Original Post by Hannah Claycomb:
You are the manager of a Wildlife and Wetland Refuge on the Ashepoo River in South Carolina. The Corps of Engineers would like to build a dam on the Ashepoo River and you need to make a convincing argument as to how that would affect your refuge which consists of domed peat forests and tidal freshwater marshes. These wetlands would be flooded by the reservoir. Use the info I gave you in the powerpoint and your reading to list why this action would destroy your wetlands.
Damming a flowing body of water is dangerous to many ecosystems. Domed peat forests and freshwater marshes would greatly suffer consequences if the Ashepoo River would be dammed and the wetlands were flooded by the reservoir. Domed peatlands and freshwater marshes are in close proximity of one another, portraying a symbiotic relationship. The freshwater marshes act as a sediment barrier and natural filter, protecting forested peatlands (Flanagan 2021b). If a dam was installed, the freshwater marsh would be flooded, thus the peatland would also be flooded with increased sediment and nutrients that would not sustain life in a peatland forest.
The freshwater marsh would also suffer if the river was dammed, because it would not be given proper inflows from the river. When such inflows stop, chemistry of the marsh will change dramatically and would kill off vegetation and fauna. When the vegetation dies, so does the barriers in place to protect the domed peatland forest. In turn, this would cause an influx of nutrients to the domed peatland forest and decomposition will outcompete peat accumulation. This will destroy habitats and vegetation in the domed peatland forest. Both wetlands give rise to diverse communities of vegetation and animals. The dam would immensely lower both wetlands’ productivity. Preservation of these wetlands is absolutely needed.
Explain the connection between dry and wet cycles of alluvial cypress swamps using both websites and the Cypress powerpoint. How long can a swamp stay dry? What is the best cycle for cypress-tupelo forest health and regeneration? How does the hydrology feed the plant life of swamps?
The hydrology of alluvial cypress swamps include annual flooding and periodic drying (Flanagan 2021a). Every decade a swamp needs to completely dry out to allow for regeneration of vegetation. Cypress trees are not aquatic plants but can sustain waterlogged soils for a certain amount of time, thus, they need to be able to germinate on moist land. When flooding occurs, rivers and tributaries flood the swamp and can be held in large swamps for weeks and small swamps for days (Flanagan 2021a). Flooding transports nutrient-rick sediments to the swamps.
Fish move to pools in alluvial cypress swamps to spawn when flooding occurs; when water levels decrease the fish will meander back to rivers and tributaries (Flanagan 2021a). Fish are hatched in individual pools to increase survival from predatory species. When winter rains come, channels and pools are flooded and the young fish are connected to the river. The occurrence of floods and drying spells are vital for a cypress swamp to survive and produce life. The best cycle for cypress-tupelo forest health and regeneration is continuous flooding via pulsing of hydrologic inflows in the spring and winter (Mitch and Gosselink 2015, 381, 401). Drying periods of the swamp occur during the summer. This cycle would increase its primary productivity.
Compare bogs and fens.
Bogs and fens are a couple of the most important wetlands distributed around the world. They are both mainly found in the northern hemisphere under colder, temperate climates where humidity is high. Precipitation usually exceeds evapotranspiration leading to a positive water balance. Peat accumulation is greater than decomposition due to low temperatures, waterlogged conditions, and acid conditions. Bogs and fens are also vital carbon sinks around the globe. When compared to other wetlands, bogs and fens are generally low in productivity. The main limiting nutrients in bogs and fens are nitrogen and phosphorous. Vegetation adaptations are also similar; plants develop aerenchyma or lacunae for oxygen supply, oxygen consumption is reduced, and oxygen tends to leak from roots to produce a locally aerobic root environment. (Mitsch and Gosselink 2015)
Bogs and fens also show dissimilarities in several aspects. Hydrologic complexities are different where bogs are generally ombrotrophic (open only to precipitation) and fens are minerotrophic (receive water that has passed through mineral soil). This in turn creates differences in soil pH, bogs being more acidic than fens. Fens can be slightly acidic to alkaline depending on inflows and chemistry. Further, because fens receive inflows from groundwater and surface water sources, fens tend to have more nutrients compared to bogs. This difference also contributes to differing flora and fauna; bog species have adaptations to low-nutrient conditions. Bogs primarily create an environment supporting acidophilic plants; typically containing Sphagnum, various sedges, ericaceous shrubs, pines, tamaracks, and spruce trees. Fens support a diverse array of vegetation like bryophytes, sedges, dicotyledonous herbs, and grasses. Ground cover for bogs is usually Sphagnum whereas sedges are for fens. (Mitsch and Gosselink 2015)
Anthropogenic activities have been destroying wetlands for far too many years. Bog and fen restoration is extremely important due to its unique species composition and ability to capture ample amounts of carbon. The first step in restoring a bog is preparing/fixing land to sustain the necessary species and hydrological complexities (Bloodnick 2021). Next would be to actually introduce vegetation by harvesting proper plants and spreading them evenly over the area. I would monitor soil chemistry and water chemistry frequently to ensure nutrient, pH, and toxins are at appropriate levels.
Bloodnick, Ed. 2021. “The 6 Steps to Restore a Peat Bog.” Pro Mix. https://www.pthorticulture.com/en/training-center/the-6-steps-to-restore-a-peat-bog/
Flanagan, Kathryn. 2021a. “Freshwater Swamps – Cypress/Tupelo Alluvial Swamps” PowerPoint. Accessed July 20, 2021.
Flanaga, Kathryn. 2021b. “Peatlands – South Carolina” PowerPoint. Accessed July 20, 2021.
Mitsch, William J., and James G. Gosselink. 2015. Wetlands. John Wiley & Sons, Inc.
Hi Hannah (Question 1),
It is important to highlight the domed peatlands and freshwater marshes have a symbiotic relationship. The proximity factor that the post mentioned goes along with a general theme of the course concerning how the one water body’s ecosystem impacts others that surround it. For example, we discussed that the rising ocean tides cross into the salt water marshes and ultimately impact the freshwater marshes, as well. Also, I appreciate that the post emphasized damming that leads to decreased amounts of water inflow does not merely impact water quantity. It also changes water quality on a chemical basis. Once again, you’re portraying how the transitive property is applied to wetland ecology. I particularly applaud how it all ends with illustrating the connection between vegetation, wildlife and habitat health.