Tree biology-based tools and corresponding soil chemistry to track natural resources and processes that represent ecological conditions along the Appalachian Trail corridor

The Appalachian National Scenic Trail (AT) is situated along a system of mountain ridges and peaks ranging from Georgia to Maine. High elevation and ridge-top ecosystems along the AT corridor are subject to high levels of air pollution and are sensitive to acidic deposition. Vegetative species, water chemistry, and wildlife depend upon the physio-chemical makeup of this environment and are especially susceptible to deleterious changes caused by air pollution that can result in limited buffering capacity of poorly developed, or non-existent, soils. The overarching purpose of this study was to evaluate the condition and sensitivity of the AT with respect to acidic deposition by investigating current impacts on water, soil and vegetation, and use that data in modeling efforts to predict the time necessary for the ecosystem to recover under future deposition scenarios. The specific goal of this sub-study was to use metabolic and chemical changes in sapwood plugs from mature trees and foliage from seedlings with corresponding soil chemistry to examine current health conditions of trees growing along the AT corridor. Along the northern section during the growing season of 2010, and the southern section in 2011, sapwood plugs from 15 mature trees and foliage from 10 seedlings of randomly chosen red spruce (RS), sugar maple (SM), chestnut oak (CO), or oaks in the white (WO) or red/black (RO/BO) family were collected from a total of 14 intensive study sites within the AT corridor. Tabular data include free polyamines, free amino acids, soluble ions, chlorophyll, and soluble protein analyzed by HPLC, ICP-OES and spectrophotometer. Corresponding soil samples were collected within the same time frame. From an area that encompassed the vegetation study plots from each site, nine soil cores representing A and B horizons were collected and later combined into three samples for laboratory analysis. Three soil pits were excavated and samples of Oe, Oa and/or A, and two to four horizons/depths from the B and C horizon (where found) were collected and analyzed separately. Tabular data include soil pH, % organic matter, total N and C, exchangeable ions, acidity, base saturation and cation exchange capacity determined by pH meter, C/N Elemental analyzer, potentiometric titration and ICP-OES. At one site within this study there was an elevation survey which included sampling of 9 soil cores, foliage from 10 seedlings and sapwood plugs from 15 mature chestnut oaks randomly chosen at each of three elevations; Low (773 feet), Mid (960 feet) and High (1343 feet).
These data were collected to examine the effects of environmental/ecological conditions and to assess the current health status of trees growing along the Appalachian National Scenic Trail by analyzing sapwood and foliar metabolism and physiology, and corresponding soil chemistry. An elevation survey from one site was included to examine localized effects of elevation.
For more information about this study, see Lawrence et al. (2015).