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Forest soil acidification assessment using principal component analysis and geostatistics
Abstract
Soil acidification and consequent Al release is a problem particularly under forests in mountainous areas of the Czech Republic. It is controlled by a number of factors, like acid deposition, forest type, parent rock, altitude, etc. The Jizera Mountains region presents an area heavily influenced by acidification and forest decline. This paper focused on the effect of stand factors on spatial distribution of soil characteristics of the surface organic (O) and sub-surface (B) horizons from 98 sites using a combination of principal component analysis (PCA) and geostatistics. In the PCA, five principal components (PC) describing more than 70% of total variation were selected. The properties of the O and B horizons (pH, C, N, and S content, potentially dangerous Al forms) were in most cases separated, suggesting different processes and effects in each horizon. Spatial variation of PC scores was analysed using variograms, maps of their distribution were created using kriging. Spatial correlation with stand factors (altitude, slope aspect, forest type and age, soil unit, liming, and grass cover) was analysed using cross-variograms. The surface horizons are more sensitive to external influence (acid deposition, liming, grass expansion) and their spatial variation is stronger. The B horizons are more influenced by forest type (beech vs. spruce) and age, and by soil units (cambic vs. spodic horizons). The effect of stand factors is complex and often indirect. Nevertheless, used combination of pedometrical methods provided concise information about spatial variation and relationships between soil characteristics and the effect of stand factors.
... The static modelling of dependences between abiotic predictors and the forest receptor was based on the statistical selection of the most mutually correlating quantities from the general matrix of variables and evaluation of their interrelationships (Borůvka et al. 2007). The modelling was conducted by multivariate exploratory data analysis (MEDA), canonical correlation analysis (CCA) and linear regression (LR). ...
... A coherent underestimated approximation in the specific forest ecosystem properties occurred in the Šumava Mts., Tábor Hillycountry, Křivoklát Hillycountry, Doupov Mts., Ore Mts., in the western half of the Lužice Mts., in the Jizera Mts., Rychleby Mts., in the western parts of Hrubý Jeseník Mts., in the eastern Drahany Upland, in the central part of Chřiby Mts., Hostýnsko-vsetínské vrchy Hills, and along the Radhošť Plateau of the Moravian-Silesian Beskids continually. The underestimated approximation in the forest ecosystem basic properties was very similar, more continuous on the North-Eastern slopes of the Ore Mts., in the Děčín Table 4 tions even more (Modrzyński 2003, Bridges et al. 2002Borůvka et al. 2007, Fiala et al. 2009). Local large-areal closed young-growth stands on the restored clearing after unregulated fellings and continuous natural forests con-Upland, along the entire Lužice Mts. as well in the Giant Mts. and Orlické hory Mts. ...
... The CCA of forest ecosystem basic properties was used to distinction of concentrated disrupted forests on the Jizera Massif in the Jizera Mts. (Borůvka et al. 2007), on the plateau of the Ore Mts. (Bridges et al. 2002), the windthrown region of Trojmezí in the Šumava Mts. ...
The closeness of dependence level between growth environment (abiotic predictors) and forest ecosystem (receptor) indicates accordance or discrepancy between site and forest state. Our forest ecosystem analysis was focused on static model approximation between abiotic predictors with the closest dependence and properties of the receptor at 11 km grid in the Czech Republic (Central Europe). The predictors have been selected from natural abiotic quantities sets of temperatures, precipitation, acid deposition, soil properties and relative site insolation. The receptor properties have been selected from remote sensing data, density and volume of above-ground biomass of forest stands according to the forest management plans, and from surface humus chemical properties. A selection of the most dependent quantities was made by combining factor analysis and cluster analysis. The static modelling of the dependences between selected predictors and receptor properties was conducted by canonical correlation analysis. Average temperature, annual precipitation, total potential acid deposition, soil base saturation, CEC, total acid elements and site insolation index closely corresponded to NDVI and surface humus base saturation, Corg and acid elements content at 30% of the analysed grid of forest soils and it indicated forest state within the confidence interval at 69% of the forest soil grid (rCCA = 0.79; P < 0.00001). The forest ecosystem state that corresponds to the selected abiotic predictors was demonstrated in hilly altitudes. The tested procedure is inconvenient for forest state analysis in floodplains and moorlands. Based on approximation deviations, highland and mountain forests were divided into areas with non-optimum or more optimum ecosystem state than as corresponds to the values of the predictors.
... A toposequence of Haplic Podzols at high altitudes, Dystric Cambisols at low altitudes and Entic Podzols in transition of these two soils is characteristic of mountainous areas in Central Europe with boreal forest zones characterized by a humid and cold climate (e.g. Boháč & Nálevka 1971;Němeček & Tomášek 1983;Lundström et al. 2000a;Borůvka et al. 2005Borůvka et al. , 2007Bonifacio et al. 2006). Dystric Cambisols are characterized by weathering of the parent material without any further differentiation of the profile through the vertical movement of its components. ...
... Mean annual deposition rates of SO 3 reached several tens or even hundreds of g/m 2 during the 1970s and 1980s (Czech Hydrometeorological Institute 2010). Though the acid emissions have decreased significantly in recent years, the ecosystem still remains threatened by acidifying agents accumulated in soil (Oulehle et al. 2006;Borůvka et al. 2007;Hédl et al. 2011). The most affected were forest stands at the highest elevations (Purdon et al. 2004). ...
... Anthropogenic acid deposition, which has intensively occurred for decades, very probably plays a certain role in the enhancement of podzolization process in the area as an important factor in chemical changes connected with podzolization (Olsson & Melkerud 1989;Lundström et al. 2000a;Borůvka et al. 2007). The soils have a very low buffering capacity, so a further increase of acidification can start the podzolization process. ...
Mountainous areas represent regions with specific soil cover pattern that is naturally given by an altitudinal gradient. The objective of our study was to describe the soil cover development on the altitudinal gradient under changed environment given by man-planted vegetation and acidification. The studied area is characterized by spruce monoculture planting that replaced the original broadleaf natural vegetation and high load of anthropic acidification. The common hypothesis considering the sequence of Dystric Cambisol-Entic Podzol-Haplic Podzol with increasing altitude was not proved. The results of our study indicate that the influence of spruce vegetation causes the occurrence of Haplic Podzols at low altitudes where the natural soil formation does not induce their development. Results showed that the vegetation type can overrule other altitude-related soil-forming factors. The conversion of natural broadleaf and mixed forests to spruce monocultures leads to the expansion of podzolization process to lower altitudes.
... 5.5-6.5; and 7.5-8.5. As the number of variables is large, the principal component method was used [89][90][91]. The second reason for PCA application is that it provides a complex view on the properties of soil horizons. ...
... The loading diagram is shown in Figure 7. It reflects the known relationships between the properties of soil horizons: strong positive correlations between the total C and N, Al 2 O 3 , and Fe 2 O 3 , and negative correlation with exchangeable Ca and Mg [89,[92][93][94]. There is also a positive correlation between the number of main groups and hydrolytic acidity (pK a 4.0-5.0, ...
Potentiometric titration in a fast and simultaneously high-resolution modality was proposed for the identification and quantification of protolytic groups of variable strength at the surface of primary soil particles. The method is implemented by titrimetric data processing as multicomponent spectra (pKa spectrotitrimetry). Due to the high resolution, the error of acidity-constant assessment (3–5%) is lower, compared to existing approaches; due to the fast titration, the effect of soil hydrolysis is minimized. The soil profiles for acidic Retisols (podzolic soils)—under a spruce crown and in the intercrown space—were studied. These soils, which have similar bulk properties and genesis but developed under different plant covers, were distinguished by pKa spectral features at 4–5; 5.5–6.5; 6.5–8.5; 7.5–8.5; and 9–10, as well as total group concentrations. Differences in acidic and basic-group distribution (carboxyl groups, amorphous aluminosilicates, carbonate species, amino groups, soluble (poly)phenolic compounds, phospholipids) and Al and Fe complex compounds within the same soil profiles and between two Retisols were found and quantified. The acidity constants and group concentrations found by pKa spectrotitrimetry were compared with conventional soil-composition indicators (total organic carbon, oxalate-soluble Fe and Al, and phosphorus), using principal component analysis. The main correlations are between the concentrations of oxalate-soluble Al and groups with pKa values of 5.0–6.5 and 8.5; oxalate-soluble Fe and pKa values of 9.0–10.0; and P2O5 and pKa values of 4.0–6.0 and 6.5–8.5. The method provides a set of major acidity values without a priori information on a soil sample and can be used for screening and identifying similar soils.
... Land use, intricately tied to planning and policies, undergoes continuous evolution, necessitating an increasing emphasis on soil quality [35,36] and sustainable development natural soil functions. Recognizing the factors of the spatial distribution of soil characteristics will allow distinguishing areas with the highest risk of forest damage, as well as subsurface and surface water pollution [37]. How these new threats affect soil multifunctionality is a topic that deserves new research efforts, especially considering real field situations. ...
... Forest soils are one of the major carbon sinks on Earth because of their high organic matter content [51,52]. However, carbon stocks can potentially be influenced by soil disturbance events [53], forest type [37], or topographic parameters [54]. Petrášová et al. [55] state that in the top layer of Cambisols managed in different ways in the Czech Republic, the content of total organic carbon ranges from 2.7 % (Přemyslov-Tři Kameny, 803 m a.s.l.) to 1.3 % (Naměšť n/Oslavou, 430 m a.s.l.). ...
Currently, little is known about the spatial variability of significant soil properties and their relationships to forest ecosystems of different vegetation grades. This work evaluates the variability of the properties of the upper layer of Cambisol taxa and their relationship to altitude and forest ecosystems of 2nd to 5th forest vegetation grades selected in the Western Carpathians using PCA and regression analysis. The content of clay, total carbon and total nitrogen, humus, energy, and ash in the soils varied between 5.43 and 11.53 %, 21–65 mg g⁻¹, 1.9–4.7 mg g⁻¹, 36–112 mg g⁻¹, 438.4–5845.7 J g⁻¹ and 852.9–946.3 mg g⁻¹, and C/N, pHH2O, and pHKCl values ranged between 11.2 and 16.7, 4.0–5.8 and 3.1–4.6. PCA showed that EAC in the 3rd oak-beech vegetation grade had significantly higher pH values and significantly lower energy content, ESC in the 4th beech vegetation grade had a significantly higher ash content and a significantly lower energy content, and DC in the 5th fir-beech vegetation grade had a significantly higher content of Ct, Nt, and humus. Linear regression revealed a strong negative correlation between the energy content and soil reaction (R² for pHH2O = 0.48; R² for pHKCl = 0.38) for all Cambisol taxa. Ct content and ash show a strong negative correlation (R² = 0.78). The positive relationship between altitude and FVGs was found only for the soil Ct (R² = 0.87), Nt (R² = 0.81), and humus content (R² = 0.87). A strong negative linear relationship between altitude and FVGs showed the ash content (R2 = 0.77). In turn, the oscillatory, polynomial course had a relationship between the clay content (R2 = 0.65) and energy (R2 = 0.75) to altitude and FVGs. Recognizing significant soil variables and better understanding their impact on the development of forest ecosystems is a prerequisite for distinguishing areas with the highest risk of their damage under conditions of various anthropogenic interventions and climate change. Therefore, this topic continues to require increased research efforts. For this reason, a better understanding of the relationships between soil properties and ecologically differentiated communities of forest ecosystems will allow us to identify areas with the highest risk of ecological changes that could lead to the degradation of European forests in the future.
... Yang et al. (2016) found that cokriging improved the result by 45.5% compared with kriging, with soil bulk density as a primary variable and soil water content as an auxiliary variable. Moreover, a few studies combined geostatistics with principal component analysis (PCA) in order to extract auxiliary variables (Borůvka, Mládková, Penížek, Drábek, & Vašát, 2007;Levi & Rasmussen, 2014;Markhvida, Ceferino, & Baker, 2018). Borůvka et al. (2007) applied the combination of geostatistics and PCA to study how stand factors affect the spatial distribution of soil characteristics. ...
... Moreover, a few studies combined geostatistics with principal component analysis (PCA) in order to extract auxiliary variables (Borůvka, Mládková, Penížek, Drábek, & Vašát, 2007;Levi & Rasmussen, 2014;Markhvida, Ceferino, & Baker, 2018). Borůvka et al. (2007) applied the combination of geostatistics and PCA to study how stand factors affect the spatial distribution of soil characteristics. All these interpolation methods have mainly been applied to the studies of soil properties, but how to assess litter amount using cross-validation and select comprehensive auxiliary variables is not fully understood. ...
Abstract Litter is essential to promote nutrient cycling and maintain the sustainability of forest resources. However, its variability has not been sufficiently studied at the local scale. The prediction of litter amount using ordinary cokriging with Pearson correlation analysis (COKP) and ordinary cokriging with principal component analysis (COKPCA) was compared with that using ordinary kriging (OK) based on cross‐validation at the local scale of a 1‐ha plot over natural spruce–fir mixed forest in Jilin Province, China. Litter samples in semidecomposed (F) and complete decomposed (H) horizons were collected using an equidistant grid point sampling of 10 m × 10 m. Pearson correlation analysis and principal component analysis (PCA) were used to confirm auxiliary variables. The results showed that the amount of litter was 19.65 t/ha in the F horizon and 10.37 t/ha in the H horizon. The spatial structure variance ratio in the H horizon was smaller than that in the F horizon, indicative of its stronger spatial autocorrelation. Spatial distributions of litter amount in both horizons exhibited a patchy and heterogeneous pattern. Of the selected stand characteristics and litter properties, litter moisture content indicated the strongest relationship with litter amount. Cross‐validation revealed that COKPCA using the comprehensive score as an auxiliary variable produced the most accurate map. The average standard error and root‐mean‐square error between the predicted and measured values were always smaller, the mean error and mean standardized error were much closer to 0, and the root‐mean‐square standardized error was closer to 1 than COKP using litter moisture and OK. Therefore, a clear advantage of cokriging based on principal component analysis was observed and COKPCA was found to be a very useful approach for further interpolation prediction.
... However, compared to subsoils, topsoils are more susceptible to constant or episodic external factors, such as trampling, digging, excretions of animals, input of plant litter, plant-soil interactions, mass movement, acid depositions, and human land use. These combined factors can lead to considerable variabilities and uncertainties in the distribution of surface soils at fine scales (i.e., low spatial continuity; Borůvka et al., 2007;Schöning et al., 2006), possibly reducing the predictive power of landform variables for soil spatial variability. In addition, the depth and thickness of a B horizon may be highly variable due to the effects of, for example, preferential flow paths and unstable wetting fronts. ...
... For example, higher concentrations of base cations in the A horizon resulted most probably from the significantly higher amount of organic matter, and therefore, higher CEC. Several previous studies showed higher spatial continuity in lower-situated soil horizons than in topsoils (e.g., Borůvka et al., 2007;Schöning et al., 2006). One explanation for this is that upper horizons are more susceptible to external effects that dramatically reduce the importance of topography to soil spatial variability (see ection 1.2. ...
Research has shown that the performance of soil–landform models would improve if the effects of spatial autocorrelation were properly accounted for; however, it remains elusive whether the level of improvement would be predictable, based on the degree of spatial autocorrelation in the model variables. We evaluated this problem using 11 soil variables acquired from the A and B horizons along a hillslope of Žofínský Prales in the Czech Republic. The results showed that, with no exception, there were increases in R² and decreases in the Akaike information criterion (AIC), residual autocorrelation, and root-mean-square errors (RMSEs), after incorporating the spatial filters extracted by spatial eigenvector mapping into non-spatial regression models. Furthermore, the improvement of the model was positively proportional to the degree of spatial autocorrelation, inherent in the soil variables. That is, there were strikingly linear and significant relationships, in which strongly autocorrelated soil variables (i.e., having a high Moran's I value) exhibited greater increases in R² and decreases in AIC, residual autocorrelation, and RMSEs than their more weakly autocorrelated counterparts. These findings indicate that the degree of spatial autocorrelation present in soil properties can serve as a direct indicator for how much the performance of a traditional non-spatial soil–landform model would be enhanced, by explicitly taking into consideration the presence of spatial autocorrelation. More generally, our results potentially imply that the need for and benefit from incorporating spatial effects in geopedological modeling proportionally increases as the soil property of interest is more spatially structured (i.e., landform variables alone cannot capture soil spatial variability).
... PCA. PCA is a multivariate exploratory technique commonly used in the geosciences to elucidate relationships within complex, large data sets (Helena et al. 2000;Farnham et al. 2003;Borůvka et al. 2005Borůvka et al. , 2007Li et al. 2007;Mandal et al. 2008). In this study, PCA was performed on correlations using JMP software v.13.0.0 (SAS Institute 2016). ...
... We therefore omit PCs 4-12 from further discussion. In general, the amount of variance explained by PCs 1-3 is similar to other studies of geologic data (Helena et al. 2000;Borůvka et al. 2005Borůvka et al. , 2007 and, in this case, reflects the natural variability in factors of soil formation that drive geochemistry and pH across such a large variety of settings. ...
Soil pH is essential for understanding weathering, nutrient availability, and biological-edaphic relationships. However, standard pH measurement on soils requires friable material, thereby excluding most paleosols. In this article, bulk geochemical proxies for pH are developed for soil B horizons using indices that track pH-dependent mineralogical transformations. Geochemical relationships within a continental-scale modern soil data set (n=619) reveal a close association between pH and log-transformed CaO and little influence of refractory oxides on pH. These results guided the formulation of three geochemical indices that consist of ratios of Fe2O3, TiO2, and Al2O3 to CaO, herein referred to as FeCa, TiCa, and AlCa. After careful screening for anthropogenic influence, pedotransfer functions relating each index to pH were derived using sigmoidal regressions on a calibration data set (n=305). Each index has similar predictive capacity for pH (r2=0.70–0.74, root mean square error=0.83–0.88). The models were cross-validated on an external testing set (n=130), which returned root mean square prediction errors (RMSPEs) similar to regression results (RMSPE=0.81–0.86). While soil pH shows a significant correlation with mean annual precipitation, partial correlation analysis of FeCa, TiCa, AlCa, and a number of widely used paleosol weathering indices revealed that the relationship between B horizon composition and pH is significant, even when climate is held constant. This finding implies that bulk geochemical indices used in pedotransfer functions for climate primarily track pH, which in turn responds to climate state. A case study is examined, where the pH transfer functions were applied on a succession of Triassic alluvial paleosols that experienced a large range of soil-forming conditions. Reconstructed pH values closely track interpreted vegetation, climate, and pedogenesis. These pedotransfer functions offer a new pathway to estimate an ecologically significant parameter in deep-time Critical Zones.
... Soil pH is a consequence of several soil forming factors and parallel soil processes (Boruvka et al., 2007). Analysis based on the LUCAS topsoil database show that climate has a substantial role in controlling this mechanism. ...
... In line with findings of Boruvka et al. (2007) on forest land, our observations suggest that acidic soils (pH<5.5) become more prevalent over the higher altitude grassland soil compared with the acid soil of croplands where generally the neutral and alkaline are present on a wider area (Fig. 1, Fig. 5).Within cropland area, the top soil pH, suffers changes as result of liming, which based on the LUCAS topsoil data are determined by natural conditions. ...
As part of the 2012 Land Use/Land Cover Area Frame Survey (LUCAS), topsoil samples were collected in Bulgaria and Romania using the same methodology as for other EU Member States in an equivalent survey carried out in 2009. In total, 664 Bulgarian and 1384 Romanian samples were collected which enabled a comparative assessment of topsoil properties under different land covers within, and between, these countries, as well as in a broader European context. The samples were analysed for basic soil properties, including particle size distribution, pH, organic carbon, carbonates, nitrogen, phosphorus, potassium and cation exchange capacity together with multispectral signatures. The current paper describes the LUCAS Topsoil 2012 project and provides both an overview of topsoil properties of cropland and grassland in Bulgaria and Romania, together with a comparative assessment with earlier findings with the analysis of data from other 25 EU Member States and data from small scale European soil database. Results show similarities with data from Member States with comparable climatic conditions in properties where non-anthropogenic soil forming factors play major role (texture, pH, calcium-carbonate, soil organic carbon content). There are considerable variations in certain soil properties between different land use types, (e.g. soil organic carbon content in croplands and grasslands in Romania; or potassium content in croplands and grassland in both countries). However, the most remarkable facts drawn from the current study are the very low phosphorus content in agricultural land in the two countries relative to other EU Member States, the significantly lower contents of organic carbon compared to modelled data of literature and legacy national data and the difference in the distribution of texture classes compared to European datasets. © 2016 Gh. Asachi Technical University of Iasi. All rights reserved.
... Soil mapping has revealed extensive variability of forest soils over small areas and short distances (Boruvka et al., 2007;Bruckman et al., 2011;Phillips and Marion, 2005). Such mappings usually show greater variability in forest -than in similar non-forest soils (Phillips and Marion, 2005). ...
... A varimax rotation with Kaiser Normalization (Kaiser, 1958) was performed in the Principal Component Analysis (PCA). The essence of the latter was to redistribute the variance in each parameter in such a way that each contributes strongly to one of the components and little to the others (Boruvka et al., 2007). The PCA allows for the identification of clusters of parameters that are interrelated by identifying latent principal components (PCs) and the eigenvalue of a PC explains the extent to which a particular PC explains multiple correlations of the analyzed parameters (Burstyn, 2004). ...
Understanding soil spatial variability and identifying soil parameters most determinant to soil organic carbon stock is pivotal to precision in ecological modelling, prediction, estimation and management of soil within a landscape. This study investigates and describes field soil variability and its structural pattern for agricultural management decisions. The main aim was to relate variation in soil organic carbon stock to soil properties and to estimate soil organic carbon stock from the soil properties. A transect sampling of 100 points at 3 m intervals was carried out. Soils were sampled and analyzed for soil organic carbon and other selected soil properties along with determination of dry aggregate and water-stable aggregate fractions. Principal component analysis, geostatistics, and state-space analysis were conducted on the analyzed soil properties. The first three principal components explained 53.2% of the total variation; Principal Component 1 was dominated by soil exchange complex and dry sieved macroaggregates clusters. Exponential semivariogram model described the structure of soil organic carbon stock with a strong dependence indicating that soil organic carbon values were correlated up to 10.8 m. Neighbouring values of soil organic carbon stock, all water-stable aggregate fractions, and dithionite and pyrophosphate iron gave reliable estimate of soil organic carbon stock by state-space.
... This suggests an inverse relationship between Ca treatment difference and limed solution pH values. The Ca and pH variables in PC3 were observed to be strongly correlated previously (Borůvka et al., 2007). ...
Agricultural lime is an important natural resource for changing soil pH values. Annual lime applications in the UK have fallen for decades. Estimating soil factors that contribute to the retention and losses of lime would be useful for farmers making resource decisions. The aim of this research was to analyse the soil factors contributing to leaching loss and retention of agricultural lime in Scottish grassland soils. This research also tested the applicability of a large centrifuge method for measuring leached solutions from soil, suggested as an alternative to leaching columns. The soils studied in this research were highly variable in their response to lime. Measures of soil exchange capacity (cation exchange capacity, lime buffering capacity and organic matter) and clay content were highly associated factors to calcium loss and retention within a soil. Suggestions to farmers include consideration of soil clay content, organic matter content (as expressed through C) and cation exchange capacity as factors in lime decision making. Higher exchange capacity soils lost more calcium, likely due to the greater liming requirement of these soils and potential increased excess calcium applied. It is suggested that methods for improving calcium exchange and soil uptake be explored for improving lime retention after liming events.
... The data were standardized to zero, mean, and unit variance, and the analysis was done on the correlation matrix. Principal component analysis (PCA) for different soil parameters among the sampled forest sites was done using R statistical software (Team, 2014) (Borůvka et al., 2007). ...
... The CV followed the opposite trend, with a higher CV for soil properties of external sources in the subsurface than in the surface layer. This finding is comparable to the study of [53]. This can be explained because the soil chemical properties of external sources are more affected by soil disturbances in the surface compared to the subsurface layer, of which formation is related to geology and topography. ...
The formation of spatial pedocomplexity in forested landscapes is an issue that has not yet been comprehensively resolved. This study analysed the effects of tree disturbances on the spatial variability of soil chemical properties in order to explain the spatial pedocomplexity in one of the oldest forest reserves in Europe. A total of 1545 sites over an area of 74 ha were assessed in terms of soil taxonomy, morphology, and profiles. We quantified the spatial autocorrelation of soil chemical properties and analysed the effects of soil disturbance regimes on soil chemical properties in both the surface and subsurface layers using geostatistics and redundancy analysis, respectively. A paired difference test revealed that the factors involved in the soil formation of the two layers are different. The neoformation of the surface layer proceeds rapidly after soil disturbance and, therefore, some formerly disturbed surface layers become mature above immature subsurface layers. The effect of tree disturbances on soil chemical properties was significant for totally decomposed treethrows. Treethrow density partially explained the variation in soil chemical properties in both layers, but even more so in the subsurface layer. This study further elucidates the impact of treethrows on soils and shows that they are an important driver of soil spatial pedocomplexity.
... These results may help to estimate the suitable ecological niches of the dominant fungi [79] and to predict the fate of these important fungal taxa with ongoing climate change. Indeed, among the changes expected at the global scale, both an increase in atmospheric N deposition [80,81] and acidification of forests [82,83] are expected; the latter is already observed in the Salajka forest [34]. From our findings, most of the dominant taxa will be positively affected by an increase in pH but negatively affected by an increase in N. Nevertheless, we demonstrated that many dominant taxa were not affected by pH or C/N, so we can assume that the important decomposition functions will be maintained. ...
Deadwood represents an important carbon stock and contributes to climate change mitigation. Wood decomposition is mainly driven by fungal communities. Their composition is known to change during decomposition, but it is unclear how environmental factors such as wood chemistry affect these successional patterns through their effects on dominant fungal taxa. We analysed the deadwood of Fagus sylvatica and Abies alba across a deadwood succession series of >40 years in a natural fir-beech forest in the Czech Republic to describe the successional changes in fungal communities, fungal abundance and enzymatic activities and to link these changes to environmental variables. The fungal communities showed high levels of spatial variability and beta diversity. In young deadwood, fungal communities showed higher similarity among tree species, and fungi were generally less abundant, less diverse and less active than in older deadwood. pH and the carbon to nitrogen ratio (C/N) were the best predictors of the fungal community composition, and they affected the abundance of half of the dominant fungal taxa. The relative abundance of most of the dominant taxa tended to increase with increasing pH or C/N, possibly indicating that acidification and atmospheric N deposition may shift the community composition towards species that are currently less dominant.
... The renewal of organic and A-horizons after windthrow events is more rapid than in the mineral B-horizons, where restoration lasts many years after the levelling of typical pit-mound micro-morphological forms. Borůvka et al. (2007) observed the opposite result (higher spatial continuity in lower-situated horizons) in managed forests of the Jizerské Mts. Those authors attribute this to the fact that organic horizons are more susceptible to external impacts while the B-horizons are more influenced by regional factors-forest type, forest stand age and soil taxonomic unit. ...
Deadwood represents a source of nutrients, carbon and water for metabolism within forest ecosystem. Nutrients are mobilized due to the decomposition of wood, which is a long-term process that can be best studied by analysing environmental data on a temporary scale. Our study provides physico-temporal data on the downed logs of three major tree species in European temperate forests: Abies alba Mill., Fagus sylvatica L. and Picea abies (L.) Karst. Time since death was obtained using tree censuses (repeated for 40 years) and dendrochronology for each single downed log, the oldest being 75 years old. Standard laboratory methods were used for the determination of wood density and moisture changes. F. sylvatica was decomposed rapidly in the initial phase – mass loss was 50% during the 5 years after death, while A. alba and P. abies lost 13% and 16%, respectively. Downed logs of F. sylvatica contained 391 kg of water per m3, while these of P. abies 279 kg. A log-transformed linear model was created that shows the dependence of time since death on mass loss. According to the model, F. sylvatica had the shortest total decomposition time (39 years), followed by A. alba (58 years) and P. abies (86 years).
... sized by several authors (Müller 1887, Hüttle and Schneider 1998, Boruvka et al. 2007, Zanella et al. 2011. The detailed research, which focused on the acidity of soils and on mechanisms of complete soil profile acidification, was conducted for both cases, i.e. in the conditions of agricultural (Eidukeviciene et al. 2011) and silvicultural land uses (Iwald 2016). ...
The active acidity (pH) of forested mineral lands’ topsoil, its relationships with alternative soil acidity characteristics and the influence of soil acidity on forest soils’ profile fabric and functioning are analysed in the pedo-ecological conditions of northeastern Europe. The active acidity of the forest floor (O-horizon) was taken as the baseline for this analysis. The acidity of the forest floor was studied in accordance with the underlying soil horizons, which are humus and/or raw-humus horizons in the more fertile soils, whereas in less fertile soils, they are podzolized horizons. The data on soil acidity are presented by main soil types, forest site types, forest humus cover types (pro humus forms) and forest stand groups. In this work, the influences of forest floor acidity on mineral topsoil fabric, soil processes and peculiarities of carbon sequestration are explained. The active acidity of the forest floor provides a great indicative value in elucidating the regularities of the forest soil cover, as a whole, formation and functioning. For evaluating the normality of soil functioning, or the absence of disturbances in ecosystem functioning, the intervals of soil type specific reference pH levels have been established.
... Corg and Nt the most differ vertically between various horizons in soil body. BS, pH a CaO the most differ between various soil units and CEC as well as grain size differ at various altitudes the most (Borůvka et al., 2007). The characterization of the catenas was carried out by frequencies in the presented terrain and bedrock types according to Culek et al. (2005). ...
More frequent occurence of hillwashes in altitudinal‑differentiated landscapes causes changes of relationships among terrain, bedrock and soils. The aim of the study was to characterize catenas of the terrain‑bedrock‑soil relationships by PCA of forest soil properties generalized into 2 × 2 km grid in Outer Western Carpathians (OWC) of the Czech Republic. The spatial relationships of the soil catenas with terrain and rocks were verified by ANOVA. Typification of the catenas was carried out by frequencies in the presented terrain and bedrock types according to biogeographical division system. Base saturation, CaO and P 2 O 5 divide forest soils in OWC to ten catenas. The catenas characterized by moderate correspondence of soils and bedrock are concentrated in Outer Depressions, while catenas with moderate correspondence of soils and terrain are concentrated in Flysch Range. The Outer Carpathian Depressions are covered predominantly by floodplains, flat waterlogged, loess‑covered and luvic hillycountries (67% of the grid). The Flysch Range is covered predominantly by proluvial slopes, broken hillcountries and submountain to mountain slopes (65% of the grid). The Floodplains, broken nutrient‑medium hillycountries and mountain slopes have medium to marked soil horizon properties heterogeneity. The flat landforms, proluvial and submountain slopes have moderate soil properties heterogeneity. The statistical significant differences between values of properties at A and B horizons suggest rate of an surface matter translocation effect on the soil catena heterogeneity.
... The semivariograms reported by Schöning et al. (2006) indicated that C stocks in forest soils are very variable at distances of less than 5 m. Carbon stocks can potentially be affected by soil disturbance events (Šamonil et al., 2011), forest type (Borůvka et al., 2007), or topographic parameters (Spielvogel et al., 2009). ...
Data from forest inventories provide information on C stocks under various tree species. However, based on the literature, the effects of tree species can be insignificant due to variation caused by the influence of site-related factors. The aim of this study was to explore the effects of soil texture, pH H2O , elevation, and dominant tree species on soil carbon (C) stocks in forest soils of Poland using data mining. Data were obtained from 468 investigation sites, spread over the entire area of Poland, representing forest sites with five dominant tree species (Scots pine, Norway spruce, Silver fir, deciduous oak and European beech), different elevations (lowlands, uplands, and mountains) and variable soil texture. We analyzed the effects of these characteristics using generalized additive models (GAM). Total soil-profile (up to 100 cm) C stocks (on average 26 t ha −1 in the organic horizon and 66 t ha −1 in the mineral soil) in forest soils of Poland were slightly lower than those reported previously for European forests. Simple ANOVA results implied that soils of pine stands contained significantly less stored C than soil under the other coniferous species (spruce and fir) and under deciduous oak and beech. The GAM analysis enabled quantification of the overall contribution of variables to variation in C stocks, namely fine-fraction (FF; silt and clay) content (15%), pH H2O (13%), altitude (8%), and dominant tree species (3%). The FF content positively affected C stocks (up to 10 t C ha −1 particularly in sandy soils (80-100% sand). The effect of elevation was most evident in the organic horizon and 0-10 cm mineral layer, which resulted in an increase of ∼40 t C ha −1 from 300 to 1000 m above sea level. The GAM analysis also showed that in all horizons the C stocks were lowest in soil pH H2O range 4.5-5.5. Decreased pH H2O or increased pH H2O resulted in an increase of 10-40 t C ha −1 in C stocks. Tree species alone explained about 3% of variation in C stocks, but a large portion of the effects of pH H2O may be attributable to the dominant tree species.
... SOM-induced acidification is another cause of decrease in pH value in forest soils. Aluminum release is strongly influenced by organic matter mineralization, since it naturally bound into organic complexes and that increases soil acidity (Borůvka et al. 2007). ...
Gökçeada is the biggest island, and it is also known as the organic island of Turkey. Approximately 65% of the Gökçeada lands have slope > 12%. Climate, topography, land cover, and soil characteristics are considered to be the main natural factors affecting soil erosion severity in the Gökçeada. Prevention of soil degradation, hence the preservation or improvement of the overall quality of the soil, is directly related to the presence of stable soil aggregates. In addition, the resistance to weathering and replacement of soil particles are also relevant aspects in terms of sustainability. Aggregate stability (AS) and erodibility of land (Kfac) are related to soil properties. However, this relationship can vary under different circumstances. In this study, 248 surface soil samples have been taken from forest and semi-natural areas (FSNA) and agricultural areas (AGRA) according to CORINE 2006. Eleven selected soil properties were measured, and their impacts on AS and Kfac (RUSLE-K) were determined by using the CRT (classification and regression tree) in Gökçeada. Results showed that the relations among soil characteristics changed according to the land cover classes. Total organic carbon is much more associated with AS in AGRA, while total carbon is associated with AS in FSNA. The effect of calcium carbonate on Kfac was higher than other soil properties when the land cover type was ignored. On the other hand, in AGRA, the effect of between clay content on Kfac was greater than those of FSNA.
... They compared fire regime characteristics at different topographies and found that fire regime parameters are different in slope aspect, slope position, and elevation. Borůvka et al. (2007) investigated acid soils of forests in mountainous areas of the Czech Republic. Spatial autocorrelations of O and B horizons was analyzed using cross-variograms. ...
Forests are spatially variable due to multiple interactions among state (vegetation, species distribution, understory cover, soil, and topography) and forcing variables (climate and human) variables. In general, the spatial structure is resulted as combined effect of these external and internal variables. Geostatistical methods can aid characterizing the spatial structure of forest ecosystems. The shape and parameters (nugget, sill, range) of semivariograms provide important information on the characteristics of spatial structure. In addition, the geostatistical interpolation methods (e.g. kriging) are effective tools for constructing surface maps of variable of interest. Thus, the geostatistical methods have been used increasingly for characterizing forest spatial structure across different spatial scales for last 30 years. In this literature study, sources of spatial variability of forest ecosystems are explained and results of several geostatistical studies are discussed. Özet Ormanlar zorlayıcı (dışsal) ve etkilenen (durum) değişkenleri arasındaki çoklu etkileşimler nedeniyle uzaysal değişkenlik gösterirler. Genel olarak, uzaysal değişkenlik bu değişkenlerin ortak etkisinin bir sonucu olarak ortaya çıkmaktadır. Joeistatiksel yöntemler uzaysal yapının karakterize edilmesine yardımcı olabilmektedir. Semivaryogramın şekli ve parametreleri (nugget, sill, range) uzaysal yapı hakkında önemli bilgiler sağlar. Ayrıca, jeoistiksel enterpolasyon yöntemleri (örneğin, krigleme) ilgili değişkenin yüzey haritalarının çıkarılmasında oldukça kullanışlı araçlardır. Dolayısıyla, jeoistatistiksel yöntemler son 30 yılda ormanların uzaysal değişkenliklerinin karakterize edilmesinde artan bir şekilde kullanılmaktadır. Bu literatür çalışmasında, ormanların uzaysal değişkenliğinin başlıca kaynakları verildikten sonra, bu kaynakların bir fonksiyonu olarak ortaya çıkan uzaysal değişkenliğin karakterize edilmesinde yapılmış bazı jeoistatiksel çalışmaların sonuçları tartışılmıştır.
... In addition, a range of studies have demonstrated that interpolation accuracy and mapping quality can be effectively improved by the use of secondary variables as supplementary information [4,[11][12][13][14][15][16][17][18]. Land use, soil type, grassland type, and geology type might be expected to play a significant auxiliary role in controlling the spatial variation of soil properties. ...
Spatial discontinuity often causes poor accuracy when a single model is used for the surface modeling of soil properties in complex geomorphic areas. Here we present a method for adaptive surface modeling of combined secondary variables to improve prediction accuracy during the interpolation of soil properties (ASM-SP). Using various secondary variables and multiple base interpolation models, ASM-SP was used to interpolate soil K+ in a typical complex geomorphic area (Qinghai Lake Basin, China). Five methods, including inverse distance weighting (IDW), ordinary kriging (OK), and OK combined with different secondary variables (e.g., OK-Landuse, OK-Geology, and OK-Soil), were used to validate the proposed method. The mean error (ME), mean absolute error (MAE), root mean square error (RMSE), mean relative error (MRE), and accuracy (AC) were used as evaluation indicators. Results showed that: (1) The OK interpolation result is spatially smooth and has a weak bull's-eye effect, and the IDW has a stronger ‘bull’s-eye’ effect, relatively. They both have obvious deficiencies in depicting spatial variability of soil K+. (2) The methods incorporating combinations of different secondary variables (e.g., ASM-SP, OK-Landuse, OK-Geology, and OK-Soil) were associated with lower estimation bias. Compared with IDW, OK, OK-Landuse, OK-Geology, and OK-Soil, the accuracy of ASM-SP increased by 13.63%, 10.85%, 9.98%, 8.32%, and 7.66%, respectively. Furthermore, ASM-SP was more stable, with lower MEs, MAEs, RMSEs, and MREs. (3) ASM-SP presents more details than others in the abrupt boundary, which can render the result consistent with the true secondary variables. In conclusion, ASM-SP can not only consider the nonlinear relationship between secondary variables and soil properties, but can also adaptively combine the advantages of multiple models, which contributes to making the spatial interpolation of soil K+ more reasonable.
... Diversos estudos com atributos do solo integram o uso da estatística multivariada com a estatística espacial (ALMEIDA; GUIMARÃES, 2016;BORŮVKA et al., 2007;RIBEIRO et al., anualmente no período entre agosto e outubro (após a colheita) sendo a dose calculada com base na análise de solo e na recomendação para o Estado do Espírito Santo (PREZOTTI et al., 2007). Esta mesma forma de manejo é realizada anualmente desde 2006, com os mesmos períodos de colheita, adubação e poda. ...
Soil attributes may be influenced by the relief generating homogeneous productivity zones. From this hypothesis, we identified soil attribute groups, its spatial variability and relationship with productivity and relief by Factor Analysis (FA) and geostatistics methods. The study was conducted in a Oxisol cultivated with Conilon coffee in the State of Espírito Santo. The AF group in Factor 1 (F1) attributes related to soil aggregation was not associated with relief and productivity. Its spatial variability is influenced by management as showed by the lower spatial continuity and dependence in 0-0.10 m depth and by pure nugget effect in 0.10-0.20 m depth. From the factor 2 (F2), obtained in two depths, can be grouped soil attributes related to water retention, mainly the clay, microporosity and moisture which together increase at a higher altitude and lower slope where occur higher productivity areas. The spatial variability of F2 indicates greater continuity and spatial dependence, suggesting influence of relief in the spatial variation structure.
... The effectiveness of secondary variables for reducing predictive error. The distribution of soil properties is controlled by several environmental variables, such as land use, soil type, and slope 33 . The soil property distribution could vary significantly within small spatial scales because of different soil environment types, which can make it difficult to obtain accurate interpolations using AW-SP when such obvious secondary variables are ignored. ...
The concept of spatial interpolation is important in the soil sciences. However, the use of a single global interpolation model is often limited by certain conditions (e.g., terrain complexity), which leads to distorted interpolation results. Here we present a method of adaptive weighting combined environmental variables for soil properties interpolation (AW-SP) to improve accuracy. Using various environmental variables, AW-SP was used to interpolate soil potassium content in Qinghai Lake Basin. To evaluate AW-SP performance, we compared it with that of inverse distance weighting (IDW), ordinary kriging, and OK combined with different environmental variables. The experimental results showed that the methods combined with environmental variables did not always improve prediction accuracy even if there was a strong correlation between the soil properties and environmental variables. However, compared with IDW, OK, and OK combined with different environmental variables, AW-SP is more stable and has lower mean absolute and root mean square errors. Furthermore, the AW-SP maps provided improved details of soil potassium content and provided clearer boundaries to its spatial distribution. In conclusion, AW-SP can not only reduce prediction errors, it also accounts for the distribution and contributions of environmental variables, making the spatial interpolation of soil potassium content more reasonable.
... In managed forests, where soil disturbances are less common, surficial processes and pedogenesis work to even-out the spatial variability in soils, as microtopography is less pronounced. Greater spatial continuity in deeper horizons, as revealed Borůvka et al. (2007) in mountain spruce and beech managed forests in the Czech Republic, was attributed to the fact that organic horizons are more susceptible to external impacts, whereas B horizons are more influenced by regional factors (forest type, forest stand age and geomorphology) in regions where geometry of bedrock weathering fronts is not exceptionally complex. ...
Uprooting represents a key disturbance process in forests, forming pit-mound microtopography, which can then dramatically impact pedogenesis and the forest ecology. At our study sites in northern Michigan, where well-drained, sandy Spodosols dominate, pit-mound microtopography tends to persist for millennia. Because of its persistence, the influence of this type of microtopography is greater here than in most forests. In that respect, our sites represent an end member along a continuum of forest soil disturbance by uprooting. We studied post-uprooting pedogenesis (at 14 dated pit-mound pairs), mapped and characterized the pit-mound topography (over 2.8 ha), the soils below (within 317 soil profiles), and the trees above, to better understand the complex interactions among this type of disturbance regime and forest dynamics.
... The distribution of soil pH is controlled by several environmental factors, such as acid deposition, parent rock, altitude, soil types, land use types, vegetation cover, human activities, etc. (Boruvka et al., 2007). The soil pH data may vary severely within a short horizontal distance. ...
Soils contaminated with potentially toxic trace elements (PTTE) often have serious consequences for terrestrial ecosystems. Several phytoremediaction have been developped to reclaim contaminated soils; however the efficiency and capacity of these techniques to reduce excessive concentrations of trace elements or their (phyto) availability in contaminated soils have to be assessed. The present work is focused on studying the effectiveness of two phyoremediation options such as phytostabilisation and phytoextraction assisted by organic and inorganic amendments to remediatethe high concentrations of PTTE in contaminated natural soils and technosoils. Total PTTE concentrations were determined in soil pore water (SPW) sampled by Rhizon soil moisture samplers. The soil exposure intensity was assessed by DGT (diffusive gradient in thin films) probes. The PTTE phytoavailability was characterized by growing dwarf beans on potted soils and analyzing their foliar PTTE concentrations. Then a model of artificial neural network was applied to understand the factors most relevant for the variability on the phytoavailability of trace elements. Both options were found to be able to reduce the concentrations or phytoavailability of PTTE in the presence of amendments. The artificial neural network has been very effective to predict missing results and to determine the control parameters of the variability of the PTTE phytoavailoability from the soil parameters.
... Multi-year fluctuations in soil properties depend on mutual relations among external factors and on internal factors of the soil development. Forest soils develop more or less naturally and can thus form a matrix for estimates of the deviations of succession in other ecosystems (Borůvka et al. 2007). Models of forest soils ecology are usually defined using a set of chemical balance equations and applied to catchments (Lin 2006). ...
Fluctuations in forest soil properties were described using a time series analysis of the clay content, the chemical (CaO, MgO, C-org, and N-tot) and physicochemical (pH and base saturation (BS)) soil parameters from 1953 to 2008. The analysis involved the dominant acidic, nutrient-rich, and waterlogged forest ecosystems on the territory of the Bohemian Massif and the Outer Western Carpathians (Czech Republic). Trends in the development of the time series of soil properties were optimized by Gauss-Newton's transformation of the exponential combination of the cyclometric function and Euler's number. Identical functions of regression equations on the fluctuations of nutrients, pH, BS, and C-org indicated parallel trends of soil development in different forest ecosystems. Equations representing identical, predictable patterns in C-org fluctuation indicated the stability of the trend. Differences in temporal patterns of nutrients, pH, and BS in different forest ecosystems indicated the susceptibility of developmental trends to external factors. Different regression equations of fluctuations of soil clay and N-tot indicated the occurrence of permanent differences during the soil development. During the period of 1953-2008, soil pH, BS, and CaO concentration decreased but the content of C-org and N-tot increased. Regression functions indicate that pH and BS of forest soils in the Czech Republic have temporarily increased and the content of C-org and N-tot have decreased during the period 2009-2014. Continuous increase in BS is only sustainable if concurrent with an increase in C-org.
... A literatura apresenta que os índices propostos por Biondi et al. (1994) e Cambardella et al. (1994 são muito utilizados na área da Ciência do Solo (Grego et al., 2006;Simões et al., 2006;Boruvka et al., 2007;Duffera et al., 2007;Gallardo & Paramá, 2007;Gontijo et al., 2007;Vieira et al., 2009;Guedes Filho et al., 2010;Sampaio et al., 2010;Silva et al., 2010;Siqueira et al., 2010;Alvarenga et al., 2011;Ávila et al., 2011;Miqueloni & Bueno, 2011;Oliveira Júnior et al., 2011;Skorupa et al., 2012). Esses trabalhos são uma amostragem da, já extensa, gama de pesquisas sobre variabilidade espacial em solos e demonstram a importância de se terem medidas para possibilitar a descrição da estrutura de dependência espacial. ...
O semivariograma possibilita uma avaliação visual da dependência espacial, mas sem resultar diretamente em um valor numérico único que expresse a mensuração de tal dependência. Contudo, a partir dos parâmetros estimados do modelo teórico ajustado ao semivariograma experimental, é possível construir uma medida dessa dependência espacial. Atualmente, há dois índices na literatura, com uso cada vez mais frequente; porém, há inadequações nesses índices existentes. O objetivo deste trabalho foi propor um novo índice para medir a dependência espacial de dados geoestatísticos, que supere as incipiências dos atuais. Esse novo índice utiliza a relação existente entre o semivariograma e o correlograma, contemplando dessa forma todos os aspectos da dependência espacial. Realizaram-se uma comparação, por simulação, entre o índice proposto e os índices já existentes e também verificação da aplicabilidade do índice proposto utilizando pesquisas reais publicadas, em que ocorreram ajustes dos modelos teóricos esférico, exponencial e gaussiano. Verificou-se que o índice proposto foi melhor que os índices existentes. Além disso, observou-se que os índices existentes podem levar a equívocos nas interpretações do grau de dependência espacial, evidenciando que devem ser evitados. Em decorrência, recomenda-se a utilização do novo índice proposto para medir o grau da dependência espacial.
... All data were standardized to zero mean and unit variance prior to cross-variogram calculation. Cross-variograms were not used to assess the significance of the correlation; therefore, the hulls of perfect correlation (Wackernagel, 2003;Borůvka et al., 2007) are not shown. Instead, they were used to judge the general tendencies (e.g., positive/negative, stronger/weaker correlation) in the context of the spatial dependence. ...
... The substantial forest decline in the Jizera Mountains (North Bohemia) observed during the period of just about 1975-1995 is common knowledge (Borůvka et al. 2007). Nearly 12,000 ha of forests were affected by air pollution load (sulphur dioxide) arisen from industrial enterprises, chiefly thermal power stations. ...
Support of European beech (Fagus sylvatica L.) and sycamore maple (Acer pseudoplatanus L.) plantations by amelioration has been tested in air-polluted sites in the mountains since 1993. The research locality is a site with humic podzol soils at an altitude of 960 m asl. Dolomitic limestone (1 kg per tree) was mixed with soil used for planting tree
seedlings. According to the results of a 15-year investigation (1993–2008), liming had a positive effect on beech tree growth, while the positive effect of liming on tree growth was ...
... Even though many environmental properties have been correlated with soil carbon (C) at the site-specific/plot scales, studies using comprehensive datasets comprising multiple environmental properties to model soil C are less prominent, both at the regional scale (e.g., Ryan et al., 2000;Henderson et al., 2005;Minasny et al., 2006), and field scale (e.g., Terra et al., 2004;Simbahan et al., 2006). Moreover, according to Grunwald (2009), only a few studies have quantified soil C at multiple depths (e.g., Bor• vka et al., 2007;Grimm et al., 2008), thus our understanding of C differences among soil layers, and assessment of deep C stocks is still limited over large extents. (Guo et al., 2006a), and more detailed studies have been limited to specific ecosystems, and soil types. ...
... Soil acidifi cation, as well as various degrees of soil sensitivity to acidifi cation, depend on wet and dry sulphur, nitrogen, and carbon dioxide depositions [2], increased precipitation, geological base -parent rock [1], soil properties (current acidity, base saturation, cation-exchange capacity, soil texture, organic matter content), land use and vegetation [11]. Soil acidifi cation as a form of soil degradation can cause major problems in environmental quality [9]. ...
Acidification, as a form of soil degradation is a process that leads to permanent reduction in the quality of soil as the most important natural resource. The process of soil acidification, which in the first place implies a reduction in soil pH, can be caused by natural processes, but also considerably accelerated by the anthropogenic influence of excessive S and N emissions, uncontrolled deforestation, and intensive agricultural processes. Critical loads, i.e. the upper limit of harmful depositions (primarily of S and N) which will not cause damages to the ecosystem, were determined in Europe under the auspices of the Executive Committee of the CLRTAP in 1980. These values represent the basic indicators of ecosystem stability to the process of acidification. This paper defines the status of acidification for the period up to 2100 in relation to the long term critical and target loading of soil with S and N on the territory of Krupanj municipality by applying the VSD model. The Inverse Distance Weighting (IDW) geostatistic module was used as the interpolation method. Land management, particularly in areas susceptible to acidification, needs to be focused on well-balanced agriculture and use of crops/seedlings to achieve the optimum land use and sustainable productivity for the projected 100-year period.
... A varimax rotation with Kaiser Normalization (Kaiser 1958) was performed in the principal component analysis (PCA) after data for analysis were standardized to zero mean and unit variance. This procedure was necessary to ensure that variance in each variable contributes strongly to only one of the components and very little to the other (Boruvka et al. 2007). All these analyses (along with multiple regressions) were performed using Predictive Analytics SoftWare (PASW) 18.0 software (SPSS 2010). ...
To gain additional knowledge and better understand forest soil management on a small scale, geostatistical analytical tools were employed to examine the spatial distribution in dry aggregate mean weight diameter (MWD) and other selected soil properties and to assess the possible relationships between MWD and other soil properties. Selected properties of forest soils collected along a 300-m transact in the Nimbia Forest Reserve of Nigeria exhibited moderate to high variability in distribution with sodium ion displaying the greatest variability [coefficient of variation (CV, 91.2%)] and principal component analysis revealed the exchange complex cluster as influencing total variation of field soil properties. The autocorrelation function showed significant spatial correlation from 1 lag in soil organic carbon up to 17 lags (51 m) in soil moisture content (). The spherical and Gaussian semivariogram models described the spatial structure of most soil properties; however, for clay, cation exchange capacity (CEC), and soil organic carbon (SOC), an exponential model analyzed their spatial dependence.
Most of traditional spatial interpolation methods such as the family of Kriging or Inverse Distance Weighted (IDW) methods are based on spatial autocorrelation weight coefficients by using spatial distances and some assumptions to simplify the complexity of geospatial data and computation. Due to the complex non-linear relationship between spatial distance and autocorrelation weight, those traditional methods have limitations for obtaining highly accurate estimates. To address this problem, in this paper, we propose a meta-learning based spatial interpolation method, namely MetaSWNN, using a BP neural network to learn information from a sample dataset. Firstly, the MetaSWNN eliminates abnormal data by using a clustering algorithm for cleaning the sample set. Secondly, designing the spatial weighted neural network (SWNN) to calculate the spatial correlation weight coefficients, a predicted property value is estimated by the coefficients and the property values of the corresponding samples. Finally, MetaSWNN optimizes the network weights to obtain the accurate estimated values of predicted points by integrating with the mechanism of model-agnostic meta-learning. Our MetaSWNN method is utilized for a system of soil testing and formulated fertilization for intelligent agriculture. We compared MetaSWNN with eight state-of-the-art interpolation methods, and the results show that our MetaSWNN method outperforms the eight methods significantly.
Abstract1
Background and Objectives: Assessing soil quality and balancing between crop production and
quality of natural resources are essential issues in sustainable soil management for agricultural and
natural resource protection. In agricultural fields for optimum management and maximum economic
productivity, knowledge of the factors affecting the soil quality is necessary. Also, determining the
appropriate method for soil quality evaluation is important for sustainable soil management and soil
degradation prediction. This study was carried out with the aim of assessing soil quality of paddy
fields, determining the minimum data set for soil quality evaluation and investigating the effect of
soil quality index using different methods on rice yield in Pirbazar region of Guilan province.
Materials and Methods: Based on the mean annual rice yield, the selected paddy fields were
divided into low (<4.6 t ha-1
) and high (≥4.6 t ha-1
) productivity. Sixty soil samples were collected
from 0 to 30 cm depth. The rice products were harvested at a 1 m2
plot at each site. In this research,
using the principal component analysis (PCA) method, among 20 physical, chemical and biological
soil indicators as total data set (TDS), 6 indicators were selected for the minimum data set (MDS).
Then, the soil quality of high and low productivity paddy fields was evaluated by simple additive
integrated quality index (IQISA) and weighted additive integrated quality index (IQIWA) in two
collections of soil properties include MDS and TDS.
Results: To evaluate soil quality of paddy fields, an MDS was established with organic carbon, total
nitrogen, available potassium, clay percentage and urease activity and these explained about 67% of
the soil quality variability. The significant differences were found between the soil quality index of
low and high productivity paddy fields when IQIWA and IQISA were developed based on MDS.
So that, the mean IQISA-MDS and IQIWA-MDS of the high productivity paddy fields (0.84 and 0.89,
respectively) were higher than low productivity paddy fields (respectively 0.78 and 0.80,
respectively). Additionally, data indicated that IQISA-MDS and IQIWA-MDS were most strongly
correlated with crop yield, the correlation coefficient ranged between 0.44-0.54.
Conclusion: Significant differences between the soil quality indices based on MDS for low and
high productivity paddy fields indicated that the MDS more efficiently shows the difference of
soil quality between paddy fields with different productivity. The significant correlation between
IQISA-MDS and IQIWA-MDS indices with rice yield indicated that an MDS with a limited number of
indicators was carefully selected and effectively evaluated the status of soils as a rice production
medium. Therefore, using an MDS can save time and money and assess the reliable soil quality
indices of paddy fields in the study area.
A rapid change in soil chemistry caused by long-term acidic deposition directly and indirectly disturbs natural habitats and ecosystem functions. The aim of this paper was to analyse long-term depositions of sulphur and nitrogen, their relationship with the soil’s chemical properties, and areas currently/potentially at risk of ecosystem degradation. Models recommended by the Convention on Long-Range Transboundary Air Pollution (CLRTAP) were applied. Critical Loads calculations were derived for acidification, eutrophication and biodiversity using the VSD model. Changes in plant diversity and soil properties of beech forests and highland grasslands were simulated using the VSD\(+\)PROPS model based on future air pollution and RCP 4.0 climate scenarios. The results showed areas and biological receptors with varying degrees of vulnerability and susceptibility to air pollutants, as well as identifying areas that are adversely affected by the long-term deposition of sulphur and nitrogen. Mountain forests and high mountain grasslands developed on shallow soils exhibit the highest levels of sensitivity to acidic pollutants and climate change in Eastern Serbia. To provide a background for interpreting the results of the comparative analysis on air pollution and climate change effects at regional level, process-based and spatial distribution modelling were used. Estimated critical loads on both a regional and local level indicate ecosystems’ sensitivity and potential risk of degradation, providing a good basis for planning emission reduction on a regional level and evolving adaptive management measures in situ.
Toprak değişkenliğinin sistematik bir yapı göstermesi halinde jeoistatistiksel yöntemlerle analiz edilmesi klasik istatistiksel yöntemlere göre önemli avantajlar sağlamaktadır. Bu çalışmada Ilgaz Dağı doğal orman alanlarında birebirine bitişik saf Uludağ Göknarı (Abies nordmanniana subsp. Bormülleriana) ve Sarıçam (Pinus sylvestris ) – Saf Uludağ Göknarı karışımı iki meşcerede 0-15 ve 15-30 cm toprak derinliklerinde bazı toprak özelliklerinin uzaysal değişkenliğinin karşılaştırılması amaçlanmıştır. Toprak özelliklerinin deneysel semivaryogramları modellendikten sonra, bayağı (ordinary) krigleme yöntemi ile yüzey haritaları oluşturulmuştur. Karışık meşcerede üssel modelin saf meşcerede ise küresel modelin genellikle toprak özelliklerinin uzaysal yapısını daha iyi tanımladığı belirlenmiştir. Nugget etkisi %0,03 ve %100 arasında değişen değerler almış olup, genelde her iki meşcerede de yüksek olması, toprakların kısa mesafelerde oldukça değişken olduğunu göstermektedir. Jeoistatistiksel range (Ao) 4,38 ve 167,03 m arasında değişen değerler almıştır. Ancak, Ao değerleri bakımından meşcere tipi ve toprak derinlikleri arasında sistematik bir farklılık bulanamamıştır. Her iki meşcerede de toprak özelliklerinin uzaysal bağımlılığı 0-15 cm derinlikte daha düşük bulunmuştur. Toprak özelliklerinin kısa mesafelerde aşırı değişken olması nedeniyle krigleme entepolasyonundan başarılı sonuçlar alınamamıştır. İleride yapılacak benzer çalışmalarda bu hususun özellikle dikkate alınarak örnekleme aralıklarının daha kısa tutulması önerilmektedir.
Acidification due to acid atmospheric deposition affected strongly soils of many forested areas with long-term consequences. Liming is often used for amelioration, however, detailed assessment of soil and stand conditions is necessary to avoid possible undesirable effects. The aim of this paper is to apply and compare two spatial modelling methods to delineate probability that the criteria for potential liming in the Jizera Mountains region strongly impacted by acidification are met and to assess the uncertainty.
Soil characteristics from the last ten years were evaluated. Specific stands were excluded from consideration (peats, too skeletic stands, waterlogged stands, protected areas). Soils have low pH, low base saturation, and low content of base cations, so that most soil criteria required for potential liming approval are met. Only the ratios C/N and C/P in organic horizons fluctuate around thresholds of 20 and 250, respectively, and their distribution is thus crucial for decision making on liming. Two methods were tested: i) indicator regression-kriging with elevation as a covariate to map the probability that both criteria are met at once, ii) sequential Gaussian simulation to map the probabilities separately and then combining them by multiplying the probabilities. While both methods yielded similar maps of probabilities that the criteria are met, the second approach provided a more diverse map of error distribution, which may play an important role in the decision-making process.
Scots pine (Pinus sylvestris L.) is a widespread unpretentious forest tree-species; however, its adaptability to environmental change differs among sites with various buffering capacity. In this study, we compared the effect of precipitation and nitrogen deposition (ND) on biomass density in natural and man-made pine stands of differing soil fertility using lag geographically weighted multiple regression (LGWMR). Soil fertility was defined using ecological series as zonal trophic (27.9%), acidic (48.2%) gleyed (15.2%) and as azonal exposed (2.5%), maple (2.4%), ash (0.8%), wet (2.1%) and peat (0.9%) of the Czech Republic in Central Europe (4290.5 km²; 130–1298 m a.s.l.). Annual precipitation and ND in every pine stand were estimated using zonal statistics from 1 × 1 km grid for years of severe non-specific forest damage spread. Biomass density was obtained from a MODIS 250 × 250 m raster using the normalized difference vegetation index (NDVI) for years 2000–2014, with a decrease in NDVI indicating non-specific damage. Environmental change was assessed by comparing predictor values at NDVI time t and t+λ. Non-specific damage was registered over 51.9% of total forest area. Less than 8.8% of damaged stands are natural and the rest (91.2%) of damaged stands are man-made. Pure pine stands are more damaged than mixed. ND stand damage is more significant than damage due to the precipitation lack since 2007. ND during 2000–2010 decreased NDVI the most significantly at 2012. Exposed natural pine sites are the most sensitive to environmental change (R² = 0.11–0.86). The most widespread man-made pine stands on acidic sites are damaged at more open significance interval (R² = 0.07–0.88). Mixed forest and sustainable management at natural sites provide effective remediation reducing damage by ND.
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 mono- and 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.
The study area is located in the middle part of Jiangxi Province, China, and cover 6156.92 km\(^{2}\). It includes the Ji’an municipal district, Ji’an county and Taihe county. It is a typical red soil hilly region of South China. Respectively, the precipitation in the counties is 1458, 1438 and 1381 mm per annum and the mean annual temperature is 18.1, 18.4 and 19.0\(^\circ \)C which are typical values for a subtropical monsoon climate. The elevation decreases from the periphery towards the center with altitude ranging from 1204.5 to 42.0 m. According to the 1/1000 000 scale soil maps reported by National Soil Census Office in 1995 (Fig. 16.1), the soils in the study area are classified into 7 groups: red soils, paddy soils, purple soils, fluvo-aquic soils, yellow soils, alluvial soils and limestone soils.
The semivariogram provides a visual assessment of spatial dependence but without directly resulting in a single numerical value that expresses the measurement of such dependence. However, from the estimated parameters of the theoretical model adjusted to the experimental semivariogram, it is possible to construct a measure of this spatial dependence. Currently, there are two indices in literature that are widely used; however, these indices show some gaps. The aim of this study was to propose a new index to measure the spatial dependence of geostatistical data to overcome problems shown by existing indices. This new index uses the relationship between the semivariogram and the correlogram, thus including all aspects of spatial dependence. A comparison by simulation between the proposed index and existing indices was carried out, and the applicability of the proposed index was verified using actual published research, where adjustments of spherical, exponential, and Gaussian theoretical models were made. It was found that the proposed index was better than existing ones. Furthermore, it was observed that existing indices can lead to errors in the interpretation of the degree of spatial dependence, indicating that they should be avoided. As a result, the use of this new index to measure the degree of spatial dependence is recommended.
Forest productivity is dependent on soil quality, which in turn is related to litter; yet there is limited understanding of the relationships between litter and soil quality. The effects of litter removal treatment on tree growth and soil properties were examined in a Pinus caribaea stand with the aim of providing an understanding of consequences of litter removal on soil patterns. This knowledge is important for planning appropriate long-term forest management. Three pairs of 30 × 30 m2 plots (each pair a control and treatment) were established in the center of a P. caribaea stand in April 2002. The controls were left undisturbed with an intact litter layer, while litter was removed monthly from treated plots. The diameter and height of the P. caribaea decreased and soil quality was degraded over the experimental period in litter-removed (treated) plots. Litter removal also produced a significant increase in soil bulk density at 0–20 and 20–40 cm depths. The capillary porosity, capillary moisture capacity, and natural water content in controls at 0–20 and 20–40 cm depths were significantly greater than treated plots. The non-capillary porosity in controls at the 0–20 cm depth was also significantly higher than treated plots. The organic carbon, total nitrogen (N), total potassium (K) and alkalized N content in each layer, and available P and exchangeable K at 0–20 and 40–60 cm depths in control plots were significantly greater than litter-removed plots. The numbers of bacteria at 0–20 and 40–60 cm depths and of fungi at 20–40 and 40–60 cm depths were higher in control than treated plots. The number of actinomyces and urease, catalase, and acid phosphatase activities in controls at each depth were significantly greater than litter-removed plots.
The development of Podzols is conditioned by many factors. One of them is vegetation cover. The aim of this study was to examine in detail special chemical properties, micromorphological features and water retention ability of Podzols under two different vegetation covers (spruce forest and grass). The study was performed in the Jizerské hory Mts., which were strongly influenced by atmospheric acidificant depositions in the past. The study was focused on the assessment of a 30-year grass amelioration impact on soils on the former forest land. It was shown that larger differences in the studied chemical properties (pHKCl, pHH2O, eCEC, content of Ca, Mg, AlKCl, AlH2O, Al(X)1+, Al(Y)2+ and Al3+ species) were in the surface organic horizons and decreased with depth. Podzolization intensity was higher under the spruce forest than under the grass cover. Higher amounts of potentially dangerous Al forms were detected in the soils under the spruce forest than under the grass. Grass expansion on clear-cut areas (former forest) as a natural amelioration step results in the particular restoration of soil conditions. The micromorphological features studied on the soil thin sections using the optical microscope and soil water retention curves measured on the undisturbed 100 cm3 soil samples showed a significant influence of the organic matter presence on the soil structure and retention ability of H and Bhs horizons. Soil under the grass cover had denser structure (e.g. greater fraction of small capillary pores) and higher retention ability than soil under the spruce forest. Very similar retention curves were measured in the Ep and Bs horizons under both vegetation covers. Micromorphological features studied on the thin soil sections clearly documented a podzolization mechanism (e.g. organic material transport and its accumulation, weathering process and Fe oxidation and mobilization).
http://eusoils.jrc.it/ESDB_Archive/eusoils_docs/other/EUR23290.pdf
Soil acidification represents a serious problem in mountainous areas of the Czech Republic. It is mainly caused by acid parent materials, high precipitation, the type of vegetation, and acid deposition. These factors act in different combinations and result in different soil conditions. The aim of this chapter is to distinguish areas in the Jizera Mountains with different levels of soil acidification and sensitivity using fuzzy classification. A set of 98 sampling sites was analysed and sampling density was approximately 2 one site per 2 kin. Samples were collected from surface organic horizons (0), depth ranged from 4 to 22 cm depending on site conditions. Soil analysis included active and exchangeable soil pH, total content of C, N, and S, pseudototal content of Ca and Mg (after aqua regia digestion), and the ratio of absorbances of soil sodium pyrophosphate extract at the wavelengths of 400 and 600 nm as indicator of humus quality (A(400)/A(600)). Moreover, concentrations of exchangeable Al in KCI extract and organically bound Al in Na4P2O7 extract were determined. Soil classes were calculated using fuzzy k-rneans method with extragrades. Five classes were selected. The first class with high exchangeable A] content, high S and N, and low Ca, represents the area that was most affected by the acid deposition. The second class with the lowest pH represents strongly acid soils that have very high sensitivity to acidification, but with smaller acid deposition. The third class with high Ca content includes the areas that were limed in the past. The fourth class includes principally the sites with the highest S and N deposition that are populated by grass. The fifth class includes the areas with high Mg content; its distribution corresponds to beech forests that have more favourable effects on soils than spruce forests. Fuzzy classification distinguished soils with strongest sensitivity to acidification. Positive effect of beech forest, grass cover, and liming on surface organic soil horizons is shown.
Az Europai Unio 2002-es „Egy tematikus talajvedelmi strategia fele” cimű kozlemenyeben definialta a talaj funkcioit es a talajainkat veszelyeztető legfontosabb nyolc tenyezőt, melyek a kovetkezők: erozio, talaj szervesanyag-csokkenes, talajszennyezes, talajlefedes, talajtomorodes, talaj biodiverzitas csokkenes, szikesedes, arvizek es foldcsuszamlasok. Az „Environmental Assessment of Soil for Monitoring” (ENVASSO) Projekt az EU 25 tagallamanak reszvetelevel, egy harmonizalt modszertan kidolgozasat tűzte ki celul a talajtulajdonsagokban bekovetkező valtozasok nyomon kovetesere. Ennek erdekeben minden egyes talajt veszelyeztető tenyező vizsgalatara egy indikator harmast (TOP3) dolgozott ki. A talajainkat veszelyeztető nyolc tenyező kozul a talaj biodiverzitas csokkenesevel foglalkozunk reszletesen, melynek legfontosabb kivalasztott indikatorai: a foldigiliszta (BIO1) es ugrovillas (BIO2) diverzitas (fajdiverzitas), es a mikrobiologiai talajlegzes (BIO3) (biologiai funkcio). Kutatasunk celkitűzese az volt, ho...
We studied soils at three sites of natural mountain spruce (Picea abies (L.) Karst.) forests on metamorphic, volcanic and sedimentary bedrock. A total number of 1107 soil profiles were described within the continuous areas ≥ 40 ha. Geostatistical techniques were used to describe the spatial pattern and to detect the scale (range) and the degree of spatial dependence in soil data from 1 to 300 m distance in order to answer the following questions: Are there some general patterns of soil variability in natural mountain spruce forests? How does soil variability develop through spatial scales on different geological bedrock? How do soil spatial patterns reflect the structure and disturbance history of forest stand?
The study focused on the influence of several soil properties and forest species composition on spatial distribution of organic carbon stock in soils developed from the contrasted parent materials: Tertiary claystones and sandstones, and Qurternary sands of different origins. Soil sampling was performed on 110 plots, while forest mensuration was conducted on 82 ones. The content of <0.05 mm fraction determined by the type of parent material played a key role in the distribution of carbon stock in soils. Higher content of fine fraction favoured the accumulation in mineral part of soil, while higher sand content had an indirect influence on accumulation of carbon in the organic horizon. Forest species composition and biomass volume are more important for C accumulation in the O horizons. Taking into account the geological heterogeneity, the size of investigation area played a prominent role for the statistical significance of the observed correlations between carbon stocks and the other soil properties.
Empiric evidences indicate that agricultural soils of Argentina tend to acidify. The objective of this study was to determine the pH values of no-tilled and urea-fertilized-agricultural soils of Argentina during several years. Results indicated that both the actual pH (pHA) and the potential pH (pHP) values were lower in humid than in dry environments. The ratio between «mean annual precipitation:mean annual temperature» of the sites explained between 60 and 80% of the variability in pH values. This suggests that climatic conditions were responsible for current soil pH values. The pHA was 1.14 points higher tan pHP in all studied sites (p<0.01), indicating that a generalized natural acidification process existed. In soils of drier environments, differences between both pHA and pHP were, on average, higher than 1.21, indicating a more intense acidification process. However, pH values were not low enough to affect the normal growth of crops and soil organisms. In soils of humid environments, differences between pHA and pHP were higher than 1.10, being pHA values (6.17 and 5.80) acidic enough to affect the microbial activity and the development of pH sensitive crops. Fertilization with urea decreased pHA between 0.18 and 0.32 points compared to non-fertilized treatments (p<0.05), indicating that fertilization contributed to a decrease in pH values in the studied soils. In conclusion, fertilization with urea slightly increased the natural tendency to soil acidification in most of the studied soils.
The aim of this contribution was to describe spatial distribution of soil characteristics of forest floor in the Jizerské Mountains region and to assess the effect of stand factors by means of geostatistics, using structural correlation coefficients. Most soil properties showed a low spatial dependence with variogram range of 6000 m. Kriged maps of spatial distribution of soil properties were created. Most characteristics were influenced by altitude. A general decrease of pH and Ca and Mg content and an increase of potentially toxic Al forms (AlKCl) due to high S and N loading were demonstrated. An effect of liming on the decrease of AlKCl content, and higher pH and Mg content and lower AlKCl under beech forest were shown. Lower acidity and a better humus quality were found at higher altitudes under grass cover (Calamagrostis villosa) in spite of high S and N content. The ratios S/Ca and S/(Ca + Mg) can serve as an indicator of soil acidification level.
Three sources of soil acidity (bicarbonate leaching: base-cation accumulation in aboveground wood, roots, and forest floor;and acid atmospheric deposition) were evaluated in relation to exchangeable acidity of three forested Udults in Tennessee. The Udults have low effective CEC (CEC/sub e/), from 2.4 to 3.7 cmol/sub c/ kgâ»Â¹. In the three soils, H/sup +/ from bicarbonate leaching averaged 0.60 kmol/sub c/haâ»Â¹ yrâ»Â¹ over 2 yr. In five forest stands, 30 to 80 yr in age, H/sup +/ from accumulation of excess base cations in aboveground wood, roots, and forest floor averaged 1.11 kmol/sub c/ haâ»Â¹ yrâ»Â¹. Atmospheric H/sup +/ inputs, estimated from bulk precipitation, averaged 0.67 kmol/sub c/ haâ»Â¹ yrâ»Â¹. Total deposition of atmospheric acidity to these eastern Tennessee forests is on the order of 1 kmol/sub c/ haâ»Â¹ yrâ»Â¹. Variations in H/sup +/ inputs were caused by annual differences in the hydrologic cycle and by stand differences due to nutrient-cycling and soil-chemistry effects. In these forest ecosystems, sources of soil acidity from annual bicarbonate leaching and cation accumulation appeared to exceed atmospheric inputs. Exchangeable acidity in the forested Udults was large compared with annual fluxes of acidity. In the upper 60 cm of the three soils, KCl-exchangeable acidity ranged from 100 to 274 kmol/sub c/ haâ»Â¹, and BaClâ-TEA (triethanolamine) acidity ranged from 505 to 820 kmol/sub c/ haâ»Â¹. Despite low precipitation pH and low soil CEC/sub e/, the additional H+ from acid deposition has not caused significant alteration of soil acidity or base solution of these Udults.
Labile Al forms can be dangerous in acid soils due to their potential toxicity to plants. This paper deals with the distribution of exchangeable, weakly organically bound, and total organically bound Al forms in soils on 98 sites of the Jizera Mountains region. For the extraction of these Al forms, 0.5M KCl (AlKCl), 0.3M CuCl2 (AlCuCl2), and 0.05M Na4P2O7 (AlNa4P2O7) solutions were used, respectively. Aluminium concentrations in all extracts were determi- ned by means of ICP-OES. Following mean concentrations of Al forms were found in the O and B horizons (mg/kg): AlKCl - 1236 and 832, AlCuCl2 - 4268 and 1945, and AlNa4P2O7 - 5043 and 8420. Basic soil characteristics were determi- ned by commonly used methods. Their influence on Al forms distribution was assessed. Factor analysis showed that the most important soil factors controlling Al forms distribution were soil reaction and the total content of Ca (or Ca and Mg in the B horizon).
Three sources of soil acidity (bicarbonate leaching; base‐cation accumulation in aboveground wood, roots, and forest floor; and acid atmospheric deposition) were evaluated in relation to exchangeable acidity of three forested Udults in Tennessee. The Udults have low effective CEC (CEC e ), from 2.4 to 3.7 cmol c kg ⁻¹ . In the three soils, H ⁺ from bicarbonate leaching averaged 0.60 kmol c ha ⁻¹ yr ⁻¹ over 2 yr. In five forest stands, 30 to 80 yr in age, H ⁺ from accumulation of excess base (EB) cations [EB = (Ca + Mg + K) − (P + S)] in aboveground wood, roots, and forest floor averaged 1.11 kmol c ha ⁻¹ yr ⁻¹ . Atmospheric H ⁺ inputs, estimated from bulk precipitation, averaged 0.67 kmol c ha ⁻¹ yr ⁻¹ . Total deposition of atmospheric acidity to these eastern Tennessee forests is on the order of 1 kmol c ha ⁻¹ yr ⁻¹ . Variations in H ⁺ inputs were caused by annual differences in the hydrologic cycle and by stand differences due to nutrientcycling and soil‐chemistry effects. In these forest ecosystems, sources of soil acidity from annual bicarbonate leaching and cation accumulation appeared to exceed atmospheric inputs. Exchangeable acidity in the forested Udults was large compared with annual fluxes of acidity. In the upper 60 cm of the three soils, KCl‐exchangeable acidity ranged from 100 to 274 kmol c ha ⁻¹ , and BaCl 2 ‐TEA (trieth‐anolamine) acidity ranged from 505 to 820 kmol c ha ⁻¹ . Despite low precipitation pH and low soil CEC e , the additional H ⁺ from acid deposition has not caused significant alteration of soil acidity or base solution of these Udults.
Acid rain and repeated harvests reduce the amount of calcium available for forest growth. Ecosystem budgets suggest that the exchangeable (a pool is insufficient for forest regeneration, yet young stands appear to mobilize more than enough (a from the soil to meet their needs. Extractions of soil parent materials indicate that apatite provides a previously unappreciated source of plant-available Ca for forests in New Hampshire, upstate New York, and Maine with granitold parent materials. The threat of Ca depletion may not be as grove as previously predicted on these soil types. In contrast, apatite is not important of sites in Pennsylvania With sedimentary parent materials.
In two Czech catchments covered by Norway spruce forests, the MAGIC model was used to simulate annual stream water and soil chemistry for the period 1851-2030. These two sites represent geochemical end-members of ecosystem sensitivity to acidification (acid-sensitive granitic Lysina catchment vs. acid-resistant serpentinitic Pluhuv Bor catchment). Although the total deposition of sulphur to the catchments declined by 75% between 1990 and 2002, the recovery of stream water pH was relatively small over this period. At Lysina, the annual discharge-weighted mean pH of stream water increased only from 3.92 to 4.01. although SO4 concentration declined very sharply from 570 μeq L-1 in 1990 to 150 μeq L-1 in 2002. Stream water buffering was caused mainly by dissociation of organic acids. At Pluhuv Bor, the annual mean pH varied inversely with the annual discharge. Stream water concentrations of SO4 declined dramatically at Pluhuv Bor, from 1040 μeq L-1 in 1992 to 220 μeq L-1 in 2002. Using atmospheric deposition as specified in the Gothenburg Protocol, the model predicts that, at Lysina, stream water pH will increase to 4.3 and soil base saturation will increase to 6.0% by 2030 (from 5.6% in 2002): corresponding pre-industrial stream water pH was simulated to be 5.5 and soil base saturation to be 25%. At Pluhuv Bor, the pre-industrial pH was estimated to be 7.2 and the corresponding base saturation was 94%. Large anthropogenic acidification in the 20th century caused only a small decline in pH (to 6.9) and base saturation (to 88%). Simulations in accordance with the Gothenburg Protocol predict that the pH should increase by 0.2 pH units and the base saturation by 1% by 2030. Under this protocol, critical loads of atmospheric deposition for SO4 and NO3 will not be exceeded at Pluhuv Bor but will be exceeded at Lysina.
Little is known about solubility and soil solution concentrations of most elements occurring in the solid phase of soils. This study reports changes in solution concentrations of 60 mineral elements following CaCO3 addition to a moderately acid semi-natural soil, and possible mechanisms accounting for the differing solubility patterns as related to soil acidity are discussed. Soil solutions were obtained by high-speed centrifuging and ultrafiltration (0.2 μm) of samples at 60% water-holding capacity of the A horizon of a Cambisol developed from a shale-gneiss moraine and supplied with CaCO3 at 20 rates to yield a soil solution pH range of 5.2-7.8. Concentrations of elements were determined in the solutions by ICP-AES or (for most elements) ICP-MS. Several distinct patterns of soil solution concentrations as a function of soil solution pH were demonstrated. Positively related to pH and CaCO3 supply were soil solution concentrations of As, Br, Mo, S, Sb, Se, U, and W, and to a lesser degree, Co, Cr, Hg, Mg, and Sr. Inversely related to pH were concentrations of Al, B, Ba, Bi, Cs, Ce, Eu, Ga, Ge, Fe, Li, K, Rb, Na, Th, and Ti; less distinctly inversely rated were Dy, Er, Gd, Hf, La, Lu, Mn, Nd, Pr, Sm, Sc, Si, Tl, Tm, and Yb. 'U-shaped' relationships to pH were demonstrated for the concentrations of Ag, Cd, Nb, Ni, P, V, and Zr. There were no or irregular relations between pH and concentrations of Be, Cu, Ho, Pb, Ta, and Tb. Differences between elements in their soil solution concentrations as related to total (HNO3-digestible) concentrations and the solubility of organic C were also treated. Increasing the pH of a soil by adding CaCO3 changes the solubility of most mineral elements substantially, the several distinct patterns observed being governed by, for example, ionic properties and charge, affinity for organic compounds, and pH-dependent formation and solubility of complexes.
The effect of grass sward formation on soil environment was studied on a site affected by air pollution in the Moravian-Silesian Beskydy Mts. (Czech Republic). Acidophilous grasses (Calamagrostis arundinacea and C. villosa), common on clear-cut areas, were planted in blocks of soil inserted in plastic boxes modified to lysimeters. Their intensive growth resulted in a decrease of both the acidity of the soil percolates and the amount of nitrogen, especially of nitrates, in lysimetric waters leached from soils. Leaching of base cations (Ca2+ and Mg2+) was two to three times lower as from bare soil without grasses. An excess of labile Al was substantially eliminated in variants with grasses. Formation of a grass sward also coincided with a considerable decrease of conductivity of percolates. The biomass of soil microorganisms increased by 30% in variants with grasses. Thus, it is suggested that grass sward formation has a positive effect on the reduction of nutrient losses from the soil and partly eliminates negative processes associated with soil acidification.
The paper studies the effect of a single use of a textural fraction of dolomitic limestone (5.11 per ha) on soil reaction (pH/KCl and pH/H 2O) and the content of exchangeable Ca and Mg (in the soil layer of 0-30 cm or in F, H and A horizons) during a 6-year experiment under a mature Norway spruce stand and a 4-year experiment on a clear-felled area. The increase in pH culminated in the 3rd or in the 3rd-6th year of the experiment. Maximum effects were achieved applying the fine fraction of a particle size ≤ 1 mm. The coarse fraction of a particle size > 1 mm showed virtually negligible effects. The increase in Ca and Mg content culminated in the last 6th year of the experiment. Maximum effects were achieved applying fine fractions again. The effect of the coarse fraction was also virtually negligible. After 6 years, maximum increase in all values under study occurred in the upper narrow F horizon while the increase rapidly dropped downwards.
The degradation of forest ecosystems may be attributed to various natural and anthropogenic factors such as climatical extremes, biotic stresses, selection of tree species, harvesting regimes, litter raking, off-site amelioration measures, former land use, air pollutant deposition and soil acidification, as caused by internal and external processes. An important factor for a loss of tree vitality are nutritional disturbances, eventually leading to declining stand stability and productivity. Therefore, the potential risks of forest fertilization as a major tool for rehabilitation of naturally or anthropogenically degraded ecosystems are discussed. In this respect, both salt-like and lime fertilizers contribute positively to revitalization of nutrient deficient stands. Experience indicates that forest liming may indeed counterbalance the progress of soil acidification as caused by high H deposition. However, specific reactions within the rhizosphere, the enhanced mineralization and loss of organic matter, the mobilization of heavy metals and Ma+ cations and an increased NO3 leaching are possible risks of forest liming. The results from experiments with salt-like fertilizers do not show any negative influence of dissolved aluminium on root vitality but succeeded in revitalization of nutrient deficient stands. In the case of sulfatic fertilizers, both increased sulfate leaching and storage of sulfate in the bulk soil have been reported. Therefore, selection of fertilizer has to be based on a precise characterization of site specific chemical and physical conditions, including relevant stand parameters. Besides fertilization, forest regeneration with site-adapted tree species may greatly contribute to the rehabilitation of forest ecosystems, since the capacity for storage of C and N and hence, for a closer nutrient cycling, may be improved significantly through this approach.
In the present study we characterized the buffering system including aluminum in the organic surface horizon (O) of field experiments with replicated plots of pure Norway spruce (Picea abies (L.) Karst) and replicated plots of spruce with a birch (Betula pendula Roth and B. pubescens Ehrh.) admixture. Our results show that a change in tree species composition may have a rather large, short-term (12 years) effect on the concentration of organically bound aluminum in the humus layer (H) of the O horizon. The pure spruce plots had a significantly higher concentration of exchangeable aluminum (Ale) and organically bound (pyrophosphate extractable) aluminum (AlP) in the H layer and a lower concentration of each base cation. Furthermore, our results confirm earlier findings that aluminum has base cation properties in acidic organic horizons. Thus, the change in tree species composition did not affect the pH in spite of a change in base saturation, because base cations were mainly compensated for by aluminum. The change in organically bound aluminum was accompanied by a similar change in organically bound pyrophosphate extractable iron (FeP). The observed differences between the mixed and pure spruce plots in the amounts of AlP and FeP in the H layer could not be explained by estimated differences in biocycling of Al and Fe either by above-ground litterfall or by root turnover.
Massive forest damage has been observed in certain mountainous regions affected by acidification. Declining of trees is ascribed to direct effect of SO2 and also increasing concentration of mobile forms of Al in soils. The aim of this paper is to describe the influence of stand factors to distribution of Al forms in the Jizera Mountains region, Czech Republic. A set of 251 samples from 98 sites was collected. Basic soil characteristics and the content of different Al forms were determined. The amount and relative share of these Al forms under different types of vegetation was evaluated, with emphasis on the surface organic horizons. The results showed that phytotoxic mobile Al forms are the most influenced by altitude and organically bound Al forms by forest type. Non-toxic forms of Al are more abundant in broadleaved forest. Soils under coniferous forest are more affected by acidification.
In the last two decades, the anthropogenically induced acceleration of forest soil acidification has been a topic of environmental concern. Aluminum extractability and solubility were investigated in detail in six horizons of a Typic Haplohumod (FAO:Haplic Podzol) from southern Switzerland. Pyrophosphate and oxalate extractions as well as successive acid leaching indicated that in the Ah, (AE), and Bh horizons reactive Al is mainly bound to soil organic matter, whereas in the Bs, BC1, and BC2 horizons it is of inorganic nature. In the latter three horizons, infrared (IR) spectroscopy and transmission electron microscopy (TEM) revealed the presence of imogolite. Batch equilibrium experiments at 20 C in the pH range of approximately 3.5 to 5.5 showed that the podzol profile can be divided into two parts of different Al solubility control. In the Ah and (AE) horizons, Al solubility was found to be controlled by complexation reactions to soil organic matter. Kinetic studies with samples of the Bh, Bs, BC1, and BC2 horizons showed that ion activity products with respect to both Al(OH){sub 3} and imogolite, (HO){sub 3}Al{sub 2}O{sub 3}SiOH, reached a constant value after reaction times of 16 d. For pH {gt}4.1, the compilation of all data revealed pAl + 0.5 pSi = 3.05 pH {minus} 7.04 (r{sup 2} = 0.99) and pAl = 2.87 pH {minus} 8.07 (r{sup 2} = 0.99). These data could be shown to be consistent with either Al solubility control by imogolite-type material (ITM) with a log *K{sub s}{sup 0} = 6.53 {+-} 0.09, which dissolves incongruently, or a simultaneous equilibrium with ITM and hydroxy-Al interlayers of clay minerals. For pH {lt} 4.1, data indicated solubility control by a 1:1 aluminosilicate, e.g., poorly crystalline kaolinite.
Ten experiments were installed on acid soils in different ecoclimatic conditions of the Belgian Ardenne. Soil pH, exchangeable cations and P contents as well as foliar nutrient concentrations were monitored 1 and 3 years following the application of either (1) 3 t ha-1 of a dolomitic limestone or (2) 3 t ha-1 of a dolomitic limestone plus different amounts of P (0-800 kg natural phosphate) and/or K (0-250 kg K2SO4). Dolomite rapidly increased Ca and Mg concentrations in the 0-10 cm soil layer and in the tree leaves. After three years, exchangeable Al was significantly lower in the first soil layer but it still represented more than 50% of the exchangeable cations. Mean pH increase in the 0-10 em layer was less than 0.5 pH units. Dolomite alone tended to reduce mean K concentrations in the soils and/or leaves of the beech stands. The addition of potassium sulphate to dolomite generally increased the soil and foliar K contents in the spruce stands contrary to the beech stands It also tended to increase the resaturation of the exchange complex with Ca and Mg ions. The effects of natural phosphate addition were restricted to a slight increase of P foliar concentrations. The B foliar concentrations were reduced by both treatments, whereas Zn concentrations increased significantly. The between stands variability of soil and foliage chemical properties was important but did not influence the effects of the treatments.
Geostatistics offers a variety of models, methods and techniques for the analysis, estimation and display of multivariate data distributed in space or time. The book presents a brief review of statistical concepts, a detailed introduction to linear geostatistics, and an account of three basic methods of multivariate analysis. It contains an advanced presentation of linear models for multivariate spatial or temporal data, including the bilinear model of coregionalization, and an introduction to non-stationary geostatistics with a special focus on the external drift method. The 30 chapters are presented in five parts: preliminaries, geostatistics, multivariate analysis, multivariate geostatistics, non-stationary geostatistics. -from Publisher
Little is known about solubility and soil solution concentrations of most elements occurring in the solid phase of soils. This study reports changes in solution concentrations of 60 mineral elements following CaCO3 addition to a moderately acid semi-natural soil, and possible mechanisms accounting for the differing solubility patterns as related to soil acidity are discussed. Soil solutions were obtained by high-speed centrifuging and ultrafiltration (0.2 μm) of samples at 60% water-holding capacity of the A horizon of a Cambisol developed from a shale–gneiss moraine and supplied with CaCO3 at 20 rates to yield a soil solution pH range of 5.2–7.8. Concentrations of elements were determined in the solutions by ICP-AES or (for most elements) ICP-MS. Several distinct patterns of soil solution concentrations as a function of soil solution pH were demonstrated. Positively related to pH and CaCO3 supply were soil solution concentrations of As, Br, Mo, S, Sb, Se, U, and W, and to a lesser degree, Co, Cr, Hg, Mg, and Sr. Inversely related to pH were concentrations of Al, B, Ba, Bi, Cs, Ce, Eu, Ga, Ge, Fe, Li, K, Rb, Na, Th, and Ti; less distinctly inversely rated were Dy, Er, Gd, Hf, La, Lu, Mn, Nd, Pr, Sm, Sc, Si, Tl, Tm, and Yb. ‘U-shaped’ relationships to pH were demonstrated for the concentrations of Ag, Cd, Nb, Ni, P, V, and Zr. There were no or irregular relations between pH and concentrations of Be, Cu, Ho, Pb, Ta, and Tb. Differences between elements in their soil solution concentrations as related to total (HNO3-digestible) concentrations and the solubility of organic C were also treated. Increasing the pH of a soil by adding CaCO3 changes the solubility of most mineral elements substantially, the several distinct patterns observed being governed by, for example, ionic properties and charge, affinity for organic compounds, and pH-dependent formation and solubility of complexes.
Soil solution and needles of three mature spruce stands in Upper Austria were analysed in order to investigate the uptake and possible toxic effects of Mn and Al, as these two elements become highly mobilised in the soil due to increasing acidity. The Ca/Al molar ratio in the soil solution was below 0.2 in the most damaged stand during almost the whole vegetation period. Despite different dynamics, Al reaches almost identical values in all stands at the end of the vegetation period in both 1-year (current) and 2-year-old needles, respectively. Therefore, needle analysis is not a useful tool for estimation of free Al in the soil. Needle contents of other elements could provide a better information for understanding the forest decline. Mn in the needles correlates significantly with Mn concentrations in the soil solution. As soil Mn will be mobilised by acidic input, Mn needle content can increase to very high levels. Manganese distribution, its interaction with calcium, and possible toxic effects are discussed.
Al chemistry was studied in two acidic watersheds, one with a podzol, the other with an acid brown soil, in the Vosges mountains (N.E. France), by analysing both leaching and centrifugation soil solutions and spring waters over 3 yr. In the podzol, Al was mobilized in the eluvial horizons under the predominant influence of organic acidity, then leached down the profile as organic and F-bound Al. Strong undersaturation with respect to proto-imogolite and imogolite showed that the proto-imogolite theory of podzolization could not apply. Al was transferred from the soil to spring water mostly as Al3+ and Al-F. Al3+, as well as additional minor species (AlOH2+, AlSO4
+), originated from the redissolution of the top of the spodic horizons under the influence of both soil solution acidity and the occurrence of mobile anions derived from atmospheric deposition. Conversely, in the acid brown soil, Al mobilization was regulated by nitrate and occurred mainly as Al3+. Most of Al was retained in the deep soil and only traces of monomeric Al reached spring water. In the podzol eluvial horizons, soil solutions were undersaturated with respect to all relevant mineral phases and their chemical composition agree with the concept of a mobilization of Al from the solid soil organic Al and a control of Al3+ activity by complexation reaction with the solid and soluble soil organic matter and F. In the acid brown soil, soil solutions were found to be in equilibrium with natural alunite, and the formation of this mineral, if confirmed, would account for the occurrence of 'open' vermiculites instead of the expected hydroxy-Al interlayered vermiculites. Al solubility control in surface water of both watersheds remains unclear. The Al-F species in both watersheds and the likely control of Al solubility by alunite in the acid brown soil emphasize the influence of acid deposition on Al chemistry in acid watersheds.
Processes governing the mobilization of Al and Cd in podzols and cambisols of S. Sweden having different tree layer vegetation (Picea abies, Fagus sylvatica, or Betula pendula) were investigated. Speciation of Al and Cd in soil solutions were performed by a column cation exchange procedure (cf. Driscoll, 1984) in combination with thermodynamic calculations. Podzols in spruce and beech stands were characterized by a high release of organic compounds from the O/Ah horizons, resulting in a high organic complexation of Al (c. 93%) in the soil solution from the E horizon (15 cm lysimeters). Organic complexes were mainly adsorbed/precipitated in the upper Bh horizon and the overall transport of Al at 50 cm depth was governed by a pH dependent dissolution of a solid-phase Al pool. In the cambisols, inorganic Al forms were predominant at both 15 and 50 cm depth, and Al solubility was closely related to solution pH. Secondary minerals like synthetic gibbsite, jurbanite, kaolinite or imogolite could generally not explain measured solution Al3+ activities. Results instead indicated that the relatively large organically bound solid-phase Al pools present in both soil types could do so. The column fractionation procedure could be used only qualitatively for Cd, but results strongly indicated that Cd-organo complexes contributed significantly to the overall mobilization of Cd in the podzol E horizons. In all other soil solutions, Cd2+ was the predominant species. Both solid-phase and solution chemistry suggests that ion exchange processes controlled the Cd2+ activities in these solutions. All reactive solidphase Cd was extractable by NH4Cl and Cd2+ activities could in most cases effectively be modeled by the use of ion exchange equations. Solubilized Al3+ efficiently competed for exchange sites and played an important role for the Cd mobilization in these soils.
The properties of the soil and soil solution of two mixed spruce-beech forests in Southern Germany were investigated in order to identify non-additive effects of tree species compared to the monocultures. At five subplots in each of the two monocultures and at 10 subplots in each of the two mixed stands humus morphology, topsoil acidity as well as nitrate and sulphate concentrations in seepage water below the rooting zone were measured. At the Hglwald site, an 88 m sampling grid was also installed. Tree species composition within a 10 m circle surrounding each sampling point was correlated with the soil properties and the soil solution properties using the method of breakpoint estimation as well as a linear and a cubic model. At both sites, thickness and acidity of the forest floor as well as sulphate and nitrate concentrations in seepage water were significantly higher in the spruce monocultures than in the beech monocultures. Non-linear patterns in the correlation between both the thickness and the acidity of the forest floor and tree species composition occurred at both sites. In addition, nitrate concentration in the seepage water showed a non-linear correlation pattern at the Hglwald site. The correlation patterns were site specific and depended on stand history. While the influence of spruce at the Hglwald site was greater than expected from spruce monocultures, the opposite was found at the Schongau site. Interaction effects on nitrate concentration were absent at the Schongau site. Interaction effects on sulphate concentrations were absent at both sites. Current knowledge about the complex processes and patterns in mixed species stands is still limited. At least for certain properties, mixed species stands cannot be treated as a summation of the corresponding monocultures.
The primary goal of this work is to present a geostatistical software library known as GSLIB. An important prerequisite to geostatical case studies and research is the availability of flexible and understandable software. Flexibility is achieved by providing the original FORTRAN source code. A detailed description of the theoretical background along with specific application notes allows the algorithms to be understood and used as the basis for more advanced customized programs. The three main chapters of this guidebook are based on the three major problem areas of geostatistics: quantifying spatial variability (variograms), generalized linear regression techniques (kriging), and stochastic simulation. Additional utility programs and problem sets with partial solutions are given to allow a full exploration of GSLIB and to check new software installations.
An analytic criterion for rotation is defined. The scientific advantage of analytic criteria over subjective (graphical) rotational procedures is discussed. Carroll's criterion and the quartimax criterion are briefly reviewed; the varimax criterion is outlined in detail and contrasted both logically and numerically with the quartimax criterion. It is shown that thenormal varimax solution probably coincides closely to the application of the principle of simple structure. However, it is proposed that the ultimate criterion of a rotational procedure is factorial invariance, not simple structure—although the two notions appear to be highly related. The normal varimax criterion is shown to be a two-dimensional generalization of the classic Spearman case, i.e., it shows perfect factorial invariance for two pure clusters. An example is given of the invariance of a normal varimax solution for more than two factors. The oblique normal varimax criterion is stated. A computational outline for the orthogonal normal varimax is appended.
Labile Al forms and species can be a threat in acid soils due to their potential toxicity to plants. However, there is no universally accepted extraction method. Several extraction reagents for Al release from soil have been tested. KCl (0.5 or 1 M) is recommended for extraction of exchangeable Al, while 0.5 or 0.3 M CuCl(2) is suggested for extraction of 'weakly organically bound Al'. Both 0.1 and 0.05 M Na(4)P(2)O(7) are shown to be suitable for the extraction of 'total organically bound Al'. These extractions are relatively simple, robust, and applicable to different soils and soil horizons. In the second part of the paper, detailed speciation of exchangeable soil Al by means of an HPLC instrument equipped with an ion column (IC) is presented. An experimental set-up is described and tested on a set of samples. Interpretation of the speciation results is proposed, based on the separation of Al ions and Al complexes according to their charge. Speciation is shown to be dependent mainly on soil pH and organic matter quality. A general scheme of Al fractionation and speciation in soil is proposed.
Soil acidification and Al release in forest soils is controlled by a number of factors, like acid deposition, forest type, parent rock, altitude, etc. This paper studies the principal stand factors affecting spatial distribution of the content of KCl-extractable Al (Al(KCl), mainly exchangeable), Na4P2O7-extractable Al (Al(Na4P2O7), mainly organically bound), and other soil characteristics related to acidification in surface organic (O) and subsurface mineral (B) horizons in the Jizera Mountains region. Geostatistical methods were exploited. The highest Al(KCl) contents in the O horizons were related to high S and N content, low pH and low Ca and Mg content in soil. Liming decreased Al(KCl) contents in the O horizons. Al(Na4P2O7) in the O horizons was more abundant under spruce than under beech; in both horizons it was increased on the immission clear-cut areas populated by grass. Surface horizons are more sensitive to external influence (acid deposition, liming) and their spatial variation is stronger. In the mineral horizons, the effect of pedogenetic processes is more important. The effect of stand factors on Al behaviour is complex and often indirect, mediated for example by organic matter or soil reaction. It is difficult to clearly distinguish the effects of the particular factors.
An Introduction to Multivariate Statistical Analysis Speciation and mobilization of aluminium and cadmium in podzols and cambisols of S
- T W Anderson
Anderson, T.W., 2003. An Introduction to Multivariate Statistical Analysis, 3rd edition. John Wiley and Sons, Hoboken, NJ. Berggren, D., 1992. Speciation and mobilization of aluminium and cadmium in podzols and cambisols of S. Sweden. Water, Air and Soil Pollution 62, 125–156.
Aluminum solubility control in different horizons of a Podzol
- Zysset