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Stream chemistry in the New Jersey pinelands: The influence of precipitation and watershed disturbance
Author(s) -
Morgan Mark D.,
Good Ralph E.
Publication year - 1988
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/wr024i007p01091
Subject(s) - pine barrens , sulfate , environmental science , environmental chemistry , streams , precipitation , watershed , weathering , hydrology (agriculture) , disturbance (geology) , sediment , acid rain , chemistry , geology , ecology , geochemistry , geomorphology , geotechnical engineering , machine learning , meteorology , computer science , computer network , physics , organic chemistry , biology
Bulk precipitation chemistry in the New Jersey Pinelands from July 1984 to July 1986 was influenced by both marine and continental air masses. The marine air masses were less acidic and dominated by Cl − , Na + , and Mg +2 while the continental air masses were high in ions typical of acid rain in the northeastern United States (SO 4 −2 , H + , and NO 3 − ). Over the same period, Pinelands streams draining undisturbed watersheds were acidic and very low in dissolved substances. The dominant ions were Na + and Cl − , followed by SO 4 −2 , Mg +2 , H + , and Ca +2 . Streams draining watersheds disturbed by residential and agricultural development exhibited elevated concentration of Ca +2 , Mg +2 , K + , SO 4 −2 , and NO 3 − , and lower H + . The altered levels of each of these ions was directly related to inputs from human activities and illustrated the sensitivity of Pinelands ecosystems to disturbance. Using Cl − as a tracer, enrichment factors were calculated for the major solutes. In undisturbed streams the enrichment factors showed that Na + and K + were passed through the system and that H + , Ca +2 , NH 4 + , NO 3 − , and SO 4 −2 were retained. Of the measured materials only Mg +2 was exported from undisturbed streams, although previous work has shown that iron, aluminum, and organic matter are also exported. The retention of SO 4 −2 was probably related to sulfate reduction in the extensive wetland systems of the Pinelands. These data strongly support earlier work that suggested sediment weathering in the Pinelands contributes few of the measured ionic constituents to stream discharge. Undisturbed Pinelands stream chemistry appears to be highly dependent on precipitation input and is modified primarily by biological activity within this ecosystem.