Redwood Quest

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(Addertongue only grows in a Redwood forest Biome)

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A whole ecosystem….

 

Totally by accident, I discovered a picture of a most beautiful flower commonly called Adderstongue (Scoliopus bigelovii) that I had never seen before. Of course I had to look it up…

I learned that Adderstongue only grows in old growth forest in the understory of the ancient Redwood trees of California in moist mossy places that are shaded. It grows from a rhizome, and I immediately suspected the plant must have a symbiotic relationship with the Redwood’s underground fungal network. The flower is pollinated by fungus gnats, the fruit is a drooping capsule and when it bursts the seeds are carried away by ants. The moment I laid eyes on the picture I longed to see one in the flesh… and this is what got me started on my Redwood Quest.

Once Redwoods grew throughout North America as well as along the coasts of Europe and Asia, but now they are now restricted to the Pacific coast. And I have never seen one.

The earliest Redwoods -Sequoia sempervirens -(the name Sequoia is Cherokee in origin) appeared shortly after the dinosaurs disappeared. Redwoods have lived in their present form for about 240 million years although California didn’t become their home until about 20 million years ago.

A coastal Redwood tree can grow to 350 feet or more and have a width of 22 feet at its base. Compare this to the tallest pine tree that might be 270 feet high. What amazed me initially was learning that a Redwood’s tap root system extends into the ground for only 6 to 12 feet. However, Redwoods compensate by creating surface roots that grow at least 50 feet from their trunks, and because they live in groves the trees literally support one another by intertwining their trunks and surface roots. Consequently, they have the strength to withstand powerful winds and flooding. Taking down even one tree creates havoc for the whole ecosystem.

Redwoods live a long time perhaps even longer than the 2000 plus years that are allotted them. Many Redwoods around today are 100 – 150 yeas old but a reasonable number reach an age of 600 years.

Studies show that coastal Redwoods capture more carbon dioxide than any other tree on Earth. And, as the climate changes, the Redwood forests are one of very few places that can provide a refuge for plants like the Adderstongue. Many wild creatures thrive in these forests because the area has many micro – climates, and is cooled by coastal summertime fog. California’s North Coast provides the only such environment left in the world. A combination of longitude, climate, and elevation limits the redwoods’ range to a few hundred coastal miles. The cool, moist air created by the Pacific Ocean keeps the trees continually damp, even during summer droughts. Fog precipitates onto the forest greenery and then drips to the forest floor. Fog accounts for about 40 percent of the redwoods’ moisture intake. When fog isn’t present, a grove of redwoods will make its own: a single large tree can transpire up to 500 gallons of water a day. The fog condenses on tree crowns and drips to the earth below. A Redwood’s ability to perpetually move this water hundreds of feet straight up from ground to crown defying gravity is a source of awe to me.

Exactly why the redwoods grow so tall remains a mystery.

Resistance to natural enemies such as insects and fire are built-in features of  coastal Redwoods. Diseases are virtually unknown (or were until recently) and insect damage insignificant thanks to the high tannin content of the wood. Thick bark and foliage that rests high above the ground provides protection from all but the hottest fires.

The Redwoods’ unusual ability to regenerate also aids in their survival as a species. They do not rely upon sexual reproduction, as many other trees do. New sprouts may come directly from a stump or downed tree’s root system as a clone.

Cloning is defined as the process of producing genetically identical individuals of an organism either naturally or artificially. Cloning in biotechnology refers to the process of creating clones of organisms or copies of cells or DNA fragments. Although grammatically correct, I object to the use of the word clone because it suggests to most people an artificial process – one that distances us from the fact that we are talking about a living organism that is reproducing itself. The Redwood’s ability to clone itself means that many of the forest’s trees are related to one another.

Cathedral or family groups are trees that have grown up from the living remains of the stump of one fallen Redwood, and since they grew out of the perimeter, they are organized in a circle. The genetic information in the cells of each of these trees is identical to that of the stump they sprang from.

Amazingly, Basal burls — hard, knotty growths that form from dormant seedlings on a living tree — can also sprout a new tree when the main trunk is damaged by fire, cutting, or toppling.

Undoubtedly, the most important environmental influence upon the coastal Redwood is its own biotic community. The complex soils on the forest floor contribute not only to the redwoods’ growth, but also to a verdant array of greenery, fungi, and other trees. A healthy redwood forest usually includes massive Douglas-firs, Western Hemlocks, Tanoaks, Madrones, among others. The emerald ferns and leafy redwood sorrels, mosses and mushrooms help to regenerate the soils. And of course, when Redwoods die they eventually fall to the forest floor where they decay and provide more nutrients to create new life.

The coastal redwood environment recycles naturally; because the 100-plus inches of annual rainfall leaves the soil with few nutrients, the trees rely on each other, living and dead for their vital nutrients. The trees need to decay naturally to fully participate in this cycle, so when logging occurs, the natural recycling is interrupted.

Many different shrubs populate the understory of old-growth redwood forests. Among them are berry bushes such as red and evergreen huckleberry, blackberry, salmonberry, and thimbleberry. Black bears and other inhabitants of the forest make use of these seasonal food sources.

Perhaps the most famous and spectacular member of the redwood understory is the brilliantly colored California rhododendron. In springtime, rhododendrons apparently transform the redwood forests into a dazzling display of purple and pink colors.

The survival strategies of these trees like their ability to reproduce identical relatives astonishes me. A 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.

Another unusual survival strategy is the Redwood burls. The growth of a burl is held in check by the presence of chemical signals in a living Redwood. However, if the tree should die, or even be stressed, say by drought 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.

Sexual reproduction can also occur by seeding. About 20% of today’s present Redwood trees sprang from seeds ( some Redwoods don’t even produce them). The rest came from one of the various cloning/family-based proliferation strategies. This means that some of these trees could be the latest incarnations of the same line that stretches back 20,000 or 30,000 years.

Coastal Redwoods also have the unique ability to survive rising soil levels. Rising ground levels are commonly brought about by flood deposits, deposits that typically smother other trees root systems, killing them. The Redwood simply grows a new lateral root system. Seven successive layers of roots were observed on one fallen Redwood meaning that the ground level had risen dramatically up the tree seven times and each time the tree responded with a new root system. It has been observed that some 1000+ year old Redwoods have experienced and survived rises in ground level of as much as 30 feet.

Redwoods compensate for induced leans caused by shifting slopes, collisions of other trees, flood pressure and tectonic induced tilting, by the unusual ability to “buttress” their undersides through accelerated growth on the downhill side. What this means practically is that it is possible to find whole groves of trees that are leaning in the same direction.

Recalling that as a human I share 25 percent of my DNA with trees, it seems quite natural that I would want to meet a forest composed of my most astonishing relatives and perhaps visit with the Addertongue in the process!