title: Self-Affinity, Self-Similarity and Disturbance of Soil Seed Banks by Tillage.
abstract: Soil seed banks were sampled in undisturbed soil and after soil had been disturbed by tillage (tine, harrow or plough). Seeds were sorted by size and shape, and counted. Size-number distributions were fitted by power law equations that allowed the identification of self-similarity and self-affinity. Self-affinity and thus non-random size-number distribution prevailed in undisturbed soil. Self-similarity and thus randomness of size-number distribution prevailed after tillage regardless of the intensity of disturbance imposed by cultivation. The values of fractal dimensions before and after tillage were low, suggesting that short-term, short-range factors govern size-number distribution of soil seed banks.
authors.affiliation: Department of Biology, School of Sciences and Technology, University of Évora, Ap. 94, Évora 7002-554, Portugal. lsdias@uevora.pt.
authors.forename: Luís S
authors.initials: LS
authors.lastname: Dias
keywords: disturbance; fractal; seed shape; seed size; self-affinity; self-similarity; soil seed banks; tillage