engleski

FRACTAL ANALYSIS OF SPATIAL VARIABILITY OF ORGANIC CARBON IN ANTHROPOGENIC SOILS. CASE STUDY: KASTELA BAY, CROATIA

Soil organic carbon (SOC) is a key variable of the soil, agriculture and whole environment. The spatial variation of SOC is controlled by many spatially independent processes and their complex interactions which operate on its own discrete scale. Understanding the causes and characteristics of SOC spatial variation can help knowing how to measure it and to design better site-specific management strategy or precision farming. The objectives of the research are to characterize spatial variability of SOC in the anthropogenic soils and identify the principal factors that determine its spatial pattern. In the total of 206 top-soil samples (0-30 cm) collected on a 4 960 ha of the anthropogenic soils at the Kastela Bay, Croatia, SOC was analyzed. The mean SOC content was 22.19 g C kg−1 and ranged between 7.75 and 40, 87 g C kg−1. The SOC has shown a multifractal behavior characterized with partial spatial indepedence over a scale of 5 000 m separated with break point. Estimated fractal parameters for SOC, derived by variogram method, for maximum distance between point par of 21 000 m, were: fractal dimension (D) 1.92, ordinate intercept - gamma (γ) 1.09 and associated coefficient of determination (R2 ) 0.50. The very high fractal D 2 indicated a very small spatial continuity of SOC. This has shown that short-range effects prevail over long-range ones in affecting the overall complexity of distribution and that variations of SOC at small scale are significant. The results of research showed that spatial variability of SOC, at selected scale, probably is related with the differences of parent material, composition of the colluvial deposits and its spatial periodicity as well as differences and repeatability of topography.

soil organic carbon ; fractal dimension ; break point

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