NERC Foliar Chemistry Database

This interactive site provides access to a large database of foliar chemistry for the northeastern US. The elements and compounds in the databse are Ca, Al, Mg, Mn, P, K, Sr, nitrogen, lignin, cellulose, hydrogen, and carbon.

This data can be used to model the growth of forests, or simulate decline if there is one nutrient in short supply. For example, from field data collection in the northeast, we know that nitrogen concentration in foliage is closely related to the growth rate of woody biomass.

Environmental science, biology, botany, chemistry, general science.

Comparison of forests, evaluation of forest health, relationship of forest growth to external factors (e.g. fertilization, other nutrients.)

- Using data to graph foliar chemistry.
- Using foliar chemistry as inputs to models of tree biomass.

This data is raw data with column headers, provided as a comma-separated text file. It can be viewed online as a table. There are also graphic images produced.

Data viewing and download is a simple registration—your email, your name and address and a login ID and password that you choose. To obtain data, login and go to the View Data tab. Select year, state, species, tree or plot level, and an element or compound. Average values are returned on the webpage with links to download all the values, which could be put into a spreadsheet. There is also a link to a graph of all the values. The link to download the data as a comma-separated file requires the user to use the browser's "save as" menu item under "File".

One use for the data could be to select different plots, or species and compare the graphs made by the website of their particular elements. From the download of the data into a spreadsheet, a user could compare graphs of multiple years or plots or any of the other selection criteria.

The NERC Foliar Chemistry website is designed for data retrieval and does not include a data manipulation feature. Search results can be saved as a comma separated file and imported into a spreadsheet. This would allow for the comparison of different species, years, geographic extent, etc using a spreadsheet application or other analysis tool.

Foliar chemistry is the chemical analysis for specific elements and compounds in the leaves or needles of trees.
Units - concentration by weight (%), ppm (parts per million)

The website has a tab for methods used to determine the foliar chemistry.

• Aber, J.D., CL. Goodale, S.V. Ollinger, M.-L. Smith, A.H. Magill, M.E. Martin, R.A. Hallett, J.L. Stoddard, and Northeastern Ecosystem Research Cooperative Participants. 2003. Is nitrogen deposition altering the nitrogen status of northeastern forests? Bioscience 53:375-389.
• Hallett, R.A., Martin, M.E., and Hornbeck, J.W. 1997. Predicting elements in white pine and red oak foliage with near infrared reflectance spectroscopy. Journal of Near Infrared Spectroscopy.
• Martin, M.E. and Aber, J.D. 1994. Analyses of forest foliage III: Determining nitrogen, lignin and cellulose in fresh leaves using near infrared reflectance data. Journal of Near Infrared Spectroscopy 2 : 25-32.
• McLellan, T., Martin, M.E., Aber, J.D., Melillo, J.M., Nadelhoffer, K.J., and Dewey, B. 1991. Comparison of wet chemistry and near infrared reflectance measurements of carbonfraction chemistry and nitrogen concentration of forest foliage. Canadian Journal of Forest Research 21 : 1689-1693.

Education resources about foliar chemistry projects:

Seedling Canopy Chemistry, 1992-1993 (ACCP) https://daac.ornl.gov/cgi-bin/dsviewer.pl?ds_id=422

Canopy Chemistry Study [ftp://popo.jpl.nasa.gov/pub/docs/workshops/93_docs/29.PDF]