Category: In the Field

We took the first of two field trips that are part of Gary Evans’ Introduction to Ecology at the Graduate School, USDA. We visited two sites in Prince William Forest Park, the first a farmed-out agricultural area that is undergoing old field succession on its way to becoming deciduous forest, and the second an area that was apparently never farmed intensively.

The site of the old Taylor Farm homestead is mowed regularly, so the veg is largely panic grass and broom sedge, but nothing seems to be a match for this humungous eastern redcedar (Juniperus virginiana).

We spent a lot of time with the soil profiles of the two sites. This soil pit is from our second study site, in the drainage of the South Fork of Quantico Creek. Laid out in the spade, left to right, you can see the samples from the O horizon (organic material), the mineral-leached A horizon (cocoa brown), and the iron-enriched B horizon (ruddy orange). A Munsell color chart is visible in the right of the picture. The green sprigs of princess pine (Lycopodium clavatum) bespeak a sandier soil than at the farm site. Mountain laurel also appears here.

I also appreciate that Dr. Evans discusses some of the economic aspects of the study of nature, for instance, pointing out that the tighter growth rings for oaks and chestnuts are what make these hardwoods valuable to furniture makers and handcraftsmen. He also noted that much of the public lands acquired in the Roosevelt New Deal era were the result of forced relocation of starving farmers who had nothing left but their patches of knackered land.

Just in case anyone is listening, the marker post for the Fairfax Cross County Trail on the south side of Silverbook Road at White Spruce Way is down. It’s especially hard for someone coming from the north side of Silverbook to pick up the trail, which continues unpaved and otherwise unmarked along the south side of the road. This trouble spot is about 100 yards from the place where the trail is informally rerouted around a closure of the trail for about 10 yards, right at the corner of the old prison facility.

Immediately behind me, as I made this image, is a rather birdy spot, considering the time and season. It’s waste ground in a little hollow, filled with tangled veg (and at least some rubbish). Flycatchers like the vantage point of the top of the old fence, at least where there is a rail for perching.

Only a light frosting of snow this morning on the still-sleeping woods (the bigger dump is expected this evening). We welcomed three new volunteers to the nest box program, and those of us working the main pond got instant satisfaction, as old reliable box #7 already showed a clutch of six Hooded Merganser eggs. Green-winged Teal and Northern Pintail are lingering in the wetland. Paul reported a big flock of White-throated Sparrows.

I walked the southernmost two miles of the Fairfax Cross County Trail, from the marina on the Occoquan River to just beyond the Furnace Road underpass. The trail begins across the river from the picturesque marina and arts town of Occoquan, Virginia, then makes a long and steady climb of 250 feet, coming out of the valley to traverse less appetizing venues.

At present, the trail passes the landfill on the right, then swings around the remains of the prison complex at Lorton, currently under redevelopment. After a stretch on the verge of Va. 123, passing the new Workhouse Arts Center, the trail follows Lorton Road, crossing broken pavement, before skirting more government property and diving into another patch of land under redevelopment. Where there is a patch of green to be found, bluebirds like the edgy habitat. Fortunately, the trail is well-posted in this stretch.

Just before mile marker 39, the trail passes under Furnace Road via a brick barrel-vaulted bridge.

I did a short bird walk this morning with NVBC. Nothing too special, a quick look at a Field Sparrow. The venue was Fort C.F. Smith Park in Arlington, which turns out to be a charming little pocket park overlooking the river to the north from a slip of land between North 24th Street and the George Washington Parkway. Acquired by the county in 1994 from the Hendry family, the park provides a mix of civilized amenities (it’s popular for weddings) and bird-friendly features (see the area managed for meadow in the right part of this image). We walked for a short time with David Farner, park manager, who pointed out activity to control invasive English Ivy.

The property is prized by historians, as ruins of the earthworks that comprised Ft. Smith are still visible. Built in 1863, he fort was part of the perimeter protecting Washington from Confederate attack from the south and west.

I did the northernmost 2.5 miles of the Potomac Heritage Trail with a loosely-organized Meetup group. One of the objectives of the event was to assemble as many hikers as possible for a relatively short 4-mile round trip from Turkey Run Park to the northern trailhead, with spur hikes to the south for the more ambitious. And I’d say the goal was reached, with nearly 100 hikers assembled in the parking area.

The weather was nearly perfect, with sun breaking out of the clouds and temperatures rising into the 60s. The trail itself is not particularly difficult; one ill-planned scootch over some rocks left me with a wet butt. However, the footing at this time of year was a bit treacherous: it alternated among residual snowpack, refrozen snowpack, and mud—mud chewed up by 100 pairs of boots and sneakers. The switchbacks that drop steeply down to the river trail from the parking lot could use some T.L.C.

The trail’s northern terminus is in a small subdivision, in sight of the American Legion Bridge that carries I-495 over the river into Maryland.

Along the way, views of the Potomac are quite fine. At many points the trail drops to within a few feet of the river’s edge, so I would expect these sections to be impassable in high water. South of the park, the terrain flattens and dries out, and was more fun walking. The trail climbs a ridge to join the George Washington Parkway right of way. I was a bit weary, and knew that I still had some icy muck to negotiate on my way back, so I called it a day.

(Update: I understand now that this section of trail is just a short unit of a planned 800-mile system.)

Pohick Creek, waking up after several days of double wintry cold.

We mustered out this morning to do some finish work on a stream restoration project at Huntley Meadows Park, under the direction of Park Manager Kevin Munroe. The watercourse is East Barnyard Run, which is thought to rise from a spring near the park boundary. Nonetheless, it also drains nearby subdivisions and flows downstream into the main wetland of the park. The streambed is almost fenceline-straight; perhaps it follows the path of an old drainage ditch. In any case, the objective of the restoration project, performed by contractors, is to add some obstacles to the water to calm its flow: an old log, a vein of small boulders, a little island to make a traffic circle.

Our work was to finish some shrub plantings that had been started a couple of weeks ago: elderberry, buttonbush, Viburnum species including Arrowwood (Viburnum dentatum) and Blackhaw (V. prunifolium). Last time out we also planted plugs of Virginia Wildrye (Elymus virginicus), a member of the grasses, and some asters, as I remember. The point of the plantings is to establish a root system to hold the clay of the streambed in place, lest it wash downstream as silt, choking the crayfish and other watery denizens of the marsh.

Much of today’s work was installing anti-deer tree protectors around our shrub plantings. Rather than the familiar plastic tubes, we used a biodegradable gadget made of thin stakes (of cedar?) lashed together and closed around the stem with a bead-and-loop gizmo. It’s sort of like macramé for naturalists. None of what we planted is taller than the protectors yet, so what you see now in the photo is just a grove of stakes. We also surrounded each shrub with a ring of matting to discourage competing plant life.

The island of stakes is easy to find: from just north of the main parking lot, follow the sanitary sewer easement northwest about 150m to the stream, then go downstream about 50m. I will check back in the spring to see what has leafed out.

As Kevin Munroe notes in the most recent newsletter from Friends of Huntley Meadows Park, some prized bird and plant species returned to breeding status in the park this past year. Birds include Virginia Rail (Rallus limicola), which I got to see in May, and Least Bittern (Ixobrychus exilis), still a jinx bird for me. For the botanists, there was Green Milkweed to be found, and the carnivorous Bladderwort (Utricularia sp.), last seen in the wetland eighteen years ago.

The day began brisk and clear for a hike of the northern third of the Appalachian Trail in Maryland, from Pen Mar Park just south of the surveyor’s line laid by Mason and Dixon to our endpoint at Maryland Route 77, a line of asphalt laid by latter engineers. We followed the signs pointing to Georgia.

Senior Naturalist Stephanie Mason of Audubon Naturalist Society set a fast pace so that we could cover the 8.5 miles in 7:30. I was grateful for the quick march, because I had underdressed for the newly Octoberish weather on the ridgeline. This stretch of the trail is fairly flat, with just a 600-foot climb to High Rock, followed by a drop from the peak of 750 feet before climbing again to Raven Rock. But much of the footing is fairly rocky, and with a generous litter of Chestnut Oak leaves, somewhat tricky.

We took the loop branching off the AT to see High Rock, but as this viewpoint is directly accessible by road, the towniness of the place is rather unpleasant.

Better, and more dramatic, are the views from Raven Rock, a couple of miles to the south.

Along the way, we stopped for close looks at Common Witch-hazel (Hamamelis virginiana) in wispy flower (the common name Winter-bloom makes a lot of sense), a handful of Redback Salamanders (Plethodon cinereus) under logs, and the fine white stripes (visible under hand lens) on the needles of a White Pine. Much of the Hay-Scented Fern, so much in evidence on September’s walk, is now dried and brown. Generally, when Stephanie stops to point something out, she will ask, “Does anyone know what this is?” and she will follow up with hints and questions, as needed. On this trip, most of the geology questions were answered by the group, since we had my car pool mate Bret along (a staff geologist with the Nuclear Regulatory Commission) as well as others who knew their rocks. We looked at a lot of leaves and nuts: bright red Sourgum, Sugar and Red Maple, Sassafras, Sarsaparilla, Yellow and Black Birch, Eastern Hemlock (a few specimens looking almost healthy), Hickory, some sapling American Chestnuts, Tuliptree.

Stephanie paused at the fall of a rather substantial oak to point out the niche ecosystems and topography—so-called pit and mound—formed by treefall.

As we parked at the Kensington Armory this evening to see a show—it was early dusk, about 7:15—we saw a sizable flock of Chimney Swifts (Chaetura pelagica) swirling about, ready to come into to roost for the evening. We didn’t find the chimney that they were using, but it is no doubt somewhere nearby.

A good hike today, the Appalachian Trail from I-70 to Maryland 77, led by Cliff Fairweather of Audubon Naturalist Society. We spent a lot of time looking at living things, so we covered the 8.5 miles (or 9.5 miles, no one is quite sure) in 7:45. Not quite a “naturalist’s shuffle,” but leisurely. The path lies between 1300 and 1800 feet on the elevation chart: I measured at most a change of 600 feet. The climbing is not too hard, rising through a long tract of mountain laurel, and most of the walking is fairly easy, but there is a stretch of rocks along the ridgetop of South Mountain that’s good for some knee-twisters (as my left one can attest) and ankle-breakers.

We paused for a look at sawfly larvae on the leaves of an American Chestnut. Only one of the chestnuts we saw was head-height; most were about 3 or 4 feet high. Participant Joe was working on his mycology, so we stopped several times to see many, many fine examples of fungus. We smelled the faint sweetness of Hay-Scented Fern (Dennstaedtia punctilobula). Cliff pointed out a saddleback caterpillar that my point-and-shoot was not able to image. Towards the end of the hike, we saw some very dark brown examples of Squawroot (Conopholis americana). Squawroot is a parasitic plant of the Broomrape family, which also includes Beech Drops.

We took side trips to Annapolis Rocks to the west and an unnamed viewpoint to the east. Table Mountain Pine (Pinus pungens) at Annapolis Rocks and a fun little rock scramble to reach the eastern view. Not much in the way of bird life: woodpeckers, a few chickadee friends, Blue Jays imitating hawks, a couple of mystery vocalizations, maybe a tanager? Participation on these hikes is pretty broad, all the way from hikers who don’t stop for much of anything to shoe-gazing botanists. My carpool mate Susan and I were the most experienced birders.

By far the big sighting of the trip was this lovely butter-yellow Timber Rattlesnake (Crotalus horridus) that sauntered across the track. A first sighting for a lot of us; as for myself, it’s been several years since I’ve seen one of these guys.