Botany Photo of the Day

Is this valley the result of erosion or glaciation?

Will Brent put his presentation on the web for those of us not in the Vancouver area?

You know what? I bet it might be the wind is a factor too.

Also, I have noticed that along the Columbia River, there is sparse vegetation from Vantage WA southward... The road is on the East side of the river, and it seems there is just a bit alongside the river. Seems kind of odd, being such a big river. (I live on the wet side of WA, and am so used to green everywhere.)

Also historical and/or current land use - maybe logging and/or intensive grazing by the owner of the west facing slope?

For purposes of scale, the notch in the valley rim (upper center of the photo) is known as the "Big Nick". Formed by the headwall of another glaciated valley on the opposite side, it is approximately 400 feet from top to bottom.

May help to put things in perspective for people who haven't been there.

The photo reminds me of the island of Oahu. The windward side is dryer. The leeward side is greener and more lush, with more dramatic cliffs. The leeward side holds the moisture whereas the windward side loses it more rapidly. Are the prevailing winds in Oregon west to east?

It's a well known gardening fact that shade loving plants will often tolerate morning sun. Perhaps it is because afternoon sun is hotter (and drier, since the dew has long since evaporated).

Another idea is that there could be less sun on many mornings due to morning fog or mist that burns off later in the morning. And this fog or mist frequently does not materialize until after the sun sets, so plants getting afternoon sun never see this extra protection.

Ah, another reason that I can think off - rate of snowmelt.

To answer the questions - yes, a glacially-formed valley. And I would think the prevailing winds here are almost certainly west to east.

I would bet on precipitation explaining most of the difference, but if i had to give another reason, i would say that there seems to be significantly more quaternary erosion on the western slope than on the eastern one. Glaciation tends to have an almost sand-paper like effect on rocks, scraping and polishing them flat, even perhaps in the case of nearly-horizontal sedimentary beds like these. I would think that a smooth polished surface, combined with a steeper slope, like on the eastern face, would make it much more difficult for plant colonizers. For example, if you look at a comparison of the cliffs and valleys on the left side of the picture, the cliffs are barren while the valleys are lush. However, one might again make the argument that the increased erosion and sedimentation in the west is ALSO a direct result of increased precipitation, so...

how many glacial years ago
did all this happen its quite
whether beaten has the land
been grazed by sheep or bison
that sounds dumb but i can almost
see our ancestors trying to
farm the gorge

a full moon picture of the gorge
would be nice to see

I've been to Steens Mountain many times. This view is one of my favorites.

The notch in the east rim is visible from Burns, about 60 miles to the north. The canyon is about a mile wide at the top and about 2000 feet deep. It's easy to find scour marks from glaciers that covered the mountain several millennia ago.

I think the vegetation growth patterns have a lot to do with the availability of water. The east rim is drier because it doesn't have as much holding capacity for snowmelt. The west rim goes back for about 15 miles and can hold considerably more water, which seeps out through the summer. There is still snow on the west rim in the photo which was probably taken in August or September.

This is very nice to see as we don't have mountains in western Massachusetts. We have the foot hils to the Berkshires and then on to Adarondics in New York State.
Thank You,
Margaret-Rae