Friday, October 16, 2009

Grafton Ponds

On October 13th, Rebecca Wilson, of the Virginia Department of Conservation and Recreation, led a return trip to Grafton Ponds Natural Area Preserve (adjacent to Newport News Park) to take a look at some fall-blooming grasses and wildflowers, and to explore some of the plant communities growing around its unique coastal depression ponds. They exist here because of dissolving calcium deposits from ancient seabeds, which create shallow sinkholes in the ground above. The depressions are home to ephemeral ponds which vary in size, disappearing and reappearing over the years.
A small group of VNPS members met Rebecca at the Aeromodel Flying Field off of Richneck Road. Rebecca is part of the Virginia Natural Heritage Program that is cataloging vegetation communities throughout the state. Their work is also being incorporated into the National Vegetation Classification project. The map below shows the location of many of the ponds and is color coded by vegetation community. Inside the preserve, Rebecca explained to us some of the different ecosystems that exist there.
On this trip we looked at three kinds of plant communities:
1. Coastal Plain Depression Pond with swamp tupelo, sweetgum, red maple and cypress swamp sedge.
2. Coastal Plain Depression Pond with Buttonbush, swamp smartweed, and warty panicgrass.
3. Coastal Plain Seasonal Pond with narrow plume grass, southern waxy sedge, and short-bristle horned beaksedge.

The first pond we looked at (the picture at the top of the post) was a mix of the first two pond types. So here we found swamp tupelo growing above buttonbush. I was happy to finally see a swamp tupelo (Nyssa biflora), which is very similar to the more familiar black gum (N.sylvatica). Below you can see one of its distinguishing features, the double fruits, which grow from the paired flowers (hence, biflora).
We also found clethra, itea (below), and leucothoe growing at the edge of the pond. Interestingly, all these shrubs had similarly shaped racemes of seeds. I wonder why they have all adopted this same floral strategy...
We also saw lots of southern blueberry (Vaccinium formosum) which Rebbecca identified by the hairy midrib on the underside of the leaf. Click on the picture below and you may be able to see the hairs in the enlargement. Update - this id is pending...see the discussion at the end of the post.
Walking between ponds we saw several sourwoods, which are very common in our area. Rebecca pointed out that a good way to identify them in the winter is by their oblong boles (trunks), and also mentioned that young scouts get a kick out of chewing the leaves. The green or fall red leaves will color your spit accordingly, though no one wanted to try it. We also came across sphagnum moss and patches of the strange looking Indian Pipe (Monotropa uniflora) scattered around the forest floor.
Next we visited a coastal plain seasonal pond dominated by narrow plume grass (Saccharum baldwinii), a relative of sugar cane. The day we were there, the pond was dry.There was also a lot Cypress swamp sedge (Carex Joorii) and short-bristled horned beaksedge (Rhynchosporas corniculata, below) around the edges of the pond. By the way, there's an example of the common name being almost as bad as the latin! After the tour of the ponds, we headed out of the forest and came across this interesting velvety fungus growing on a tree trunk at the edge of the woods. Anyone know what kind it is? I'm still looking for a mushroom expert who can lead a field trip for us sometime.
In the utility easement we saw more of the Saccharum baldwinii, indicating somewhat moist conditions, as well as a couple of other graminoids: warty panicgrass, nodding beaksedge, slender woodoats, little bluestem, and a species of Dichanthelium that we couldn't identify.
We were a little disappointed by the wildflowers in the easement. We had expected to see a nice display of flowers there and along the access road, but they had been recently sprayed by Virginia Power. There were a few things blooming , but they were mostly stunted and disfigured by the herbicide. Among the survivors were gerardia (below), goldenrod, asters, tickseed sunflower and Maryland golden aster.At the end of the trip we came across a small persimmon tree loaded with fruit. Jan Newton bravely tried one of the fruits, but I was hesitant, having once had a bad experience with some "takpa" fruit (that's the Coushatta word for mouth-puckering). I thought it took a frost to make them edible, but evidently not. When I finally tried one it was very flavorful. If you want to taste one yourself, look for a fruit that has developed a translucent skin.
Hey, you know when your watching a nature show about some beautiful spot with amazing flora and fauna, and then in the last 5 minutes of the program the buzz-killing narrator starts talking about how threatened it is? Well, here goes: Construction will soon begin on the widening of Fort Eustis Blvd.,which cuts the preserve in half, causing an even more of impediment to wildlife like the marbled salamanders that we saw earlier this year.
And see the lovely woods below? Soon it will be cut down for a huge new retirement complex, with only a 100 foot buffer to preserve some of the adjacent ponds. On the plus side, maybe when I'm 90 years old I can move there and take long walks in the preserve. And by that time I won't need a guide book because I'll have plant identifying chips embedded in my occipital lobe!
Thankfully, there's still quite a large area that is protected so I'm hoping for the best. Many thanks to Rebecca for taking us back to Grafton Ponds!

From Rebecca:
OK - I just talked to Gary Fleming about Vacciniums...its even more complex than I thought. Once upon a time - Gary and others would have called what we saw "Vaccinium corymbosum". But Alan Weakly and Tom Weibolt are now saying that V. corymbosum is a mountain species and we don't have it in the Coastal Plain. V. fuscatum is super duper fuzzy and V. formosum is super duper smooth and then there is the plant that we saw which is MOSTLY smooth with just a few hairs. So what is it? Alan and Tom think that it is a hybrid between V. formosum and V. fuscatum. Gary thinks that it might be that V. corymbosum really can creep into the coastal plain. The jury is out on both ideas.

So what do we call our guy? I thought that V. formosum could have a few scattered hairs on the mid rib but Gary says that for now he is calling everything that has any hairs at all V. fuscatum and only calls the completely hairless ones V. formosum. So for now I have to admit to being wrong and call the plant we saw Vaccinium fuscatum (although it doesn't look at all like the typical fuzzy wuzzy V. fuscatum to me) and NOT V. formosum.

Apparently this issue is being debated and will come under review before the printing of the new Flora of Virginia. Stay tuned!


Enzie Shahmiri said...

What a cool looking mushroom photo! Thanks for visiting my blog!

Janet said...

So many things to say--- first, glad you went earlier in the week and not now...the ponds would be filled. Sorry to see Ft. Eustis Blvd widened at the expense of the wetlands, but even more disappointing is the development planned. So where do you think the BMP pond will go?
Glad you showed the difference between the two Black Gum...good to know info.

Les said...

Thanks for talking about the sink holes, I find geological history very interesting, particularly as it relates to biology. The Indian Pipes are so cool looking, are they a fungus or just unusual? The loss of some of this land is disheartening

how it grows said...

Les, the indian pipes are a parasitic perennial that is in the ericaceae family, believe it or not.

Janet, Rebecca brought a copy of the site plan and there was a bmp in the middle of the building complex, so hopefully they won't be using one of the depression ponds as a bmp.