Oak Ridge NEON / ORNL

Oak Ridge National Laboratory (ORNL) is a terrestrial NEON field site located in the Cumberland Plateau within Anderson and Roane Counties, TN. The 57.4 km² (14,000 acre) field site is managed by a combination of the Department of Energy (DOE) and Tennessee Wildlife Resources Agency (TWRA). The DOE's Oak Ridge National Laboratory is famous for its involvement in creating atomic bombs associated with the Manhattan Project. The surrounding region includes the world’s longest expanse of hardwood-forested plateau and is home to some of North America’s greatest diversity of fish, mollusk, and wildflower species. ORNL is part of NEON Domain 07 - Appalachians & Cumberland Plateau, which includes eastern Tennessee, most of Kentucky, southern Ohio, and parts of North Carolina, Georgia, Indiana, and Illinois. D07 includes four other NEON field sites, including two additional terrestrial sites and two aquatic sites. ORNL is colocated with the WALK aquatic field site. [1] [2] [3]

The climate at ORNL is characterized by moderately large variations in temperature and abundant precipitation. In particular, ORNL has hot and humid summers and cool, mild winters. The mean annual average temperature is 14.4°C (58°F) and mean average precipitation is 1340 mm (53 in.). The site is occasionally subjected to high wind events, thunderstorms, droughts, flooding, and rare wildfires. Summer afternoon thunderstorms are common, and winters will see occasional snow accumulation which melts shortly afterwards (depending on elevation and sun exposure). [6] [20]

ORNL is part of the Cambrian-aged Upper Knox Group, consisting of dolostone and limestone. The parent materials are residuum, colluvium, and local alluvium. [4]

The ridges and valleys of the Cumberland Plateau are famous for their status as the world’s largest hardwood-forested plateau. The canopy in the area is dominated by oaks and hickories and includes a mixture of deciduous species in the valleys with patches of shortleaf pine (Pinus echineta) and Virginia pine (Pinus virginiana) on the ridges. Mixed hardwoods at the site include chestnut oak (Quercus prinus), tulip poplar (Liriodendron tulipifera), red maple (Acer rubrum), white oak (Quercus alba), and American beech (Fagus grandifolia). While 91% of the plots are forested, 9% are unforested (either pasture or grassland). [8] [9]

The area surrounding ORNL hosts about 60 species of fish and 60 species of reptiles and amphibians, ~200 species of migratory, transient and resident birds, and 35 species of mammals, as well as many invertebrate species. Among these, 17 were identified as federally- or state-listed (endangered, threatened, or in need of management) in surveys done in the 2000s. Some large mammals found in the area include the following: white-tailed deer (Odocoileus virginianus), red fox (Vulpes vulpes), gray fox (Urocyon cinereoargenteus), and elk (Cervus canadensis). More recently, coyote (Canis latrans) and wild boar (Sus scrofa) have moved into the area. Other common mammals include raccoon (Procyon lotor), striped skunk (Mephitis mephitis), Virginia opossum (Didelphis virginiana), and a plethora of small mammals. NEON provides data on five types of wildlife: small mammals, birds, mosquitoes (family Culicidae), ground beetles (family Carabidae), and ticks (order Ixodidae). Small mammal species commonly sampled in ORNL include the following: deer mice (Peromyscus spp. – majority Peromyscus leucopus, with some potential for Peromyscus maniculatus), eastern chipmunk (Tamias striatus), cotton rat (Sigmodon hispidus), and the occasional northern short-tailed shrew (Blarina brevicauda). [9] [10] [21]

The nearby Walker Branch watershed has a long history of research. In 1942, the United States government selected the rural area for the development of nuclear weapons and materials for the Manhattan Project. Originally called the Clinton Engineering Works, the Oak Ridge Reservation includes three facilities: Oak Ridge National Laboratory (ORNL), Y-12 National Security Plant, and the Gaseous Diffusion Plant, now known as the East Tennessee Technology Park (ETTP). In 1943, the reservation housed the world's first operational nuclear reactor, used for the production of plutonium during World War II. After World War II, the U.S. government dissolved the Manhattan Project and established the Atomic Energy Commission to produce and control nuclear energy for military and civilian applications during peace time. In the 1960s, research at the reservation focused on environmental research such as energy efficiency, renewable energy technologies, and nuclear technologies and systems. In 1989, the U.S. Department of Energy’s Environmental Management (DOE-EM) and National Nuclear Security Administration began to oversee nuclear clean-up activates at the site. Today, ORNL continues to take part in cutting-edge scientific research, Y-12 National Security Complex continues to be used for nuclear weapons processing and materials storage, and the East Tennessee Technology Park (ETTP) is considered a sensitive area with national security concerns. [9] [12] [13]

NEON’s ORNL site is situated on the Oak Ridge Reservation (ORR). THE ORR is owned by the U.S. Department of Energy (DOE), but is often managed jointly by DOE and TWRA depending on the area. Some of NEON's plots are in restricted access areas that require security clearance, and some plots are open to the public for recreational opportunities, such as hiking and deer and turkey hunting. While the land is dominated by forest, a few areas are cleared by burning for idle pasture, hay, or other agriculture or general uses. ORR is one of the six international biosphere reserve units of the Southern Appalachian Biosphere Reserve. Remnants of pre-Manhattan Project settlements are present within ORR. Due to leftover hazardous waste from the Manhattan Project, the DOE contracts companies to perform environmental remediation projects at ORNL. The Division of Remediation’s Oak Ridge Office oversees all DOE environmental protection/restoration activities on the ORR. Because the ORR is on the EPA National Priority List of Superfund Sites, a tri-party agreement between the state DOE and EPA was formed under a temporary “Memorandum of Agreement” to manage this land towards eventual environmental remediation. The ORNL Natural Resources Management Program also conducts natural resources management tasks. Other environmental studies may also be taking place within ORNL, because it's considered to be an “outdoor laboratory” for research and education, but no non-NEON research is allowed within NEON-established plots. [4] [13] [14] [15] [16] [17] [18] [19]

Initial site establishment at ORNL began in 2014. Plots were allocated across the site using NEON standard criteria and avoiding existing research. Plots located within the National Laboratory were not allocated to areas that required additional security clearance. The 2006 National Land Cover Database (NLCD) was selected for stratification purposes. TOS Tower Plots were allocated according to a spatially balanced design in and around the NEON tower airshed. Initial operations capability/capacity review took place in November 2014 for terrestrial sampling and in March 2015 for instrumentation sampling. Transition to operations happened in the summer of 2015 for both terrestrial observation and instrumentation sampling.