HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wilcke, W. Articles by Amelung, W. Search for Related Content PubMed Articles by Wilcke, W. Articles by Amelung, W. Agricola Articles by Wilcke, W. Articles by Amelung, W.

Small-Scale Heterogeneity of Aluminum and Heavy Metals in Aggregates along a Climatic Transect

Institute of Soil Science and Soil Geography, Univ. of Bayreuth, Postbox 101251, 95440 Bayreuth, Germany

*Corresponding author (wolfgang.wilcke{at}uni-bayreuth.de).

ABSTRACT

Concentrations and forms of AI and heavy metals in aggregate core and surface fractions of forest soils in Central Europe differ significantly. The objectives of this study were to (i) test if there is a similar small-scale metal heterogeneity in topsoils of the native North American prairie and (ii) investigate the influence of climatic parameters on this heterogeneity. Aggregates of eight A horizons along a climatic transect in the North American prairie were separated into core and 0.5-mm-thick surface fractions. Seven forms of Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were determined in the aggregate fractions using a sequential extraction procedure. The differences of metal concentrations between aggregate surface and core fractions are 1 to 25% of the total concentrations of the core fractions. The percentages of easily extractable metals are up to 120% higher in the aggregate surface than in the core fractions. The percentages of the mainly silicate-bound metals (extractable only with strong acids) are up to 25% lower than in the core fractions. These results support the hypotheses that (i) preferential weathering of aggregate surfaces causes a shift from strongly to more weakly bound metal forms and (ii) atmospheric metal input is sorbed preferentially at the aggregate surfaces, and (iii) this input is weakly bound only. Lead is significantly enriched in the surface fractions compared with the cores, indicating ubiquitous input of Pb to the soils. The depletion of the mainly silicate-bound metals in the aggregate surface fractions compared with the core fractions correlates with the mean annual temperature and the mean annual precipitation, which both favor silicate weathering.

Received for publication October 4, 1995.

This article has been cited by other articles:

				D. B. Smith and C. Reimann Low-density geochemical mapping and the robustness of geochemical patterns Geochemistry: Exploration, Environment, Analysis, November 1, 2008; 8(3-4): 219 - 227. [Abstract] [Full Text] [PDF]

				M. K. Zhang, Z. L. He, D. V. Calvert, P. J. Stoffella, X. E. Yang, and Y. C. Li Phosphorus and Heavy Metal Attachment and Release in Sandy Soil Aggregate Fractions Soil Sci. Soc. Am. J., July 1, 2003; 67(4): 1158 - 1167. [Abstract] [Full Text] [PDF]