Distribution of aluminium fractions in acid forest soils: influence of vegetation changes

Abstract

This study examines aluminium as a potentially phytotoxic element in acidic forest soils. Concentrations of Al forms in soils are generally controlled by soil chemical conditions, such as pH, organic matter, base cation contents, etc. Moreover, soil conditions are influenced by the vegetation cover. This study analyzed the distribution of Al forms in soils after changes in vegetation. HPLC/IC was used for the separation of three Al fractions in two soil extracts according to their charge. An aqueous extract (AlH2O) simulated the natural soil conditions and bioavailable Al fractions. Potentially available Al form was represented by a 0.5 M KCl extract (AlKCl). We demonstrated that the vegetation type influences the concentrations of different Al fractions, mainly in the surface organic horizons. Differences were more common in the KCl extract. The trivalent fraction was less influenced by vegetation changes than the monoand divalent fractions. Afforestation increased the concentrations of AlKCl and AlH2O. In contrast, grass expansion after deforestation led to significantly decreased concentrations of AlKCl and AlH2O. Concentrations of AlH2O in organic horizons were higher in spruce forest than in beech forest. A long-term effect of liming on soil pH and concentrations of potentially toxic Al fractions was not apparent. The results provide information on the variations of Al fractions distributions following vegetation type changes and indicate the existence of some natural mechanisms controlling Al toxicity. Furthermore, the results can be used in the management of forested areas endangered by soil acidification.

Modeling and Assessing the Spatial and Vertical Distributions of Potentially Toxic Elements in Soil and How the Concentrations Differ

“…All of the PTEs showed relatively high variability in both soil horizons except for the Fe (46.31%) in the organic soil. The spatial distribution of the heterogeneity of the PTEs suggest that the metals are enriched by intensive sources of from the industrial, commercial, domestic and agricultural sectors [ 3 , 5 , 13 ]. However, the content of the PTEs varies between the soil horizons, yet the organic soil had higher mean values across the metals, excluding Mn.…”

“…The annual precipitation reaches about 1500 mm at the top of the mountains. Most areas are covered by forests ( Figure 1 ), though in some areas, the regeneration of trees has been slow after intensive forest decline in the 1980s and 1990s [ 5 , 13 ]. Coniferous species, namely Norway spruce ( Picea abies ) and the European beech ( Fagus sylvatica ), are key forest trees.…”

“…The presence of PTEs in soil has been attracting reasonable attention because of their ecological and biological risks. Several studies in different biomes have been performed to identify the sources of PTEs in the soils [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ].…”

Effect of natural and anthropogenic acidification on aluminium distribution in forest soils of two regions in the Czech Republic

“…Soil samples from 52 selected sites were then used for comparison with soils from the Novohradské Mountains. The pure spruce forest plots were selected to eliminate the differences between soils of spruce and beech forests documented by Tejnecký et al (2010) and Pavlů et al (2018). The sampling plots with a forest age exceeding 40 years were preferred to nullify any clear-cut effect.…”

“…A different situation was found in the mineral horizons. Only pedogenetically similar horizons were compared (Pavlů et al 2018). Hydromorphic or humus-enriched spodic B horizons were excluded from statistical analysis.…”