Effects of lining and fertilization on soil solution chemistry in North German Forest Ecosystems

The effect of aboveground liming and fertilization as well as ploughing and liming of forest soils on soil solution chemistry was studied in various experimental plots of the German Solling area. Due to low solubility of limestone, aboveground liming had only moderate effects on soil pH and base saturation of CEC. Calcium and Mg concentration increased and Ca/Al and Mg/Al ratios of the soil solution improved. Despite extreme doses of lime, nitrate leaching did not increase in the case of a beech plot. Elevated nitrate leaching was found in the case of a spruce and a beech plot previously fertilized with N. Nitrate concentrations are far from drinking water thresholds in the case of beech. Nitrate levels of soil solution of the unfertilized spruce plot are in the range of 3 to 8 mg L^–1. Liming did increase these values slightly in the first years, and nitrate levels reached those of the untreated plot in the following years. Ploughing connected with high liming doses obviously led to inhomogeneous distribution of lime. No significant deacidification of seepage water at a depth of 100 cm occurred because of leaching of sulfate from the industrial lime used. This was followed by Alleaching. Nitrate levels slightly exceeded drinking water standards throughout the first winter period after the measure. The development of young trees was significantly improved.     

Determinants of soil organic matter chemistry in maritime temperate forest ecosystems

While the influence of climate, vegetation, management and abiotic site factors on total carbon budgets and turn-over is intensively assessed, the influences of these ecosystem properties on the chemical complexity of soil organic matter (SOM) remains poorly understood. This study addresses the chemical composition of NaOH-extracted SOM from maritime temperate forest sites in Flanders (Belgium) by pyrolysis-GC/MS. The studied forests were chosen based on dominant tree species (Pinus sylvestris, Fagus sylvatica, Quercus robur and Populus spp.), soil texture and soil-moisture conditions. Differences in extractable-SOM pyrolysis products were correlated to site variables including dominant tree species, management of the woody biomass, site history, soil properties, total carbon stocks and indicators for microbial activity. Despite of a typical high intercorrelation between these site variables, the influence of the dominant tree species is prominent. The extractable-SOM composition is strongly correlated to litter quality and available nutrients. In nutrient-poor forests with low litter quality, the decomposition of relatively recalcitrant compounds (i.e. short and mid-chain alkanes/alkenes and aromatic compounds) appears hampered, causing a relative accumulation of these compounds in the soil. However, if substrate quality is favorable, no accumulations of recalcitrant compounds were observed, not even under high soil-moisture conditions. Former heathland vegetation still had a profound influence on extractable-SOM chemistry of young pine forests after a minimum of 60 years.     

Effects of liming,fertilization and acidification on pH,soil moisture,and ATP content of soil from a spruce forest in Southern Germany

Short-term and medíum-term effects of liming (CaCO₃), fertilization [5Ca(NO)₃)₂·NH₄NO₃], and acidification on soil bioactivity were measured in a spruce stand in Southern Germany. The experiment was set up in a randomized block design. Acid precipitation lowered the pH, liming increased the pH, while fertilization caused only small alterations in pH values. Significant differences in soil moisture occurred only in the mineral horizons. The soil ATP content of the humus layers decreased in all plots (control included) up to day 100. On all sampling dates, a pronounced decrease in ATP content followed the acidification. Minor decreases in ATP were observed after fertilization, while liming produced no defined effects. Similar trends, but less pronounced, were observed in the mineral horizons. Only a few significant correlations were found between pH values and ATP or between moisture and ATP within a treatment and sampling date. Present address: Institut für Biologie II (Zoologie), RWTH Aachen, Kopernikusstrasse 16, D-52056 Aachen, Germany     

The effects of forest liming on fertilization on fine-root growth

Results are reported from the investigations of fine-root development in Norway spruce and Scots pine stands in South and Central Sweden, subjected to different liming and fertilization regimes. The growth responses of the fine roots to varying mineral nutrient regimes seem to be dependent on the tree species, the age of the tree population and soil conditions. Nitrogen fertilization in some of the investigated stands had negative effects on the development of fine roots, resulting in a reduction in the amount of fine roots to about 50% of that in the control. However, negative effects were not consistent in all stands, positive growth responses were also obtained. In these stands, the amount of fine roots was increased by 2 to 3 times. Liming in combination with fertilization resulted in a strong decrease in the amount of fine roots to about 30% of that in the control in some of the investigated stands. Liming in high doses is expected to produce a persistent increase in pH (H₂O and base saturation in the soil. However, results from the present study suggest that liming may have a negative effect on the development of tree fine roots, particularly in areas with a high N deposition. The application of crushed dolomite had less negative effects on fine root development than crushed calcitric lime and different types of residue products, such as wood and peat ashes.     

The effects of forest liming on fertilization on fine-root growth

Results are reported from the investigations of fine-root development in Norway spruce and Scots pine stands in South and Central Sweden, subjected to different liming and fertilization regimes. The growth responses of the fine roots to varying mineral nutrient regimes seem to be dependent on the tree species, the age of the tree population and soil conditions. Nitrogen fertilization in some of the investigated stands had negative effects on the development of fine roots, resulting in a reduction in the amount of fine roots to about 50% of that in the control. However, negative effects were not consistent in all stands, positive growth responses were also obtained. In these stands, the amount of fine roots was increased by 2 to 3 times. Liming in combination with fertilization resulted in a strong decrease in the amount of fine roots to about 30% of that in the control in some of the investigated stands. Liming in high doses is expected to produce a persistent increase in pH (H₂O) and base saturation in the soil. However, results from the present study suggest that liming may have a negative effect on the development of tree fine roots, particularly in areas with a high N deposition. The application of crushed dolomite had less negative effects on fine root development than crushed calcitric lime and different types of residue products, such as wood and peat ashes.     

Acid deposition in the German solling area: Effects on soil solution chemistry and Al mobilization

The Al chemistry of soil solutions was evaluated in two forest ecosystems in the North-German Solling area which is heavily impacted by acidic deposition. The principal H⁺ buffering process in these soils is the release of Al ions. Within the stand of Norway spruce, Al concentrations increase with soil depth up to 370 umol/L. Ca/Al ratios of the soil solution decrease with depth and suggest high risk of Al toxicity to tree roots and potential antagonistic effects for ion uptake. The Al concentrations of the soil solution in the upper horizons do not appear to be in equilibrium with mineral phases of Gibbsite, Alunite and Jurbanite as suggested by the depth gradients and temporal patterns in ion activity products. Depletion of extractable soil Al in the upper horizons is occuring. The release of Al to the soil solution under these conditions seems to be restricted by kinetic constraints.     

Simulation of solution chemistry in an acidic forest soil

The computer simulation model SOILEQ was used to estimate soil solution chemistry over a 7 week period from October 3 to November 14, 1988 in the soils of a sugar maple forest located near St. Hippolyte, Quebec, Canada. Model parameters for pH-dependent CEC and exchangeable cations were calculated from laboratory measurements while soil solution chemistry, including Al solubility, at the start of the simulation was taken from values obtained from lysimeter samples. Model predictions were compared with values obtained from 12 sets of soil solution collectors over the same time period. Predicted values of Ca, Mg and K in the mineral soil horizons at 25-, 75- and 125-cm depths generally fall within the 95% confidence interval of the median for the measured values. Simulated values of pH and inorganic Al are not as close to the measured values. Some error due to drift is apparent, most notably for base cations in solutions leaving the organic surface horizons, and may be attributable to decomposition of organic matter, not included in the simulation model. The results indicate that other mechanisms that release H* (nitrification, for example) and base cations (mineral weathering or mineralization of organic matter) need to be considered.     

Effects of forest age on surface drainage water and soil solution aluminium chemistry in stagnopodzols in Wales

The influence of forest development on soil solution and surface drainage water aluminium chemistry was investigated in Sitka spruce (Picea sitchensis) plantations in Wales. Comparisons with semi-natural grassland and moorland sites are described. A highly significant positive relationship was shown between increasing forest age and soilwater aluminium concentrations in the B horizons. Shortterm/episodic peaks in Al concentrations were strongly related to incidences of high concentrations of neutral, marine-derived, salts in the soilwater. Nitrification may be an important factor in soil acidification and the mobilization of Al in soilwaters beneath the older mature-forest plantations in Wales. Labile monomeric Al concentrations were largest in surface waters draining the oldest forestry plantations compared with younger forest catchments and moorland, although response to discharge of soilwater acidity to the surface waters at individual sites was dependent on the acid neutralizing capacity of the groundwater component of the surface waters.     

Decomposition rates and feeding activities of soil fauna in deciduous forest soils in relation to soil chemical parameters following liming and fertilization

 This study investigated the influence of liming and P/K fertilization on the feeding activities of soil fauna and leaf litter decomposition rates in deciduous forest soils. The parameters examined were correlated to soil chemical characteristics. In 1994, we established a field experiment with six plots in an oak-beech forest and added different amounts of dolomite, partly combined with P/K fertilization. Two years thereafter a bait-lamina test was used to examine the feeding activity of soil fauna and a minicontainer test to study beech-leaf decomposition. In 1996, the feeding activity in the Ah horizon was lower in the plots left untreated in 1994 than in the plots which had been fertilized in 1994. The highest feeding activity was found in the treatment with 6 t dolomite ha^–1 plus P/K. In all plots, the feeding activity decreased with increasing soil depth. The decomposition rates varied from 0.49% to 0.78% week^–1 in the period April–October 1996. In 1996, the plots treated with 6 t dolomite ha^–1 had the highest decomposition rates and differed significantly from those treated with 9 t or 15 t dolomite ha^–1. No significant differences were found between the untreated plots and those treated with 9 t or 15 t dolomite ha^–1. These results were confirmed by those obtained in 1997. The C/N ratio of litter also decreased, mostly in the treatment with 6 t dolomite ha^–1. Feeding activities in the Ah horizon correlated positively with pH and concentrations of mobile Ca, Mg, K, and negatively with concentrations of mobile Al and heavy metals. We concluded that an increased supply of mobile nutrients and a decrease in mobile Al and heavy metals in these forest soils, as well as a balanced ratio between macro- and micronutrients, led to increased biological activity. Received: 26 June 1998     

Effects of acid anion additions (trifluoroacetate and bromide) on soil solution chemistry of a northern hardwood forest soil

Experimental plots within the Hubbard Brook Experimental Forest, NH, were treated with sodium trifluoroacetate (TFA) and lithium bromide (Br), to study the impact of TFA alone and in the presence of increased anion concentrations (e.g. acid deposition) on the soil solution chemistry of a northern hardwood forest soil. Trifluoroacetate is a major atmospheric degradation product of replacement compounds of chlorofluorocarbons (CFC) and Br is widely used as a hydrologic tracer. Calculated drainage losses via soil water flow were less than 60% of inputs, added during the summer, and TFA and Br were temporarily retained in the soil until fall. The initial indication of an acid input of the treatments (HTFA, HBr) in the Bs2 horizon, which reflects stream water chemistry as well, was an increase of base cations in the soil solution, decreasing the soil's acid neutralizing capacity. Thereafter, trifluoroacetate and Br concentrations peaked after the peak in base cations, synchronous with peaks in H⁺ and Al concentrations. Organic anions, nitrate and chloride played the major role in accompaning base cations out of the solum. Sulfate retention at soil adsorption sites was increased by the presence of TFA and Br, reducing its role as a mobile anion of base cations in this experiment. Relative retention of anions for the whole profile of this northern hardwood forest soil was estimated by correlation analyses and input-output balances in decreasing order on an equivalant basis: SO₄ > TFA = Br ≥ Cl > NO₃ > organic anions. Recovery from acid additions were recorded within several weeks after the treatments were stopped. Evaluating the impact of added chemical compounds to soils must be considered within the context of linkages among element cycles and pools.     

Liming and fertilization as mitigation tools in declining forest ecosystems

In central Europe the ‘new type’ forest damages have been observed since the mid 1970's. Various investigations indicate that the declines are frequently associated with nutritional disturbances. Good correlations between the site specific substrate chemistry and the actual nutritional status of the trees/stands were found. To explain the sudden and widespread appearance of the forest declines, adverse anthropogenic impacts mainly due to elevated emissions of air pollutants and their atmospheric derivatives are hypothesized in combination with natural stress factors. Causal mechanisms include soil degradation due to accelerated soil acidification and increased nutrient leaching from the canopy of forest stands. Fertilization and liming experiments have demonstrated that a fast and sustained revitalization and restabilization of declining forest ecosystems marked by nutritional disturbances can be achieved. This is demonstrated by chemical and histological foliar analyses generally combined with a visible improvement of the phenotype. Soil analyses reveal a considerable positive change of the chemical soil status due to the site and species specific application of appropriate amounts of fast soluble fertilizers and lime. Considering these recent favorable findings, as well as based on observations from historic fertilization and liming trials nutrient supplementation and liming have become common tools to counteract the new type forest damages in West Germany.     

Soil solution and extractable soil nitrogen response to climate change in two boreal forest ecosystems

Several studies show that increases in soil temperature result in higher N mineralization rates in soils. It is, however, unclear if additional N is taken up by the vegetation or accumulates in the soil. To address this question two small, forested catchments in southern Norway were experimentally manipulated by increasing air temperature (+3°C in summer to +5°C in winter) and CO₂ concentrations (+200 ppmv) in one catchment (CO₂T-T) and soil temperature (+3°C in summer to +5°C in winter) using heating cables in a second catchment (T-T). During the first treatment year, the climate treatments caused significant increases in soil extractable NH₄ under Vaccinium in CO₂T-T. In the second treatment year extractable NH₄ in CO₂T-T and NO₃ in T-T significantly increased. Soil solution NH₄ concentrations did not follow patterns in extractable NH₄ but changes in soil NO₃ pools were reflected by changes in dissolved NO₃. The anomalous behavior of soil solution NH₄ compared to NO₃ was most likely due to the higher NH₄ adsorption capacity of the soil. The data from this study showed that after 2 years of treatment soil inorganic N pools increased indicating that increases in mineralization, as observed in previous studies, exceeded plant demand and leaching losses.     

Aluminium chemistry of the soil solution in an acid forest soil as influenced by percolation rate and soil structure

The predicted activity of Al in the soil solutions of acid forest soils often differs from that observed in the field. We have investigated the influence of soil structure and flow rate of the soil solution on the aluminum release to explain this divergence. Disturbed and undisturbed samples of soil were collected from the A and B horizons of a dystric cambisol at Waldstein (Fichtelgebirge, Germany). The samples were irrigated with solutions mixed according to field data on throughfall or soil solution composition with pH 3.5 with flow rates of 4 mm d^?1, 12 mm d^?1 and 36 mm d^?1. The percolates were analysed for major ions. Resulting relations between pH and pAl were compared with batch experiments. In neither the A horizon nor in the B horizon did soil structure influence the relation between pH and pAl. The apparent equilibrium between pH and pAl was described as the pK_app value with pK_app= pAl—a pH (where a is an empirical constant). It was found that the pK_app values for the column percolates were in the range of variation of those found in batch experiments. Flow rate had no influence on pK_app at 4 and 12 mm d^?1. At 36 mm d^?1 a significant increase of pK_app was observed. This relative undersaturation of Al was more pronounced in the A horizon than in the B horizon. When flow is fast Al release into the percolating soil solution might be limited by diffusion.     

Long-term fertilization, manure and liming effects on soil organic matter and crop yields

Yield decline or stagnation and its relationship with soil organic matter fractions in soybean (Glycine max L.)–wheat (Triticum aestivum L.) cropping system under long-term fertilizer use are not well understood. To understand this phenomenon, soil organic matter fractions and soil aggregate size distribution were studied in an Alfisol (Typic Haplustalf) at a long-term experiment at Birsa Agricultural University, Ranchi, India. For 30 years, the following fertilizer treatments were compared with undisturbed fallow plots (without crop and fertilizer management): unfertilized (control), 100% recommended rate of N, NP, NPK, NPK+ farmyard manure (FYM) and NPK + lime. Yield declined with time for soybean in control (30 kg ha⁻¹ yr⁻¹) and NP (21 kg ha⁻¹ yr⁻¹) treatments and for wheat in control (46 kg ha⁻¹ yr⁻¹) and N (25 kg ha⁻¹ yr⁻¹) treatments. However, yield increased with time for NPK + FYM and NPK + lime treatments in wheat. At a depth of 0–15 cm, small macroaggregates (0.25–2 mm) dominated soil (43–61%) followed by microaggregates (0.053–0.25 mm) with 13–28%. Soil microbial biomass carbon (SMBC), nitrogen (SMBN) and acid hydrolysable carbohydrates (HCH) were greater in NPK + FYM and NPK + lime as compared to other treatments. With three decades of cultivation, C and N mineralization were greater in microaggregates than in small macroaggregates and relatively resistant mineral associated organic matter (silt + clay fraction). Particulate organic carbon (POC) and nitrogen (PON) decreased significantly in control, N and NP application over fallow. Results suggest that continuous use of NPK + FYM or NPK + lime would sustain yield in a soybean–wheat system without deteriorating soil quality.     

Effects of acidic deposition on soil ecosystems under forest in the Chongqing region of China

The effects of acidic deposition on soil ecosystems under temperate coniferous forest in the Chongqing region of China were investigated from 1993 to 1994. Precipitation, throughfall, stemflow, soil solutions, and soil samples were collected to estimate the acidification of soil ecosystems through the changes of their chemical components. The concentrations of ion species in the throughfall and stemflow under masson pine forest in Mt. Zhenwu were higher than those under mixed coniferous forest in Mt. Jinyun and under camphor tree forest in Laojundong, suggesting that Mt. Zhenwu is located in the vicinity of the Chongqing center and that it allowed the canopy of masson pine to intercept air pollutants. However, the level of aluminum dissolution into soil solutions was relatively low under masson pine forest in Mt. Zhenwu in spite of the low pH in the stemflow.     

不同肥料对油茶林土壤氮素含量、 微生物群落及其功能的影响

【目的】氮素的转化、 吸收和利用是油茶生长和高产的关键要素。为了研究不同肥料对油茶林土壤氮素含量和相关微生物数量及其生物作用强度的影响,探讨不同肥料对土壤氮素养分循环及土壤微生物类群影响的内在联系,以期为油茶合理施肥提供理论依据和科学指导。【方法】以江西省九江市庐山区海会镇油茶基地赣无油茶无性系(Camellia oleifera Abel)为试验对象,设计油茶专用肥(ZYF)、 生物有机肥(YJF)、 复合肥(FHF)和不施肥(CK)4个处理,每个处理设3个重复样地。【结果】不同施肥处理油茶林土壤中全氮、 硝态氮和铵态氮含量均存在显著差异,全氮年平均含量ZYF＞FHF＞YJF＞CK,不同处理土壤全氮含量季节变化均为春季至秋季呈递增趋势,秋季达到最大值。铵态氮年平均含量为ZYF＞YJF＞FHF＞CK,硝态氮年平均量为ZYF＞FHF＞YJF＞CK,不同处理铵态氮和硝态氮季节动态变化均不一致。不同施肥处理氨化细菌数量间和亚硝化细菌数量间均存在显著差异,氨化细菌与亚硝化细菌年平均量均为YJF＞ZYF＞FHF＞CK。氨化细菌数量秋季最高,冬季最低,但亚硝化细菌数量季节变化不明显。氨化作用强度与硝化作用强度年平均量均为YJF＞ZYF＞FHF＞CK。不同处理氨化作用强度均为从春季到秋季呈递增趋势,之后递减,冬季达最小。不同处理硝化作用强度季节动态变化较为复杂。不同施肥处理油茶林土壤中铵态氮含量与土壤氨化细菌数量、 氨化作用强度显著相关(P0.01)。土壤硝态氮含量与土壤硝化细菌数量、 硝化作用强度显著相关(P0.01)。FHF、 YJF、 ZYF与CK相比,油茶单株平均产量分别增加了27.55%、 76.10%、 77.57%。【结论】施用复合肥、 油茶专用肥和生物有机肥对提高土壤氮素含量、 微生物群落数量及其生物作用强度以及油茶产量均有显著效果。尤其富含有机质和有益菌的生物有机肥和营养元素更全面的油茶专用肥的效果更佳。因此,在生产实践中应根据实际情况,因地制宜地在施用常规复合肥的同时,增加油茶专用肥和生物有机肥的应用。     

Micro-scale variation of solid-phase properties and soil solution chemistry in a forest podzol and its relation to soil horizons

In order to evaluate micro-scale heterogeneities 55 micro suction cups were placed in an array at 15 mm intervals in a profile face of a cambic podzol. The chemistry of soil solution (mineral anions, pH, UV absorption as a measure for DOC) was compared with solid-phase properties from soil samples (2 cm³ volume), which had surrounded the suction cups. Sequential extraction techniques (water, NF₄Cl, hydroxylamin-hydrochloride, citrate-bicarbonate, oxalate, dithionite-citrate-bicarbonate) and base titrations were applied to characterize the solid phase. Although the average soil solution concentrations between horizons often differed significantly, the spatial distributions of pH and SO₄^2? did not correlate with soil horizon borders. Even if concentration isolines and soil horizon borders were parallel, marked concentration gradients could be observed within individual soil horizons. The less intense the interaction between solute ion and soil matrix, the greater was the variation in solution concentration within a soil horizon. For the soil solid phase only a weak correlation of slow buffer reactions to soil horizons was found. The distribution of extractable Fe and Al was typical for a podzol profile, however, with very steep gradients within single soil horizons. Except for pH, which was related mainly to citrate-bicarbonate extractable aluminium, no solid-phase characteristic showed a clear correlation with soil solution chemistry.     

Initial effects of fire and mechanical thinning on soil enzyme activity and nitrogen transformations in eight North American forest ecosystems

This study assessed the first-year effect of three ecosystem restoration treatments (prescribed fire, mechanical thinning, and their combination) on soil enzyme activity, soil N transformations, and C:N ratios of soil organic matter and mineral soil in eight North American forested ecosystems. The ecosystems we studied were part of the larger Fire and Fire Surrogate (FFS) network, and all had a history of frequent fire that has been altered by almost a century of organized fire suppression. Across all eight sites there were no statistically significant effects of the three manipulative treatments on phosphatase activity or chitinase activity; in contrast, at the network-scale phenol oxidase activity was reduced by fire alone, relative to the control. There was no significant network-scale effect of the three treatments on net N mineralization or net nitrification. Soil C:N ratio increased modestly after mechanical thinning, but not after prescribed fire or the combination of fire and thinning. There was a statistically significant reduction in forest floor C:N ratio as a result of all three treatments. Ordination of the differences between the treated and control areas indicated that fire alone resulted in greater changes in phenol oxidase activity and net nitrification than did the other two treatments. Large-scale restoration treatments such as those utilized in this study produce modest proximate effects on soil microbial activity and N transformations.     

Effects of biochar application in forest ecosystems on soil properties and greenhouse gas emissions: a review

Purpose

Forests play a critical role in terrestrial ecosystem carbon cycling and the mitigation of global climate change. Intensive forest management and global climate change have had negative impacts on the quality of forest soils via soil acidification, reduction of soil organic carbon content, deterioration of soil biological properties, and reduction of soil biodiversity. The role of biochar in improving soil properties and the mitigation of greenhouse gas (GHG) emissions has been extensively documented in agricultural soils, while the effect of biochar application on forest soils remains poorly understood. Here, we review and summarize the available literature on the effects of biochar on soil properties and GHG emissions in forest soils.

Materials and methods

This review focuses on (1) the effect of biochar application on soil physical, chemical, and microbial properties in forest ecosystems; (2) the effect of biochar application on soil GHG emissions in forest ecosystems; and (3) knowledge gaps concerning the effect of biochar application on biogeochemical and ecological processes in forest soils.

Results and discussion

Biochar application to forests generally increases soil porosity, soil moisture retention, and aggregate stability while reducing soil bulk density. In addition, it typically enhances soil chemical properties including pH, organic carbon stock, cation exchange capacity, and the concentration of available phosphorous and potassium. Further, biochar application alters microbial community structure in forest soils, while the increase of soil microbial biomass is only a short-term effect of biochar application. Biochar effects on GHG emissions have been shown to be variable as reflected in significantly decreasing soil N₂O emissions, increasing soil CH₄ uptake, and complex (negative, positive, or negligible) changes of soil CO₂ emissions. Moreover, all of the aforementioned effects are biochar-, soil-, and plant-specific.

Conclusions

The application of biochars to forest soils generally results in the improvement of soil physical, chemical, and microbial properties while also mitigating soil GHG emissions. Therefore, we propose that the application of biochar in forest soils has considerable advantages, and this is especially true for plantation soils with low fertility.

     

Methane uptake in Swedish forest soil in relation to liming and extra N-deposition

Methane uptake to soil was examined in individual chambers at three small forest catchments with different treatments, Control, Limed and Nitrex sites, where N-deposition was experimentally increased. The catchments consisted of both well-drained forest and wet sphagnum areas, and showed uptake of CH₄ from the ambient air. The lowest CH₄ uptakes were observed in the wet areas, where the different treatments did not influence the uptake rate. In the well-drained areas the CH₄ uptakes were 1.6, 1.4 and 0.6 kg ha^–1 year^–1 for the Limed, Control and Nitrex sites, respectively. The uptake of methane at the well-drained Nitrex site was statistically smaller than at the other well-drained catchments. Both acidification and increase in nitrogen in the soil, caused by the air-borne deposition, are the probable cause for the reduction in the methane uptake potential. Uptake of methane was correlated to soil water content or temperature for individual chambers at the well-drained sites. The uptake rate of methane in soil cores was largest in the 0- to 10-cm upper soil layer. The concentration of CH₄ in the soil was lower than the atmospheric concentration up to 30 cm depth, where methane production occurred. Besides acting as a sink for atmospheric methane, the oxidizing process in soil prevents the release of produced methane from deeper soil layers reaching the atmosphere. Received: 27 September 1996