The Bark of the Coast Redwood
The relatively thick bark of the Coast Redwood is considered a soft wood (compared to the hard wood of maple, oak and walnut trees) reddish-brown in color and resistant to rot. The thick bark is one factor in containing any disease that should this species of Redwood as it is normally over 1 foot thick on mature tress. In addition, insects are discouraged by the high tannin of the Redwood.
Even though the Redwood can usually withstand insects, disease and fire (due to the low amount of resin in the bark), the tree can often be felled by highs winds and flooding. The combination of high winds and wet soil is what causes the most destructive damage in a windfall. Treetop levels respond to harsher wind conditions by producing pale green, awl-shaped needles near the top of the tree; whereas, needles nearer the ground are darker green and more lush. The tree lacks a taproot, but it has a shallow root system that seldom goes beyond 12 feet underground. These lateral roots are very large and have a wide range of about 60-80 feet that intertwine with other trees. Trees older than 20 years old have thicker bark with deep vertical grooves that help it withstand fire and various diseases including fungi. Younger trees and seedlings are more at risk for disease and fire due to their lack of thick bark.
The Effects Of Fire In A Redwood Forest
Fire ecology in a redwood forest proves to be very beneficial. It aids the nutrient recycling, clears the understory, controls forest insects and diseases and prepares the soil for seeds. Vulnerability is created in redwoods to disease and catastrophic large fires when natural fires are suppressed.
For more information:
http://bioweb.uwlax.edu/bio203/s2009/hemmeric_nata/Adaptations.htm
http://bss.sfsu.edu/holzman/courses/Fall99Projects/redwood.htm
http://www.redwoodworld.co.uk/redwood_types.htm
