Sequoia National Park is an incredible place to seek inspiration from the quiet majesty of these spectacular trees and learn about the role they’ve played in developing our understanding and appreciation of nature and the history of our National Park System. I’d wanted to visit Sequoia for years, but it took me until my 86th to achieve that goal, and maybe that was a good thing. An earlier visit might have changed the course of my career had I been as impressed as I was this past September. It has taken me weeks to write about this experience in a manner more objective than emotional.
Sequoia National Park is not simply a grove—or a series of groves—of giant sequoia trees. It is a 631-square-mile portion of the Sierra Nevada mountain environment. Combined with adjacent Kings Canyon National Park, which is under the same management, the total area encompasses 1,353 square miles in which 1,552 species and sub-species of vascular plants are documented, including 26 species of deciduous trees and 21 evergreen species. It’s a botanist’s and dendrologist’s paradise, and the changes that have occurred to it since Euro-American exploitation of it began in the first half of the nineteenth century have taught us much about-and led to better management of–our forest resources.
The giant sequoia is extraordinary, not just because of its size and longevity. The General Sherman tree shown in my previous blog post is the world’s largest living tree by volume and is presumed to be more than 3000 years old, but there are interesting facts about the species that may not be generally understood. For example, much attention was given this past summer to human efforts to protect the giant sequoias in Yosemite National Park’s famous Mariposa Grove from a forest fire, but it has long been known that the trees are flame resistant. Older trees have very thick bark, which contains no flammable resins, as do pine trees. This is not to say that the bark will not burn, but the burn scars on many of the trees attest to the protection that the inner cores of older trees have been given over the years as they have continued to grow to heights of almost 300 feet. When forest fires occur, heat rises into the treetops, drying the cones and allowing them to open. The seeds then fall into the recently burned soil and germinate.
Giant sequoias are also resistant to fungal rot, wood-boring beetles, termites, and other wood-eating organisms. In fact, the long-horned wood-boring beetle’s larvae will dig into the cones which dry and shrink allowing the seeds to release over a period of six months to a year. Douglas squirrels also contribute to regeneration by eating the scales of the sequoia cones and cutting and caching the cones.
Sequoias also are intolerant to shade. Though they appear to thrive in forests of mixed conifers, the presence of other large trees negatively impacts their regeneration. For years forest management included protection of the sequoias from fire and that contributed to a reduction of seed germination and tree regeneration. Only recently has the use of controlled burns been used as a method to promote giant sequoia regeneration, and the trees can grow as much as 24” in a year under ideal conditions.
Lumber companies invested heavily in giant sequoia harvesting in the late nineteenth and early twentieth century, with expensive and disappointing results. Although the wood has a good weight-to-strength ratio, is stable, has little shrinkage, and doesn’t rot or decay, its bole (trunk) is brittle and can shatter if the tree is cut down. Conventional logging techniques resulted in large amounts of waste, and much of the lumber, unsatisfactory for construction, was used for fenceposts and plant stakes. It was expensive to cut, and profits were not only difficult to achieve, but the mills often operated at a loss.
The giant sequoias became a catalyst for political action, and public sentiment supported preservation of the trees and made it possible to set aside many of the groves as State and National Forest lands even before the establishment of National Parks for that purpose. Yellowstone National Park, established on March 1, 1872, was the first National Park and it was followed 18 years later by the creation of Sequoia on September 25, 1890, and Yosemite, just six days later, on October 1, 1890. Thus was our National Park System created, although the National Park Service was not established under the U. S. Department of the Interior until August 25, 1916