Tuesday, 8 November 2005
7

Surface Aggregation in Sandy Forest Soils as Influenced by Disturbance and Recovery.

Noel Cawley, Willie Harris, and Joseph Prenger. University of Florida, 106 Newell Hall, PO Box 110510, Gainesville, FL 32611

Aggregation in sandy soils has not been extensively studied, but is a potentially sensitive indicator of ecological disturbance and recovery in sandy surface horizons. The objective of this study was to characterize the nature and abundance of aggregates found in the A-horizon of deep sandy forest soils ranging in extent of disturbance and time since disturbance. Aggregate abundance was assessed by a dry sieving method, as modified for sands from methods applied to loamy soils. Ignition of organic matter was used in conjunction with sieving in order to assess organic matter influence on aggregation. Aggregates were described and categorized qualitatively and photographed under a dissecting microscope. Results show that the aggregating agent is predominantly organic matter. Percent aggregates are under reported by correcting for sand because sand is a primary component of these aggregates. Aggregation developes within a few years after severe soils disturbance. Extant methods of determining aggregate size requires modification for sandy soils due to the delicate nature of aggregates in these soils.

Handout (.pdf format, 80.0 kb)

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