Photo Tour: Redwood, Sequoia sempervirens
A hobby of mine since I started climbing trees as a graduate student has been finding the tallest trees. There are many record-keepers among tree-lovers, and I do not profess to be the sole authority. Today on Earth there are only 5 tree species with living individuals known over 300 feet. I have climbed and measured the total height of the tallest live-topped individual of each of these species. As of 2009, these were Sequoia sempervirens (379 feet), Eucalyptus regnans (327 feet), Pseudotsuga menziesii (318 feet), Picea sitchensis (318 feet), and Sequoiadendron giganteum (311 feet). All but one of these (E. regnans) live in California.
North America now has 7 species with living individuals known over 262.5 feet: Sequoia sempervirens, Pseudotsuga menziesii, Picea sitchensis, Sequoiadendron giganteum, Abies procera (287 feet), Abies grandis (267 feet), and Chamaecyparis lawsoniana (266 feet). In 2008, the tallest living Pinus lambertiana (270 feet) died. Only Australia and Malaysia have more species this tall. According to Brett Mifsud, Australia now has at least 8 species over 80 meters (all Eucalyptus), and Malaysia has at least 7 (Koompassia excelsa and several Dipterocarpaceae). Further searching will no doubt reveal more super-tall tree species.
A redwood tree grows tall in a forest if left undamaged. The lucky few escape injury and approach their maximum heights in 600 years or so, but most trees get damaged in storms from wind and falling neighbors, and the crowns of many old trees have burned in forest fires. A high resistance to both wood decay and fire bestows great longevity on redwood, and trees can survive for more than a millennium after experiencing severe and repeated damage. Here is a brief description of what I have learned about the growth of Sequoia sempervirens from climbing in old-growth forests since 1987.
Poria sequoiae to invade and initiate decay. Over the centuries, chunks of wood not consumed in the fire, but weakened by decay, calve off and fall to the ground, such as in this redwood that lost a large section of its main trunk. Note the reiterated trunks on both sides of the cavity.">
The beauty of old-growth redwood forests is easily appreciated, and I have been lucky to see these forests from vantages few others experience. Here Marie and I share some of our favorite photographs.
Organisms that live on the surfaces of plants without parasitizing them are called epiphytes. Redwood forests support a wide variety of epiphytes, and much of my research has addressed questions about their ecology. Here is some of what we have learned about redwood epiphtyes.
Old-growth redwood forest canopies are home to a multitude of animal species, most of which are tiny and only visible with a microscope. Some larger and very interesting animals also inhabit the canopy, but these are difficult to see without sustained effort on ropes or via continuous video monitoring. My overall impression of the redwood forest compared to other forests in which I have climbed trees extensively is that the canopy is very quiet. There are relatively few insects, birds, and mammals living in redwood crowns, perhaps because the trees are toxic to herbivores and highly resistant to pathogens.
Other Photo Tours
This photo tour explores my work with Sequoiadendron giganteum, the giant sequoia. This species is confined to California's Sierra Nevada, where they reach sizes greater than the biggest living coast redwoods and ages up to 3200 years.
Before logging took its toll on the Douglas-fir forests of British Columbia, Washington, and Oregon, specimens over 400 feet tall were measured. Today the highest concentration of Douglas-firs over 300 feet tall reside in northwestern California amidst the redwoods, as shown in this photo tour.
Targeted by loggers for its wood, whose strength to weight ratio is among the highest on Earth, very little old-growth Sitka spruce forest remains. As with Douglas-fir, the highest concentration of Sitka spruce over 300 feet now resides in northwestern California amidst the redwoods.
Eucalyptus regnans is the undisputed tallest flowering plant in the world. There are, for instance, many well-publicized claims of several trees over 400 feet that were either logged or burned in the 19th and 20th centuries. Today the tallest living individual is a 327-foot-tall Tasmanian tree. This photo tour takes you into Australia's tallest forests.