Monday, July 26, 2010

The wetlands at Pleasant Valley Conservancy

Our wetland plants are really flourishing! The mid-April burn obviously helped a lot, although our wetland has always had a fairly diverse flora. Reed canary grass is under control. The six inches of rain last Thursday and Friday resulted in a transient flooding, but by Sunday the water had dropped almost back to normal. The fire break between the Crane Prairie and the wetland provides a great walking trail, and the new boardwalk brings one right into the wetland and all the way to the creek.

We have had lots of rain this summer, which has helped our upland areas, but the wetland, being spring-fed, never has a shortage of water. Most of the substantial rains have been spaced far enough apart so that flooding has not occurred, but the rains of last Thursday-Friday came all at once. Our rain gauge registered almost six inches. When Amanda arrived for work Saturday morning, the whole wetland was flooded, including the boardwalk, as shown on her photo here. However, by the time I arrived on Sunday morning, the boardwalk was again high and dry.

During the much heavier rains in June 2008, our wetland had standing water for several days before it finally subsided. Of course, wetland plants are adapted to occasional flooding, and survived without any problems.

We have several vegetation types in our wetlands. Sedge meadows are the most common, but where there is higher water levels, cattails are extensive. On a few of the higher spots, willows and gray dogwood are present. For some reason, we don't have any red osier dogwood, a common wetland shrub. This is probably to our benefit, as this shrub can often be fairly aggressive.

Probably because of the burns, Joe Pye weed and swamp milkweed have been really prolific this year. There are quite large stands of Joe Pye (Eupatorium maculatum), as the photo below, taken from the boardwalk, shows.

Walking along the fire break between the Crane Prairie and the wetland gives one a close-up view of how things are going. The photo to the left is an example of what one can see. I was struck by the diversity of wetland plants. New stands of sweet Indian plantain (Hasteola suaveolens), a State-listed species (Special Concern with a C value of 8; the white-flowered plant in the photo to the left) are present, mixed in with Joe Pye, cup plant, and swamp milkweed. Very adaptable species such as black-eyed Susan, golden Alexanders, and blue vervain, are also present.

In past years, we have found sweet Indian plantain primarily along the creek and next to spring-fed pools, but this year it has moved in closer and is growing right next to the trail. This is a rare opportunity of seeing an interesting species that is not especially common. According to the State Herbarium records, this species is found in Wisconsin solely in the southwestern part of the state (mainly the Driftless Area).


Another nice species of the wet prairie is mountain mint (Pycnanthemum virginianum). Since this is an Eastern U.S. species, I suspect its common name comes from its original discovery in the Appalachian Mountains, probably of Virginia. We have always had this species scattered throughout our wetland, but this year it seems especially lush, probably because of the favorable growing conditions.

Cup plant (Silphium perfoliatum), of course, is fairly common and is flowering now. Although distributed more widely in Wisconsin than Hasteola, it is mainly concentrated in the southwestern part of the state.

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