PRINCIPAL INVESTIGATOR
      Gene E. Likens
      Institute of Ecosystem Studies

OTHERS INVOLVED
      see References

BEGIN DATE
       June 1967

END DATE
      On-going

LOCATION
       NW Inlet to Mirror Lake

LOCATION DESCRIPTION
       Collected from a small riffle approximately 10m upstream from the lake and 30m downstream of the USGS stream-gauging flume. This sub-catchment (35 ha area) of the Mirror Lake watershed contains 3 seasonal homes and one unpaved (un-salted in winter) road. 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).

DATA DESCRIPTION
       Concentrations (mg/L) in weekly streamwater samples. Base cation data are available since 1967: pH since 1968. 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.

SAMPLING DESIGN
       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.

REFERENCES

• Likens, G. E. 1972. Mirror Lake: its past, present and future? Appalachia 39(2):23- 41.
• Likens, G. E. (editor). 1985. An Ecosystem Approach to Aquatic Ecology: Mirror Lake and its Environment. Springer-Verlag New York Inc. 516 pp.
• Buso, D.C., G.E. Likens, and J.S. Eaton. 2000. Chemistry of precipitation, streamwater, and lakewater from the Hubbard Brook Ecosystem Study: a record of sampling protocols and analytical procedures. Gen. Tech. Rep. NE-275. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northeastern Research Station. 52 p.

ACCESS
       Public, from 6-1967 to 12-1995. 5-year withholding policy in effect for these data.

DATA LOCATION
      Institute of Ecosystem Studies, Robert S. Pierce Ecosystem Laboratory, Hubbard Brook Experimental Forest, W.Thornton, NH

LAST UPDATED
      April, 2001

CONTACT PERSON
      Gene Likens
      Institute of Ecosystem Studies
      Millbrook, NY 12545
      Telephone: (845) 677-5343
      E-mail: LikensG@ecostudies.org

VARIABLES
      Records: 1017 samples
      Columns: supplied with the following headers:
            ws - watershed (designated as 72)
            year - year
            mo - month
            dy - day
            Ca - calcium concentration in mg/L
            Mg - magnesium concentration in mg/L
            K - potassium concentration in mg/L
            Na - sodium concentration in mg/L
            NH4 - ammonium concentration in mg/L
            pH - pH
            SO4 - sulfate concentration in mg/L
            NO3 - nitrate concentration in mg/L
            Cl - chloride concentration in mg/L
            PO4 - phosphate concentration in mg/L (soluble-reactive phosphate)
            SiO2 - silica concentration in mg/L (measured as silicate)

CODES
       Missing data are coded with -3

DATA FILE NAME(S)
      ASCII file name: ml-nw.txt