Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.
Volume 8
Issue 1
Available Online: http://www.ejpau.media.pl/volume8/issue1/art-11.html


Valerie Vranová, Pavel Samec
Department of Geology and Pedology, Faculty of Forestry and Wood Technology, Mendel University of Agriculture and Forestry, Brno



The sorption complex of forest soils ensures the capability of pedons to adsorb exchangeable ions from soil solution and releases them mainly for interactions with plant roots. In this way it determines the physiologically utilisable trophic potential of the site. Its significance for biocoenose preservation on polluted localities increases mainly when it becomes the bearer of homeorhesis for ensuring of the succession processes. The present state (autumn 2002) of the effective and potential values of forest soil sorption complex basic characteristics and their momentary correlative relationships was studied in experimental substitute stands with varying tree-species composition in south-western part of the Broumovská vrchovina Highlands (Czech Republic). The mean annual temperature and the average annual precipitation are 6.9 °C and 671 mm, respectively. Two volumetric samples were taken from Ferralic Cambisols. The stands were afforested at a homogenized ground by ploughing. Due to an absence of old organic surface layers and an artificial homogenisation, the remarkable effects of pure and mixed tree species stands were evaluated. The highest values of the measured elements and quantities were detected at H-horizons. Predominantly, the differentation of Ca2+ and Mg2+ content and base cation content (BCC) were observed and links to varying tree-species composition and humification were statistically evaluated. The total potential values of cation exchange capacity (CECp) were not significantly differenced by varying stand tree-species composition; it depends mainly on the quantity of protons (H+) inputs.

Key words: cation exchange capacity (CEC), sorption complex, soil, phytocoenose.


Character of soil pedochemical properties depends on interrelationships between soil solution as a medium and pedogenetic residues which form the sorption complex (SC). The site trophic potential is the final result of the cooperation of these factors. Stimulated humification, translocation of decomposition products and their transformation into compounds acceptable by plant root system are basic demonstrations of natural biological and biochemical soil activity. Trophic potential (TP) of forest sites can not be studied without participation of biocoenosis as it is the source of organic matter for decomposition and humification resulting in occurence of soil colloidial sorption complex [2]. SC is the main bearer of the cation exchange capacity (CEC). CEC indicates the ability of soil to adsorb exchangeable ions from soil solution and to release them predominantly for interactions with rhizosphere. The significance of CEC for TP increases mainly on antropogenically-devastated localities. The air-pollution load by industrial deposition can be considered as a main cause of this devastation in the central-european environment [36]. It is possible to study the determinable quantities of SC as effective, determined at pH of soil solution or as potential helping to indicate the total capacity of binding points for participation in sorption processes [11, 31].

A set of six permanent research plots (PRPs) was selected as a model object for examination of the present state of SC and for detailed quantification of succession processes at antropogenically-influenced forest sites in experimental substitute stands in south-western part of the Broumovská vrchovina Highlands near the air-pollution source Trutnov-Poříčí (pollution damage zone B). The substitute stands in this demonstration object (DO) are used for monitoring of the effects of biological amelioration in air-polluted area [14, 16, 17, 33].


The six selected plots are a set of monocultures or mixed pole-stage stands with native or introduced tree species (Table 1) on the Poříčský hřbet Plateau (50°33'44'' N, 15°57'19'' E; 530 m a. s. l.). These stands with the area of 400 m2 were taken as experimental plots where all pedological, phytocoenological and forest mensuration research was conducted. The site (+6.9 °C; 671 mm) is situated in mezoclimatic and soil-type homogeneous area with uniform distribution of atmospheric precipitation over the vegetation and the dormant season [15]. Local biota generally corresponds with potential phytocoenoses of acidophilous beechwoods from the Luzulo-Fagetum association [6, 7, 23]. Developed recent soils at the study plots are represented by Ferralic Cambisol [11] [L – F – H – Ah (Ahe) – Bz (ABz) – Bv – BC – Cr]. Soil profile still shows significant marks of overall ploughing done in connection with the previous salvage felling due to air-pollution in 1965. The artificial homogenization by ploughing made an unified habitat without old dead organic matter layering. In top-soil of such material, the morphometrical and inner signs were closely related to the both direct and indirect effect of the selected forest tree species. [14, 20, 32]. The experimantal substitute stands were established on homogenized sites in 1966 – 1967 [20]. Surface humus layer has developed in dependence on character of dead organic matter sources, its decomposition and stage of humification into four subforms [9]: Hemimor, Mormoder, Mullmoder and Leptomoder.

Table 1. Basic data of selected PRPs (measured in October 2002, unpublished data)



Medium stem

Stand basal area (m2.ha-1)

Species composition (%)

canopy (%)

d1.3 (cm)

h (m)


Picea abies







Picea pungens







Pinus strobus







Fagus sylvatica







Betula pendula






Salix caprea






Quercus rubra






Betula pendula







Quercus rubra






Fagus sylvatica







Populus tremula





The PRPs are covered with pole-stage stands of Norway spruce (Picea abies), Blue spruce (Picea pungens), Scots pine (Pinus sylvestris), European beech (Fagus sylvatica), European birch (Betula pendula) and mixture of beech and European aspen (F. sylvatica+Populus tremula). Characteristic ground flora species are represented by Deschampsia caespitosa, D. flexuosa, Luzula luzuloides, L. pilosa, L. sylvatica, Fragaria vesca, Vaccinium myrtillus, Lycopodium annotinum [14, 30], and mosses from genera Dicranum, Dicranella or Pleurozium. Bioindicative values of herb species spreading by succession [3] indicated some relations between biota and site conditions [30].


Soil survey on the six selected PRPs was carried out in October 2002. The samples were taken from three randomly selected points at each plot. The sampling concentrated on H-horizon and on A-horizon in thickness 2 – 5 cm (A1 layer) and 5 – 20 cm (AB2 layer) according to Kantor (1989) [14] and Podrázský (1995) [26]. Assessment of the effective values of SC quantities was carried out by Gillman's method [8, 9] with repeated BaCl2 extraction at soil solution pH. The volumes of Mg2+, Ca2+, K+, Na+, Fe2+/Fe3+, Al3++ (Ha) were assessed from the extract by spectrophotometry techniques and CECeff values were calculated as sums of concentrations of the assessed ions. Base cation content (BCC1) was assessed as ∑(Ca2+;Mg2+;K+;Na+). Assessment of potential sorption values was performed by BaCl2 extraction at pH 8.1 [1, 38]. These Ba2+ ions were extracted by CaCl2. The concentration of exchangeable Hp+ was assessed by titration with HCl measuring solution. Potential CECp value was calculated (Formula 1) according to direct dependence between concentration (c) of removed Ba2+ and weight of the matter (m). Value of BCC2 in sorption complex of the analysed soil samples was taken according to assessed CECp as CECp difference. All result obtained data were evaluated using by statistical analyses of global linear modelling (GLM) as well as non-linear models. Constructions of correlative linear models and analysis of variance (ANOVA) as a parametric test with randomised effects were used as GLM methods. Results were always tested by Fisher-Snedecorov´s F-test at P<0.05. The significance of regression models was verified by methods of regression diagnostic [19].

Formula 1. [mmol.kg-1]


Two-way ANOVA detected statistically significant differences of the studied sorption quantities in dependence on soil profile depth (Fig. 15) or between individual plots. The highest values of the studied quantities were generally observed in H-horizons (Table 2). Nevertheless, value differences in H-horizons in contrast to A-horizons were not always found to be statistically significant. The obtained CEC values are significantly different in individual horizons only. Its values show similar character in individual PRPs. The results of H+, K+, and BCC2 analyses (Table 3) were analogous. Statistically significant differences between PRPs were unambiguously detected for Ca2+ and Mg2+. Distribution of magnesium varied with soil profile depth, too. Calcium distribution in soil profile on individual plots seems to be almost homogeneous with the maximum concentrations in H-horizons. Differences found in Na+ concentrations were insignificant. The obtained BCC1 values for H-horizons are influenced by methodical mistake, although they admit statistically significant differences between individual PRPs according to evaluation of base cation content. The CECeff values ranged from 81.6 to 177.7 mmol.kg-1 in H-horizons. Permanent research plot (PRP) with P. pungens stand showed the highest CECeff value, the lowest value was found in PRP with B. pendula. However, its higher values of averages (in interval of 81.6 – 174.6 mmol.kg-1) were obtained for broadleaved stands (139.0 mmol.kg-1). The A1 layer was characterized by CECeff values ranging from 38.7 to 86.8 mmol.kg-1. The AB2 layer showed the value interval of 41.2 – 65.3 mmol.kg-1. The CECp values in H-horizons were between 115.3 and 544.0 mmol.kg-1. Again, the maximum value was found in P. pungens and the minimum value in B. pendula stand. However, the CECp value strongly dependes on H+ concentration in these cases (Fig. 6), that is why concentration of reached 433.2 mmol.kg-1 at PRP with P. pungens while on PRP B. pendula it was 89.2 mmol.kg-1 only. Analogously, low values were obtained for Ca2+ content (2.9 mmol.kg-1) and Mg2+ content (20.8 .mmol.kg-1) in H-horizons on this plot, similarly to plots with coniferous stands (Ca2+ ; Mg2+ mmol.kg-1). The highest values for both bases were obtained on PRPs F. sylvatica+B. pendula (Ca2+ 17.8 mmol.kg-1; Mg2+ 129.4 mmol.kg-1) and on P. tremula+F. sylvatica (Ca2+ 16.5 mmol.kg-1; Mg2+ 107.9 mmol.kg-1). For PRP P. tremula+F. sylvatica the indicated situation remains the same also in A1 and AB2 layers. The state of CECp appears to be statistically dependent on concentration in the whole examined profile though with reduced probability P<0.10 in A1 layer (Fig. 78). The final value of CECeff seems to depend mainly on K+ (Fig. 910) and Mg2+ (Fig. 11) contents. Calcium showed some influence on CECeff at P<0.10 only (Fig. 12). Therefore, the correlation between CEC and BCC was detected at P<0.03 (Fig. 13).

Fig. 1. Statistical non-linear functions of CEC

Fig. 2. Statistical non-linear functions of BCC

Fig. 3. Models of H+ concentrations in soil

Fig. 4. Model of Mg2+ concentrations in soil

Fig. 5. Model of K+ concentrations in soil

Fig. 6. Linear model for CEC and H+ in H-horizon

Fig. 7. Linear model for CEC and H+ in A1 layer

Fig. 8. Linear model for CEC and H+ in AB2 layer

Fig. 9. Linear model for CEC and K+ in H-horizon

Fig. 10. Linear model for CEC and K+ in A1 layer

Fig. 11. Linear model for CEC and Mg2+ in H-horizon

Fig. 12. Linear model for CEC and Ca2+ in H-horizon

Fig. 13. Linear model for CEC and BCC in H-horizon

Table 2. Description (average +/- 95% standard deviation) of sorption quantities and selected nutrient elements [mmol.kg-1]

Horizon layer




















2 -5 (cm)











5 -20 (cm)











Table 3. The comparison of effective and potential sorption quantities statistical functions in soil profile (P<0.20)



Regression formula




















The Podkrkonoąí region was one from the most air-pollution affected areas of the Czech Republic [19]. This area includes a large depression between the Krkonoąe Mts., the Jizerské hory Mts., the Kozákovské pásmo Range and the Broumovská vrchovina Highlands in the nothern part of Bohemian Massive [25] where most of the pollution was from local sources [22]. At the present, the Orlické hory Mts. and the Kruąné hory Mts. reprezent the most air-pollution affected forest regions of the whole Czech Republic. Main air pollutants in Podkrkonoąí region were , F-, and Cl- significantly accompanied by alkali ash deposition. Between 1980 - 1986 the SO2 deposition amounted on average to 59 µg.m-3 here. The significant decrease of ash deposition was measured during 1982 – 1983. The pollution source Trutnov-Poříčí power station was completely desulphurized in 1998, however, a significant decrease of SO2 deposition to 14 µg.m-3 occurred in the DO already in 1994 – 1996. Its present level around the PRP reaches 10 µg.m-3 on average. Pollution load gradually ceased to be the limiting factor for existence of forest stands in the DO [20 – 22]. In connection with the present minimization of pollution load, processes of natural revitalization of forest soils are going on [16, 17, 27, 37]. Decomposition and humification are important aspects of these processes [12, 24, 26 – 28], although they are limited by meteorological and climatic fluctuations and forest decline [18].

We confirmed that the cation exchange capacity is primarily linked to products of humification: the highest values of CEC were found in H-horizons. The results showed that a decrease in humic substances was followed by a decrease in CEC and no evidences for a higher role of clay minerals were presented. On the study plots with homogenised A-horizons, there were found no differences in BCC which contrasted much to H-horizons under particular forest tree species. On the contrary, we did not find statistically significant differences in plots of different tree species stands which were bound to PRPs. Such conclusions were reinforced by bulk densities (Db) and specific densities (Ds) [29] in A1 layers and AB2 layers. The values of the properties on the selected PRPs (and, on the homogenised soil material) were closely related to an amount of humic substances in a horizon studied. On the contrary, no relations were found between these values and changes of layering of surface dead organic matter [30]. We treated a seasonal dynamics of Db a Ds values and presented just slight differences which did not show statistically significant relations to particular forest tree species [4]. We were fully aware that Ds values are relatively constant, just depending on a changeable volume of high-density minerals (the positive feedback) and soil organic matter (the negative feedback) [5].

The CEC values in H-horizont showed similar patterns as commensurate measurements on the selected PRPs. Kantor (1989) [14] gave data on linkages among base saturation in H-horizont and the particular forest tree species and spoke about a biological amelioration. He presented a positive effect of F. sylvatica, Salix caprea and a combination P.tremula+F.sylvatica on PRPs. Nevertheless, the statistical significances were not proved due to very high variance of the data treated. In addition, a general usage of Kappen method can influence the final conclusions due to its methodological limitations.

Biological and chemical processes in soil accompanied by climate fluctuations can still cause soil acidification even in case of decreasing H+, and N deposition and in this way influence the chemistry of soil solution and runoff water [17]. The forest soil buffering actions could be influenced by long-term air-pollution acidification on large areas of Central Europe [33 – 36]. Although the studied sites correspond to aluminium buffering of soil [16], the Al3+ released here does not necessarily originate from pedogenetic matrix; in upper soil horizons it may originate from ash. If the Ca2+ and Mg2+ concentrations, which were both significantly different at individual plots, correctly indicate dominant participation in BCC, then the biological melioration by litterfall and ecological cover of substitute stands influences SC quantities of forest soils under submontane conditions of the Podkrkonoąí region. Distortion of SC quantities results may be caused by presence of soluble salts or carbonates, by partial dissolving of organic matter, selectivity of extract sorption during pH assessment, buffer solution or by ionic strength of the forming electrolytes [31].


  1. On one study site with and identical climatic and after artificial homogenization of mineral material by ploughing, the values of soil sorption estimations and amounts of bioavailable mineral nutrients showed statistically significant differences among individual PRPs.

  2. The highest values of CECeff ani CECp were determined in H-horizont.

  3. The values of CECeff and CECp were closely related to the depth of a horizon sampled.

  4. The statistically significant differences among the PRPs were proved in particular in H-horizons for the three items: the contents of Ca2+ and Mg2+ and BCC values.

  5. The values of CECp were closely related to H+p concentrations.

  6. The values of CECeff were closely related to both K+ and Mg2+ concentrations.


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Valerie Vranová
Department of Geology and Pedology,
Faculty of Forestry and Wood Technology,
Mendel University of Agriculture and Forestry, Brno
Zemědělská 3, 613 00, Brno, Czech Republic
Phone: +420 545134530,
fax: +420 454211422
email: vranova@mendelu.cz

Pavel Samec
Department of Geology and Pedology,
Faculty of Forestry and Wood Technology,
Mendel University of Agriculture and Forestry, Brno
Zemědělská 3, 613 00, Brno, Czech Republic
Phone: +420 545134530
fax: +420 454211422
email: psamec@post.cz

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