Hubbard Brook Experimental Forest: Chemistry of Mirror Lake NE Inlet streamwater 1967 - 2010
Hubbard Brook Experimental Forest: Chemistry of Mirror Lake NE Inlet streamwater 1967 - 2010
Gene E. Likens
Cary Institute of Ecosystem Studies
2801 Sharon Turnpike
Millbrook, NY 12545

Phone: (845) 677-5343
Numerous studies have been conducted on Mirror Lake since the mid-1960s, including extensive physical, chemical, biological, and paleoecological research (Likens 1985). This data set includes concentrations (mg/L) in weekly collections of Northeast Inlet streamwater samples for base cations, pH, ammonium, anions, and dissolved silica.
KEYWORD SET: Hubbard Brook Ecosystem Study LTER
ammonium, calcium, chemistry, chloride, HBEF Mirror Lake Study, HBR, Hubbard Brook LTER, lake, magnesium, nitrate, pH, phosphate, potassium, profile, silica, sodium, sulfate.
KEYWORD SET: LTER Core Research Areas
inorganic nutrients.
NE Inlet to Mirror Lake
West bounding coordinate: -71.696076
East bounding coordinate: -71.689735
North bounding coordinate: 43.945922
South bounding coordinate: 43.940460
Collected from a small waterfall 10m above the USGS stream-gauging flume, approximately 30m upstream from the lake. This small, sub-catchment (2.6 ha area) of the Mirror Lake watershed has been contaminated heavily by road salt (NaCl) from the adjacent Interstate highway (I-93), which opened in 1971. Numerous studies have been conducted on Mirror Lake since the mid-1960s, including extensive chemical, biological, and paleoecological research which are described in detail in the book: An Ecosystem Approach to Aquatic Ecology (Likens, 1985).
Samples are collected in acid-washed, deionized water-rinsed, polyethylene bottles. The normal sampling interval is weekly, with more frequent samples taken at times of increased discharge. At low flows (drought conditions), samples may be taken from undisturbed pools by clean polystyrene syringe.
Concentrations (mg/L) in weekly streamwater samples. Base cations and pH are available since 1967. Ammonium, anions, and dissolved silica have been measured routinely since 1970, and phosphate was determined routinely first in 1972, although some data are available prior to these dates for each solute.
  • Buso, D.C., Likens, G.E., and Eaton, J.S. 2000. Chemistry of precipitation, streamwater, and lakewater from the Hubbard Brook Ecosystem Study: a record of sampling protocols and analytical procedures. USDA Forest Service, Northeastern Research Station Gen. Tech. Rep. NE-275. 52 pp.USDA Forest Service, Newtown Square, PA.
  • Buso, D.C., Likens, G.E., LaBaugh, J.W., and Bade, D.L. 2009. Nutrient dynamics. In [Eds.], Mirror Lake: Interactions among Air, Land and Water, 69-203University of California Press.
  • Likens, G.E. 1972. Mirror Lake: its past, present and future?. Appalachia 39(2):23-41.
  • Likens, G.E. 1985. An Ecosystem Approach to Aquatic Ecology: Mirror Lake and its Environment.
  • Likens, G.E., and Buso, D.C. 2010. Salinization of Mirror Lake by road salt. Water, Air and Soil Pollution 205:205-214.
  • Rosenberry, D.O., Bukaveckas, P.A., Buso, D.C., Likens, G.E., Shapiro, A.M., and Winter, T.C. 1999. Migration of road salt to a small New Hampshire lake. Water, Air, and Soil Pollution 109:179-206.
Data Access Guidelines for Mirror Lake Datasets

We are happy to share these data on the chemistry of Hubbard Brook ecosystems. The public dissemination of these data that we have collected is a responsibility that we take very seriously. As stewards of these long-term data, our highest priorities are:

a. to maintain the integrity of these long-term data;

b. to allow adequate time for the analysis, quality assurance, and publication of results by principal investigators;

c. to acknowledge properly and responsibly the appropriate funding sources.

Therefore, it is HBES policy to make these data available on this web page two years after the date of collection. Also, in sharing these data with users like yourself, we ask that you adhere to the following guidelines as a matter of common courtesy and ethical responsibility:

1. Please inform us in advance of your interest and plans for use of these data (

2. The sources of funding used to collect these data must be acknowledged properly. We will provide the appropriate information when we learn what data are being used.

3. We would like to review any manuscripts that utilize extensive amounts (e.g. multiple years) of these data. If data use is extensive, or if these data have not been published previously, it may be appropriate for us to be included as authors on publication that are generated given the additional requirements from us for analysis and interpretation.

Data Use Policy

The re-use of scientific data has the potential to greatly increase communication, collaboration and synthesis within and among disciplines, and thus is fostered, supported and encouraged. Permission to use this dataset is granted to the Data User free of charge subject to the following terms:

1) Acceptable use. Use of the dataset will be restricted to academic, research, government or other not-for-profit professional purposes.

2) Redistribution. The data and metadata are provided for use by the Data User. The Data User will not redistribute the original Data Set or metadata to others without the explicit permission of the Principal Investigator.

3) Citation. It is considered a matter of professional ethics to acknowledge the work of other scientists. Thus, the Data User will properly attribute the Data Set in any publications or in the metadata of any derived data products that were produced using the Data Set. Citation should take the following general form: Creator, Year of Data Publication, Title of Dataset, Publisher, Dataset identifier.

Citation example: Holmes, R.T. 2012. Bird Abundances at Hubbard Brook (1969-2010) and on three replicate plots (1986-2000) in the White Mountain National Forest. Durham, NH. Hubbard Brook Data Archive [Database]. (23 July 2012)

4) Acknowledgment: The Data User should acknowledge any institutional support or specific funding awards referenced in the metadata accompanying this dataset in any publications where the Data Set contributed to its content. Acknowledgments should identify the supporting party, the party that received the support, and any identifying information such as grant numbers.

Acknowledgment example: Data on [topic] were provided by [name of PI] on [date]. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station, Newtown Square, PA. Significant funding for collection of these data was provided by [agency]-[grant number], [agency]-[grant number], etc.

5) Consultation and questions. Data users are strongly encouraged to consult with the Principal Investigator(s) who collected these data for further information. Also, when appropriate, Data Users should consider including the Principal Investigator as a collaborator and/or co-author in the use of these data.

6) Notification. The Data User will notify the Principal Investigator of any publication or derivative work based on the Data Set. The Data User will also provide the Principal Investigator and/or the administrator of the Hubbard Brook Ecosystem Study with a pdf or two reprints of any publication(s) resulting from use of the Data Set.

7) Disclaimer. While substantial efforts are made to ensure the accuracy of data and documentation contained in this Data Set, complete accuracy of data and metadata cannot be guaranteed. All data and metadata are made available "as is". The Data User holds all parties involved in the production or distribution of the Data Set harmless for damages resulting from its use or interpretation.

8) Terms of Agreement. By accepting this Data Set, the Data User agrees to abide by the terms of this agreement. The Data Owner shall have the right to terminate this agreement immediately by written notice upon the Data User's breach of, or non-compliance with, any of its terms. The Data User may be held responsible for any misuse that is caused or encouraged by the Data User's failure to abide by the terms of this agreement.


Information Manager, Hubbard Brook LTER
234 Mirror Lake Road
North Woodstock, NH 03262

Phone: (603) 726-8902

Data file: ml-ne.txt
Description: Mirror Lake chemistry of NE inlet streamwater
Notes on Data: These samples are physically located at the Robert S. Pierce Laboratory Hubbard Brook Experimental Forest, N. Woodstock, NH. NOTE REGARDING NITRATE DATA: After careful and exhaustive inter- and intra-laboratory tests we determined that nitrate concentrations in stream water were no longer remaining stable after collection, as they had in the past (see Buso, Likens and Eaton 2000). It is possible that the biological community in some streams of the HBEF has changed in recent years, affecting the nitrate concentration in complicated ways. While there was no systematic bias to the data, the situation occurred primarily during summer, when nitrate concentrations and streamflows are very low. Thus, we urge some caution in using the streamwater nitrate data collected since 2006, when nitrate stability was last confirmed. In 2013, new protocols were instituted to prevent decay of nitrate concentrations after collection and the problem has been resolved. There is no evidence that nitrate concentrations in the long-term precipitation record have been affected.
ColumnVariableDescriptionUnitsCoded?Missing value label
1wsWatershed (designated as 71)noneynone
5Cacalcium concentration in mg/LmilligramPerLitern
6Mgmagnesium concentration in mg/LmilligramPerLitern
7Kpotassium concentration in mg/LmilligramPerLitern
8Nasodium concentration in mg/LmilligramPerLitern
9NH4ammonium concentration in mg/LmilligramPerLitern
11SO4sulfate concentration in mg/LmilligramPerLitern
12NO3nitrate concentration in mg/LmilligramPerLitern
13Clchloride concentration in mg/LmilligramPerLitern
14PO4phosphate concentration in mg/L (soluble-reactive phosphate)milligramPerLitern
15SiO2silica concentration in mg/L (measured as silicate)milligramPerLitern


Variable: ws

Missing Value Code
Code Explanation
Data missing or not taken at this time
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