Blue Ridge Expeditions: Turk Mountain

Time Travel on the Talus of Turk

On the morning of May 23, a crew of 16 people met for the day’s adventure on Turk Mountain in Augusta County, Virginia. Our journey was one of scales: geological, ecological and cultural. Our expedition began with some flexing of the imagination, 550 million years ago upon white sand beaches. Skolithos tube worms left their marks in the form of linear tube-shaped trace fossils. We moved forward through time watching mountains climb and fall and continents collide as our beach sands were crushed beneath the resulting weight and pressure – transforming them into the quartzite the gives us Turk Mountain today. We stood, 15,000 years ago, deep beneath the peri-glacial ice and snow and watched the freeze-thaw activity break the quartzite into massive blocks. They tumbled from the cliffs above and crept down the north face of the mountain. We watched the ice and cold depart northward, and the tundra, fir, spruce  and northern hardwood forests with it. Those ancient ecosystems with all their cold climate plants and animals long ago found their home in up-state New York and Canada. But, they once were here in Virginia. In only a few special places, with cold and sheltered micro-climates, do we find vestiges for the few disjunct plant communities that remain behind. So is the case for the Paper Birch of Turk Mountain. We stood in a forest that was logged repeatedly over the past couple hundred years, and engulfed in a roaring fire less than 50 years ago. The scars in the forest tell that story, and a story of renewal as part of fire ecology. Lastly, we stood in the future, pondering the changes, or lack-thereof, upon this complex and varied Blue Ridge landscape.

Dry-mesic Oak-Hickory-Pine Heath forest 
During the majority of the hike we passed through a dry-mesic pine-oak-hickory forest with a heath dominated understory. Written in this landscape is a logging operation and an intense fire. The multi-trunked and fire resistant chestnut oak trees spoke of the region’s appetite for iron-smelting. The demand on the forests for charcoal production was high, and no trees within reasonable reach were spared, not even those gnarled and stunted chestnut oaks on Turk mountain. Not too long ago a fire cleaned out the understory…possibly 30-40 years ago. Pignut hickory, scarlet oak, table mountain pine and pitch pine are prevalent in the canopy. American chestnut is ever present rising to as high as 25 feet from the acidic and rocky forest floor along with bear oak, downy serviceberry, red maple, minniebush, mountain laurel, pinxter azalea, mountain holly and witchhazel. Deerberry, bracken fern, and two blueberry species blanket the ground leaving very little room for sedges and herbaceous perennial flowering species. Spicebush swallowtail butterflies oviposit on sassafras seedlings and an eastern fence lizard darts through the dry leaves on the ground. Ovenbirds gave us song the entire way. We stopped in the trail at about 2,600 feet elevation and made haste, off trail,  in the direction of 60 degrees west of north, up a steep slope, and around the “back side” of the mountain.

Low Elevation Boulderfield Forest (<3,200 ft. ele)
Eventually the ground began to move beneath our feet. The angle of slope increased and shifting quartzite talus became the dominant substrate. We transitioned gradually to an Appalachian boulderfield forest, consisting of black birch, paper birch (two small clusters), northern red oak, chestnut oak, striped maple, mountain maple, minniebush, Appalachian gooseberry, northern lowbush blueberry, marginal wood fern, American alumroot, Virginia creeper,  very little  else. Growing conditions are harsh at this site. There is very little opportunity for fine sediment accumulation and soil building processes. Access is difficult as well, and this likely resulted in the preservation of certain trees during the massive clear cutting that occurred during the 19th-20th centuries. The hypothesis must be tested, but I believe there are small pockets within this ecosystem that are “virgin forest” – that is, areas that have never been logged, cleared, burned, or otherwise affected by anthropogenic activities. The most longest lived flora may be the giant gnarled black birch trees reaching up from the ocean of quartzite boulders in the open canopy areas. Moving west the talus turned from small boulders to giant blocks. Ahead we could see the bright white slopes free of vascular growth.

Lichen / Bryophyte Nonvascular Boulderfields 
Lichen-dominated boulderfields are scattered across the backside of the mountain in a great patchwork. In some cases bits of the forest reach into the boulder fields, following nutrient-rich sediment pockets. In other cases, the boulderfields completely engulf small patches of forest. The quartzite boulders offer very little in the way of nutrients for plants. The lichens that cover them find little competition, and thus they have diversified to fill every little niche. The following unique lichen species are indicators for this ancient non-vascular plant community: Cladonia furcata, Cladonia rangiferina, Cladonia uncialis, Melanelia culbersonii, Cladonia squamosa, Xanthoparmelia conspersa, Dimelaena oreina, Lasalia pensylvanica, Lasallia papilosa, Hypogymnia physodes, and Physcia subtilis. An occasional Appalachian rock polypody (Polypodium appalachianum) clings to the talus. Dragonflies, sawflies, millipedes, spiders and an occasional lady bug made their presence among the lichens, and though we did not encounter any, the potential of disturbing timber rattlesnakes kept us on alert.

Betula papyrifera vs. Betula cordifolia
After braving the steep slopes and shifting talus to reach our destination, we explored the ecology of the paper birch tree. Using a detailed dichotomous key, participants observed the attributes that make these trees unique. While the Mountain paper birch (Betula cordifolia) is well documented in the area (an ice-age relic species that likely diverged from the northern paper birch long ago, gifting the Blue Ridge with yet another unique species), our target tree,  Paper birch (Betula papyrifera), has not been confirmed south of the Potomac River. We counted veins on leaves, observed the pubescent twigs, the cuneate to truncate leaf bases, the distinct bark, and other characteristics. Comparing these attributes sheds light on the differences between the trees. We departed, grateful to have the opportunity to visit these trees and to be gifted such a beautiful day. We ventured back through changing ecosystems, downslope, upward in temperature and forward in time. Back in Charlottesville we found ourselves in temperatures 10-12 degrees warmer than the north slopes of Turk Mountain - and 25 to 30 degrees warmer than the cold pockets of air at the base of the talus slope - among the cavernous blocks of quartzite that offer the disjunct paper birch trees a tiny refuge here in the Blue Ridge.

Ecosystem-based species observations from the hike:

Dry-mesic Oak-Hickory-Pine Heath forest

1. Acer pensylvanicum (striped maple)

2. Acer rubrum (red maple)

3. Betula lenta  var. lenta (sweet birch)

4. Carex appalachica (Appalachian sedge)

5. Carya glabra (pignut hickory)

6. Carya species unid. (unid. Hickory)

7. Carya tomentosa (mockernut hickory)

8. Castanea dentata (American chestnut)

9. Coreopsis verticillata (thread-leaf coreopsis)

10. Dioscorea villosa  (Wild yam)

11. Dryopteris marginalis (marginal wood fern)

12. Gillenia stipulata (American ipecac)

13. Hamamelis virginiana (witch hazel)

14. Hieracium venosum (Rattlesnake weed)

15. Houstonia longifolia (longleaf bluet)

16. Hypoxis hirsuta (Yellow star grass)

17. Ilex Montana (mountain holly)

18. Iris cristata (dwarf crested iris)

19. Kalmia latifolia (mountain laurel)

20. Maianthemum racemosum (False Solomon’s seal)

21. Menziesia pilosa (minniebush)

22. Papilio troilus (spicebush swallowtail butterfly)

23. Parthenocissus quinquefolia (Virginia creeper)

24. Pinus pungens (table mountain pine)

25. Pinus rigida (pitch pine)

26. Polygonatum biflorum (Solomon’s seal)

27. Potentilla Canadensis (dwarf  cinquefoil)

28. Pteridium aquilinum (bracken fern)

29. Quercus coccinea (scarlet oak)

30. Quercus ilicifolia (bear oak)

31. Quercus falcata (black oak)

32. Quercus montana (chestnut oak)

33. Quercus rubra (northern red oak)Rhododendron periclymenoides (pinxter azalea)

34. Rubus flagellaris (Common dewberry)

35. Sassafras albidum (sassafras)

36. Sceloporus undulatus (eastern fence lizard)

37. Seiurus aurocapilla  (ovenbird)

38. Taenidia integerrima  (Yellow pimpernel)

39. Uvularia perfoliata (Perfoliate bellwort)

40. Vaccinium angustifolium (northern lowbush blueberry)

41. Vaccinium pallidum (hillside blueberry)

42. Vaccinium stamineum (Deerberry)

43. Viola pedata (Birdsfoot violet)

44. Zizia aurea (golden zizia)

Low Elevation Boulderfield Forest

1. Acer pensylvanicum (striped maple)

2. Acer rubrum (red maple)

3. Acer spicatum (mountain maple)

4. Amelanchier arborea (downy serviceberry)

5. Betula lenta  var. lenta (sweet birch)

6. Betula papyrifera var. papyrifera  (paper birch)

7. Diervilla lonicera (northern bush-honeysuckle)

8. Dryopteris marginalis (marginal wood fern)

9. Hamamelis virginiana (witch hazel)

10. Heuchera americana var.hispida (American alumroot)

11. Ilex Montana (mountain holly)

12. Menziesia pilosa (minniebush)

13. Parthenocissus quinquefolia (Virginia creeper)

14. Polypodium appalachianum (Appalachian rock polypody)

15. Quercus Montana (chestnut oak)

16. Quercus rubra (northern red oak)

17. Ribes rotundifolium (Appalachian gooseberry)       

18. Vaccinium angustifolium (northern lowbush blueberry)

19. Vireo olivaceus (red-eyed vireo)

20. Narceus americanus (American giant millipede)

21. (Unidentified spider)

Lichen / Bryophyte Nonvascular Boulderfields

1. Cladonia furcata (cup lichen)

2. Cladonia rangiferina (gray-green reindeer lichen)

3. Cladonia squamosa (cup lichen)

4. Cladonia uncialis (cup lichen)

5. Dimelaena oreina (golden moonglow)

6. Hypogymnia physodes (tube lichen)

7. Lasallia pensylvanica (Pennsylvania toadskin lichen)

8. Lasallia papulosa (blistered naval lichen)

9. Melanelia culbersonii (Culberson's black-parmelia)

10. Physcia subtilis (rosette lichen)

11. Polypodium appalachianum (Appalachian rock polypody)

12. Xanthoparmelia conspersa (peppered rock-shield)

13. (Unidentified dragonfly)

14. Coccinella septempunctata  (seven spotted ladybug)

15. (Unidentified spider)

Resources:

1. Gallery of Photographs from this hike: https://goo.gl/photos/ESBYNLvkr6owhppz6

2. Exploring the Talus of Turk: Discovery of a Possible New Virginia Tree: http://blueridgediscoverycenter.org/blueridgediscoverycenterblog/2011/07/exploring-talus-of-turk.html

3. Natural Plant Communities of Virginia: http://www.dcr.virginia.gov/natural_heritage/natural_communities/ncoverview.shtml

4. Paleogeographical Maps of North America: https://www2.nau.edu/rcb7/nam.html

5. Digital Atlas of Virginia Flora: http://vaplantatlas.org