To someone who has never seen one, a Redwood tree must seem to be something from a tall tale. Averaging eight feet to as much as twenty feet in diameter, and some as tall as three hundred and seventy five feet. That is a tree taller than the Statue of Liberty, from base of the pedestal to the tip of the torch. A tree larger around and through than a Greyhound bus. Absolutely the largest living thing on earth. A typical Redwood forest contains more biomass per square foot than ANY other area on earth, and that includes the Amazonian rain forests.
The Redwoods in Pre-History.
These largest of living things are from an ancient line, and near-relatives of redwoods were present on earth at the same time as the dinosaur. Once found almost world-wide, their natural range is now restricted to the foggy coastal belt of Northern California (the sequoia sempervirens), a strip in the Sierra Nevada mountains of sequoiadendron gigantia and a small group of meta sequoia (Dawn Redwood) in a remote valley in China. These are the only living forests left of a tree line that at one time spanned most of the the earth.
The Role of Weather in Redwood Growth and Range.
The Coastal Redwoods thrive on, and indeed require, the heavy fogs that are normal daily occurrences along the coast. These 300 foot plus tall giants actually pull moisture into their needles at the tops of the tree where the circulation system of the tree can’t pump to. The 50-60 degree average temperature of the area are also important to the life cycle of these trees. These two conditions are limits to the modern day range of these awesome giants. They will grow about anywhere, as evidenced by photos people have sent us over the years of trees growing in such disparate places as Fresno California, Waycross Georgia, Florida and even one hardy voyager in Phoenix Arizona. But they will never attain their true size and stature without the Coastal fogs and temperatures that nurture them and at the same time keep other competing species, such as pines, stunted and sodden.
Redwood Survival Strategies Are Varied and Intricate.
The bark of a coastal redwood is very thick, as much as a foot in places. And it exhibits an unusual property when exposed to fire - it chars into a heat shield. It actually turns into a pretty effective abalative, similar to the way a heat shield on a re-entry vehicle works. The chemical composition of the tree itself is apparently distasteful or even poisonous to normal tree pests like termites and ants. That is why it was used as the first layer of boards in a wall, because termites and carpenter ants won’t burrow into it. In the 30’s to the early 60’s redwood was used as a separator between the plates of electrolytic (auto, truck and airplane) batteries. The wood could withstand the battery acid and still retain its shape. Redwood is very resistant to water-associated rot. It is not uncommon to drill a well in a creek bed in this area and end up drilling right through a redwood log that may have been buried there for thousands of years. The wood comes out of the pipe sound and in good shape.
Unusual Redwood Proliferation Strategies.
A live redwood that is knocked over will attempt to continue growing via its limbs. If undisturbed, the limbs pointing up will turn into trees in their own right, and this is indeed the source of many row groups of trees.
Cathedral or family groups of trees are simply trees that have grown up from the living remains of the stump of a fallen redwood, and since they grew out of the perimeter, they are organized in a circle. If you looked at the genetic information in a cell of each of these trees, you would find that they were identical to each other and to the stump they sprang from. They are clones!
The redwood burls are another survival strategy. Their growth is held in check by the presence of chemical signals in a living redwood. If the tree should die, or even be stressed, say by low rainfall or fire, the chemical signal weakens or vanishes and the burl will burst forth into verdant life. Burls kept in a shallow pan of water will grow almost indefinitely. They can also continue on to become a full grown redwood tree. At the very least, if watered they will produce a lovely fringe of green pseudo branches and make a very interesting looking and unusual house plant.
Lastly, there is the conventional sexual reproduction system of seeds. About 20% of today’s present trees sprang from seeds. The rest came from one of the various cloning-based proliferation strategies. Genetically, it’s the same tree after each successive cloning process. 80% of the trees now growing were produced in one these cloning processes. If you connect these two facts, you will come to realize that some of those trees out there could be the last in a 20,000 or 30,000 year (or more) line of the SAME tree reproducing itself over and over again! Genetically, they are the same tree that grew from a seed all those centuries ago! Would it be proper to place the age of one of these trees as the true age of its unchanged genetic material? I don’t know, but these amazing trees are truly ever-living.