Vegetation Warming Experiment: 15N Uptake Experiment Water-Extractable Soil Nutrients, Utqiagvik (Barrow), Alaska, 2018

DOI: https://doi.org/10.5440/1784755
NGEE Arctic Record ID: NGA260
Data Version: 1.0
Abstract

This dataset consists of measured water-extractable carbon and nutrients measured on soils collected from warming experiment enclosures and paired control plots. Harvest types include both natural abundance and enriched soils.

Vegetation warming chambers (Zero Power) were deployed on the Barrow Environmental Observatory (BEO), Utqiaġvik, Alaska. These chambers (Figure 1) consistently elevated air temperatures by approximately 4°C using a self-venting system described by Lewin et al (2017). Five chambers were deployed from June 17, 2018 to September 24, 2018 on the BEO within a 1 km2 area centered on 71.275N, -156.641W. Each chamber was co-located with an ambient plot where temperatures were not manipulated on patches of tundra containing the target species Arctagrostis latifolia. An intensive field campaign in late July investigated the impact of warming had on A. latifolia biomass, chemistry, and uptake of 15N labeled ammonia that was injected into the surface soils for one week. Initial measurements were taken on July 21, 2018. Harvest occurred on July 27, 2018. Water-extractable nutrients in soils were measured in July following harvests of A. latifolia plants and underlying soils. Availability of ammonia, nitrate, and phosphate throughout the growing season was measured by extracting nutrients bound to anion and cation binding resins deployed from July through September. Environmental variables (thaw depth, surface soil temperatures, surface soil moisture) were measured. Leaf traits and root traits of A. latifolia were also measured.

The Next-Generation Ecosystem Experiments: Arctic (NGEE Arctic), was a research effort to reduce uncertainty in Earth System Models by developing a predictive understanding of carbon-rich Arctic ecosystems and feedbacks to climate. NGEE Arctic was supported by the Department of Energy’s Office of Biological and Environmental Research.

The NGEE Arctic project had two field research sites: 1) located within the Arctic polygonal tundra coastal region on the Barrow Environmental Observatory (BEO) and the North Slope near Utqiagvik (Barrow), Alaska and 2) multiple areas on the discontinuous permafrost region of the Seward Peninsula north of Nome, Alaska.

Through observations, experiments, and synthesis with existing datasets, NGEE Arctic provided an enhanced knowledge base for multi-scale modeling and contributed to improved process representation at global pan-Arctic scales within the Department of Energy’s Earth system Model (the Energy Exascale Earth System Model, or E3SM), and specifically within the E3SM Land Model component (ELM).

 

Authors
Verity Salmon (salmonvg@ornl.gov) 0000-0002-2188-551X
Joanne Childs (childsj@ornl.gov) 0000000220027337
Colleen Iversen (iversencm@ornl.gov) 0000000182933450
Breann Spencer (shangping888@gmail.com)
Alistair Rogers (arogers@bnl.gov) 0000-0001-9262-7430
Kim Ely (kely@bnl.gov) 0000-0002-3915-001X
Shawn Serbin (sserbin@bnl.gov) 0000-0003-4136-8971
---more---
Dataset Citation
Verity Salmon, Joanne Childs, Colleen Iversen, Breann Spencer, Alistair Rogers, Kim Ely, Shawn Serbin. 2021. Vegetation Warming Experiment: 15N Uptake Experiment Water-Extractable Soil Nutrients, Utqiagvik (Barrow), Alaska, 2018. Next Generation Ecosystem Experiments Arctic Data Collection, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, USA. Dataset accessed on [INSERT_DATE] at https://doi.org/10.5440/1784755.
Dates
2018-07-27 - 2018-07-27
Geographic Location
NGEE Arctic Utqiagvik (Barrow), Alaska
North71.35
South71.2
East-156.4
West-156.7
Place Keywords:
Utqiagvik , Alaska | Barrow Environmental Observatory (BEO), Alaska
Subject Keywords:
N/A
GCMD Keywords
EARTH SCIENCE > LAND SURFACE > SOILS
EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > WATER QUALITY/WATER CHEMISTRY
Methodology
Warming treatment was implemented in Utqiaġvik, Alaska on the Northern coastal plain using zero power warming chambers that elevate air temperatures by approximately 4°C. Details on design and impact of the warming chambers are documented in Lewin and others (2017). At one location within each chambered plot and co-located ambient plot, 9 x 9 cm areas of A. latifolia were harvested. A serrated knife was used to cut the organic layer (approximately 8 cm in depth) into a square block. Organic soil and intact vegetation were then removed together. To sample roots and soils beneath the organic layer, a soil core was collected from within the footprint of the harvested block (diameter=5 cm). Soil cores spanned the bottom of the organic horizon to frozen ground. Immediately following collection, soil cores were separated in into 5 cm depth intervals. All equipment was wiped down with ethanol between plots to prevent isotopic contamination. Organic horizon samples were taken to the field lab where A. latifolia biomass was separated from organic soils within 48 hours and sorted by tissue type (attached litter, blades, sheaths, inflorescences, rhizomes, fine roots). Plant materials were then dried at 65°C for 24 hours. In the field lab, organic soil samples and soil cores were also subsampled for bulk density, gravimetric water content, and bulk soil %C and %N. All soil samples were then frozen and shipped to Oak Ridge National Laboratory, Oak Ridge, TN (ORNL) for further processing At two replicate locations within each chambered plot and co-located ambient plot, a trace amount of 15N was introduced to the soil pool with a 15N-NH4Cl solution (2.4 mmol 15N-NH4Cl L-1; Sigma Aldrich >= 98 atom% 15N, Lot # MBBC2459). The solution was injected using a spinal port needle inserted to 3 cm depth. Each labeled area was 12 x 12 cm and injections were performed at 3 cm intervals in a gridded pattern. At each of the 16 injection points, a 5 ml aliquot of the 15N-NH4Cl solution was injected. Test injections of food coloring into the soil at this site revealed that the diffusion of this solution volume was approximately 1.5 cm- this method therefore ensured we applied a consistent, even label of +200 mg 15N m-2 (similar to loading in McKane et al., 2002). To protect 15N-labeled vegetation from herbivores, a wire mesh cage was installed around each injection area. After a period of six days, the inner 9 x 9 cm of each 15N-labeled areas were harvested following the protocol described above. At ORNL, water-extractable pools of NH4, NO3, DOC, and TN were measured on 10 g fresh soil for each depth interval. Soil subsamples were thawed and extracted with 50 ml of nanopure water, agitated for 60 mins, and then vacuum extracted through Whatman GF/A filters (1.6 µm pore size). Soil extract solution was then frozen prior to analysis for NH4, NO3 and PO4 on a a Lachat 8500 autoanalyzer (Hach Company, Loveland, CO). The methodological range for ammonium was 0.01 to 1 mg (Lachat method 12-107-06-1-A). The methodological range for phosphate was 0.10ug to 500ug (Lachat method 10-115-01-1-B modified with a 60cm sample loop) and TN and DOC on a Shimadzu TOC-l CSH/CSN analyzer. Water blanks were agitated and filtered alongside soil samples and analyzed for analytes. Values presented here have been blank-corrected by subtracting the average blank concentrations from all soil extracts resin concentrations. If blank correction resulted in a negative number, values were converted to zero.
Related References
Verity Salmon, Joanne Childs, Colleen Iversen, Breann Spencer, Alistair Rogers, Kim Ely, Shawn Serbin. 2021. Vegetation Warming Experiment: 15N Uptake Experiment Arctagrostis latifolia Canopy Traits, Utqiagvik (Barrow), Alaska, 2018. Next Generation Ecosystem Experiments Arctic Data Collection, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, USA. https://doi.org/10.5440/1784759
Verity Salmon, Joanne Childs, Colleen Iversen, Breann Spencer, Alistair Rogers, Kim Ely, Shawn Serbin. 2021. Vegetation Warming Experiment: 15N Uptake Experiment Environmental Observations and Thaw Depth, Utqiagvik (Barrow), Alaska, 2018. Next Generation Ecosystem Experiments Arctic Data Collection, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, USA. https://doi.org/10.5440/1784757
Verity Salmon, Joanne Childs, Colleen Iversen, Breann Spencer, Alistair Rogers, Kim Ely, Shawn Serbin. 2021. Vegetation Warming Experiment: 15N Uptake Experiment Arctagrostis latifolia Biomass and Chemistry, Utqiagvik (Barrow), Alaska, 2018. Next Generation Ecosystem Experiments Arctic Data Collection, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, USA. https://doi.org/10.5440/1784750
Verity Salmon, Joanne Childs, Colleen Iversen, Breann Spencer, Alistair Rogers, Kim Ely, Shawn Serbin. 2021. Vegetation Warming Experiment: 15N Uptake Experiment Arctagrostis latifolia Root Traits, Utqiagvik (Barrow), Alaska, 2018. Next Generation Ecosystem Experiments Arctic Data Collection, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, USA. https://doi.org/10.5440/1784749
Verity Salmon, Joanne Childs, Colleen Iversen, Breann Spencer, Alistair Rogers, Kim Ely, Shawn Serbin. 2021. Vegetation Warming Experiment: 15N Uptake Experiment Arctagrostis latifolia 15N Uptake, Utqiagvik (Barrow), Alaska, 2018. Next Generation Ecosystem Experiments Arctic Data Collection, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, USA. https://doi.org/10.5440/1784751
Verity Salmon, Joanne Childs, Colleen Iversen, Breann Spencer, Alistair Rogers, Kim Ely, Shawn Serbin. 2021. Vegetation Warming Experiment: 15N Uptake Experiment Inorganic Nitrogen and Phosphorus on Resins, Utqiagvik (Barrow), Alaska, 2018. Next Generation Ecosystem Experiments Arctic Data Collection, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, USA. https://doi.org/10.5440/1784752
---more---
Related Identifiers
N/A
Metadata Contact
Contact information for the individual or organization that is knowledgeable about the data.
Person: Hannah Blanco
Organization: Oak Ridge National Laboratory
Email: blancohl@ornl.gov
Point of Contact
Contact information for the individual or organization that is knowledgeable about the data.
Person: Verity Salmon
Organization: Oak Ridge National Laboratory
Email: salmonvg@ornl.gov
Dataset Usage Rights
Public Datasets

This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0.

See the NGEE Arctic Data Policies for more details https://ngee-arctic.ornl.gov/data-policies.

Distribution Point of Contact
Contact: Data Center Support
Organization: Next-Generation Ecosystem Experiments (NGEE) Arctic Project, Oak Ridge National Laboratory
Email: support@ngee-arctic.ornl.gov