Tenaceous Yellow Birch at Agate Beach
We saw this extremely tenaceous tree when we went to Agate Beach on May 30, 2022. It is strenuously resisting the efforts of Lake Superior to wash it away.
Here it is from the side, with Sam and Rosie for scale. The roots have managed to hold together a thin finger of soil about 20 feet long, while the rest of the beach-side cliff collapsed all around it.
I think the tree is a Yellow Birch, Betula_alleghaniensis. The bark is quite distinctive. These are fairly common trees around here, particularly in wet environments. It looks like that main root in the front is probably providing most of the support for the tree (and probably providing most of the water it needs to survive, too). The roots at the back are primarily stabilization so that it doesn’t fall over.
To give you an idea of what the poor tree is up against, here is what the beach looks like. Sam is posing next to what is left of a tree that lost the battle with the lake. The rounded stones that you see were probably mostly polished smooth by the glaciers that dug the lake, but it was the wave action of the lake that threw them way up on the beach like that (the water is off the left side of the picture).
And here is a stretch of the cliff that was not protected by tree roots. The cliff is about 15 feet high. The lake is probably advancing into that cliff by a foot or so every few years.
The high ground that is being eroded away is a public park, which has been progressively getting smaller over the years.
The lake looked pretty calm at the time, but don’t be fooled. When the ice is breaking up in the spring, and the 15-foot waves are shoving around massive ice floes, it can move a lot of rock and soil in a hurry!
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One would think that the lake would eventually run out of erodable land. It’s volume doesn’t increase and so at some point, it would no longer be able to take and hold land.
Spell check thinks that erodable isn’t a word. Bah! Spell check lacks imagination like a barkerwolf caught in a splatterstorm.
Yes, eventually the land will erode into the lake, and the lake will fill up. But, the lake is only about 10,000 years old (which was when the glaciers that dug it out finally melted back). It hasn’t had much time to fill in, and still has a lot of room to continue to ingest beachfront property for the next 100,000 years or so.
Although, if it finishes eroding out the rapids at Sault Ste. Marie, the lake level will drop about 25 feet until it matches Lake Huron. This would tend to re-expose a lot of previously eroded beaches.