an example of another exfoliating tree not mentioned in any of our ranch library books. . . . I’m 81 years old and collected this piece of Birch bark perhaps 70 years ago.




Picture of toy canoe. Photograph taken by J. David.


I now recall as a little boy attempting to make a canoe out of Birch bark as the Indians had done. It was beyond a young lad of 10 or 11 to do, so I decided I’d make a toy canoe and had some small success using horse hair, sticks and glue and of course a pocket knife. It was crude but it looked good as I proudly showed it to my mother and she was quite proud of me. But when launched on its maiden voyage in the spring box, it was very poorly balanced and quickly turned over. I’m almost certain that this is not the Birch bark toy canoe that I made. I have no idea how long it’s been on display in our “make shift museum”, but it is a good example of how the American Indians used some of our exfoliating trees to build their transporting vessels. There are a 105 species of Birch trees. The Complete Trees of North America by Thomas S. Elias describes 22 species but since I know this sample species in the picture came from Ohio I’m using the species “Paper Birch” (Betula papyrifera Marsh) to describe it and I quote “This tree is widely known for its use on birch bark canoes.”



Crape Myrtle (Lagerstroemia indica L.) not a true Texas native, but it exfoliates like those in discussion. Photograph taken by J. David.


I didn’t know at the time of planting that Crape Myrtle was not a native plant. I just knew that I loved flowering trees and Texas has a lot of them. They are considered a non-native species especially abundant in Australia and Central and South America. However, 4 genera native to North America occur only in Southern Florida. Originally they were introduced here for their ornamental value or to serve as windbreaks. Now they’ve become quite popular and can be found in most any local nursery. . . . Interesting for me was in 1979 having bought 12 acres on Babcock Road in San Antonio, the folks building the Fiesta Amusement Park noticed 25 very large Crape Myrtles on an old abandoned house on the property for which they paid me $2,500.00! Now, I wonder if that caused me to overlook the non-native part when I introduced 5 here on the ranch! Money sometimes does strange things to people.



American Sycamore (Platanus occidentalis). Photograph taken by J. David.


Look closely for the peeling bark as my pictures don’t show the exfoliating bark as clearly that is the “Question to Ponder” of these two blogs. Part of that is my excuse that I got around to taking the pictures a little late and the other part is I never had the same interest in these additions to the subject of the Madrone trees until you readers started alerting me. The Sycamore family contains 10 closely related species all belonging to a single genus only 3 of the species occur in the United States. I’ve noticed here on the ranch and in the Hill Country they are quite prolific and once again there are some landowners who don’t care for them claiming they clog up creeks and consume too much water. It’s of little value to wildlife, but I like its looks and smell and recommend it to you.


I’m somewhat sorry that my penchant for projects and challenges has kept me a conservationist rather than a biologist all these years. So I don’t speak genus and species very well, but I have a world of experience in doing things to help Mother Nature along and I appreciate all this modern stuff that allows us to share information and work together to create natural places for all living things other than us to live a long, happy and useful life.

1 comment:

Charles said...

J. David,
In addition to the fruit you enjoy from the Tx. persimmon, they do serve a valuable role on the ranch. This tree along with the agarita and a few other early spring blooming trees (e.g. elm and oak), provide a valuable source of nectar and pollen for the ranch honeybee hives and the feral bee colonies. These early bloomers provide a source of nectar and pollen right about the time the queen bee starts laying eggs again after the winter hibernation period. So this nectar and pollen is vital for feeding the young brood during the hive buildup...as well as pollinating the persimmon so you, deer, and the birds can enjoy the fruit (first come, first served).
Chuck
(P.S.) Comments are long so feel free to edit or delete).