Maple in the Midden (click to enlarge)
This Bigleaf maple (Acer macrophyllum) stands on the beach – below the highwater mark – in Montague Harbour Marine Park on Galiano Island. It’s an unusual setting for a large tree: Bigleaf maples often grow alongside streams, but that’s fresh water. This one must endure having its roots bathed in salt water with every day’s high tide.
I don’t usually think of trees as inhabitants of the intertidal zone – that’s the niche for sea asparagus, barnacles, starfish and clams. But this individual seems to have managed quite nicely. Like many Bigleaf maples, it has developed multiple trunks and a rather chaotic look, but judging by its canopy it seems healthy enough.
The beach it`s growing on is white, but neither sandy nor tropical. Montague was the site of a huge Coast Salish village for about 3000 years, with the residents and their visitors relying on clams and other shellfish as the mainstay of their diet. All those clams made for a lot of debris, and thus the beach is a part of a large, deep midden, made from the fragments of thousands of years of dumped shells. (I suppose this gives the maple a plentiful supply of calcium.)
I couldn`t resist photographing the maple last fall, when we pulled our dinghy up onto the beach to take a walk in the park. I was drawn by the intense colour of the leafy canopy against the bleached-out tones of the shells, drift logs, tree trunks and lichen – along with the surprise of finding such an improbable giant on a salt-soaked west coast beach.
With the publication of this article I’m celebrating a personal milestone of sorts: this is my 100th blog post! A heartfelt thank you to all readers and commenters for your visits and kind words since I launched this site in the fall of 2011.
Eye on Environment 
What a great, and highly unusual, find Laurie! These maple trees we have out here on the west coast are truly incredible. I love this shot and the accompanying info you’ve shared here, I really enjoyed this post!
Congratulations on your 100th blog post. And thank you for this interesting perspective about the magnificent maple amid the ancient midden.
Thank you, Diane!
Like this tree, the midden extends into the beach, and indeed underwater. The reason is that the land is sinking, slowly. What was upland 5000 years ago is now subtidal, and 3000 years ago land is now mid- intertidal. The site is actually intact in these places, at least partly, since it has not been totally eroded during the marine transgression.
I am guessing the tree might be hundreds of years old, and likely has been slowly undercut by the ongoing erosion that is happening everywhere in the Gulf Islands as this side of Vancouver Island slowly rotates underwater (the west coast is rising as the big submarine plates slide under it and the island rotates on a hinge somewhere to the west of the Salish Sea).
Very interesting, ehpem! I have been thinking that some sea level rise has occurred since early aboriginal settlement times (since a lot of our area’s middens can be seen to extend underwater – very visible from a kayak). The idea of rotation on a “hinge” and subsequent sinking of the land in the region helps to explain this.
As for the tree’s age – hard to say. I researched bigleaf maples and read that they can live to 300 years and sometimes longer, but no clarity on how much longer. I would like to think that the midden grew around the tree, but I can’t imagine the tree is old enough to have been there at the same time as the village. I haven’t been able to find info on when the village stopped being occupied – do you know that?
One other reader wrote to say that he suspects there is enough freshwater runoff from nearby bluffs to cause isostatic pressure that resists saltwater intrusion.to the area of the tree’s roots, which likely start in the slope above the beach and go deep underground. That could be a factor as well I expect.
Hi Laurie, I don’t know when it was last occupied, I would imagine a place that was being used up into at least the early historical period. I suspect the big leaf maple can live longer than 300 years just from the huge size they can reach – for instance one at English Camp park on San Juan Island. However, I also suspect that larger villages had little in the way of trees growing right in them – not sure why I think this other than many of the more recently occupied sites only have younger trees on the middens but older trees on the periphery.
This tree probably has a network of roots leading onto land as well. If erosion was slow, it could easily have settled down on the beach with time to establish a root system in the right places, including into any sources of freshwater running through the area.
The midden or shell deposits you see from a kayak are usually going to be eroded and redeposited materials and probably the result of recent wave action. But there are submerged middens around, often buried under more normal looking beach surfaces. Montague Harbour was the among the first discovered and saw some underwater archaeology on the submerged part a few decades ago.
Very interesting. Thanks ehpem!
Congratulations on your 100th 🙂
Thanks Martin. It’s a minor accomplishment in the world of blogging, of course – but all the same, it feels significant enough to celebrate!
Your post made me think of a picture I had taken at Medicine Beach on Pender Island. You can see it in the pictures in this post:
http://islandhomeblog.wordpress.com/2013/10/27/fall-on-the-beach-medicine-beach-pender-island-bc-canada/
Do you think it is the same type of tree? It also would get its feet wet at high tide. You have left me thinking of all the different beaches that have trees close to the shore.
Thanks for the comment, Deb. That’s definitely a Bigleaf maple in your photos (nice photos BTW – and I do love Medicine Beach). I’ve often seen them very close to the shore like that, but standing completely below the high tide line is definitely unusual.
Happy 100th, Laurie! What a beautiful tree to celebrate with! It has a lot of character. Strength, too, to survive there. 🙂
I have no idea how old the tree is, but I like to think it might be 100. Thanks for the comment, Robin – I agree, this is one hardy (and beautiful) tree!
This is a magnificent tree. I can see why you were drawn to it. Congratulations on your 100th post, Laurie. I always look forward to your posts for the combination of beauty and deep reverence for the natural world you share every time! xo
Thanks so much, Sherry! I always look forward to your posts and photos too, and the insights you share.
What a majestic old tree!
God has certainly gifted you Laurie , with wonderful eyes!
Beautiful shot! Thanks for sharing.
Susan
Thanks, Susan! Magestic is a good word for that lovely old tree.