Saturday, July 26, 2008

What Tree Geeks Do on Rainy Days - Blog

When you’re in the Maine woods for 4 days, and it’s raining pretty much non-stop, the best thing to do is to check out the trees. Seriously, the rain is putting a damper on the usual lakeside activities- swimming, sailing, canoeing, jumping off the floating raft and visiting the nearby waterfall. We’ve long since broken out the TV and videos for the kids and are considering an expedition to a multiplex this afternoon.

The coolest thing about Northern New England for a Westerner is all the fresh water. This part of the continent is packed with lakes, as is Minnesota, Northern Wisconsin and a huge swathe of Canada. That’s because they’re all part of the same geologic feature, the Canadian Shield, which is basically cool-sounding term for a very rocky landscape. The rocky soil means that it drains water poorly so that much of it pools into lakes and ponds.

Tangent: The downside of the Shield is that it also offers many stagnant pools for mosquito reproduction. Anywhere you go in the Shield in the summertime is Bug Central.

The rockiness is the result of the glaciers, which dragged lots and lots of rocks, boulders and gravel along with them, leaving the Shield behind when they finally retreated ~10K years ago.

The lakes and ponds are fascinating, full of interesting fish, snapping turtles and unusual birds (Loons and a Great Blue Heron are two fine examples on this lake) and almost any lake/pond up here could be the subject of a great blog.

Tangent: In fact, there are already a couple of great blog-like books on just this topic. 2 great ones are Franklin Russell’s “Watchers At The Pond”, and Bernd Heinrich’s “A Year In The Maine Woods”.

I’ve always loved lakes more than the ocean. I love the quiet, open space, the cool water. I’ve been coming up to these lakes for more than 35 years. There’s so much I could go on about, but the story of these lakes in Maine isn’t really the point of the blog, so instead I’ll include this “Highlight Map of the 5-Kezar Ponds which you can click on and check out if you’re interested.

A Bit About The Trees

Eastern forests have always frustrated me: too many trees all jumbled together. But this trip I find that they’re starting to make sense, mainly because of my efforts this year in identifying, categorizing and understanding trees back home.

Just like the Wasatch, there’s a broad division between leafy trees and Piney-looking trees. The biggest difference is that there are several leafy trees- they most common around the lakes are Northern Red Oak, American Beech, Red Maple and Striped Maple. But since I’m already on a PLT-theme back home, let’s look at those.

There are 4 PLTs I’ve found in the vicinity of the lake. 2 are Pines, 1 is a Hemlock, and 1 is a Larch. One of the Pines and the Hemlock are super-common; the other 2 PLTs you have to look just a bit harder for…

The 2 pines are Eastern White Pine (pic left), Pinus strobus, and Red Pine, Pinus resinosa. As I mentioned way back when, when I talked about Pines on Little Creek Mountain, Pines have been divided into 2 groups, or sub-genera, for the last 130 million years: soft pines and hard pines. Eastern White Pine is a soft pine; Red Pine is a hard pine. Eastern White Pine is by far the most common Pine (and most common conifer?) in the Northeast, and its range stretches up into Quebec and Newfoundland. It’s also the tallest tree in the Northeast, approaching 200 feet in height (pic of trunk right, Twin A for scale.) It’s been an important timber tree for centuries, valued for ship masts, and providing easily-worked, knot-free wood. It’s easy to identify: it’s the tallest tree around, by far the most common pine, and its needles are grouped in bundles of 5. Eastern White Pine is closely-related to Western White Pine, a common Pine of the Sierras which we’ll visit next month when we take our Tahoe vacation.

Here’s an interesting thing about Eastern White Pine: it’s only partially evergreen. Each fall it loses about half its needles. When the needles fall they’re a beautiful gold color. They often carpet the bare (highly acidic) forest floor in mature groves, and they’re a pretty sight in the Fall.

PLT #2, Red Pine, is far less common that Eastern White Pine, and only distantly-related to it. In fact, the closest relative of Red Pine seems to be our old friend Scots Pine, Pinus Sylvestris, a common exotic here in North America, which we visited back in May when I was bemoaning my pollen-related respiratory difficulties. Red Pine has a Northeasterly range, just barely encircling the Great Lakes, which seems to be a relic of it’s common Laurasian* ancestry with P. Sylvestris. Red Pine seems to have a very low level of genetic variation as a species- possible evidence of a past “genetic bottleneck” from which only a small pool of survivors emerged.

*Geeky Paleogeological Tangent: A couple hundred years million years ago, all the continents were bunched together into one super-continent called “Pangea”. Around 200 million years ago, Pangea split into a Northern super-continent, “Laurasia” and a Southern super-continent, “Gondwanaland”. Laurasia eventually split again into Eurasia and North America, with the final split between Greenland and Europe occurring around 60 million years ago. This timeline makes the speciation split between Red Pine and Scots Pine kind of interesting for us, in that we’ve looked at a number of very, very ancient speciation splits, like Gymnosperms vs. Angiosperms, and Monocots vs. Dicots, and of course we’ve looked at lots and lots of recent or ongoing speciation events in everything from Douglas Fir to Black-headed Grosbeaks to Moose, but this is the first speciation event we’ve looked at in the ~60-70 million years ago timeframe…

Red Pine does well in sandy soils with lots of sunshine (it’s shade-intolerant) and here around the ponds I’ve only found it on the sandy eskers separating the ponds. When you do find it, it’s also easy to identify. The bark is clearly reddish, from root to crown, on red pines of all ages. The needles are bundled in 2’s (just like Scots Pine or Austrian Pine) and are noticeably longer than White Pine needles.

PLT #3 is a Hemlock, which is cool for me as there are no native Hemlocks in Utah. Tsuga is a fairly small genus, with only 8 -10 species, 4 of which are native to the U.S. They include Western Hemlock, Tsuga heterophylla (the biggest, and which I saw plenty of last month in and around Mendocino), Mountain Hemlock, Tsuga mertensiana, (of which I’ve seen just one to date, mtn biking last summer in Tahoe), Carolina Hemlock, Tsuga caroliniana, down in the Smoky Mountains of TN and NC (never seen it, don’t know when I will- I rarely get to the backcountry in the Southeast) and Eastern Hemlock, Tsuga canadensis, which is all over the place here in Maine, as well as all along the Appalachians and into the Great Lakes region.

Hemlocks are easy to recognize once you’ve seen one; they have lots of very short needles on twigs that branch a zillion times, and have lots of teeny-tiny (1/2”) cones. They’re shade tolerant, and their dense foliage shades out other stuff underneath. Dense Hemlock stands are dark, shady, and on rainy days, a bit depressing.

The future of Eastern Hemlock is uncertain. Over the past several decades the Wooly Adelgid, Adelges tsugae (Cool electron-microscope pic right), an exotic sap-sucking bug from Asia (man I am telling you again- like all the nasty stuff comes from Asia), has been killing huge stands of Hemlock throughout Appalachia. It’s progress North seems to have slowed a bit but is continuing. So it’s a good idea to check out Eastern Hemlock now; it could be the 21st-century version of the Chestnut Tree.

Tangent: The American Chestnut, Castanea dentata, has been nearly extinct in the wild for decades. If most of us have ever heard of “Chestnuts” it’s probably only from corny Christmas songs. But until the early 20th century, Chestnut were the largest, and one of the most common, leafy trees in the Eastern US. (I’ve read that 1 out 4 broadleaf trees in the Appalachians was a Chestnut. Former range shown left.) Chestnut Blight, a disease, or more accurately infestation, of the fungus Cryphonectria parasitica arrived in 1904 and quickly wiped out all but a few survivors. We’ve looked at several exotics in this blog- Tamarisk, Dandelions, Musk Thistle, Crabgrass, Dyers Woad. The story of C. parasitica is probably the saddest of them all for a tree-lover.

Fourth, last and rarest (at least around these here ponds) is Tamarack, or Eastern Larch, Larix laricina which is cool because it’s a Larch, another Pinaceae genus absent from Utah. At first glance, Larches look like Spruces with something wrong with them. Then you get up close and see that the short needles actually grow in groups, like a Pine, but in “tufts” rather than bundles (pic right). And if you see Larches in Winter, you’ll most likely mistake them for dead Spruce or Fir, because they’re bare, like any good deciduous tree in Winter. Larches have teeny-tiny Hemlock-like cones, only a tad smaller.

Larches are way cool because they’re the only deciduous conifer, and they’re wildly successful. Tamarack, 1 of 3 Larches native to North America, has a range from Newfoundland to Alaska and Indiana to the Hudson Bay! (Range shown left.) Larches aren’t just some weird offshoot line of evolutionary freaks; they’re a fundamentally different way of being a successful conifer.

And speaking of conifers, it’s time to wrap up our review of Wasatch PLT’s, and get out of this endless rain and back home to the 2nd-driest state in the Union.

1 comment:

SLW said...

Ahh... hemlocks and white pines are my two favoritest trees! Residue of childhood in the northeast... Larch would be too if I'd ever been near them.

Did you know Tsuga is the Japanese word for "tree mother"? So they say...

Great post!