Wednesday, May 13, 2009

Shifting Sands

Last Saturday was International Migratory Bird Day, and it was great. I spent the day at Magee Marsh Wildlife Area, along with ten or fifteen thousand other people. A good time by all, and oodles of birds, but I needed some serious solo time after that. So, on Sunday, I went over to the Oak Openings, just west of Toledo to botanize and otherwise explore. The Oak Openings is about 130 square miles of old dunes and beach ridges from a time long ago, when Lake Erie far exceeded its present boundaries. In general, there are more rare plants and animals here than anywhere else in Ohio.

The Ohio Ornithological Society will be holding its 5th annual meeting here on Saturday, and all the details ARE HERE. If you would like to attend, please e-mail me at: ambrosia@columbus.rr.com

The Girdham Road Sand Dunes, part of Oak Openings Metro Park, and one of the coolest slices of classic Oak Openings habitat. This is one of my favorite locales in the state, and it is loaded with interesting flora and fauna. I'll be hanging out here on Sunday, and if you are up for the OOS conference I'll be glad to show you some of the highlights. Among others, Red-headed Woodpecker, Summer Tanager, and Lark Sparrow were singing away as I took this shot.

The Oak Openings is a giant sand box, and nowhere is this more visible than at Girdham Road. These open sands have been shifting about for the last 12,000 years, and most blowouts like this have long been colonized by plants in a process known as vegetative succession.

Here's how the transformation from open sand to oak woods begins. This is the start of a tough plant called Low Sand Sedge, Carex rugosperma. It is one of few species able to get a foothold in hot shifting sands. Note how it grows in the pattern of a concentric ring, growing outward. This growth habitat is essential to the process of ecological succession.

Here we have a somewhat older sedge, and note how it has formed a tussock as sand builds up around the plant. As the core center area of the sedge tussock becomes more stable and protected from the elements, other plants begin to colonize the middle of the sedge plant. In effect, Low Sand Sedge is a vegetable moat staving off the attacking sands, and allowing stability and other growth to occur within the center.

A mature sedge. Doesn't look like much, even though this specimen is in full flower, and fruits have even formed. So obscure is Carex rugosperma that it was completely missed when the first book that attempted to thoroughly cover this segment of Ohio's plants was produced in 1967. Many a botanist had walked right over top of it, probably just thinking the plant was an immature tuft of grass. Rather ironic, given that this species is one of the most important plants in the process of Oak Openings ecological succession, and the Oak Openings are one of Ohio's most significant habitats.

We dive down into the depths of the tussock, and the flowers and fruits of the Low Sand Sedge are revealed. These reproductive parts cannot be seen standing upright; one must get down on hands and knees and part the blades to see what is going on. The purplish column-like structure is the staminate, or male, flowers; the plump greenish scaled part to its right is the perigynia, or fruit. Ants and other ground-crawlers are undoubtedly the vectors for dispersal.

As the Low Sand Sedge ages and expands, various herbs begin to take advantage of the relative stability formed within the concentric ring of sedge. This is one of those herbaceous pioneers, the Dwarf Dandelion, Krigia virginica. A dandelion in name only, it is vastly different than the lawn weed and is listed as threatened in Ohio. Dwarf Dandelion is one of many sand specialists adapted for the Gobi-like conditions of Oak Openings sand barrens.

Eventually, woody plants begin to invade the areas where our sedge began the process of stabilization. The one above is a great rarity in Ohio: Sand Cherry, Prunus pumila var. cuneata, which is state-endangered. There are some nice colonies at Girdham Road, and they are now in fine bloom. These shrubs will eventually succeed to larger woody plants, such as oaks, and then the climax stage of the Oak Openings will have been reached, and interesting sand pioneers such as the sedge will be long gone.

But while the short-lived shrub communities persist, interesting birds abound. The above may be the most coveted of Oak Openings specialty birds, the Lark Sparrow. This male is on territory at Girdham Road, and was flying all about giving his curious whistly buzzy song. Last year, a Clay-colored Sparrow was on territory here.

Once again, if you are interested in our OOS conference, or even wish to take advantage of the room rates that we've secured at the beautiful Holiday Inn-French Quarter, please feel free to contact me.

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2 comments:

Wil said...

Wow, thanks for the botany lesson. Fascinating. What a great place. I will have to make the trip there soon.
Wil

KatDoc said...

See you this weekend. Will you please arrange for it to rain every day, so that I feel "at home?" Forget the birds; the Snail and Slug Society needs a lot of rain for our event to off as planned. ;-)

~Kathi