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Title: Nutrient leaching from conifer needles in relation to foliar apoplast cation-exchange capacity

Technical Report ·
OSTI ID:5387204

Limited evidence to date suggests that acidic precipitation promotes leaching of nutrient cations from conifer foliage. In order to evaluate the relative contribution of the apoplast cation exchange complex and symplast nutrient pools to the leached ions, the magnitude of potential foliar leaching in response to acidic precipitation was compared to foliar apoplast cation exchange capacity (CEC) for two conifer tree species (Pseudotsuga menziesii and Picea engelmanii). Leaching increased with decreasing pH and increasing time of immersion. At pH 2.1 and 3.1, equivalents of H+ depleted from the acidic solutions approximated equivalent of cations gained by the solutions. Maximum amounts leached were less than 40 micro equiv/g dry weight of needles for all ions combined. Measured foliar apoplast CEC for these species was approximately 120 micro equiv/g dry weight of needles. These relative magnitudes indicated that the apoplast provided the leached ions.

Research Organization:
Environmental Protection Agency, Corvallis, OR (United States). Environmental Research Lab.
OSTI ID:
5387204
Report Number(s):
PB-92-153378/XAB; EPA-600/J-92/081
Resource Relation:
Other Information: Pub. in Environmental Pollution, v75 p259-263 1992. See also PB90-132697 and PB90-245242. Prepared in cooperation with Agricultural Univ., Wageningen (Netherlands). Sponsored by NSI Technology Services Corp., Corvallis, OR. Environmental Research Lab
Country of Publication:
United States
Language:
English