Master's Thesis Plan of Work

Plant Community Description and Correlation to Soil, Water, and Nutrient Gradients in Southern Appalachian Bog/Swamp Forest Complexes: A Baseline Study for Development of a Restoration Plan

Jane Almon


Abstract

Mountain wetlands have attracted attention in recent years as the rapidly diminishing habitat for a number of endangered plant and animal species. There are several small remnant wetlands left in Shady Valley, a broad alluvial valley between Iron, Cross, and Holston Mountains in extreme northeastern Tennessee. Most are less than a couple of acres in size and are scattered across the valley. Orchard Bog is a 1-acre remnant surrounded by 64 acres of drained and cultivated farmland that was formerly bog and swamp forest. The Tennessee Field Office of The Nature Conservancy has acquired this land with the intent of restoring the bog- forest complex to expand habitat for the endangered bog turtle (Clemmys muhlenbergii). This project will be carried out in cooperation with T-DOT, which will receive mitigation credits for the restoration. The Shady Valley bogs are the home of the only known native extant population of bog turtles in Tennessee. Several northern disjunct plant species are also found on these bogs, including cranberry and cottongrass.

To restore the farmland to its original bog state, it is necessary to characterize the soil, vegetation, and hydrology of the system and determine how the plant communities are distributed over gradients of soil, water, and nutrients. To this end, we have identified 5 bogs in Shady Valley and one in Carter County, TN to serve as references for characterization of the bogs.

The objectives of this study are as follows:

1. To determine the current characteristics of the restoration and reference sites by sampling their soils, vegetation, water, and microtopography;

2. Classify the plant communities, and;

3. Correlate environmental factors to community types.

Transects for vegetation sampling were laid out perpendicular to the main drainage of the bog. Percent cover of woody and herbaceous species in 5m x 5m quadrats was recorded, as well as number and diameter of woody stems. A soil sample was collected from each quadrat and will be analyzed for macro- and micronutrients, pH, and CEC. At least one soil pit will be dug on each bog to describe the soil profile. A water sample from each plot was collected from the ground surface by depressing the peat mat, from rivulets flowing through the plot, or from a well if there was one in the plot. Samples will be analyzed for pH, nitrogen, ammonia, phosphorus, potassium, calcium, magnesium, sodium, iron, manganese, sulfides, and conductivity. At least one continuously recording water level monitor has been installed at each site. Data will be examined to determine depth to water table and frequency and duration of flooding. Surface elevation will be determined at each well and plot center for correlation with plant community composition.

Two-way indicator species analysis (TWINSPAN) (Hill, 1979; Gauch and Whittaker, 1981) or some other cluster analysis will be used to classify plant community types. Canonical correspondence analysis (CANOCO) (Palmer, 1993) will be used to directly relate species composition to soil chemical and physical characteristics, mean water level, water chemistry, stage duration and frequency of modulation, and surface elevation.

References

Gauch HG, Jr and Whittaker RH. 1981. Hierarchical classification of community data. Journal of Ecology, 69:135-152.

Hill MO. 1979. TWINSPAN-A FORTRAN program for arranging multivariate data in an ordered two-way table by classification of the individuals and attributes. Ithaca, NY: Ecology and Systematics, Cornell University.

Palmer MW. 1993. Putting things in even better order: The advantages of canonical correspondence analysis. Ecology, 74(8):2215-2230.