Monthly Archives: August 2011

Lady’s Tresses Orchids in Prairie Seedings

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I love mysteries. 

I don’t know much about orchids, but my understanding is that they can be difficult to establish in restored (reconstructed) prairie, largely because they rely on mycorrhizal fungi that are unlikely to be present in soils after years of row crop agriculture.  Regardless of that information, or maybe because of it, (I can be somewhat obstinate) we keep harvesting seed from nodding lady’s tresses orchids (Spiranthes cernua) whenever we can find the plants after they’ve gone to seed in the fall. 

…and darned if they’re not showing up in our prairie seedings!  To date, I’ve found Spiranthes in at least four separate prairie seedings in our Platte River Prairies.  When I saw the first plant, I came up with all kinds of explanations for how it might have occurred, none of which included our seed (there was some bulldozer activity near where the plant was, so surely some plant material and soil came in with the dozer…).  By the third and fourth sites, though, I finally came around to the idea that the plants had to be a result of our seed.  I’m still not sure of that, but it’s pretty hard to think of other reasonable explanations.

We've found nodding lady's tresses plants like this one in at least four prairie seedings now. Those seedings were planted in 1995, 1995, 1997, and 1999, respectively.

So – what’s going on?  Is there something special about the sandy loam soils that allowed myccorhizal fungi to survive many decades of row crop agriculture?  Are those fungi somehow making their way into the soils once prairie vegetation establishes?  Are orchids less reliant on those fungi than we thought – or maybe just able to use a wider variety of fungi species than we thought?

I don’t have any answers, just lots of questions.  I’m hoping to hear from some of you about your experiences with Spiranthes species in prairie seedings.  I’m also hoping that some of you know more about myccorhizal fungi than I do (I still have to check the spelling every time I type it…) and can explain what I’m seeing.

Help?

Photo of the Week – August 12, 2011

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As the sun neared the horizon during my evening prairie walk in Missouri last week (see last week’s Photo of the Week post) I had to be more selective about what I tried to photograph.  The low light intensity and the light breeze that was kicking up made it difficult to photograph flowers or insects – or anything else that moved or swayed very much. 

I found two last opportunities before I gave up and headed back to the hotel.  The first was a close-up photo of a compass plant leaf that was backlit by the sunset. The initial challenge was to find a leaf that was positioned so that I could set up the camera with the lens parallel to the leaf (which allowed me to get the whole leaf in focus).  I also needed the leaf to have shadows behind it so that the background, as seen through the spaces between the lobes of the leaf, would be dark and uniform in color/texture.  Once I found an appropriate leaf, I played around with exposure until I found the right balance between light coming through the leaf and the shadowed background.  Fortunately, the leaf was low enough to the ground that the light breeze didn’t move it too much.

A compass plant leaf lit from behind by the setting sun. Taberville Prairie, Missouri.

The second shot was simply a silhouette of a compass plant against the setting sun.  By shooting right at the sun, and not caring if the foreground went fairly dark, I was able to use a fast-enough shutter speed to freeze the slightly swaying compass plant.  The trick was to find an exposure that preserved some color in the sky but also enough detail in the foreground to make the photo interesting.  I was able to do a little correction in Photoshop to accentuate both, but in order for that to work, I still had to capture both the light and detail in the original photo.

Compass plant silhouette against the sunset. Taberville Prairie, Missouri.

It was a great evening.  Thanks again to the Missouri Department of Conservation for the invitation, and to Len Gilmore and Matt Hill for the tour of Taberville Prairie.  I look forward to going back sometime to see more of the beautiful prairies in southwest Missouri.