Tuesday, December 2, 2008

St. George Botany in 3 Mountain Bike Rides - Intro

Botany in a Day A Note About Today’s Post: The title is a total rip-off from Thomas J. Elpel’s excellent book, “Botany in a Day,” which I heartily recommend to readers who, like me, are fascinated by botany, but have a 4th-grade attention span.

Here’s a great holiday tip: Move 2,500 miles away from your and your spouse’s families. Go someplace warm and have someone else make the holiday meal.

IMG_7570 That winning formula (I swear I should write self-help books) resulted in an awesome nuclear-family-Thanksgiving down in St. George. (Trifecta pictured left.) The getaway included plenty of family and pool time, hiking, mountain biking and botany. Who could ask for more?

Every time I go down to Southwest Utah I come back with head brimming full of things to blog about. But this time I’m going to try to be systematic and constructive about it, and so I plan to do 3 posts (4 if you include this one) this week with a common theme. The idea is that each post will suggest an excellent mountain bike ride somewhere in the greater St. George/Hurricane area, give an overview of what’s botanically interesting about that ride, and if I can manage it, spotlight some cool botanical item specific to each ride. In this first post, I’ll provide an intro to the series and overview of the area.

Tangent: It’s worth mentioning that I could have done- and may someday do- a similar series of posts concerning the geology of the Virgin River basin, which is nothing short of incredible. And with a bit more research, I could probably even do a series on the archeology/paleo-anthropology of the area, which is also fascinating. Seriously, there are so many great reasons to hang out in Southwest Utah…

IMG_7505 Two things make the greater St. George area a place like nowhere else in Utah – elevation and intersection. First, elevation. The Virgin River drainage basin is laid out in distinct “terraces” or levels ranging from over 10,000 feet (Pine Valley Mountains) to under 2,000 feet (Virgin River George), and these terraces support wildly different temperatures and plant communities. The “alien planet effect” I blogged about this summer in California can be achieved several times in the same day in Washington County by car or even bike. There are at least 5 distinct elevational/botanical terraces worth checking out, and 3 of these will be the focus of the rides I’ll highlight.

In St. George proper, we’re on the “Floor” of the valley. Up on Gooseberry Mesa or Little Creek, we’re on what I call the “Mesa” level. In between, around the (somewhat odd) little town of Virgin, we’re on what I call the “Bench” level, which is intermediate between “Floor” and Mesa” in temperature, altitude and flora. Up in and behind the Pine Valley Mountains is true PLT forest, which we can think of as the “Attic” level.

It’s easy to think of St. George/the “Floor” as the bottom terrace, but if we continue driving just 10 minutes South into Arizona on I-15, it’s obvious that’s not the case. Once in Arizona, I-15 quickly descends into the spectacular Virgin River Gorge, which is immediately and obviously different again from the “Floor” and so I think of the Gorge- and Littlefield and Mesquite and beyond- as the “Basement” level.

SG TerracesBut the really amazing thing about the Virgin River Drainage is the intersection of hot and cold desert, which I think happens more dramatically here than anywhere else in North America.

If you drive down to Moab, get out of the car and poke around a bit, you’ll notice a bunch of “desert” plants- Pinon, Juniper, Sagebrush, Rabbitbrush, Shadscale,etc. And for the most part, the plants you’ll find aren’t that much different than many of the plants you’ll find in the lower areas up here in Northern Utah. If you get back in the car, and drive East to Rifle, or Southwest to Cortez, or South to the Big Rez, or North to Vernal or West to Hanksville or Escalante, and get out of your car again, you’ll find pretty much the same set of plants, varying of course based on your elevation.

SG Terrace BoundariesAnd even if you head out off the Colorado Plateau and strike out West across the Great Basin for Austin, NV or Winnemucca, when you get out of your car you’ll find a similar set of plants, which while not quite identical (and generally a subset of what you’ll find back on the Colorado Plateau) pretty much seem a continuation of the same overall Great Basin/Colorado Plateau/”Cold Desert” theme.

Now similarly it you get out of the car in Bakersfield, California and look around you’ll see a bunch of very different plants-most notably Joshua trees and Creosote and Yuccas. And if you get back in the car and drive to Las Vegas or Mesquite or Laughlin or Yucca Valley or Victorville, and get out again, you’ll see- more or less- those same plants again. And what’s more, if you get back in the car and drive clear to Phoenix or El Paso, though much will be changed, you’ll still see many of those plants- especially Creosote and Yuccas- that you saw way back in Bakersfield. All across the “hot” deserts- Mojave, Sonoran, Chihuahuan- there’s almost a common botanical understory- or “foundation”- that’s consistent across them.

But if you get in your car in Cedar City, and drive the 40-something miles down to St. George on I-15 and get out of the car- BAM!- everything is different. Different trees, shrubs, flowers. And that’s what makes St. George and the Virgin River basin so darn interesting- that super-clear, almost violent transition between the hot and cold deserts of North America.

Next Up: Riding on the “Floor”…

No comments: