The Great Smoky Mountains National Park contains over 800 acres of old growth eastern hemlock (Tsuga canadensis), more than any National Park Service unit. Called the “redwood of the east” eastern hemlock grows to it’s grandest proportions in the Smokies. Hemlock forests are widely distributed over almost 90,000 additional acres in the park. Some of the largest and oldest eastern hemlocks known grow in the Smokies, commonly exceeding 150 feet tall, six feet in diameter, and may reach 500 years of age. Old-growth forests of the park have become increasingly important in recent years as harbors of biodiversity, as preferred habitat of neotropical bird species, for research of forest dynamics, and for recreation and aesthetics. Hemlock has been shown to moderate stream temperatures summer and winter thereby easing heat and cold stress on aquatic organisms. A variety of birds, mammals, invertebrates, and plants are associated with hemlock and hemlock-dominated communities. Hemlock’s dense canopy provides food, shelter, and breeding sites across the seasons. Scientists have found that 16 of 30 species of breeding birds were significantly correlated with hemlock. In 2002 the hemlock woolly adelgid (Adelges tsugae), native to Asia, was identified in the park. The hemlock woolly adelgid (HWA) is a small “aphid-like” insect that covers itself in a white, waxy, “wool” which acts as a protective coating. HWA infestations can be easily recognized by the appearance of tiny “cotton balls” at the base of hemlock needles. The “wool” is most conspicuous on the underside of the branch Fall through Spring. The HWA feeds on the sap at the base of the needles, disrupting nutrient flow to the foliage. The needles eventually change from deep green to an ashen gray and then fall off. Without needles the tree starves to death in as little as three to five years. This insect has now been identified throughout the park and has the potential to eliminate hemlock trees from the landscape. Shenandoah National Park has lost almost 95% of their hemlocks due to HWA. Hemlocks in developed areas and backcountry sites accessible by administrative roads are treated with insecticidal soap or horticultural oils. Sprayed from truck-mounted spray units, these sprays smother and dry-out the adelgids on contact. Generally, developed areas are easily accessible by vehicles allowing for the use of high pressure sprayers. The equipment adequately sprays up to 80 feet into the canopy of large roadside trees and allows efficient treatment of areas of smaller trees. This method controls only the insects that are residing on the tree at the time of application and requires retreatment every six months to one year. Hemlocks that are too tall to be adequately treated with foliar spray, are near campsites, or are large high value trees, are treated with a systemic insecticide (imidacloprid) through soil drenching or injecting directly into the trunk. Technicians temporarily remove the duff (organic matter) layer from around the base of the tree then pour an imidacloprid and water mixture around the base of the tree within a foot of the trunk. The organic matter is then replaced. The results of insecticidal treatments have been dramatic. Trees with ashen gray foliage prior to treatment recover their color and produce new growth. Releases of predatory beetles as a biocontrol began in 2002. Entomologists at the University of Tennessee, Knoxville started rearing beetles and supplying the park in 2004. These beetles feed exclusively on HWA. It will take several years before the beetles become established at a level where they can control HWA populations. Although it is too early assess the overall success of this biocontrol, preliminary monitoring results are encouraging. Although the adelgid will fundamentally and forever alter hemlock forests of the Smokies, with continued funding, dedicated staff, and committed partners, future visitors to the park will still be able to marvel at

This geospatial dataset contains location polygons for all forest types with Eastern Hemlock as a component in Great Smoky Mountains National Park. Showing vegetation classified as Hemlock at dominant and co-dominant stages. This layer is derived from the GRSM Overstory Vegetation Map and is designed to provide a rough map of hemlock forest locations within Great Smoky Mountains National Park. All forest types defined in the Vegetation Map that have hemlock listed as a component have been clipped into this layer.

Field Methods: My work will test three predictions: (1) Hemlock decline alters nutrient cycling and decomposition rates. (2) Hemlock decline alters plant and soil communities, including microbial (bacteria and fungi) and soil arthropods (ants). (3) Hemlock decline and ant interactions with ecosystem processes will vary across elevation. To test my predictions, I will establish a series of 10- 20 m2 plots throughout the GSMNP to inventory and monitor hemlock stands. I will choose sites across a gradient of elevation throughout the park. Additionally I will classify each site based on its hemlock mortality (calculated using the percent of the hemlock crown remaining). Vegetation sampling: All overstory trees within plots will be identified to species and the diameter at breast height measured. All shrubs and tree saplings will be identified to species and the density of individual stems will be calculated. All hemlock seedlings within the plots will be counted. Within each of these 20 m2 plots, 10 randomly stratified 1 m2 subplots will be established for understory woody vegetation, herbs, and ferns, which will be identified to species, and percent groundcover will be estimated to determine density. I will compare community composition, richness, and structure (for the overstory trees) across each of the 20 m2 plots. Soil community sampling: To assess the soil community I will remove soil cores, sample ants, and take measurements of soils in situ at three locations within each 20 m2 plot. To monitor the ant community, I will lay out 10 pitfall traps within each plot, which will be left open for 48 hours. After this time, pitfall traps will be collected and taken to my lab to have the contents sorted and ants identified to species. I will collect 3 soil core samples per plot, to determine the abundance of soil microbial communities using qPCR, and to determine enzyme activity and microbial biomass in the soil. Soil samples will be taken back to the lab for detailed nutrient analysis including total nutrient content, nitrogen mineralization, and carbon evolution. Hemlock leaf litter will be collected and used to measure decomposition rates, using decomposition bags. Nine decomposition bags will be placed within each of the 20 m2 plots, and three bags will be removed after 3, 9, and 15 months. I will also collect in situ soil measurements including soil moisture, temperature, and respiration using a Li-Cor, and measurements will be compared across plots.

Field Methods: My work will test three predictions: (1) Hemlock decline alters nutrient cycling and decomposition rates. (2) Hemlock decline alters plant and soil communities, including microbial (bacteria and fungi) and soil arthropods (ants). (3) Hemlock decline and ant interactions with ecosystem processes will vary across elevation. To test my predictions, I will establish a series of 10- 20 m2 plots throughout the GSMNP to inventory and monitor hemlock stands. I will choose sites across a gradient of elevation throughout the park. Additionally I will classify each site based on its hemlock mortality (calculated using the percent of the hemlock crown remaining). Vegetation sampling: All overstory trees within plots will be identified to species and the diameter at breast height measured. All shrubs and tree saplings will be identified to species and the density of individual stems will be calculated. All hemlock seedlings within the plots will be counted. Within each of these 20 m2 plots, 10 randomly stratified 1 m2 subplots will be established for understory woody vegetation, herbs, and ferns, which will be identified to species, and percent groundcover will be estimated to determine density. I will compare community composition, richness, and structure (for the overstory trees) across each of the 20 m2 plots. Soil community sampling: To assess the soil community I will remove soil cores, sample ants, and take measurements of soils in situ at three locations within each 20 m2 plot. To monitor the ant community, I will lay out 10 pitfall traps within each plot, which will be left open for 48 hours. After this time, pitfall traps will be collected and taken to my lab to have the contents sorted and ants identified to species. I will collect 3 soil core samples per plot, to determine the abundance of soil microbial communities using qPCR, and to determine enzyme activity and microbial biomass in the soil. Soil samples will be taken back to the lab for detailed nutrient analysis including total nutrient content, nitrogen mineralization, and carbon evolution. Hemlock leaf litter will be collected and used to measure decomposition rates, using decomposition bags. Nine decomposition bags will be placed within each of the 20 m2 plots, and three bags will be removed after 3, 9, and 15 months. I will also collect in situ soil measurements including soil moisture, temperature, and respiration using a Li-Cor, and measurements will be compared across plots.

This dataset results from systematic sampling on 60 randomly selected plots within the spruce-fir zone of GRSM. Researchers recorded the frequency and cover of 97 bryophyte species occurring on ground-layer substrates in spruce-fir forests, as well as tree density in mulitple strata, herbaceous layer composition and cover, and soil chemical properties. This database contains all raw data entered from paper datasheets, data acquired from GIS data layers, and data produced from post-field labwork such as tree core ring counts and soil chemical anaylses.

This dataset results from systematic sampling on 60 randomly selected plots within the spruce-fir zone of GRSM. Researchers recorded the frequency and cover of 97 bryophyte species occurring on ground-layer substrates in spruce-fir forests, as well as tree density in mulitple strata, herbaceous layer composition and cover, and soil chemical properties. This database contains all raw data entered from paper datasheets, data acquired from GIS data layers, and data produced from post-field labwork such as tree core ring counts and soil chemical anaylses.

This database includes all data related to long-term vegetation monitoring performed by GRSM I&M staff from 2003-2009. Data collection methods follow Jenkins 2008 protocol, and are generally referred to as the GRSM Vegetation Monitoring plots. This program ended in 2009 and was replaced with the Vital Signs program, however, this database will still occasionally be updated as research partners revisit plots.

Wildflower phenology data recorded from 13 plots of 2 meter square, at The Purchase area and near Chimneys Picnic Area. Most data involve species in bloom and number of blooms per species per square, but other phenophases are also recorded on flowering and non-flowering plants for most plots. Chimneys Picnic Area data extends back to 2000, Purchase data to 2011 (previously certified).

Wildflower phenology data recorded from 13 plots of 2 meter square, at The Purchase area and near Chimneys Picnic Area. Most data involve species in bloom and number of blooms per species per square, but other phenophases are also recorded on flowering and non-flowering plants for most plots. Chimneys Picnic Area data extends back to 2000, Purchase data to 2011 (previously certified).

Emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an exotic beetle that was discovered in southeastern Michigan near Detroit in the summer of 2002. The adult beetles nibble on ash foliage but cause little damage. The larvae (the immature stage) feed on the inner bark of ash trees, disrupting the tree's ability to transport water and nutrients. Emerald ash borer probably arrived in the United States on solid wood packing material carried in cargo ships or airplanes originating in its native Asia. Emerald ash borer is also established in Windsor, Ontario, was found in Ohio in 2003, northern Indiana in 2004, northern Illinois and Maryland in 2006, western Pennsylvania and West Virginia in 2007, Wisconsin, Missouri and Virginia in the summer of 2008, Minnesota, New York, Kentucky in the spring of 2009, Iowa in the spring of 2010, Tennessee in the summer of 2010, Connecticut, Kansas, and Massachusetts in the summer of 2012, New Hampshire in the spring of 2013, North Carolina and Georgia in the summer of 2013, Colorado in the fall of 2013, New Jersey in the spring of 2014, Arkansas in the summer of 2014, and Louisiana in the winter of 2015. Since its discovery, EAB has: Killed hundreds of millions of ash trees in North America. Caused regulatory agencies and the USDA to enforce quarantines (Michigan, Connecticut, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Maryland, Massachusetts, Minnesota, Missouri, Ohio, New Hampshire, New York, North Carolina, Ontario, Pennsylvania, Tennessee, Virginia, West Virginia, Wisconsin, and Quebec) and fines to prevent potentially infested ash trees, logs or hardwood firewood from moving out of areas where EAB occurs. Cost municipalities, property owners, nursery operators and forest products industries hundreds of millions of dollars.