Harvard Forest

Data Archive

HF429

Inorganic Nutrient Concentrations in Forested Headwater Streams at Harvard Forest since 2017

Related Publications

Data

• hf429-01: stream nitrogen and phosphorus data (preview)
• hf429-02: stream silica data (preview)

Overview

• Lead: Robinson Fulweiler, David Orwig
• Investigators: Melissa Hagy, Timothy Maguire, Mark VanScoy
• Contact: Information Manager
• Start date: 2017
• End date: 2022
• Status: ongoing
• Location: Prospect Hill Tract (Harvard Forest)
• Latitude: +42.53 to +42.55 degrees
• Longitude: -72.20 to -72.17 degrees
• Elevation: 280 to 420 meter
• Datum: WGS84
• Taxa:
• Release date: 2024
• Language: English
• EML file: knb-lter-hfr.429.5
• DOI: digital object identifier
• EDI: data package
• DataONE: data package
• Related links:
• Carbon Biogeochemistry of Forested Headwater Streams at Harvard Forest 2006-2007
• Prospect Hill Hydrological Stations at Harvard Forest since 2005
• Study type: long-term measurement
• Research topic: watershed ecology
• LTER core area: mineral cycling, disturbance patterns
• Keywords: ammonium, biogeochemistry, hemlock, hemlock woolly adelgid, nitrate, nitrogen, phosphorus, silica, streams, water quality
• Abstract:

  For the past 8000 years hemlock has been the foundation species throughout the northeast. The unique functional characteristics of Hemlock have dictated biogeochemical fluxes from terrestrial to aquatic ecosystems (Ellison et al. 2005). Unfortunately, it is currently in an irreversible decline due to the Hemlock Wooly Adelgid and the consequences on riparian ecology are unknown but likely profound (Adams et al. 2012). Red maple, black birch, and northern red oak are some of the most abundant trees in southern New England and are poised to replace hemlock across the landscape (Orwig et al. 2012). Decline and loss of hemlock, and its replacement with hardwood species containing different functional traits are expected to lead to changes in litterfall inputs, forest evapotranspiration, surface water hydrology, including seasonal streamflow/stormflow dynamics, stream temperature, decomposition, and nutrient release (Ellison et al. 2005; Ford and Vose 2007; Guswa and Spence 2011;Brantley et al. 2014). This anticipated shift to hardwoods has far reaching effects as it will significantly alter receiving water primary productivity and food web structure (Humborg et al. 2000, Garnier et al. 2010) by changing watershed N:P:Si export ratios and nutrient availability downstream (e.g., Currie et al. 1996, Fulweiler and Nixon 2005, Carey and Fulweiler 2013).

  The goal of this ongoing project is to quantify watershed export of inorganic nutrients overtime from the three gauged forested streams at Harvard Forest. To do this we aim to collect samples weekly and then we will calculate monthly, seasonal, and annual changes in inorganic nutrient export. Further we are investigating inorganic nutrient concentration as well as flux vs. stream discharge patterns to better understand the role of physical vs. biological processes in driving watershed nutrient export.

• Methods:

  Inorganic nutrient samples are collected weekly from three gauged streams: Nelson Brook Big Weir, Arthur Brook Lower Pipe, and Arthur Brook Upper Pipe.

  hf429-01-hf-streams-np.csv

  Water samples are filtered using 25 mm Whatman GF/F filters with the filtrate collected into 60 mL polypropylene bottles for dissolved inorganic nitrogen and phosphorus and frozen at -18 °C until analysis.

  All samples were measured using Seal AA3 Autoanalyzer using the Berthelot reaction for ammonia (SEAL Method G171-96), sulfanilamide reaction under acidic conditions for nitrite (SEAL method G173-96) and nitrate reduction to nitrite with a copper-cadmium column for nitrate+nitrite or NOx (SEAL method G172-96). For orthophosphate we reduce to a blue phospho-molybdenum complex (SEAL method G175-96).

  Note that Nelson Brook samples contribute to rapid decline in cadmium column reduction efficiency. Two methods were used to alleviate this. The first was the standard addition method whereas an aliquot of sample (unknown) is compared to an aliquot of sample with known addition of standard (known). The values are plotted and the absolute value of the x-intercept is the concentration in the unknown. Due to time involved in running each sample twice, we switched to adding EDTA to the nitrate/nitrite ammonium chloride buffer and diluting samples to lower the sample effects on column reduction efficiency.

  hf429-02-hf-streams-si.csv

  Water samples for dissolved silica are filtered using 25 mm nitrocellulose filters and the filtrate is collected into 60 mL polypropylene bottles and stored at room temperature in the dark. All samples were measured using Seal AA3 Autoanalyzer using the molybdenum blue colorimetric method (SEAL method G-177-96 for SiO2).

• Organization: Harvard Forest. 324 North Main Street, Petersham, MA 01366, USA. Phone (978) 724-3302. Fax (978) 724-3595.

• Project: The Harvard Forest Long-Term Ecological Research (LTER) program examines ecological dynamics in the New England region resulting from natural disturbances, environmental change, and human impacts. (ROR).

• Funding: National Science Foundation LTER grants: DEB-8811764, DEB-9411975, DEB-0080592, DEB-0620443, DEB-1237491, DEB-1832210.

• Use: This dataset is released to the public under Creative Commons CC0 1.0 (No Rights Reserved). Please keep the dataset creators informed of any plans to use the dataset. Consultation with the original investigators is strongly encouraged. Publications and data products that make use of the dataset should include proper acknowledgement.

• License: Creative Commons Zero v1.0 Universal (CC0-1.0)

• Citation: Fulweiler R, Orwig D. 2024. Inorganic Nutrient Concentrations in Forested Headwater Streams at Harvard Forest since 2017. Harvard Forest Data Archive: HF429 (v.5). Environmental Data Initiative: https://doi.org/10.6073/pasta/ef6bf2d7414ebb6687b2318426d9edcb.

Detailed Metadata

hf429-01: stream nitrogen and phosphorus data

1. SampleDate: date
2. Site: location of stream, sample number and date
3. SiteCode: stream site
4. NH3_uM: ammonium. Values below detection limit of 0.08 uM are flagged. NA = sample not measured (unit: micromolePerLiter / missing value: NA)
5. NH3_Flag: ND = flag indicating value between 0 and 0.08 uM
6. NO2_uM: nitrite. Values below detection limit of 0.01 uM are flagged. NA = sample not measured (unit: micromolePerLiter / missing value: NA)
7. NO2_Flag: ND = flag indicating value between 0 and 0.01 uM
8. NOx_uM: nitrite + nitrate. Values below detection limit of 0.01 uM are flagged. NA = sample not measured (unit: micromolePerLiter / missing value: NA)
9. NOx_Flag: ND = flag indicating value between 0 and 0.01 uM
10. oP_uM: orthophosphate. Values below detection limit of 0.02 uM are flagged. NA = sample not measured (unit: micromolePerLiter / missing value: NA)
11. oP_Flag: ND = flag indicating value between 0 and 0.02 uM
12. NO3_uM: Values below detection limit of 0.01 uM are flagged. NA = sample not measured (unit: micromolePerLiter / missing value: NA)
13. NO3_Flag: ND = flag indicating value between 0 and 0.01 uM
14. Time_EST: time of sampling
15. location: name of stream
16. SampleType: sample type - nitrogen and phosphate. Filtered through GF/F into clean polypropylene bottle
17. SampleTakenBy: initials of person sampling
18. Notes: weather and flow description

hf429-02: stream silica data

1. Date: date
2. SiteID: location of stream, sample number and date
3. Site: stream site
4. Si_uM: silica. Detection limit is 0.02 uM. NA = Sample not measured (unit: micromolePerLiter / missing value: NA)
5. TimeEST: time of sampling
6. location: name of stream
7. SampleType: sample type - silica. Filtered through nitrocellulose filter into clean polypropylene bottle
8. SampleTakenBy: initials of person sampling
9. Notes: weather and flow description