Healy NEON / HEAL

Healy (HEAL) is a terrestrial NEON field site located in central Alaska, 120 km (75 mi.) southwest of Fairbanks and at the northern border of Denali National Park. The 45.6 km² (11,300 acre) site is managed by the Alaska Department of Natural Resources. It sits at an average of 678 m (2224 ft.) in elevation and is situated in a high-elevation, glaciated valley where the dominant vegetation consists of dwarf shrubs and sedge meadows. This valley experiences widespread permafrost thawing, making it a valuable resource to understand how other permafrost systems in Alaska may experience and react to thawing in the future. The site is open to the public for recreation including hunting, berry picking, snowmobiling, and dog sledding. HEAL is one of the four sites (three terrestrial and one aquatic) located in the NEON Taiga Domain (D19), which comprises Alaska’s interior and the Alaska Peninsula. [1] [2]

HEAL has a subarctic climate, typified by long, cold winters and brief, mild summers. The mean annual precipitation is 385.3 mm (15 in.) and the mean annual temperature is -1.3°C (29.6°F). Due to its subarctic latitude, Healy experiences no night (only twilight) from May to early August, and only 4 to 5 daylight hours between November and January. [1] [3] [4] [5]

The bedrock at HEAL is Doxey Shale, and the soil parent material is dominantly quaternary loess over gravelly glacial till and outwash. Geomorphology includes alluvial fans and stream terraces. [2] [17]

The dominant soil at HEAL is a silty loess overlying glacial till and outwash which has been heavily reworked by environmental agents, including water, gravity, and cryoturbation. A thick (>20 cm) organic horizon is present, and organic accumulations are even heavier in areas that have undergone subsidence as a result of permafrost thawing. The majority of the site has continuous permafrost. [2]

Healy is located in a wet tundra biome, a landscape dominated by ericaceous shrubs, willow scrub, tussock grasses and (in drainages) spruce forests. The vegetation is broadly comparable to that found at the nearby Denali National Park. Common plants at the site include American dwarf birch (Betula glandulosa / Betula nana), white spruce (Picea glauca), marsh Labrador tea (Ledum palustre), bog blueberry (Vaccinium uliginosum), lingonberry (Vaccinium vitis-idaea), tealeaf willow (Salix pulchra), black spruce (Picea mariana), crowberry (Empetrum nigrum), Bigelow’s sedge (Carex bigelowii), and grayleaf willow (Salix glauca). The area around Healy has undergone dramatic changes in vegetation in association with the thawing of permafrost and development of thermokarst landscape, which falls into a wider pattern of vegetation changes in response to climate. As a NEON site, Healy offers the opportunity to study changes in vegetation structure and species diversity as the site undergoes permafrost degradation. [1] [2] [6] [7]

Animals native to this region of Alaska include Grant’s caribou (Rangifer tarandus granti), coyote (Canis latrans), red fox (Vulpes vulpes), moose (Alces alces), lynx (Lynx canadensis), gray wolf (Canis lupus), and Dall sheep (Ovis dalli dalli). The site also falls within the range of wood bison (Bison bison athabascae), a subspecies of American bison which is considered threatened under the Endangered Species Act. The small mammal species studied at HEAL include North American brown lemming (Lemmus trimucronatus), several voles in the Microtus genus, northern red-backed vole (Myodes rutilus), northern bog lemming (Synaptomys borealis), and meadow jumping mouse (Zapus hudsonius). [6] [7] [8]

Humans have been present in Alaska since the late Pleistocene, with the earliest evidence currently dating to 14,000 years ago in the Tanana River valley. At this time, the Alaskan landscape was considerably different from what we find today: a treeless shrub tundra was host to now-extinct fauna including mammoth and horse, and the ice-free corridor from Siberia still allowed passage across Beringia. Though most early archaeology is limited to low-elevation areas, an alpine (>1000 m) archaeological site in Denali National Park called Bull Run II demonstrates that people were at least seasonally utilizing high-elevation areas (such as where Healy is located) as early as 12,500 years ago. People continued to occupy central Alaska throughout the Holocene, mostly using low-elevation valleys but increasingly using high-elevation sites after approximately 6200 years ago, a shift which suggests a change in resource exploitation and possibly an increased focus on caribou hunting. Following Russian contact and colonization during the 18th century, Alaska was incorporated into the United States as the Department of Alaska. Nearby Mount McKinley National Park (now Denali National Park) was established in 1917, and non-native settlements were first established near Healy in the 1920’s when coal mining in the area began and the Alaska Railroad connected the mining camps to Fairbanks and ports on the southern coast. Since the 1980s, the Healy area has been the focus of ecological research looking at the effects of permafrost degradation. [6] [9] [10] [11] [12] [13] [14] [15]

HEAL is located on land managed by the Alaska Department of Natural Resources (DNR), and is open to the public for general recreation. The DNR manages approximately 100 million acres of land and all freshwater resources in Alaska, and oversees land use including agriculture, forestry, mining, oil and gas operations, and outdoor recreation. The site is located within major land resource area (MLRA) 228, where the primary form of land use is remote wildland recreation (subsistence hunting, backcountry hiking, mountaineering, etc.). In the area near Healy, land use also includes coal mining operations. [1] [4] [16]

Plot establishment at HEAL began in 2014, and the site was reviewed for sampling readiness in 2015. Dry runs of observational sampling began in late 2015, followed by the first publications of data products for most observational protocols in the same year. Instrumentation systems went online and began producing data in 2016.