Wednesday, December 2, 2009

Interesting Little Forest

Does this young forest look mundane? Uninteresting?
It’s quite the opposite!
At a fraction of an acre, it occupies a little corner in a long-abandoned ag field in St. Joe County, Indiana – out of cultivation for at least 30 years. Most of the surrounding land is yellow clay at the surface, and forests in the vicinity are Beech-Sugar Maple. But this little corner is dominated by Red Maple, with occasional Black Cherry and Sassafras on a sandy substrate. Unlike other Red Maple forests, this one is not in a low lying flat, but upland. The sand is almost certainly underlain with clay, keeping moisture at the surface for long periods of time.

When Red Maple forests aren’t too shady the herbaceous vegetation can be pretty exciting, especially if you like ferns, club mosses, and sedges. I first botanized this site in 1997 and found hundreds of Daisyleaf Grape Ferns (Botrychium matricariaefolium).

In 2008 I was startled to find Downy Rattlesnake Plantain (Goodyera pubescens) and Spotted Wintergreen (Chimaphila maculata).

Downy Rattlesnake Plantain Orchid (Goodyera pubescens)

Spotted Wintergreen (Chimaphila maculata)

Last week I went there to photograph Botrychium dissectum and its segregates and was fortunate to see a tiny Spiranthes orchid in seed. Its identification is guesswork, but diminutive Spiranthes ovalis is a possibility.


On the same visit I saw the lovely Shining Club Moss (Lycopodium lucidulum)!
Interestingly, the club moss was growing right at the base of a tree where water gets funneled when it rains. If you’ve never observed this, it’s worth donning a rain suit and going into the forest while it’s raining. All of the water that doesn’t drip from a tree’s limbs or get absorbed by the bark gets funneled right down the trunk, and even during moderate rain, water comes gushing down. Some plants take advantage of this. For example, Spinulose Wood Fern (Dryopteris spinulosa) will grow anywhere in mesic and wet forests, but in dryer sites it survives at the base of tree trunks. Watch for this – it’s a common sight, at least in northern Indiana. Dryopteris intermedia does this too, as shown in this photo from Warren Woods in Michigan. We should keep this in mind when doing native landscaping. And we should never pass up a chance to botanize a Red Maple forest!
Florist's Fern (Dryopteris intermedia)

4 comments:

Justin Thomas said...

Great post, Keith! I am definately going to watch tree trunks next time it rains. I have also heard that the tree trunk and immediate root mass serve as a temperature buffer since the water in the tree is slower to cool down or warm up than the surrounding soil or air. This also explains the micro habitat that is often found around the base of large trees. I wonder if there are any papers out there on the topic of tree trunk microhabitats. It would be a fascinating phenomenon to study.

P. J. Grath said...

When I saw the title "Interesting Little Forest," my first thought was of the miniature forest of club moss at the base of an old fenceline maple. Thank you for this beautiful and informative post.

Keith said...

Thanks for the kind words, P.J.! You reminded me of the time I went on a camping trip to Sleeping Bear Dunes in Michigan. The park campground was full so I found a private campground nearby. I asked the owner's permission to botanize the area, and he told of a small forest of "tiny pine trees" that had not grown in 20 years. I couldn't imagine how that could happen until he showed me the site - and I saw a colony of Lycopodium obscurum, the "Ground Pine" or "Tree Club Moss!"

Scott said...

What an interesting assemblage of plants. I wonder if red maple requires acidic soil chemistry more than it relies on a certain hydrological regime. It invades in all sorts of forests, from wet, swampy ground up to dry, rocky black oak woodlands. I don't typically think of sassafras and black cherry growing in moist or wet soils, so I wonder if the soils at this location aren't as moist at the surface for as long as you think.