Monitoring: Ion Exchange Resin Columns for Measuring Throughfall and Bulk Deposition to Forests
Measurement of deposition in throughfall is a widely used method for estimating atmospheric deposition inputs to forest ecosystems. We have developed and tested a "passive" throughfall collector based on a mixed bed (cation and anion) ion exchange resin (IER) column. Information on the construction and use of these collectors is presented here.
Precipitation or throughfall samples are collected by a funnel or funnel with a snow tube, the solution is channeled through the resin column where ions are retained by the ion exchange resin. Ammonium and nitrate ions retained by the resin are then extracted and analyzed colorimetrically. Sulfate deposition can also be measured with the IER collectors using a modified extraction procedure. Studies have shown that the IER columns can be left in the field for as long as 12 months, although our standard protocol is to exchange the columns every 6 months.
Throughfall collector with resin tube covered with a protective "shade" tube
Throughfall collector with ion exchange resin column visible
Report with full description of how to build the collectors and deploy them in the field and of the processing and extraction of the resin columns after field exposure, laboratory analyses, and calculations of atmospheric deposition fluxes from the raw data.
The information provided here is for the convenience of interested parties. Mention of trade names or products is for information only and does not imply endorsement by the U.S. Department of Agriculture.
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