There are no ancient dawn redwood trees to use as models to style dawn redwood (Metasequoia) in a naturalistic style. The oldest trees outside of China were planted in the 1940's. I have not seen many photos at all of dawn redwoods in China. The few I've seen have been grainy, black & white and with little detail. No real sense of what they look like in their home habitat.
I have several Metasequoia, of various ages, they are incredibly winter hardy, more so than bald cypress. I find that their growth habit is quite similar to bald cypress. Very upright. They will not submit easily to any "cascade styles". They are very rapid growing. For models from nature I would look to bald cypress. I think you "can't go wrong" if you follow the bald cypress model.
couple photos from a canoe trip I took over a decade ago. Notice the stump that re-grew new trunks. The stump is estimated at over 800 years old, the new trunks are in the 100 to 300 year range.
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