About Field Sites
Toolik Lake Research Natural Area (TOOL) is a terrestrial NEON field site near Toolik Field Station, AK, just north of the Brooks Range. The 60 km2 (14,800 acre) site is located 254.3 km (158 mi.) above the Arctic Circle and 188 km (116 mi.) from the Arctic Ocean. TOOL’s field sampling area is managed by the Bureau of Land Management as a Resource Natural Area and Area of Critical Environmental Concern, but housing and logistics are supported by Toolik Field Station (TFS). TFS is operated by the Institute of Arctic Biology at the University of Alaska Fairbanks, with cooperative agreement support from the Division of Polar Programs, Directorate for Geosciences at the National Science Foundation. TOOL sits at 700 - 985 m (2300 - 3200 ft.) above sea-level, which demarcates taiga and tundra ecosystems in Alaska. It provides a contrast to BARR, which is on the northern coastal floodplains. In both cases, field site boundaries overlap other ecological research networks, allowing opportunities for larger datasets and longer time series. TOOL is part of the NEON Tundra Domain (D18), which includes the northern and western parts of Alaska. D18 hosts three other NEON field sites in Alaska: two aquatic sites and the BARR terrestrial site. TOOL is colocated with the two D18 aquatic sites, Toolik Lake (TOOK) and Oksrukuyik Creek (OKSR).  
The climate at TOOL is characterized by long, cold winters; short, cool summers; and extreme seasonal variation. In the absence of sunlight, winters are long and bitterly cold, with temperatures sometimes reaching -40°C (-40°F) or lower. The summer period brings 24-hour solar input for much of June-August; as a result, it is the only time of year where average temperatures exceed 0°C (32°F). TOOL has an average mean temperature of -9°C (16°F) and it receives a mean annual precipitation of 316 mm (12.4 in).  
The majority of TOOL is located on rolling till plains and moraines with various superposed periglacial features that include stripes, non-sorted circles and thermokarst pits. Glacial and alluvial deposits from the Holocene age blanket the area. The site is also located in a continuous permafrost zone; however, taliks - pockets of non-frozen material - often underlie lakes and rivers.  
TOOL is located on rolling till plains and moraines. The lowlands have a thick organic layer, while the higher located soils are gelic (frost-churned) and exposed at the surface. Soils at TOOL contain permafrost as the site is located in the zone of continuous permafrost. The soils are characterized as Typic Histoturbels in the order Gelisols. These soils have a thick layer of organic matter at the surface and are often saturated for long periods of time. The high organic matter in the soils at TOOL is mostly due to persistent cold temperatures, which limit decomposition and promote the accumulation of organic material from vegetation. This organic material insulates the underlying permafrost.    
The landscape’s permafrost plays a major role in soil hydrology at TOOL. Climate warming brings increasing disruption to soil moisture and water table connectivity from melting permafrost layers. While solid permafrost plays a role in directing water flow, subsurface flow also impacts permafrost volume through the transfer of thermal energy via heat advection.  
TOOL is dominated by tussock tundra, a vegetation type that covers some 80% of arctic Alaska. Bigelow Sedge (Carex bigelowii) and tussock cottongrass (Eriophorum vaginatum) are especially abundant. Low shrubs, including dwarf birch (Betula glandulosa or nana) and diamond-leaf willow (Salix pulchra), grow between the tussocks and along the streams. Vaccinium vitis-idaea is also common. NEON evaluates plant diversity and percent cover in various plots across the site on an annual basis. 
The station has a long list of notable wildlife, but mammals commonly seen in the area include caribou (Rangifer tarandus), muskox (Ovibos moschatus), and red fox (Vulpes vulpes). Terrestrial field technicians collect data on small mammals, beetles, ticks, and mosquitoes, the last of which emerge in great numbers during the peak of the growing season. Aquatic field technicians collect fish data from the nearby creek and Toolik Lake. Finally, bird surveys are performed annually to collect data on breeding land birds, including species coming from Africa and Asia, such as northern wheatears (Oenanthe oenanthe) and bluethroats (Luscinia svecica). The logo for Toolik Field Station features a yellow-billed loon (Gavia adamsii), which can be commonly seen or heard on Toolik Lake during the breeding season. 
Past Land Management and Use
Human inhabitation in Alaska has been dated back to at least the Pleistocene (11,500 years ago), with evidence of Paleo-Arctic Tradition at the Upper Sun River archaeological site.
Scientific research at Toolik began in 1975, providing baseline aquatic data as part of the National Science Foundation’s project called Research on Arctic Tundra Environments. With consistent collaboration between the National Science Foundation and the University of Alaska Fairbanks, infrastructure developed over the years to make Toolik Field Station one of the premier arctic research lab and support facilities in the world today.   
Current Land Management and Use
Owned by the Bureau of Land Management, the land which supports NEON’s terrestrial sampling is protected as both a Resource Natural Area and an Area of Critical Environmental Concern (ACEC). The 335 km2 (129 sq. mi.) unit does not allow for recreational camping nor commercial mining. Largely, the land is undisturbed and preserved for field research. For that reason, Toolik Field Station is one of the premier locations to study arctic science. TFS supports researchers from all around the world, with a capacity of over 100 users. Despite the remoteness and lack of development in the sampling area, there is one manmade structure that cannot go unnoticed. Built between 1975 and 1977, the Trans-Alaska Pipeline System precedes the establishment of the reserve; however, it has little direct environmental impact. Running from Prudhoe Bay near the Arctic Ocean to Valdez, on the Southern Coast of Alaska, the 1.21 m (4 ft.) diameter, 1287 km (800 mi.) pipeline can be seen from various parts of the sampling boundary.   
NEON Site Establishment
The plot establishment and initial sampling readiness review in TOOL began in July 2017. Dry runs of observational sampling began in late 2017. Instrumentation systems went online and began producing data in March 2017.
 Terrestrial Observation System (TOS) Site Characterization Report: Domain 18. NEON.DOC.003901vB
 National Oceanic and Atmospheric Administration National Centers for Environmental Information’s (NCEI) 1981-2010 climate normals (NCEI 2015). https://toolik.alaska.edu/edc/abiotic_monitoring/metdata_summaries.php
 Institute for Arctic Biology. IAB Facilities. Retrieved from https://www.iab.uaf.edu/research/facilities on May 24 2020
 Alaska Department of Natural Resources, Division of Oil And Gas. Retrieved 2020. Trans-Alaska Pipeline System http://dog.dnr.alaska.gov/Services/Pipelines?pipeline=Trans-Alaska%20Pi…
 Bureau of Land Management, (1989). PROPOSED RESOURCE MANAGEMENT PLAN and FINAL ENVIRONMENTAL IMPACT STATEMENT for the UTILITY CORRIDOR PLANNING AREA ARCTIC DISTRICT, ALASKA.
 Toolik Field Station (2013). Toolik Field Station Long Range Facilities Plan
 Institute for Arctic Biology, University of Alaska, Fairbanks, 2016. Toolik field station fact sheet.
 Overview of Environmental and Hydrogeologic Conditions at Barrow, Alaska. U.S. Geological Survey. 1994. https://pubs.usgs.gov/of/1994/0322/report.pdf
 Michael SanClements, Robert H Lee, E D Ayres, Keli Goodman, Morgan Jones, David Durden, Katherine Thibault, Rommel Zulueta, Joshua Roberti, Claire Lunch, Adrian Gallo, Collaborating with NEON, BioScience, Volume 70, Issue 2, February 2020, Page 107, https://doi.org/10.1093/biosci/biaa005
 Environmental Data Center Team. 2020. Toolik mammal sightings. Toolik Field Station, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775. http://toolik.alaska.edu/edc/biotic/monitoring/mammal_guide.php
 Environmental Data Center Team. 2020. Toolik bird monitoring program. Toolik Field Station, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775. http://toolik.alaska.edu/edc/biotic_monitoring/bird_guide.php
 National Resources Conservation Service (2002). Toolik Lake, Moist acidic tundra. S98AK-185-002. USDA
 U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. https://mrdata.usgs.gov/mrds/
 Mulligan, D. (2019) NEON site-level plot summary toolik lake (TOOL). USDA.
 Swanson, D. K. (2002). Soil Survey of Gerstle River Area, Alaska. pg 209.
 de Grandpré I. Fortier D. Sephan E.. 2012. Degradation of permafrost beneath a road embankment enhanced by heat advected in groundwater. Can. J. Earth Sci. 49:953–962. doi:10.1139/e2012-018
 Michelle A. Walvoord, Barret L. Kurylyk; Hydrologic Impacts of Thawing Permafrost—A Review. Vadose Zone Journal ; 15 (6): vzj2016.01.0010. doi: https://doi.org/10.2136/vzj2016.01.0010
 Virtual Herbarium. 2020. Toolik Field Station, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775. https://toolik.alaska.edu/edc/biotic_monitoring/virtual_herbarium.php
 Carroll, A. B., Parker, C., & Craig, T. (2003). Toolik Lake research natural area/ACEC rare plant inventory, 2002. BLM-Alaska Open File Report 90. BLM/AK/ST-03/010+ 6700+ 025.
 History of Toolik. 2020. Toolik Field Station, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775. https://toolik.alaska.edu/about/history.php
 Potter, B. A., Irish, J. D., Reuther, J. D., & McKinney, H. J. (2014). New insights into Eastern Beringian mortuary behavior: a terminal Pleistocene double infant burial at Upward Sun River. Proceedings of the National Academy of Sciences of the United States of America, 111(48), 17060–17065. https://doi.org/10.1073/pnas.1413131111
Remote sensing surveys of this field site collect lidar, spectrometer and high-resolution RGB camera data.
This site has a flux/meteorological tower that is 9 m (30 ft) tall with four measurement levels. The tower top extends above the vegetation canopy to allow sensors mounted at the top and along the tower to capture the full profile of atmospheric conditions from the top of the vegetation canopy to the ground. The tower collects physical and chemical properties of atmosphere-related processes, such as humidity, wind, and net ecosystem gas exchange. Precipitation data are collected by a Double Fence Intercomparison Reference (DFIR) near the tower.
Soil Sensor Measurements
This site has five soil plots placed in an array within the airshed of the flux tower. Photosynthetically Active Radiation (PAR) at soil surface, soil heat flux, solar radiation, and throughfall are measured at the soil surface in each soil plot. Soil moisture, soil temperature, and CO2 concentration are measured at multiple depths in each soil plot.
At terrestrial sites, field ecologists observe birds and plants, and sample ground beetles, mosquitoes, small mammals, soil microbes, and ticks. Lab analyses are carried out to provide further data on DNA sequences, pathogens, soils, sediments, and biogeochemistry. Learn more about terrestrial observations or explore this site's data products.
Field Site Data
Bureau of Land Management
Site Access Allowed
Site Access Details
Reseachers should coordinate with the site manager and submit a site research permit via Toolik Field Station.
NEON Field Operations Office
NEON Field Operations Address
3352 College Rd.
Fairbanks, AK 99709
NEON Field Operations Phone
Mean Annual Temperature
Mean Annual Precipitation
Dominant Wind Direction
Mean Canopy Height
Dominant NLCD Classes
Dwarf Scrub, Shrub/Scrub
Average number of green days
Average first greenness increase date
Average peak green date
Average first greenness decrease date
Average minimum greenness date
Number of Tower Levels
USGS Geology Unit
USGS Geology Name
Unconsolidated and poorly consolidated surficial deposits
USGS Lithologic Constituents
Alluvial, colluvial, marine, lacustrine, eolian, and swamp deposits
USGS Geology Age
Other Domain D18 Field Sites
Other Field Sites in AK