Factors influencing the spatial pattern of the ash content of bog birch forest litter

The ash stock in forest litter influences the fertility of forest soil and should be studied. Litter samples were taken at 70 locations within a 270x60 metre transect in 2004-2007 in the bog birch forest, western Siberia. A geostatistical model with external trend was applied to describe the spatial pattern of the ash mass (kg m-2) on the forest floor. Hydrological factors, used as explanatory variables in an external trend equation, account for the main portion of spatial variation (83% and 49% in the years of, respectively, low and high spring flooding). Covariance structure of the data, connected with patterns of vegetation and silt deposits, explains the smaller portion of spatial variation (12% and 38%). The unexplained variation is minor (5% and 13%). © 2010 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Spatial Statistics 2011