1. Adu J K and Oades J M 1978 Physical factors influencing decomposition of organic materials in soil aggregates. Soil Biol. Biochem. 10, 109–115.
2. Auten J T 1945 Relative influence of Sassafrass, Black locust, and Pines upon old-field soils. J. For. 43, 441–446.
3. Berg B 1992 Under vilka trädslag bildas humus. Skogsfakta Nr 10. SLU-Info, Swedish University of Agricultural Sciences, Uppsala. (In Swedish).
4. Billings W D 1938 The structure and development of old field shortleaf pine stands and certain associated physical properties of the soil. Ecol. Monogr. 8, 437–499.
5. Binkley D, Valentine D, Well C and Valentine U 1989 An empirical analysis of the factors contributing to 20-year decrease in soil pH in an old-field plantation of loblolly pine. Biogeochem. 7, 139–154.