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Effects of Acidic and Neutral Sulfate Salt Solutions on Forest Floor Arthropods
Author(s) -
Craft C. B.,
Webb J. W.
Publication year - 1984
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1984.00472425001300030022x
Subject(s) - forest floor , decomposer , soil water , chemistry , environmental chemistry , soil acidification , litter , sulfate , salt (chemistry) , zoology , agronomy , ecosystem , soil ph , ecology , biology , organic chemistry
Acidic and neutral SO 4 2− solutions were applied to a mixed oak ( Quercus spp.) forest floor on Walker Branch Watershed in eastern Tennessee to study effects of increased acid deposition on decomposer arthropods and arthropod regulation of P cycling. Treatments consisted of ambient (no applications), 2 × (low), and 10 × (high) annual atmospheric inputs of SO 4 2− (as K 2 SO 4 ) and H + plus SO 4 2− (as KHSO 4 ). Arthropods were sampled monthly in litter and mineral soil. Soils were analyzed for Bray no. 2 P and for salt pH, NH 4 Cl exchangeable Al 3+ and K + , and water‐extractable SO 4 2− . Over a 14‐month period, the number of forest floor macroarthropods averaged 19% lower in the high SO 4 2− salt treatment compared with the control. Macroarthropod fungivores also were adversely affected by the high SO 4 2− salt treatment and by the high and the low KHSO 4 treatments. The effects of the high SO 4 2− treatment on macroarthropods may have resulted from a salt effect caused by the concentrated K 2 SO 4 applications (112 mmol K + m −2 per application). Microarthropod numbers increased significantly in response to the low K 2 SO 4 additions and to the high and low KHSO 4 treatments. Microarthropod fungivores, predators, and detritivores responded similarly. Comparison of microarthropod densities and soil K + concentrations suggested that the response resulted from a direct fertilizer effect of K + on arthropods or indirectly from an effect on microorganisms. Mineral soil pH, exchangeable Al 3+ , and Bray P were unaffected by the treatments. Soil pH (0–15 cm) was unaffected by the KHSO 4 applications because most of the H + addition was neutralized by the forest floor. Analysis of litter leachate during a single treatment interval (5 weeks) indicated that only 31% of the H + applied in the high KHSO 4 treatment reached the mineral soil. Although increased inputs of H + appear to have little effect on decomposer arthropods, effects of nonacidic SO 4 2− warrant further study.