Chestnut Blight is why. True, they also show an evolutionary bottleneck, likely caused by the Quaternary Glaciation. The big reason, though is Chestnut Blight.
It’s caused by a parasitic fungus (Cryphonectria parasitica) which was introduced from East Asia in 1904 along with Japanese Chestnut trees. American Chestnut and Allegheny Chinquapin are extremely susceptable to the disease. Other trees (including Shagbark Hickories) can be infected, but they’re less likely to die.
In 40 years, the fungus devastated the population. It’s estimated that the blight killed between three and four billion trees in the first half of the 20th Century, and radically changed the composition of the Appalachian forests.
Since the fungus only kills the above-ground portion of the tree, shoots can sprout from survivor rootstock, but they always become infected and die back before reaching maturity. Some ‘living stumps’ have been going through this cycle for a century now.
There are isolated populations that have escaped infection, and individual trees that show resistance to the fungus. There are people who have been working for decades on ways to save them: crossing and backcrossing with resistant species, innoculation, and it looks as though CRISPR may be the next tool employed. There’s been enough success with the various methods to keep alive the hope that one of the—formerly—most ecologically and commercially valuable trees in the US might once again be a genuinely viable species. But it’s going to be a long time before the tree once known as ‘The Redwood of the East’ returns to being a significant part of the ecosystem.
Have you read The Overstory by Richard Powers? It makes you realize what a tremendously sad story the destruction of this species really meant to America.
But it seems that it is not functionally extinct (unless I’m interpreting the term wrong), which would be amazing? Chestnut blight seems like it’s just another bottleneck that the species may (or may not, but I’d rather be optimistic) eventually recover from when enough trees have gained immunity, even without gene editing and dire-wolfing. Or does the fungus kill off any growth before it gets the chance of producing viable sexual offspring?
No, I havent, but I’ll add it to my recommended list. Thank you for the suggestion!
That’s it exactly. The rootstock and shoots are trapped in a state of perpetual immaturity. The shoots live long enough to feed the roots, but the fungus girdles and kills the shoots before any of them can reach maturity.
That’s one of the reasons that so much work is being done on relict populations (including those deliberately planted outside their natural range) and individual trees that show resistance. The stumps will probably never recover properly, but trees that show high resistance—whether those are naturally crossed, dire-wolfed, or transgenic—can be re-introduced into the historic territory.
This is a species I’ve wanted to see for a while. I’ve been to the beach that I found them on lots of times, but this is the first time I’ve seen these.
If this was in Sweden I’d say M. scorpioides based on habitat, size of petals and length and hairiness of calyx lobes, but in North America this is out of my league
My favorite lifer this week was Euphrasia bottnica, an unremarkable but pretty little plant that is endemic to the northern Baltic Sea coast, which is really cool as we don’t get too many endemics up here. I also really like (hemi-)parasitic plants, so that’s a bonus as well.
it’s Myostois scorpioides, you can tell by all the hairs on the calyx being straight (latifolia and sylvatica, another common invasive Myosotis to the USA have them curved, as do indeed most of Myosotis), and calyx being rather shallowly divided and roundish (laxa has it deeper divided and gives more of a trumpet shape).
The last possibility would be nemorosa, which has smaller and darkewr flowers, bui to be sure, we would need to see hairinas of the basal leaves and stemm, and if it has stolon or not (scorpioides has stolons, and the underside of the basal leaf is hairy all in the same direction (towards the tip), and basal stem/stolons are hairy upward or patent, not downwards, and the stem is not notably shiny), however, nemorosa has no observation in the USA, so i think it is relatively safe you rpobably saw the most widespread of the Myosotises in in USA.
I went to a local park this weekend, I checked it out beforehand to see what iNat observations were there and I noticed Silvery Checkerspot observations. While I was out there I found a couple (observation), always delighted to find a new Checkerspot especially.
