Extant redwoods comprise three species, each in its own genus. Having observed two of them – Coast Redwood Sequioa sempervirens and Giant Sequoia Sequoiadendron giganteum – and soon to upload several more observations of Coast Redwood, I was curious about the thrid one. Dawn Redwood Metasequioa glyptostroboides.
When I look at iNaturalist observations, filtered to show only Research Grade, I see the following map:
Now, according to Wikipedia, "It now survives only in wet lower slopes and montane river and stream valleys in the border region of Hubei and Hunan provinces and Chongqing municipality in south-central China, notably in Lichuan county in Hubei. Zooming in on the map, I find only two observations in those localities:
So, presumably, the other 399 observations are wrongly Research Grade and should technically be marked as casual. Now, ordinarily, I would hesitate to do this, since I am sure that those observations are important to the observers who made them, and it just seems like a mean thing to do to go through and do something like that wholesale. There was a whole thread about someone doing this with Bison: Wild American Bison are captive? - General - iNaturalist Community Forum, and an ensuing debate about whether this was appropriate. With trees, it is a bit different, since, per iNat guidelines, a tree planted by humans is captive/cultivated forever. However, with Dawn Redwood, I see two important factors, again from Wikipedia:
- Cutting of trees or branches is illegal, but the demand for seedlings drives cone collection to the point that natural reproduction is no longer occurring in the dawn redwood forest.
- In North Carolina, a private endeavor is working to create a Metasequioa reserve on 50 acres of uplands in the Sauratown Mountains.
The first of these suggests that marking all Dawn Redwoods as casual ouside of Hubei and Hunan would help to emphasize the dire straits the Dawn Redwood ecosystem is in; as the Wikipedia article further notes, “The species will continue to live in yards, parks and on roadsides all over China, but the M. glyptostroboides forest ecosystem could disappear when its mature trees die.”
Conversely, the second point suggests that at least some people feel that self-reproducing populations may develop if enough are planted together, as stated on the reserve’s website: Home (dawnredwood.org). Otherwise, why call it a reserve? This further suggests that assuming that all Dawn Redwoods outside China are cultivated may not be best; it would potentially obscure self-reproduction. The reserve’s stewards note, “The location of the preserve must remain vague, at least for now, for obvious reasons. If people knew there were redwoods in the vicinity, they might search for giant trees, possibly trampling seedlings in their quest.” The Dawn Redwood observations in North Carolina do not appear to be in the reserve, but nevertheless, I hesitate to dismiss them, since they do indicate a gene pool adapted to North American conditions.
To mark casual, or not to mark casual, that is the question.