Analysis of Proton Generation and Consumption of Forest Surface Soils in Hokkaido, Northern Japan

We determined proton budgets of surface soils in a deciduous forest (Df) and a coniferous forest (Cf) of Volcanogenous Regosols in Tomakomai, Hokkaido of northern Japan. The total H⁺ source was 12.9 and 11.6 kmol_c ha^?1 y^?1 at Df and Cf respectively, and the external H⁺ was 1% at Df and 2% at Cf. The primary H⁺ sources were vegetation uptake of base cations and nitrification, while the major H⁺ sinks were release of base cations and NO₃ ⁺ uptake by vegetation. Leaching incubation experiments using A horizon soils including Df and Cf with NH₄ ⁺ solutions (5.3, 15.9 mg N L^?1) showed that H⁺ from nitrification was generally higher in the Df soil than Cf soil, and nitrification of Tomakomai Df soil was the highest in both treatments. Results of multiple regression analyses suggested that pH_kCl and exchangeable Ca²⁺ contributed to the H⁺ generation via nitrification. Leaching experiments with dilute HCl (pH 3.3) revealed that cation release (mainly Ca²⁺) occurred, and the proportion of release by decrease of exchangeable cations was higher than that by mineral weathering. Mineral weathering in the Tomakomai soil was higher than the other soils.     

Initial Soil Formation Processes of Volcanogenous Regosols (Scoriacious) from Miyake-jima Island, Japan

In the initial soil formation processes of the Volcanogenous Regosols (Scoriacious) from Miyake-jima Island, Japan, the soil profile morphology showed a distinct formation of the A horizon, about 10 cm thick, over C horizons during a period of 125 years. Along with these soil formation processes under the primary succession of vegetation from bare land to mixed forest, the following changes in the soil characteristics were observed of four study sites where soil formation had occurred over a period of 16, 38, 60 and 125 years in scoriacious volcanic materials ejected during each eruption. Whole soil samples of the surface horizon showed that the proportion of the > 2mm fraction decreased and the clay fraction increased. Electron microscopic observation revealed that pores on the scoria surface were newly formed and had expanded with advanced weathering, and that the formation of a weathering zone on the scoria surface (polygonal shape) was more recognized with the passage of time. Soil pH of the surface horizon decreased, and the amount of carbon in the surface samples showed a linear increase with the passage of time. The amounts of exchangeable bases and the CEC value of the surface samples showed comparable increase rates with time. Consequently, the base saturation percentage was kept at about 100% during the 125-year period. It was suggested that the increase in the amounts of exchangeable bases was controlled by the increase in the amounts of soil organic matter accumulated during the initial soil formation processes of Volcanogenous Regosols (Scoriacious).     

Seasonal Dynamics of Biogeochemical Proton and Base Cation Fluxes in a White Birch Forest in Hokkaido, Japan

Biogeochemical proton and base cation fluxes in a 30-year old white birch forest composed of Dystric Cambisols in northern Hokkaido, Japan were estimated using data on atmospheric deposition (AD), throughfall (TF), stemflow (SF), and discharge from soils (DS) and plant uptake (UP) from early June to November 1999. In the monitoring period, proton flux was 0.20kmol_cha^?1 for AD, 0.07 for TF+SF, and 0.03 for DS, indicating that atmospheric acid input was neutralized through plant and soil. Base cation flux was 1.29 for AD, 1.23 for TF+SF, and 0.99 for DS and plant base cation uptake was 2.14, indicating that the soil was the major source of base cation for plant. However, these seasonal fluxes showed various trends. Cumulative base cation flux in TF+SF showed constant increase trend during the whole period, which was similar to AD. Proton flux in AD jumped once just after a heavy rain of 255mm for 8 days at the end of July. Trends for the proton and base cation fluxes in TF plus SF were similar to that of AD. Although proton and base cation fluxes of DS were not found until middle July because of vegetation uptake and no flow, both fluxes increased suddenly after the heavy rain in July. After August, the base cation and proton fluxes in the DS increased continuously, due to the lack of plant uptake and intermittent rainfall. In this study, it is clear that plant activity and water flow are very important driving force for seasonal dynamics of biogeochemical cycling.     

Vegetation development patterns on skislopes in lowland Hokkaido, northern Japan

The Japanese montane zones are usually covered with well-developed forests, and most ski resorts are constructed there. Therefore, the construction of skislopes requires the destruction of forest ecosystems. To detect vegetation development patterns on skislopes, I assessed vegetation on seven skislopes in the lowland of Hokkaido Island, Japan, using 155 2 m×2 m plots. The surrounding vegetation was mostly consisted of broad-leaved forests with a floor of dwarf bamboo, Sasa senanensis. The skislopes were established 5-28 years before the surveys by scraping off the topsoil and subsequent artificial seeding. The data of vegetation analyzed by TWINSPAN resulted in six different grassland types: (A) Miscanthus sinensis-Hypochaeris radicata, (B) introduced herbs with low richness, (C) introduced herbs, (D) Artemisia montana, (E) M. sinensis-Pueraria lobata-A. montana, and (F) Solidago gigantea var. leiophylla. H. radicata and S. gigantea var. leiophylla were alien species. Vegetation dominated by introduced grasses for erosion control, such as Dactylis glomerata and Poa pratensis, should be initial vegetation on the skislopes. Most tree pioneer species established in the vegetation type A, that was most natural vegetation in the skislopes. Type A seemed to proceed from types B and C, and species richness was the highest. Therefore, this type should be preferable for the management and restoration of skislope vegetation. Type D established on newer skislopes, while types E and F established on older skislopes. Results including detrended correspondence analysis suggested that those vegetation types D-F proceeded to distorted succession, i.e. biological invasion changed native successional sere. Based on these results, I recommended that the restriction of alien invasion and careful monitoring on M. sinensis grasslands are required to restore the natural vegetation.     

Effect of nitrogen deposition on CH4 uptake in forest soils in Hokkaido,Japan

Abstract

It has been well documented by short-term artificial experiments that the CH⁴ uptake is inhibited by N input, especially NH^{4 p+}-N input. To investigate the effect of the natural N input by throughfall and other factors on the CH⁴ uptake in forest soils, we measured the CH⁴ uptake rates for 6 months during the snow-free period of the year and N input by throughfall throughout the year at 10 sites in Hokkaido, Japan, from 1997 to 2002. Water filled pore space (WFPS) and pH values in the soils varied widely among the sites (38-93% and 3.9-6.2, respectively). The rates of NH^{4 p+}-N and NH^{3 p-}-N inputs ranged from 1.3 to 6.9 kg N ha^p-1 year^p-1 and from 0.8 to 2.9 kg N ha^p-1 year^p-1, respectively. The NH^{4 p+}-N input was generally higher than the NH^{3 p-}-N input. Total N input by throughfall amounted to 2.3-9.4 kg N ha^p-1 year^p-1. The highest CH⁴ uptake rate occurred within the period from July to September (41-215 μg CH⁴ m^p-2 h^p-1) each year at most sites. CH⁴ uptake rate was relatively low (~50 μg CH⁴ M-2 h^p-1) at northern sites, while a high CH⁴ uptake rate was observed throughout the year 100 (? CH⁴ m^p-2 h^p-1) at southern sites. The mean CH⁴ uptake rates were significantly different among the sites. Cumulative CH⁴ uptake ranged from 1.4 to 6.6 kg CH⁴ ha^p-1 [184 d]^p-1 with a mean values of 3.22 ± 1.36 kg CH⁴ ha^p-1 [184 d]^p-1. Cumulative CH⁴ uptake increased with increasing temperature and decreased with an increase in precipitation (Rain), NH^{4 p+}-N input (TF^NH4) WFPS, soil total C (TC), and total N (TN). There was a quadratic relationship between the CH⁴ uptake and NH^{3 p-}-N input (TF^NO3), soil pH, and C / N ratio in soil. A regression equation was obtained as follows to predict the CH⁴ uptake in forest soils: Cumulative CH⁴ uptake = 0.47 / Rain + 0.38 / TF^NH4 + 0.34 / TC - 0.30 / TF^N03 (R ^p2 = 0.74, p = 0.0001). This equation indicates that atmospheric N input into forest soils is one of the main factors that control cumulative CH⁴ uptake with precipitation, total carbon content in soil in Hokkaido, Japan.     

On the volcanic ash soil in Tokachi District,Hokkaido Island,Japan

In Japan, most of the paddy fields are laid out on alluvial plain while other land crop fields are developed on plateau. The greater part of the latter ccnsists of volcanic ash soils.     

Spatial Distribution of the Components of Carbon Cycle in Soils of Forest Ecosystems of the Northern,Middle, and Southern Taiga of Western Siberia

Eurasian Soil Science - In the course of studies in typical forest ecosystems of the northern, middle, and southern taiga of Western Siberia performed at the peak of the growing season, the spatial...     

Effects of Natural Soil Acidification on Biodiversity in Boreal Forest Ecosystems

Variations in soil acidity and in biodiversity were analysed in the National Natural Park "Russian North", European Russia. Improving soil quality from podzol, podzolic soil, derno-podzolic soil, brown earth to pararendzina leads to increase in diversity and changes in floristical composition, followed by changing of pine and spruce forest to mixed and birch forests. In PCA ordination species diversity, richness and evenness of trees, shrubs and vascular plants are closely connected with each other, and are represented by the first principal component. They are strongly correlated to the thickness of Al horizon, pH_H20 and pH_CaC12 in organic, surface and subsurface mineral horizons. Only bryophyte species richness and diversity are directly related to the thickness and weight of organic horizon, soil exchangeable acidity, and inversely related to the thickness of Al horizon and pH. Thus, the ordination of the major species diversity variables is highly related to soil pH, suggesting that pH is the best soil related predictor of species diversity parameters. Our study shows that plants notably respond to soil acidification in boreal forest ecosystems.     

Nitrous oxide emissions and nitrogen cycling in managed grassland in Southern Hokkaido,Japan

Abstract

Nitrous oxide (N₂O) emissions were measured and nitrogen (N) budgets were estimated for 2?years in the fertilizer, manure, control and bare plots established in a reed canary grass (Phalaris arundinacea L.) grassland in Southern Hokkaido, Japan. In the manure plot, beef cattle manure with bark was applied at a rate of 43–44?Mg fresh matter (236–310?kg?N)?ha^?1?year^?1, and a supplement of chemical fertilizer was also added to equalize the application rate of mineral N to that in the fertilizer plots (164–184?kg?N?ha^?1?year^?1). Grass was harvested twice per year. The total mineral N supply was estimated as the sum of the N deposition, chemical fertilizer application and gross mineralization of manure (GMm), soil (GMs), and root-litter (GMl). GMm, GMs and GMl were estimated by dividing the carbon dioxide production derived from the decomposition of soil organic matter, root-litter and manure by each C?:?N ratio (11.1 for soil, 15.5 for root-litter and 23.5 for manure). The N uptake in aboveground biomass for each growing season was equivalent to or greater than the external mineral N supply, which is composed of N deposition, chemical fertilizer application and GMm. However, there was a positive correlation between the N uptake in aboveground biomass and the total mineral N supply. It was assumed that 58% of the total mineral N supply was taken up by the grass. The N supply rates from soil and root-litter were estimated to be 331–384?kg?N?ha^?1?year^?1 and 94–165?kg?N?ha^?1?year^?1, respectively. These results indicated that the GMs and GMl also were significant inputs in the grassland N budget. The cumulative N₂O flux for each season showed a significant positive correlation with mineral N surplus, which was calculated as the difference between the total mineral N supply and N uptake in aboveground biomass. The emission factor of N₂O to mineral N surplus was estimated to be 1.2%. Furthermore, multiple regression analysis suggested that the N₂O emission factor increased with an increase in precipitation. Consequently, soil and root-litter as well as chemical fertilizer and manure were found to be major sources of mineral N supply in the grassland, and an optimum balance between mineral N supply and N uptake is required for reducing N₂O emission.     

Element Budgets in a Forested Watershed in Southern China: Estimation of a Proton Budget

We evaluated the element budgets in a forested watershed in Jiulianshan, southern China. The element input in bulk precipitation was characterized by high depositions of H⁺, NH₄ ⁺, Ca²⁺, and SO₄ ^2?, i.e., 400, 351, 299, and 876 eq/ha/yr, respectively. The outputs of H⁺, NH₄ ⁺, and SO₄ ^2? from the watershed were very low, while those of Ca²⁺ and Mg²⁺ were high, 712 and 960 eq/ha/yr, respectively. The element budgets suggested that i) the net retentions of H⁺, NH₄ ⁺, and SO₄ ^2? in this watershed were high, and ii) the net release of Mg²⁺ from this watershed was high mainly due to weathering. The net release of Ca²⁺ was not so high because of the high atmospheric deposition, while atmospheric deposition of Mg²⁺ was not so high (130 eq/ha/yr). Decrease of acid neutralizing capacity in the soil, i.e., net soil acidification, was caused mainly by the net release of Mg²⁺. Moreover, the net retention of SO₄ ^2? also contributed to soil acidification.     

Snowcover Components in Northern Japan

Snowcover surveys were carried out in Hokkaido, northern Japan. Snowpack samples were collected using a steel pipe at 80 sites in 1988, 69 sites in 1992, and 66 sites in 1996 and 2000 during the time when the water equivalents of the snowcover are the greatest. Spatial distribution maps of water equivalents and of the concentrations and the accumulated amounts of hydrogen, non-sea-salt sulfate and non-sea-salt calcium ion of the snowcover drawn by Kriging method are discussed. The distribution maps show that water equivalents and the accumulated amounts of hydrogen and non-sea-salt sulfate in all the sample years were largest in the Japan Sea region, as were the ion concentrations of hydrogen and non-sea-salt sulfate. It was estimated this was caused by air pollutants transported from a great distance. The ratio of areas below pH 5.0 increased temporally from 1988 (20%) to 1992, 1996 and 2000 (66–80%). This trend was estimated to be affected by a decline of non-sea-salt calcium concentrations derived from alkaline road dust. In addition, the effect of snowcover components was assessed by comparison between the acid loads of the snowcover and the acid neutralizing capacity of lake water. We found that lakes in the middle of the Japan Sea coast have the potential to be acidified by snowmelt.     

Nitrogen Leaching of Two Forest Ecosystems in a Karst Watershed

Karst watersheds are a major source of drinking water in the European Alps. These watersheds exhibit quick response times and low residence times, which might make karst aquifers more vulnerable to elevated nitrogen (N) deposition than non-karst watersheds. We summarize 13 years of monitoring NO ₃ ^? , NH ₄ ⁺ , and total N in two forest ecosystems, a Norway spruce (Picea abies (L.) Karst.) forest on Cambisols/Stagnosols (IP I) and a mixed beech (Fagus sylvatica L.) spruce forest on Leptosols (IP II). N fluxes are calculated by multiplying concentrations, measured in biweekly intervals, with hydrological fluxes predicted from a hydrological model. The total N deposition in the throughfall amounts to 26.8 and 21.1 kg/ha/year in IP I and IP II, respectively, which is high compared to depositions found in other European forest ecosystems. While the shallow Leptosols at IP II accumulated on average 9.2 kg/ha/year of N between 1999 and 2006, the N budgets of the Cambisols/Stagnosols at IP I were equaled over the study period but show high inter-annual variation. Between 1999 and 2006, on average, 9 kg/ha/year of DON and 20 kg/ha/year of DIN were output with seepage water of IP I but only 4.5 kg/ha/year of DON and 7.7 kg/ha/year of DIN at IP II. Despite high DIN leaching, neither IP I nor IP II showed further signs of N saturation in their organic layer C/N ratios, N mineralization, or leaf N content. The N budget over all years was dominated by a few extreme output events. Nitrate leaching rates at both forest ecosystems correlated the most with years of above average snow accumulation (but only for IP I this correlation is statistically significant). Both snow melt and total annual precipitation were most important drivers of DON leaching. IP I and IP II showed comparable temporal patterns of both concentrations and flux rates but exhibited differences in magnitudes: DON, NO ₃ ^? , and NH ₄ ⁺ inputs peak in spring, NH ₄ ⁺ showed an additional peak in autumn; the bulk of the annual NO ₃ ^? and DON output occurred in spring; DON, NO ₃ ^? , and NH ₄ ⁺ output rates during winter months were low. The high DIN leaching at IP I was related to snow cover effects on N mineralization and soil hydrology. From the year 2004 onwards, disproportional NO ₃ ^? leaching occurred at both plots. This was possibly caused by the exceptionally dry year 2003 and a small-scale bark beetle infestation (at IP I), in addition to snow cover effects. This study shows that both forest ecosystems at Zöbelboden are still N limited. N leaching pulses, particularly during spring, dictate not only annual but also the long-term N budgets. The overall magnitude of N leaching to the karst aquifer differs substantially between forest and soil types, which are found in close proximity in the karstified areas of the Northern Limestone Alps in Austria.     

亚热带区域几种典型人工林生态系统林地土壤质量评价

针对不同经营模式对林地土壤的物理性质、化学性质和生物学性质的影响,采用主成分分析方法直观定量地研究了亚热带区域几种典型人工林生态系统林地的土壤质量指数和土壤退化指数,揭示了土壤质量指数之间的相关性和差异性、以及土壤退化指数之间的相关性和差异性,并很好地识别出了土壤质量指数和土壤退化指数的主要成分。分析结果基本上反映了不同生态类型林地土壤质量状况,主成分分析土壤质量指数得分以常绿阔叶林最高,其次是混交林和阔叶纯林,连栽杉木纯林最低;主成分分析土壤退化指数表明,与次生常绿阔叶林比较,其中连栽杉木纯林退化幅度最大,而混交林和阔叶纯林次之。从而对其林地土壤质量进行了准确评价,为杉木人工林的可持续利用提供直接依据,并为亚热带区域人工林生态系统林地土壤质量评价提供参考。     

Transformation of Forest Ecosystems in Moscow Megapolis under Recreational Impacts

Eurasian Soil Science - A comprehensive quantitative assessment of the state of vegetation, soil invertebrate complex, litter horizons, and soddy-podzolic soils (Albic Retisols) in Moscow forest...     

Element Inputs and Canopy Interactions in two Pine Forest Ecosystems in Berlin,Germany

For 3 years (1986-89), element fluxes with bulk deposition and throughfall were determined in a 40 yr. old pine plantation and a 80-140 yr. old mixed pine/oak stand in the Grunewald forest in Berlin. Although SO₄-inputs are very high (60 kg S·ha^?1.a^?1) due to the urban character of the study site, acid inputs are moderate because of the buffering action of airborne alkaline dusts. This is reflected in the high Ca-inputs (12 kg·ha^?1a^?1 in bulk precipitation). Acid neutralisation was also observed in the canopies and could be attributed to 60-80% to increased Ca- and Mg-fluxes in throughfall, stemming from foliage leaching and dust interception. Heavy metal inputs were low in comparison to other Central European study sites, the decrease in Pb-inputs over the 3-year period could be attributed to the increased use of unleaded gasoline since 1987. Total inputs and canopy leaching showed clear seasonal patterns for some elements: SO₄-, H-, Ca- and Mg-fluxes were higher in winter, on the other hand, K- and Mn-enrichment in throughfall showed two peaks, in early summer and late fall.     

Mercury distribution in tephra soil layers in Hokkaido,Japan, with reference to 34,000-year stratification

Abstract

Tephra from volcanic eruptions contains only small amounts of mercury (Hg) right after the eruption because the high temperature at eruption evaporates Hg in volcanic ash. Thus, accumulation of Hg in tephra soil layers during the dormant periods of the volcano may reflect Hg deposition while the layer was exposed to the atmosphere. To estimate sequential changes in Hg deposition, we measured the Hg content and accumulation in tephra layers from 6 sites in Hokkaido known to have many tephra layers derived from volcanic eruptions over a 34,000-year period. Mercury content and accumulation rate in the soil profiles varied widely depending on the tephra. In each tephra layer, the Hg content and accumulation rates increased principally at the upper soil horizons and decreased at the lower depths. The Hg deposition rates calculated from the amount of Hg accumulated in the tephra layers were similar within the same tephra. These characteristics of Hg distribution indicate that Hg deposition accumulated on the surface of each tephra layer during the period the tephra layer was exposed to the atmosphere. Although physicochemical processes such as leaching out, wind erosion, and volatilization might lead to over- and/or underestimation of the deposition rates, our estimated amounts of Hg were markedly higher in the tephra soils after 1,600?year?BP than before that time. The results of this study suggest that tephra layers in Hokkaido offer important implications for understanding of the historical changes in atmospheric Hg deposition.     

Soil respiration and methane flux in adjacent forest,grassland, and cornfield soils in Hokkaido,Japan

Soil respiration and methane flux from adjacent forest, grassland, and cornfield were measured by using the closed chamber method from June to November, 1999 in Shizunai, Hokkaido, Japan, where the soil was an Aquic Humic Udivitrands derived from volcanic ash. The forest soil absorbed methane, at arate ranging from -0.12 to -0.02 mg C m_-2 h_-1, while the grassland soil emitted methane, at a rate ranging from undetectable levels to 0.18 mg C m_-2 h_-1. In the cornfield soil methane flux ranged from -0.01 to 0.04 mg C m_-2 h_-1. The soil respiration rate varied from 3 to 230 mg C m_-2 h_-1, 27 to 372 mg C m_-2 h_-1, and 29 to 156 mg C m_-2 h_-1 for the cornfield, grassland, and forest soils, respectively. Linear regression analysis demonstrated that the methane flux rate was positively correlated with the soil water-filled pore space (WFPS), and negatively correlated with the relative gas diffusion coefficient (D/D _o) and air-filled pore space (AFPS). Soil respiration rates were positively correlated with the soil temperature at all the sites. The Q ₁₀ value was 4.8, 3.3, and 1.9 for the cornfield, grassland, and forest soils, respectively.     

Effect of nitrogen fertilization on methane flux in a structured clay soil cultivated with onion in Central Hokkaido,Japan

Abstract

This study was conducted to investigate the effect of N fertilization on the soil CH₄ flux during the growing season of onion in a structured clay soil with stagnant water at depths of 70–80 cm and with a peat-mixed subsoil. The following 4 treatments were analyzed over a period of two years: T1) fertilized, onion growing, T2) fertilized, bare field, T3) unfertilized, onion growing, and T4) unfertilized, bare field. In the fertilized T1 and T2 treatments, fertilizers (mixture of 3 : 1 NH₄NO₃ : (NH₄)₂SO₄) at rates of 322 kg N ha^?1 in 1999 and 242 kg N ha^?1 in 2000 were applied as basal fertilizers before onion was transplanted. CH₄ fluxes among the treatments ranged from ?0.06 to 0.12 mg CH₄-C m^?2 h^?1 in 1999, and from ?0.03 to 0.01 mg CH₄-C m^?2 h^?1 in 2000, which were high after heavy rain in summer. Cumulative CH₄ flux from May to November in the fertilized T1 and T2 treatments was 59 mg CH₄-C m^?2 for both treatments in 1999, and 3.2 and ?0.9 mg CH₄-C m^?2 in 2000, respectively. On the other hand, in the unfertilized T3 and T4 treatments, the cumulative CH₄ flux was 0.2 and ?9.2 mg CH₄-C m^?2 in 1999, and ?26 and ?20 mg CH₄-C m^?2 in 2000, respectively. Although the cumulative CH₄ flux in each treatment was higher in 1999 than in 2000, the fertilized treatments in both years showed a significantly higher cumulative CH₄ flux than the unfertilized treatments. This might be ascribed to the higher level of nitrification in the fertilized treatments, because a high nitrate concentration was observed in the fertilized treatments in the onion growing season. The results also revealed that onion growing did not exert a significant influence on the CH₄ flux. The precipitation from May to November was 642 mm in 1999 and 1,008 mm in 2000, and the CH₄ emission increased when the precipitation was low. In addition, the CH₄ concentration in the soil profile increased with the increase of the depth in summer as the soil was dry. These findings indicated that CH₄ diffusion from the soil to the atmosphere was inhibited by rainwater.