Nature up close: Redwood magic
By "Sunday Morning" contributing videographer Judy Lehmberg.
There are a few moments during my childhood I can still recall in vivid detail. One of those was when I was about eight years old and at a summer camp.
It was during my first night camping out on the ground on the sandy shore of the Brazos River at Camp El Tesoro, a Camp Fire Girls camp. Our counselors and all the campers hiked to the river. We spread blankets next to the river and enjoyed a delicious dinner of peanut butter and jelly sandwiches. One girl had a multicolored quilt where we quickly discovered a "chameleon" (actually an Anole lizard). Anoles can change their skin colors. We convinced ourselves the lizard was changing colors based on where it was on the quilt. It changed from brown to green, back to brown, then green again in less than a minute. It was absolutely magical!
Later in one of my college biology classes I learned how that magic happens. Anole skin contains several layers of pigmented cells. Their skin color varies as tiny pigment-containing packages move around inside those cells, either exposing or concealing other pigmented cells beneath them. Nothing magic about that. It was one of the most disappointing things I ever learned. I wanted it to be magic, but I accidently learned the truth.
What in the world do color-changing lizards have to do with California redwoods? Well, not much, except redwoods are still magical to me. I felt the same magic the first time I saw them as that eight-year-old experienced years ago. It was as if I were still that kid and nature was waiting patiently for me to discover all of its wonders. As I looked up and up and up those magnificent trees, I found myself speaking in a whisper. I felt as if I should be bowing or curtsying to them. I should behave as if I was in the presence of royalty, because I was.
Redwoods are trees of superlatives: exceptional, marvelous, majestic and tallest are all terms that fit them. They aren't the largest organism on Earth; that honor goes to the closely-related Sequoiadendron giganteum, the giant Sequoia (or Sierra redwood). They aren't the oldest; Bristlecone pines hold that title.
Redwoods, Sequoia sempervirens, are the tallest, and at six feet per year one of the fastest-growing trees. In the 1960s the tallest redwood was believed to be the Libby Redwood at 367.8 feet tall. Later, Steve Sillett, a professor at Humboldt State University, found a 370.1-foot-high redwood. Recently a redwood in Redwood National Park, the Hyperion Tree, was discovered to be 379.1 feet high.
- Surveying species among California's redwoods ("Sunday Morning," 08/231/14)
- California's redwood trees under attack by "burl poachers" ("CBS This Morning," 05/09/14)
- Group clones California trees for global planting project
There are many facts biologists have discovered about redwoods. Their seeds are so small, about 120,000 of them weigh one pound. They depend on summer fog as a water source. Their roots form a symbiotic relationship with a fungi that absorbs more water and nutrients than it could on its own. A healthy group of redwoods contains more biomass than any other ecosystem on Earth. They can live at least 2,200 years. They are disease-, fire- and insect-resistant.
But so far, no one can explain their ability to grow as tall as they do. Redwoods (along with pines, spruce, cypress, and fir trees) are vascular plants. They have a network of cells in their bark, the phloem, which transports food made in the leaves to other parts of the tree. The wood, xylem, is a network of cells that transport water and minerals from the roots up to the leaves, where they are essential for photosynthesis. Plants don't have a heart to pump fluids from one part of a plant to another. They must rely on a combination of water pressure, adhesion and capillarity. Water molecules are attracted to other water molecules, so as one molecule moves up through the xylem cells, others follow. Nanotube capillary action creating a tremendous negative or suction pressure is the usual explanation. But even when all of those properties are considered, scientists can't explain how water can rise up as high as it does in a redwood. But it does! And that is where the magic is.
Even though I've spent most of my life learning about plants and animals, I am constantly amazed at new discoveries. But I still want some of it to be magic. To be able to look at a magnificent tree and not know why it grows so tall and survives is absolutely wonderful. I may not be able to keep the magic in lizards anymore, but I can still see it in redwoods. If some physicist figures it out, I hope I never hear about it.
Judy Lehmberg is a former college biology teacher who now shoots nature videos.
For more info:
- Judy Lehmberg (Official site)
- Judy Lehmberg's YouTube Channel
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