Our Field Trip to Hocking Hills!


Substrate-associated Plants

The first substrate (acid) associated plant is the sourwood (Oxydendrum arboreum). It is a small tree or shrub with alternately arranged serrated leaves, and it is common in the lower chain of the Appalachian Mountains. The sourwood grows in acidic, loamy, moist, sandy, well-drained and clay soils. It prefers normal moisture but has some drought tolerance.

I chewed the leaves during the field trip, and it tasted like lemon!

Eastern hemlock (Tsuga canadensis) is another acid-associated plant mentioned by Jane Forsyth. (Here is one picture of it holding by Dr. Klips! )  Eastern hemlock is a keystone species which provides canopy for both aquatic and terrestrial species. Its wood is soft, coarse-grained, and light buff in color, the lumber is used for general construction and crates. Because of its unusual power of holding spikes, it is also used for railroad ties.

The second acid-associated plant is the low bush blueberry (Vaccinium angustifolium). It is of course a low shrub with alternately arranged elliptical leaves, and it grows better with well-drained acidic soils. Low bush blueberry fruits are small sweet dark blue to black berry, full of antioxidants and flavonoids. Their fruits are smaller than the high-bush blueberry which we can find in grocery store.

 

The third acid-associated plant. is the haircap moss (Polytrichum commune). It is a medium to large moss with dark green color. They are found in a large range of damp acidic habitats, such as the Hocking hills at Appalachian Mountains! Although mosses are considered non-vascular plants, haircap moss shows clear differentiation of water conducting tissue. Those tissues are analogous to xylem and phloem in more advanced plants, how cool is that!

 


Biotic Threats to Forest Health

The first one is the Eastern Hemlock (Tsuga canadensis), it is a coniferous tree native to eastern North America and is widespread throughout the Appalachian Mountains.

Eastern hemlock populations in North America are threatened in much of their range by the spread of the invasive Hemlock woolly adelgid, which infests and eventually kills trees. It is an insect of the order Hemiptera native to East Asia, and it feeds by sucking sap from hemlock and spruce trees

 

The second one is Butternut, or white walnut (Juglans cinerea). The most serious diseases of it is the butternut canker. it is an infection caused by a fungus (Ophiognomonia clavigignenti-juglandacearum) that mainly attacks butternut trees. This fungus is considered to be introduced to North America, the fungus creates a wound (canker) that appears as patches of small, long and sunken black blemishes on a tree, and dead twigs in the crown of a butternut are the first symptoms of an infection.


Appalachian Gametophyte

The common name, Appalachian gametophyte, of course is named after where it’s found— Appalachian Mountains, and it lived exclusively in the Appalachian Mountains and Plateau of the eastern United States. It is one of the three fern species that exists exclusively as a vegetatively reproducing gametophyte.

Gemmae are bigger than spores, so it would be too big to be considered wind dispersed for long distance. Thus, they are likely dispersed short distances by wind, water, or possibly animals. Kimmerer and Young (1995) showed that gemmae have been dispersed by slugs in short distance and potentially by ants (evidence for animal dispersal).

Th e notion of limited dispersal capability in V. appalachiana is also supported by the absence of this species north of the extent of the last glacial maximum, beyond which a transplant study has shown they are able to survive. Even recently disturbed areas or other substrates that appear suitable within the range of V. appalachiana frequently remain uncolonized, while the species fl ourishes on seemingly similar substrates close by ( Farrar, 1990 ). Taken together, these data suggest that spore dispersal from a fully functioning sporophyte must have been responsible for the current distribution of  V. appalachiana. Th e truncated range of this species in southern New York likewise indicates that the gametophytes lost their ability to produce mature, functioning sporophytes sometime before (or during) the last ice age.

Th e possibility that the current populations of the Appalachian gametophyte are being sustained by long-distance dispersal from some tropical sporophyte source can be rejected based on past allozyme studies ( Farrar, 1990 ), as well as the truncated range of V. appalachiana in the southern portion of New York. Additionally, the monophyly of V. appalachiana in our plastid analysis would seem to indicate that dispersal from the tropics occurred just once, although the situation is somewhat more complicated in our nuclear tree, where one V. appalachiana allele is resolved outside the larger V. appalachiana clade. Since the dispersal of gemmae does not appear to account for the wide range of V. appalachiana, it is most likely that a fully functioning sporophyte of this species existed (and quite possibly thrived) in North America when temperatures were more favorable for tropical growth in the Appalachians. If  V. appalachiana produced sporophytes aft er the glaciers had receded, spore dispersal could have easily extended the range of this species further north


Two plants with wind dispersed fruit

It was so difficult to find wind dispersed fruit at this time because most of them are still flowering, so I found some Asters there.

Blue mistflower?

Panicled aster?

Dandelion?


Miscellaneous Other Observations.

Winter creeper (Euonymus fortunei) is an evergreen shrub with oppositely arranged elliptical leaves which grows as a vine if provided with support, and it is highly invasive and damaging in the United States, causing the death of trees and forest in urban areas.

 

Ghost pipe (Monotropa hypopitys). Unlike most plants, it does not contain chlorophyll! Plants are fleshy and grow 10–35 cm tall. True stems do not exist here. It is a parasitic plant getting nutrients upon fungi rather than photosynthesis. 

Beech drops (Epifagus virginiana). It is a parasitic plant which grows on the roots of American beech. It’s also lack of chlorophyll like the ghost pipe. It bears small white and purple flowers that appear in July through October, and the dried flower stalks will persist throughout the winter. Although E. virginiana grows off of the roots of its host, but is not known to cause significant harm to the beech tree. Beech drops germinate when a chemical signal is released from the roots of the beech, and it’s believed that the older the host tree, the more this chemical is released.

Japanese stilt grass (microstegium vimineum). It is considered to be an invasive plants in the North America, but it serves as a host plant for some native satyr butterflies such as Carolina satyr and the endangered Mitchell’s satyr.


Conopholis! The plant of my website address!