Michigan Botanical Club takes a Blue Week Field Trip in the Flatwoods

Exploring the Wet-Mesic Flatwoods, 18 May 2013

Reported by:  Ron Gamble

(Original Article in the MBC newsletter)

This MBC-led outing at Huron-Clinton’s Oakwoods Metropark near Flat Rock, Michigan was in support of the Green Ribbon Initiative (GRI) efforts to increase public awareness of the special (although sometimes quite local) natural physiographic and biological characters present in the Oak Openings Region and related natural communities.  The GRI is a partnership of about 20 conservation groups in northwest Ohio and southeast Michigan, several of which are:  Huron-Clinton Metroparks (Michigan),  Metroparks of the Toledo Ohio Area, Olander Park System (Sylvania, Ohio), The Nature Conservancy (TNC), and many well-known others.

The Wet-mesic Flatwoods community, described only recently by Michigan Natural Features Inventory (MNFI), was formerly often described as Lakeplain Forest.  If one reviews typical plant/animal species lists provided by MNFI, the Wet-mesic Flatwoods biota appear quite similar to Southern Hardwood Swamp.  One obvious difference, and we noted this, was the presence of hickories (Carya) (several species) in the Wet-mesic Flatwoods as opposed to their absence in the Hardwood Swamp community plant list.

The weather was cooperative, although the mosquitoes were active as we began our exploration of the Wet-mesic Flatwoods Community.  Our first flower of interest was arrow-leaved violet (Viola sagittata).  Although not a Flatwoods botanical indicator, it has a COC of 8, and we’ll pay attention to any plant with that Coefficient of Conservancy!

Along the east edge of the wooded area was a utility clearing.  State Special Concern-rated, Carex squarrosa, has been reported present here.  We had images of the inflorescence, but no luck finding something similar (although maybe it’s too early in the growing season).  During earlier personal conversation, Suzan Campbell indicated that she finds the utility clearing very interesting, seeing what emerges from the seedbank.

One of the oaks which I consider “unappreciated” in this area is the pin oak (Quercus palustris).  There were numerous quality specimens of this tree, which also has a COC of 8, in the woods.  As opposed to many oaks, branches of pin oak remain quite concentrated up and down the tree trunk.  It is quite distinctive from a distance, due to this minimal self-pruning habit.  This is one of the few oaks with a negative wetness coefficient at -3.

Entering the woods, we found the understory nicely open and invasive shrub intrusion was quite limited to edges.  Credit needs to be given to The Nature Conservancy people who work regularly in this location providing preservation efforts of this Flatwoods community.  Their efforts also support a State-Endangered salamander reported present at this location.

Mid-trip was a time for re-application of DEET.

Other very common flowers we noted included blooming spring cress (Cardamine bulbosa) and widespread areas (although flowering was finished) of wood anemone (Anemone quinquefolia).  These may seem strange plants to have commonly together as the former has a -5 Wetness Coefficient, and the later a +3.  We presumed the explanation for this is that mineral soil sandy ridges in these flatwoods provide for drier local areas, supporting the anemone.  The sand ridges also may provide the drier area needed by the aforementioned hickories.

There appeared to be hundreds of ash saplings, presumably green ash (Fraxinus pennsylvanica), present in the woods.  We looked unsuccessfully for healthy ash.

One highly notable observation:  During several hours of botanizing through the woods and along the forest edge area, we did not observe a single garlic mustard (Alliaria petiolata) plant.  That’s not to say there’s none anywhere, particularly along the wood’s edge.  But after a trip participant commented about the lack of garlic mustard, we began looking for it (including some of the woodland edges), and we were pleasantly surprised to find that it remained unfound.

Thanks to Lindsey Reinarz of TNC for nice booklets with many color photos of flowers and descriptions of other natural resources present in the Oak Openings Region.

Also, thanks to Dr. Todd Crail for additional descriptive help with some new interpretations of how sand and mineral soils may have been distributed by several physical processes (beyond just simple glacial lake beach shoreline location) 8,000 – 12,000 years before present.

Reported by:  Ron Gamble