Deep Woods Farm

Deep Woods, The Appalachian Gametophyte, & Ohio Geobotany

This week, we ventured south to Hocking Hills and explored a wonderful area called Deep Woods Farm that was roughly 250 acres and owned by the Blythes; who are lovers of nature and allow curious students and researchers to immerse themselves into their land. During this field trip, Dr. Klips introduced us to some new fantastic ferns, the Appalachian Gametophyte, acid-loving plants, and plants with weird modes of nutrition. It was very refreshing seeing people allow others onto their beautiful acreage simply to seek the vast knowledge of nature! Now, let’s get more into what exactly we learned here!

1. Substrate-associated Plants:

Some of the trees and plants we were fortunate enough to see on this trip were associated with the sandstone hills of eastern Ohio love acidic, dry soils as defined by Jane Forsythe’s “Linking Geology and Botany: A New Approach”, and included sourwood (Oxydendrum arboreum), chestnut oak (Quercus montana), blueberry (Vaccinium sp.), greenbrier (Smilax sp.), and eastern hemlock (Tsuga canadensis). Let’s go into 3 of these!

Sourwood

Here we have the lovely sourwood (Oxydendrum arboreum) with its oval or oblong leaves that mature into richly colored green leaves. This deciduous tree is alternately arranged, with a simple leaf complexity, and a glossy appearance on the surface of the leaf, along with small toothing on the margins. The reason this species is commonly called “sourwood” is because the leaves have a sour taste to them that reminds some people of a granny smith apple! Another reason these trees are called “sourwood” is their fruits, which are capsules that are 4-7 inches long, elliptical, finely toothed, and sour to the taste! Natural history for this tree includes Native Americans using the plant medicinally for digestive issues using the leaves, and also other accounts have said that chewing the bark can soothe intense mouth pain as well as remedy fevers. So ultimately, you should at least give the leaves a taste!
How beautiful right? Here is a closer look at the leaves that typically stick out to me as an early botanist. Something to look for when searching for sourwood are the leaf veins as they are more intensely furrowed near the center of the leaf and appear to be softer in shape near the outer edge.

chestnut oak

Chestnut oak (Quercus montana) trees are acidophiles (not to be confused with chinquapin oak trees that are calciphiles!) and have alternate, large simple leaves with rounded (slightly “rounded teeth”) lobes in pairs of 10-16. These leaves are also known to be dark green above and gray-green below and have dark, thick, and deeply ridged bark. Their habitat is of course dry upland areas with sandy, acidic, nutrient-poor soils. Some natural history of this tree includes that the wood is great for firewood, construction, and basket making. This species may also be referred to as “rock oak” or “basket oak” which gets its name from its leaves, which closely resemble those of the American chestnut (Castanea dentata). Side note: this image also has some blueberry (Vaccinium sp.) leaves in it, which is also an acidophile described by Jane Forsythe!

eastern hemlock

Here we have a marvelous specimen, eastern hemlock (Tsuga canadensis). A good way to identify this tree species is with its needles as they are short, flat, and blunt-tipped, with two distinct white stripes on the underside (I am kicking myself for not taking a photo of them on the underside, shoot!). The bark of these trees is reddish-brown with wide flat ridges and either appears scaly (when young) or cracked deeply (when mature). A (not so fun) fact about these trees is that they have been under attack by an exotic sap-sucking insect called hemlock woolly adelgids (HWA), which have been threatening to eliminate all eastern hemlock trees since the early 1990s. These can be spotted when you see a white, waxy substance as it develops that looks like cotton masses on the underside of branches (Petrides, 1972).

 

2. Ferns:

During this trip, we learned about ferns and their frond types (monomorphic, hemidimorphic, and holodimorphic) and frond dissection types (entire, pinnate, pinnatifid, pinnate-pinnatifid, and so on) to use for identification. Below I described 3 ferns I observed and included photos!

polypody fern/ rock polypody

Wow! Our first fern! Here we have a polypody fern, Polypodium virginianum, that is characterized by its pinnatifid (meaning that it is divided into the lobes that extend halfway or more to the midvein of the frond, as seen in the photo) frond dissection type and monomorphic frond type (meaning that this fern produces both fertile and sterile fronds, which have the same shape). I believe the specific species of polypody is “rock polypody” as the ferns have narrow, oblong, leathery leaves that are bright green on both sides and large circular sori on the underside of fertile leaves. I also believe this to be the species since rock polypody can tolerate dry soil, rocky soil, and drought, which all occurred at Deep Woods Farm.

spinulose woodfern

The 2nd fern I would like to talk about is a spinulose woodfern, Dryopteris carthusiana). This woodfern is tripinnate and monomorphic regarding spore production. To identify this fern, look for an individual that grows in circular clumps, with fairly well-divided fronds, and a reinform indusium type. Another great ID trick I learned was to look for its unequal-sided lowermost pinnae where it has subleaflets that are long on one side compared to the other.

cinnamon fern

Our 3rd fern is cinnamon fern, Osmunda cinnamomea! We can see how its leaflets are pinnate and pinnatifid (so, pinnate-pinnatifid). These ferns are also holodimorphic, meaning that the fern produces two strikingly different types of fronds that are either dedicated to spore production (“fertile frond”) or entirely vegetative (“sterile frond”). To identify cinnamon ferns, look for the growths of circular clusters of large fronds that have deeply pinnate-pinnatifid fronds from an underground stem. Note: of these 3 ferns we talked about, none were hemidimorphic, meaning that a fern’s fronds are divided into a “fertile portion” and a “sterile portion”. An example of this is Christmas fern!

 

3. Appalachian Gametophyte:

 

New Appalachian gametophyte description & how it is different than previously described by Flora of West Virginia (1952-1964): 

The “new” Appalachian gametophyte, Vittaria appalachiana, is described as a fern that has never had mature sporophytes and reproduces asexually via gemmae. Previously, this fern was described by Flora of West Virginia as having both sporophytes and gametophytes, as they stated that the gametophyte is found in deep, shaded regions of sandstone and quartzite rocks and that it is more commonly widespread than its sporophyte life cycle stage. We now know that this fern lives only in its gametophytic life stage and is a remarkable species due to its interesting range limits and modes of reproduction (as talked about below).

Among fern species with long-lived gametophytes, perhaps none is as peculiar as Vittaria appalachiana. Set forth its common name and describe the manner in which it is so remarkable.

Vittaria appalachiana, otherwise known as the Appalachian gametophyte is a remarkable species as it is one of the three species of ferns in which mature sporophytes are unknown. Ferns and lycophytes are known to spend the majority of their life cycle in a sporophyte stage and have alternating free-living sporophyte and gametophyte stages. This highlights how remarkable the Appalachian gametophyte has no mature sporophytes. Another noteworthy thing about the Appalachian gametophyte is that it reproduces asexually via gemmae. The areas where this species grows are exclusive to dark areas within the Appalachian Mountains and Plateau of the eastern United States.

Fern gemmae are differently sized than spores. Describe the consequence of that size difference in relation to dispersal. State three possible agents of gemmae dispersal. A 1995 publication by Kimmerer and Young is cited as evidence for one of the modes. What is that evidence?

Fern gemmae are quite large compared to spores (~0.2mm to 1.0mm) and are generally considered too large to be dispersed to long distances by wind. Fern gemmae are likely only dispersed short distances by wind, water, and even animals (3 distinct agents of gemmae dispersal) which can be backed up by the absence of this species north of the extent of the last glacial maximum, showing that they have limited dispersal methods. One might ask how animals would be responsible for short-distance dispersal of this niche species, but Kimmerer and Young found that in bryophytes gemmae dispersal has been known to be facilitated over short distances by slugs and potentially by ants as well.

The notion of limited dispersal capability in V. applachiana is also supported by consideration of a combination of the geologic history of the area, and the current distribution of the plant. Explain this evidence and how it supports a particular time frame for its loss of the ability to produce mature, functioning sporophytes.

Recently disturbed areas such as road cuts and tunnels frequently remain uncolonized with the Appalachian gametophyte, even though they appear to be suitable habitats within its range. The species flourished on seemingly similar substrates close by, likely meaning that spore dispersal from a fully functioning sporophyte must have been responsible for the current distribution of Vittaria appalachiana. However, the shortened ranch 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.

Could the current populations of the Appalachian gametophyte be being sustained by long-distance dispersal from some tropical sporophyte source? Support your answer. What is the most likely explanation for the wide range of V. applachiana?

The possibility that the current populations of the Appalachian gametophyte are being sustained through long-distance dispersal from some tropical sporophyte source can be rejected based on its limited range in the southern part of New York and the past allozyme studies. Based on phylogenetics, the monophyly in the study’s plastic analysis would indicate that dispersal from the tropics occurred just once (although this is a very complicated history on a nuclear tree).

Since the dispersal of gemmae does not appear to account for the Appalachian gametophyte’s large range, a fully functioning sporophyte of this species likely existed in North America when temperatures were more favorable for tropical growth in the Appalachians. Likely, the reason for this current wide distribution would be solely due to spore dispersal, with the sporophyte becoming extinct before/ during the Pleistocene glaciations. This is supported by the fact that the Appalachian gametophyte is unable to inhibit northward beyond the limit of the last glacial maximum. If this species produced sporophytes after the glaciers had receded, spore dispersal could have easily extended the range of this species further north.

 

4. Invasive Plants:

Oh, how I wish this was not a section we needed to cover… (Boo! Hiss!) but some invasive plants we learned about during the field trip included barberry and Japanese stilt grass. The one we will be covering below is Japanese stilt grass, going into its origins, ecological effects, and some recommended methods of control.

Japanese stilt grass

Here we have a picture of Japanese stiltgrass (Microstegium vimineum)as identified by its lance-shaped leaves that are pale green and 1-3 inches long, as well as their silvery stripe of reflective hairs that run lengthwise along the center of the upper leaves surface. The stems of this grass are thin and wiry, standing initially upright, and then laying over to form a dense mat with age. This grass typically grows to about knee height and can take over open space in sunny ecosystems.

Japanese stiltgrass originates in Asia (including China, India, Japan, Korea, and Malaysia), but has semi-recently become a big invasive problem in the United States once it was first reported in 1919 after being introduced through packing material for imported porcelain from China. This introduction of the species ultimately led to it being found across most of the eastern United States.

There are many ecological effects occurring due to this invader of forest lands, including reduced diversity of native grass and plant species, reductions in wildlife, and negative impacts on important ecosystem functions. Invasive species are often competitive and tend to grow quickly in open areas, meaning the native plants that we know and love have nowhere to go and ultimately do not make it. Correct identification of this stiltgrass is important before beginning any management activities as it’s important to only take out the invasives.

Recommended control measures for Japanese stiltgrass vary depending on the degree of infestation but often include control of seeds. Research states that seeds remain viable in the soil for less than 7 years and that populations have been shown to rapidly decline when seed head controls are taking place. Knowing this, long-term management programs have been suggested to emphasize the prevention of seedhead formation as this is vital to limit seed dispersal, which can get out of control very quickly. Ways to control seedheads include mechanical removals, utilizing herbicides that are effective against Japanese stiltgrasss, and mowing.

Citations used:

River to River. (2012). Field Guide to The Identification of Japanese Stiltgrass with Comparisons to Other Look-a-like Species. Alabama Cooperative Extension System. Retrieved from: https://bugwoodcloud.org/mura/rtrcwma/assets/File/stiltgrass/FG_Id_Japanese_Stiltgrass-orig.pdf

Neal, J., and Judge, C. (2013). Japanese Stiltgrass Identification and Management: Horticulture Information Leaflets. NC State Extension. Retrieved from: https://content.ces.ncsu.edu/japanese-stiltgrass-identification-and-management

 

5. Trees in Trouble:

During the field trip, we talked about 3 trees that are in trouble, including eastern hemlocks, American chestnuts, and butternuts. Here I will focus on issues pertaining to butternut trees and inform you on why the species is in danger of extinction in the possible future.

butternut

Here we have a butternut tree (Juglans cinerea) as a tree in trouble! This is one of my favorite pictures I took during our Deep Woods field trip as I have never seen a butternut tree in the wild (especially one this large & [hopefully] healthy!) So, about the “in trouble” part, butternut trees have been attacked with a fungus that gives the tree “butternut canker”. Butternuts are identified through their innately compound, alternately arranged leaves, and whitish bark with brown and white vertical stripes.
Butternut canker is a fungus that creates a wound (a canker) that looks like small patches of long/ sunken blemishes on the tree’s trunk. This fungus is particularly tricky to manage as it can survive as it is spread through several ways, including rain splashing pores from infected trees, wind dispersing spores up to 45 meters, and possibly animals such as flying insects that are infected with spores targeting butternut trees. It is speculated that birds can also spread this fungus once it has been contaminated.

Ecological effects of butternut cankers include the death of butternut trees through girdling cankers formed on the trunks. This further impacts the gene pool status of an area as butternut trees do not sprout from the root crown after being killed by cankers, losing their gene poop forever. Forest biodiversity can ultimately be hindered as well as a loss of food for many forest animals.

Possible remedies for butternut cankers include removing infected branches with cankers EARLY, removing infected trees from natural areas, and creating stand openings that are twice the height of surrounding trees. Sadly, there is no cure for butternut canker, but these strategies may help bring back this beautiful tree to our forests someday.

Citations used:

Natural Resources Canada. (2017). Butternut canker. Government of Canada. Retrieved from https://natural-resources.canada.ca/our-natural-resources/forests/insects-disturbances/top-forest-insects-and-diseases-canada/butternut-canker/13375

Wisconsin Horticulture, University of Wisconsin-Madison. (2014). Butternut canker. Division of Extension. Retrieved from https://hort.extension.wisc.edu/articles/butternut-canker/

Here is a picture comparing butternut leaves to black walnut leaves, note that butternut leaves typically have a terminal leaflet! Image from Petrides Trees & Shrubs Field Guide, 1972.