Total Organic Carbon Storage Research Articles

Difference Analysis of Different Land Use Types on Soil Organic Carbon in Loess Gullied-Hilly Region of China

The cycles of carbon in terrestrial ecosystems has received increasing attention worldwide. Because the balance between inputs and outputs of carbon to the soil has an important influences on the atmospheric CO2 and global climate. With the increasing deforestation and overgrazing, the impact of human disturbances on carbon storage and fluxes have exceeded the rate and extent of effects from natural variability, this could significantly raise the CO2 concentration in the atmosphere. Thus, accurate estimations of land use and land cover in soil ecosystem have become increasingly important for estimating the carbon balance of regions. One of the greatest uncertainties concerning the influence of human activities is changes in soil carbon stock. In this study, soil samples were collected form farmland, orchard, woodland, grassland, wasteland five different land use types. Each soil sample core was separated into 0-10, 10-20, 20-40 and 40-60 cm depth. The study revealed the difference of soil carbon pool storage and mass effect in different land use styles by the contrast analysis of total organic carbon, labile organic carbon and carbon management index in number, distribution and changes. The results showed that there were big differences for the density of Total Organic Carbon (TOC) among different land use types, which means soil organic carbon storages were different. The extent of variation of the mass fraction of TOC and LOC was increase with the increase of soil depth and 0-20 cm layer was significantly greater than 20-60 cm layer. Relative to wasteland, the density of LOC and NLOC, total organic carbon storage and carbon management index for other four land use types were higher, especial for woodland and grassland. The woodland use type and grassland use type were significantly increased the carbon management index and improved the quality of soil carbon pool. The change of soil organic carbon reserve is huge influenced by human land use.

鼎湖山季风常绿阔叶林土壤微生物量碳和有机碳对模拟酸雨的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 鼎湖山季风常绿阔叶林土壤微生物量碳和有机碳对模拟酸雨的响应 DOI: 10.5846/stxb201404010615 作者: 作者单位: 中国科学院华南植物园,中国科学院华南植物园，华南农业大学,中国科学院华南植物园 广州,中国科学院华南植物园 广州,中国科学院华南植物园 广州,中国科学院华南植物园 广州 作者简介: 通讯作者: 中图分类号: 基金项目: 中国科学院战略性先导科技专项(XDA05050205) Effects of simulated acid rain on soil microbial biomass carbon and total organic carbon in a monsoon evergreen broadleaved forest at the Dinghushan Nature Reserve Author: Affiliation: South China Botanical Garden,Chinese Academy of Sciences,Guangzhou,,South China Botanical Garden,Chinese Academy of Sciences,Guangzhou,South China Botanical Garden,Chinese Academy of Sciences,Guangzhou,South China Botanical Garden,Chinese Academy of Sciences,Guangzhou,South China Botanical Garden,Chinese Academy of Sciences,Guangzhou Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在鼎湖山季风常绿阔叶林设置人工模拟酸雨实验,研究土壤总有机碳含量、微生物量碳含量、土壤pH值和土壤呼吸速率几个指标对不同酸处理梯度(CK:pH值4.5的天然湖水;T1:pH值4.0;T2:pH值3.5;T3:pH值3.0)的响应。结果表明,在模拟酸雨的持续作用下,样地土壤酸化有加剧趋势。2011年的6月(CK:(603.76±46.18) mg/kg, T1:(565.41±44.48) mg/kg, T2:(521.58±30.92) mg/kg, T3:(509.49±19.40) mg/kg)、12月(CK:(488.92±22.71) mg/kg, T1:(379.65±49.46) mg/kg, T2:(346.08±33.81) mg/kg, T3:(318.00±52.35) mg/kg)和2012年6月(CK:(540.48±39.11) mg/kg, T1:(492.30±43.15) mg/kg, T2:(489.65±51.39) mg/kg, T3:(428.53±49.66) mg/kg) 3次测定的土壤微生物量碳含量有随模拟酸雨强度增加而显著降低的趋势,高强度的酸处理T3显著低于CK值(P <0.05);土壤呼吸速率在各处理中的响应与土壤微生物量碳含量变化一致。由于旱季和湿季的土壤温湿度相差较大,以上各指标在旱湿两季的差异明显,表现为湿季大于旱季。由于土壤总有机碳含量变化缓慢,其在各酸梯度处理下无显著差异(P >0.05)。以上结果显示,长期酸雨作用使土壤酸化不断加剧,并降低了土壤微生物量碳的含量,抑制了土壤的呼吸速率,有利于土壤碳的累积,但对土壤总有机碳的影响仍需长期实验研究。 Abstract:Soil is not only a pivotal link connecting the atmosphere, hydrosphere, biosphere, and lithosphere, but also an important component of carbon cycling. Meanwhile, soil is the largest carbon pool in terrestrial ecosystems, with approximately 1500 Pg of C stored in the upper meter of soil. Even small changes in forest soil composition can result in significant consequences for carbon cycling. Soil organic carbon is easily affected by environmental conditions and its stability plays an important role in forest soil. Although soil microbial biomass carbon (SMBC), one of the soil organic carbon fractions, accounts for only a small fraction of soil total organic carbon (TOC), it is more sensitive to environmental change and its turnover rate is faster than that of TOC. Consequently, SMBC is considered an early indicator of changes to TOC. Many studies of SMBC and TOC responses to acid rain have been carried out in temperate forests in developed countries such as Europe and the United States. However, very few such studies have been carried out in the subtropical forests of southern China, despite the fact that acid rain is a serious environmental threat in this region. We conducted a field experiment to simulate acid rain (SAR) in a monsoon evergreen broadleaved forest (BF) in the Dinghushan Nature Reserve of southern China. We investigated the responses of SMBC, TOC, soil pH, and soil respiration rate to SAR. The SAR treatments included control (CK, pH ≈ 4.5; natural lake water), T1 (pH=4.0), T2 (pH=3.5), and T3 (pH=3.0). The acidic solutions consisted of H2SO4 and HNO3 (1 : 1 mole ratio) in natural lake water. Results showed that pH values of forest topsoil decreased gradually with the increase of acidity, indicating increased soil acidification due to SAR. This phenomenon was consistent with results from other studies conducted at the Dinghushan Nature Reserve. Concentrations of SMBC in June 2011 ((603.76±46.18) mg/kg for CK, (565.41±44.48) mg/kg for T1, (521.58±30.92) mg/kg for T2, (509.49±19.40) mg/kg for T3), December 2011 ((488.92±22.71) mg/kg for CK, (379.65±49.46) mg/kg for T1, (346.08±33.81) mg/kg for T2, (318.00±52.35) mg/kg for T3), and June 2012 ((540.48±39.11) mg/kg for CK, (492.30±43.15) mg/kg for T1, (489.65±51.39) mg/kg for T2, (428.53±49.66) mg/kg for T3) were depressed by SAR, and SMBC contents in T3 treatments were significantly lower than in CK treatments (P < 0.05) at all three sampling times. Meanwhile, changes in soil respiration rates induced by SAR were similar to those in SMBC. Because soil moisture and temperature differed between seasons, all measured variables (soil pH, SMBC, TOC, and soil respiration rates) were higher in the warm-wet season than in the dry season. Due to its relative stability, concentrations of TOC did not significantly differ among the four treatments (P > 0.05). Our results indicate that long-term acid rain is likely to reduce the SMBC content and respiration rate of forest soil; these changes are expected to have positive effects on the accumulation of soil organic carbon. However, the effects of acid rain on TOC storage need to be further investigated. 参考文献 相似文献 引证文献

Estimation of total organic carbon storage and its driving factors in soils of Bavaria (southeast Germany)

Precise estimations of soil organic carbon (SOC) stocks at large spatial scales are a precondition for national SOC inventories but challenging due to the high spatial variability of SOC. In this study, a comprehensive data set of 1460 soil profiles completely sampled down to the parent material or at least to a depth of 1m was used to spatially predict SOC stocks for the state of Bavaria in southeast Germany using a geostatistical modeling approach. The model predicted SOC stocks of the main land uses cropland, grassland and forest with an explained variance of 52% of the total SOC variability within Bavaria. The most important factors, which control the spatial variability of SOC storage, were land use, soil type, soil moisture (indicated by the topographic wetness index) and climate (precipitation, temperature). An analysis of the generated SOC map showed that low to medium SOC stocks within the largest part of Bavaria were explained by land use whereas areas of high SOC stocks in floodplains along rivers, bogs and mountainous regions in the Alps and low mountain ranges were related to soil moisture, soil type and climate. A total SOC stock of 760Mt was calculated for Bavaria with 223Mt (29%) in cropland soils, 125Mt (16%) in grassland soils, 257Mt (34%) in forest soils, 7–29Mt (1–4%) in bogs and 159Mt (21%) under other land uses. In view of high SOC stocks in floodplains and mountainous areas, major anthropogenic disturbances of respective soils (e.g. intensification of the land use) should be avoided in these regions.

The Invasion of Spartina alterniflora Alters Carbon Dynamics in China&amp;apos;s Yancheng Natural Reserve

Ecosystem processes are tightly linked to the structure and functioning of plant communities. Large‐scale invasion of Spartina alterniflora on unvegetated intertidal mudflats is expected to reduce atmospheric CO2 through an increase in the carbon storage of coastal ecosystem. In China&amp;apos;s Yancheng Natural Reserve, plant carbon storage (PCS), soil total organic carbon storage (SCS), as well as CO2 and CH4 fluxes, were compared between Spartina invaded marsh and adjacent native marshes. PCS of Spartina marsh was 16.9 and 1.4 times higher compared to those of Suaeda and Phragmites marshes, whereas relatively larger aboveground PCS but smaller belowground PCS were found in the newly settled seaward margin of the Spartina marsh. SCS in Spartina marsh was also 1.5 times higher than that in unvegetated mudflat. Although Spartina vegetation assimilated a substantial amount of CO2, mass emission of CH4 from the invaded marsh was also noticed, especially in summer, it was 9–16 times higher than those from native marshes. Our study indicates that instead of CO2 being simply incorporated into PCS and SCS, carbon dynamics following Spartina invasion are more complicated. Detailed studies of CH4 emissions are needed before ascertaining whether, and to what degree, the invasion of S. alterniflora may affect the global warming process.

Organic carbon hidden in urban ecosystems.

Urbanization is widely presumed to degrade ecosystem services, but empirical evidence is now challenging these assumptions. We report the first city-wide organic carbon (OC) budget for vegetation and soils, including under impervious surfaces. Urban soil OC storage was significantly greater than in regional agricultural land at equivalent soil depths, however there was no significant difference in storage between soils sampled beneath urban greenspaces and impervious surfaces, at equivalent depths. For a typical U.K. city, total OC storage was 17.6 kg m−2 across the entire urban area (assuming 0 kg m−2 under 15% of land covered by buildings). The majority of OC (82%) was held in soils, with 13% found under impervious surfaces, and 18% stored in vegetation. We reveal that assumptions underpinning current national estimates of ecosystem OC stocks, as required by Kyoto Protocol signatories, are not robust and are likely to have seriously underestimated the contributions of urban areas.

Estimation of storage and density of organic carbon in peatlands of China

Based on the results of the National Survey of Peat Resources (1983–1985) and the investigation results on the peatlands of China, the storage and density of the organic carbon in the peatlands of China were estimated. The total organic carbon storage (OCS) of the peatlands in China, including bare peatlands and buried peatlands, are 1.503 × 109 t, unevenly distributed over 30 provincial level administrative units and 16 climatic zones. Peatland organic carbon storage (POCS) in Sichuan (6.45 × 108 t) and Yunnan provinces (2.91 × 108 t) is the highest, accounting for 62.29% of the total POCS. Humid zone of plateau has the highest POCS of 7.14 × 108 t, especially in the Zoige Plateau, where the POCS is 6.30 × 108 t, accounting for 41.92% of the total POCS of China. The organic carbon density (OCD) of the peatlands in China mostly ranges from 80 kg/m3 to 140 kg/m3, and the range of the maximum is 270–360 kg/m3, and the minimum is less than 80 kg/m3. Divided by the Yanshan Mountain, Taihang Mountains and Hengduan Mountains, the peatland oganic carbon density (POCD) is lower on the northwestern side than that on the southeastern side. Jiangxi Province has the highest POCD due to the ancient buried peatlands. The OCD of the bare peatlands is mostly in the range of 60–150 kg/m3, and that of the buried peatlands is more than 100 kg/m3. In the bare peatlands, the OCD generally increases from the surface layer to the below surface layer, and then decreases with the depth. Although the peatlands area in China is small, the OCS per unit area is far higher than the other soil types, so peatlands protection can effectively mitigate climate change.

The estimation of soil organic carbon distribution and storage in a small catchment area of the Loess Plateau

The distribution and storage of soil organic carbon serve as basic data for the study of soil productivity, soil hydrological properties, and the balance among carbon-based greenhouse gases. In this study, the organic carbon storage and density distribution characteristics of the soil in the Zhifanggou catchment on the Loess Plateau were studied based on field investigations, laboratory measurement, and geostatistics analysis. A total of 1,282 soil samples were collected from 215 sites in addition to 10 profiles from the catchment. The landuse within the catchment was divided into 4 types: farmland, grassland, shrubland, and woodland. The following results were obtained. 1. In the Zhifanggou catchment, the average organic carbon content of the soil at a depth of 0-100 cm is between 2.81 and 3.50 g. kg(-1). The soil organic carbon content (SOCC) for different landuse types follows the trend shrubland > woodland > grassland > farmland, whereas the soil bulk density follows. The relationship between soil organic carbon content and bulk density follows a power law function. 2. The soil organic carbon density (SOCD) at a depth of 0-100 cm is 1.24-8.34 kg m(-2). The coefficient of variation is 0.40, indicating a moderate variation in the average carbon density of 2.63 kg m(-2). The soil organic carbon density for different landuse types follows the trend shrubland > woodland > grassland > farmland. In the entire catchment, the proportion of average soil organic carbon density at a depth of 0-20 cm is 50.24%, which decreases with soil depth. The spatial distribution of the soil organic carbon density is closely related to the landuse types and topography. 3. The total soil organic carbon storage (SOCS) at a depth of 0-100 cm in the Zhifanggou catchment is 21.84x 10(6) kg. The relationship between soil depth and total organic carbon storage is linear. (c) 2012 Elsevier B.V. All rights reserved.

Impact of land use change and rainfall on sediment and carbon accumulation in a water reservoir of North Thailand

The lifespan of many tropical water reservoirs is limited by siltation due to soil erosion in the watershed. The objectives of this study were to determine, the amount of catchment-derived organic carbon accumulated in sediments of a reservoir of North Thailand and to relate it with the history of cultivation and rainfall regime in the watershed. Over a twelve-years period (1995–2006) since impoundment sediment delivery was high ( ca. 19.6 Mg ha −1 yr −1). The yearly supply of catchment-derived material was composed of coarse sediment deposits near the main inlets and of fine laminated sediment accumulations in deep-water environments. Their stable carbon isotope composition indicated that soil organic matter was the main source of organic carbon preserved in sediments ( ca. 83 wt.%). Fine sediments derived from suspended loads exported from the watershed by runoff and stream waters were related to erosive rainfall, to the extent of area under annual cropping and to crop change with a marked increase after the replacement of beans by maize. However, sediment accumulation did not respond linearly to extreme rainfall events, as shown by the supply of nearly 48% of the total amount of sediments by a single exceptional flood. Total organic carbon storage in sediments reached ca. 23.8 MgC ha −1 yr −1 in 2006, twelve years after impoundment, falling in the upper range of small to medium size reservoirs with agricultural catchments.

Transfer of organic carbon on the Moroccan Atlantic continental margin (NW Africa): productivity and lateral advection

Land—ocean transfer of sediment and organic matter along the Moroccan Atlantic margin (NW Africa) seems to have been very effective during the last 130 ka. In a marine core from this region, we found total organic carbon (TOC) values ranging from 0.3 to 1.7 dry wt% of bulk sediments. These relatively high values are fairly unusual, as the core was recovered from an open-ocean environment that is currently oligotrophic. In order to explain this trend, more typical of an upwelling eutrophic setting, three processes were evaluated: (1) in situ primary production associated with the extension of the Cape Ghir upwelling filament, (2) bottom water conditions that may favour organic carbon preservation and (3) lateral organic carbon advection. The site occasionally experienced more eutrophic conditions, especially during termination I; here, we recorded a relative high abundance of the planktonic foraminifer Globigerina bulloides, suggesting high primary production. However, given the absence of correlation between TOC and G. bulloides records, high TOC storage cannot be attributed exclusively to primary production. Preservation factors such as bottom water ventilation are also ruled out. Lateral TOC advection seems to be the most plausible process. Today, lateral advection and offshore transport of nutrients and organic matter characterize the study region. However, the triggering mechanisms deserve further investigation. Different controlling factors influencing the mobilization and advection of organic carbon from coastal upwelling sites to the deep basin are discussed. The correlation found between down-core TOC and sea-level changes suggests sea-level fluctuations as the most effective mechanism driving nepheloid layer detachment and seaward material transport.

Late Quaternary environmental changes and organic carbon density in the Hunshandake Sandy Land, eastern Inner Mongolia, China

Knowledge about changes of regional carbon density during late Quaternary is of great significance for understanding regional and global carbon cycles. Taking the Hunshandake Sandy Land, located in eastern Inner Mongolia of China as an example, this paper aims to reconstruct Late Quaternary environmental changes, and then to discuss the fluctuations of organic carbon density and storage in the desert environment of northern China. The study area with a mean annual precipitation ca. 300 mm is characterized by the occurrence of fixed and semi-fixed sand dunes reaching a maximal height of 30 m. The research methods included field observations, examinations of grain sizes, as well as carbon and calcium carbonate contents of the sediment samples. The chronology is based on Optically Stimulated Luminescence (OSL) dating and radiocarbon analyses. This work reveals that the organic carbon density in the surface layer of the Hunshandake Sandy Land changed between at least 2500 g/m 2 during the Holocene Climatic Optimum and 1500 g/m 2 when aeolian processes dominate. The dune construction was restricted by periglacial processes during the Last Glacial Maximum (LGM). The Holocene Climatic Optimum, indicated by extensive formation of kastanozem soils, occurred between 5 ka and 3 ka in the study area. Although desertification might cause a 40% loss of total organic carbon storage within several dozen of years in the study area, a considerable amount of this carbon was re-deposited in the regions of downwind directions.

Quantification of organic carbon pools for Austria’s agricultural soils using a soil information system

Within the framework of the project “Austrian Carbon Balance Model”, we estimated soil organic carbon (OC) content for the agricultural land of Austria. The basic chemical and physical data were obtained from the national electronic soil information system BORIS (Boden Rechnergestütztes Informtions System). The latter data were obtained through soil surveys performed over the past 10 yr. The BORIS data were corrected for soil gravel content, bulk densities and differences in chemical analytical methods used for soil OC. Our estimation also showed the following ranking for soil OC content (0–50 cm) under different land use systems: vineyards (57.6 t C ha-1) ~ cropland (59.5 t C ha-1) &lt; orchards/gardenland (78 t C ha-1) ~ intensive grassland (81 t C ha-1) &lt; extensive grassland (119 t C ha-1). Although the main portion of soil carbon is stored in topsoils (0–20 cm) in all land-use classes, deeper soil layers (20–50 cm) contribute significantly to the overall inventory (between 18. 2 and 27.2 t C ha-1), but appear to be less influenced by land use. A total OC storage in Austria’s agricultural soils of 284 Mt was estimated. A west-east gradient of OC storage in agricultural soils of different Federal Provinces was observed. Under Austrian conditions, extensively used grassland plays an important role for OC-storage. Wide C:N ratios in these soils suggest accumulation of poorly humified organic material and slow OC turnover. Key words: Carbon sequestration, soil organic matter, soil humus, soil nitrogen content, C:N ratio

Accumulation and properties of soil organic carbon at reclaimed sites in the Lusatian lignite mining district afforested with Pinus sp.

The accumulation of organic carbon mainly derived from litter fall and necromass (Corg recent) has been investigated within the forest floor horizons and the mineral topsoil (0–4 cm and 4–10 cm) at reclaimed forest stands of the Lusatian lignite mining district as well as on an undisturbed forest stand in the general region, planted with Pinus sylvestris (L.) or Pinus nigra (Arnold). Recently formed organic carbon (Corg recent) was differentiated from organic carbon derived from lignite and lignite derivatives (Corg geogenic), which are inherent in the dumped substrate at post-mining sites, by 14C measurements. Total organic carbon (TOC) was characterized by 13C CPMAS NMR spectroscopy. The storage of TOC, Corg recent, Corg geogenic, and of organic carbon structures was examined. We found that the accumulation of Corg recent increased with stand age at all investigated stands. The results indicate that at the reclaimed stands accumulation of Corg recent takes place in the same order of magnitude when compared to the undisturbed stand. Storage of TOC in the mineral topsoil (0–10 cm) amounted from 2.6 kg m −2 to 7.0 kg m −2 at the reclaimed stands and to 2.6 kg m −2 at the undisturbed stand. At reclaimed stands TOC in the mineral topsoil can be attributed mainly to Corg geogenic. The calculated pools of Corg geogenic effect physico-chemical soil properties. Our results indicate that Corg geogenic in the substrate may compensate in part the lack of soil organic matter derived from soil development as storage for nutrients and water.

Geostatistical estimation of tropical peat-soil volume at Bacho, Thailand: impact of spatial support size and censored information

The peat-soil volume at the Bacho site in Thailand was estimated using indicator geostatistics. The original peat layer thickness data include two types of censored observations: the physical and measurement limits. To avoid assigning values arbitrarily to them, the indicator approach was used, in which all observations are transformed into either 0 or 1 depending upon the exceedence of any given threshold. In this study, peat-soil thickness values are estimated using blocks with different sizes (i.e., change of support). Indicator kriging is applied to construct conditional cumulative distribution functions (ccdf) defines peat layer thickness at centers of estimation blocks. From the point ccdf obtained, an optimal estimate of peat layer thickness at each block is obtained by taking the mean of the point ccdf. The ccdf value beyond the maximum threshold is modeled by the linear model as it fits well to the original cumulative distribution of data. The choice of the extrapolation model needs to be guided by available information. The total peat-soil volume is estimated simply summing up the volume at each block (optimal thickness×area of the block). The estimated volumes are almost constant when the block size less than 200 m is used, indicating that the mean of the point ccdf at the center of the block can be used as the representative value of the block. When much larger block sizes are used, the ccdf at the center of the block cannot be used to estimate the block value. In such a case, the block ccdf need to be derived using different approaches such as stochastic simulation. The estimated total peat-soil volume within the investigation boundary at the Bacho site is 2.14×10 7 m 3, when the block size smaller than 200 m are used. Using the average organic carbon content value measured at the site, the total organic carbon storage is estimated 1.22×10 9 kg C.

Distribution and storage of soil organic carbon in China

Surface soils hold the largest terrestrial organic carbon pool, although estimates of the world's soil organic carbon storage remain controversial, largely due to spatial data gaps or insufficient data density. In this study, spatial distribution and storage of soil organic carbon in China are estimated using the published data from 34,411 soil profiles investigated during China's second national soil survey. Results show that organic carbon density in soils varies from 0.73 to 70.79 kg C/m2 with the majority ranging between 4.00 and 11.00 kg C/m2. Carbon density decreases from east to west. A general southward increase is obvious for western China, while carbon density decreases from north to south in eastern China. Highest values are observed in forest soils in northeast China and in subalpine soils in the southeastern part of the Tibetan Plateau. The average density of ∼8.01 kg C/m2 in China is lower than the world's mean organic carbon density in soil (∼10.60 kg C/m2), mainly due to the extended arid and semi‐arid regions. Total organic carbon storage in soils in China is estimated to be ∼70.31 Pg C, representing ∼4.7% of the world storage. Carbon storage in the surface organic horizons which is most sensitive to interactions with the atmosphere and environmental change is ∼32.54 Pg C.

Carbon cycling of alpine tundra ecosystems on Changbai Mountain and its comparison with arctic tundra

The alpine tundra on Changbai Mountain was formed as a left-over ‘island’ in higher elevations after the glacier retrieved from the mid-latitude of Northern Hemisphere to the Arctic during the fourth ice age. The alpine tundra on Changbai Mountain also represents the best-reserved tundra ecosystems and the highest biodiversity in northeast Eurasia. This paper examines the quantity of carbon assimilation, litters, respiration rate of soil, and storage of organic carbon within the alpine tundra ecosystems on Changbai Mountain. The annual net storage of organic carbon was 2092 t/a, the total storage of organic carbon was 33457 t, the annual net storage of organic carbon in soil was 1054 t/a, the total organic carbon storage was 316203 t, and the annual respiration rate of soil was 92.9% and was 0.52 times more than that of the Arctic. The tundra-soil ecosystems in alpine Changbai Mountain had 456081 t of carbon storage, of which, organic carbon accounted for 76.7% whereas the mineral carbon accounted for 23.3%.

Upscaling soil organic carbon estimates for the Usa Basin (Northeast European Russia) using GIS-based landcover and soil classification schemes

This study provides estimates of average soil organic carbon content for the Usa Basin in Northeast European Russia, using two independent databases and two separate upscaling tools. The results are very similar despite differences in sample size and spatial resolution. Based on the merged databases and landcover upscaling, the average carbon content in the Usa Basin is 10,7 Kg Cm−2 for the upper 30 cm soil layer, 25,5 Kg Cm−2 for a reference 1 m soil depth and 31,2 Kg Cm−2 for total soil. The 'peatland' cover classes, with an average 76,3 Kg Cm−2 and 30% surface coverage, account for 73% of total organic carbon storage in the Usa Basin. Upland forest and tundra classes have similar average total carbon contents—on the order of 11,2–11,4 Kg Cm−2. Detailed regional and national assessments of northern terrestrial carbon pools, upscaled using landcover or soil classification schemes like the one presented here for the Usa Basin, arrive at much higher average total soil carbon estimates than generally cited in the literature from global data sets for tundra and taiga life zones or biomes.

Nutrient and Thermal Regime, Microbial Biomass, and Vegetation of Antarctic Soils in the Windmill Islands Region of East Antarctica (Wilkes Land)

In the antarctic summer of 1996, permafrost-affected cold soils close to the Australian Casey Station in the Windmill Islands region (Wilkes Land) were investigated to determine in what way the thermal and nutrient regimes in the antarctic soils are related to microbial biomass and vegetation patterns. The soils are characterized by a high content of coarse mineral particles and total organic carbon (TOC) and a low C/N ratio (mean 11). Despite the low pH values (mean 4.0) the soils are rich in nutrients due to an input from seabirds (existing or abandoned nesting sites) and an eolian distribution of fine-grained soil material in the landscape. Vegetation influences TOC storage and the cation exchange capacity in the uppermost soil horizons, whereas total N and most nutrient levels are not affected by the vegetation, but by seabird droppings. The present nutrient level does not affect plant adaptation, because the K, Mg, and P contents are often extraordinarily high. This suggests that nutrient supply is not a limiting factor, whereas microclimate effects, such as moisture availability and ground-level wind speed, have a primary influence on plant growth. Soil-surface temperature measurements indicate a strong variability in microclimate due to small-scale variations in geomorphological surface features. Bacteria are found in all soil horizons, but not algae and yeast. Soil microbial counts are weakly correlated to the C/N ratios and soil surface temperatures. High TOC and clay contents probably improve the soil water-holding capacity and TOC contributes to the microbial food supply. The investigated microbial parameters are weakly correlated to the present vegetation carpet, the lowest counts are found in the soils with scattered or no vegetation cover.

A new estimate of changing carbon storage on land since the last glacial maximum, based on global land ecosystem reconstruction

A review of global land vegetation 18,000, 8000, and 5000 14 C years B.P. allowed map reconstructions of past ecosystem distribution. By collecting soil and vegetation carbon storage data from the ecological literature, the map reconstructions were then used to estimate the total organic carbon storage on land at each of these time slices. Our best estimate suggests that there was an extremely large increase in land organic carbon storage, of around 1500 Gt (with extreme outer error limits for the increase placed at around 900 and 1900 Gt, respectively) between the Last Glacial Maximum (LGM) and the early-to-mid Holocene. It seems that the world's terrestrial carbon reservoirs more than doubled in size between full-glacial and full-interglacial conditions, due to a great increase in the areas of forest and other carbon-rich ecosystems. Although there are many uncertainties in such calculations, comparing them to methods used in other published estimates, we suggest that the present estimate may represent an overall improvement in accuracy. Apparent problems in previous studies include the use of relatively few data points and a limited range of types of palaeoenvironmental evidence, the unselective use of carbon storage data from anthropogenically modified ecosystems, and the assignment of an anomalously high carbon storage to the LGM `steppe–tundra' ecosystem.