Newsletter – December 2008
Redwoods Make Twists and Turns
—From Elisa Webb’s virtual tour of Marcel’s Forest
Are you a good detective? Can you help solve the mystery? One of the most interesting places in Marcel’s Forest is Twisted Grove. The redwoods in this grove twist and curve as they grow, but no one knows for certain why. One forester who has spent 25 years in the coast redwood forests of the Santa Cruz Mountains said, ” It’s the most extreme case of twisting I’ve seen.”
Some people think that these trees shifted downslope because of the seismically active land that they sit on. The trees, it is suggested, responded to the shift of the land underneath them by twisting their trunks in search of sunlight. This would make sense, according to one botanist, since the “meristem,” the part of all plants that causes tip growth, would need to move toward sunlight. However, the same botanist pointed out that not all of the trees on this same, seismically active piece of land twist. Because not all of the trees here show signs of correcting their trunks in search of sunlight, another explanation might be possible.
Some people have suggested that genetics might play a part in the unusual twisting. In fact, most researchers studying coast redwoods think that twisting this extreme is due to genetics. The twisted redwoods in this grove are sprouts, meaning that they all carry the same genetic material as the parent tree. This is why so many trees in one spot look the same. If the parent tree has a gene that codes for twisting, then any clone of the tree would also twist. As one researcher said, “Everyone assumes that twisting is due to genetics but no one has taken the time to do the long-term studies required to confirm it. Being a tree geneticist takes a lot of patience [because] you see the results of one cross about every 10 to 20 years!” Although uncommon, twisting in redwoods is found elsewhere, not just in Marcel’s Forest. A redwood forest near Pescadero also contains twisted and curved redwoods.