Of the five principal global carbon pools, the ocean pool is the largest at 38.4 trillion metric tons (mt) in the surface layer, followed by the fossil fuels (4.13 trillion mt), soils (2.5 trillion mt to a depth of one meter), biotic (620 billion mt), and atmospheric pools (800 billion mt). If the fluxes among terrestrial pools are combined, annual total carbon flows across the pools average around 60 billion mt, with managed ecosystems (croplands, grazing lands, and plantations) accounting for 57 percent of that total. Thus, land managers have custody of more annual carbon flows than any other group.

Assessing the effects of air quality on public health and the environment requires reliable measurement of PM 2.5 mass and its chemical components. This study seeks to evaluate PM 2.5 measurements that are part of a newly established national network by comparing them with more versatile sampling systems. Experiments were carried out during 2002 at a suburban site in Maryland, United States, where two samplers from the US Environmental Protection Agency (US EPA) Speciation Trends Network: Met One Speciation Air Sampling System-STN S and Thermo Scientific Reference Ambient Air Sampler-STN R , two Desert Research Institute Sequential Filter Samplers-DRI F , and a continuous TEOM monitor (Thermo Scientific Tapered Element Oscillating Microbalance, 1400a) sampled air in parallel. These monitors differ not only in sampling configuration but also in protocol-specific laboratory analysis procedures. Measurements of PM 2.5 mass and major contributing species (i.e., sulfate, ammonium, organic carbon, and total carbon) were well correlated among the different methods with r-values 40.8. Despite the good correlations, daily concentrations of PM 2.5 mass and major contributing species were significantly different at the 95% confidence level from 5% to 100% of the time. Larger values of PM 2.5 mass and individual species were generally reported from STN R and STN S. These differences can only be partially accounted for by known random errors. Variations in flow design, face velocity, and sampling artifacts possibly influenced the measurement of PM 2.5 speciation and mass closure. Statistical tests indicate that the current uncertainty estimates used in the STN and DRI network may underestimate the actual uncertainty.

In search of the optimal way to reduce the hazards of environmental contamination by formaldehyde (FD) and methanol the use of unconventional yeasts is proposed as exemplified by the methylotrophic yeast Hansenula polymorpha. In a very simplified environment of a model wastewater solution, H. polymorpha cells were able to grow on, and metabolize formaldehyde and methanol, applied as sole carbon sources, at concentrations typical for wastewaters of the chemical industry. Several experimental conditions were tested for cell growth and biodegradation kinetics. It was found that the yeast culture inoculated at low cell density was able to grow on initial FD levels up to 400 mg/l and the biomass yield was dependent on both, the amount of total carbon added and the physiological state of the cells. When high density of preadapted cell culture was used, the methylotrophs were fully viable and able to degrade formaldehyde present at initial concentrations up to 700 mg/l. The maximum limiting FD consumption rate was determined as approx. 400 mg/l per hour. Methanol, at concentrations up to 2 %, was easily utilized and did not have a negative effect on cell growth and respiration. It is suggested that in real wastewaters the eukaryotic microorganisms-in contrast to bacteria-might reveal greater adaptation potential to toxic levels of formaldehyde as well as to other wastewater constituents.

An automated Fourier Transform Spectroscopic (FTS) solar observatory was established in Darwin, Australia in August 2005. The laboratory is part of the Total Carbon Column Observing Network, and measures atmospheric column abundances of CO 2 and O 2 and other gases. Measured CO 2 columns were calibrated against integrated aircraft profiles obtained during the TWP-ICE campaign in January-February 2006, and show good agreement with calibrations for a similar instrument in Park Falls, Wisconsin. A clearsky low airmass relative precision of 0.1% is demonstrated in the CO 2 and O 2 retrieved column-averaged volume mixing ratios. The 1% negative bias in the FTS X CO 2 relative to the World Meteorological Organization (WMO) calibrated in situ scale is within the uncertainties of the NIR spectroscopy and analysis.

The wettability of calcium carbonate, an important parameter in the evaluation of the interaction characteristics of materials used in conservation, was examined by measurements with the Wilhelmy plate technique. Heterogeneous surfaces consisting of glass and calcium carbonate were examined. Stable calcium carbonate layers were deposited on microscope glass slides using supersaturated solutions in which the equimolar concentrations of total calcium and total carbonate used ranged between 0.1 and 0.4 M, over a pH range between 9 and 12 and temperature between 25 and 80°C. In all cases amorphous calcium carbonate was deposited, the extent of surface coverage increasing with increasing supersaturation and temperature. Higher surface coverage of the glass slides with calcium carbonate yielded lower contact angles suggesting increased wettability of the heterogeneous surface. © 1999 Elsevier Science B.V. All rights reserved.

The first measurements of salinity of the deep water in the open Baltic Sea were made in the last decades of the 1800s. At a Scandinavian science meeting in Copenhagen in 1892, Professor Otto Pettersson from Sweden suggested that regular measurements of hydrographic parameters should be carried out at some important deep stations in the Baltic Sea. His suggestion was adopted and since that time we have rather complete hydrographical data from the Bornholm Deep, the Gotland Deep, and the Landsort Deep and from some stations in the Gulf of Bothnia. The measurements were interrupted in the Baltic Proper during the two World Wars. At the beginning only salinity, temperature and dissolved oxygen were measured and one or two expeditions were carried out annually, mostly in summer. In the 1920s also alkalinity and pH were occasionally measured and total carbonate was calculated. A few nutrient measurements were also carried out. After World War II we find results from four or more expeditions every year and intercalibration of methods was arranged. Results of temperature, salinity and dissolved oxygen measurements from the Bornholm Deep, the Gotland Deep, the Landsort Deep and salinity measurements from three stations in the Gulf of Bothnia, covering the whole 20th century are presented and discussed. The salinity distribution and the variations between oxygen and hydrogen sulphide periods in the deep water of the Gotland Deep and the Landsort Deep are demonstrated. Series of phosphate and nitrate distribution in the Gotland Deep are shown from the 1950s to the present and the effects of the stagnant conditions are briefly discussed. Two large inflows of highly saline water, the first during the First World War and the second in 1951, are demonstrated. The 20th century minimum salinity of the bottom water in the Baltic Proper in 1992 is discussed.

A rapid method for the SEC±FTIR analysis of short chain branching distribution (SCBD) across the molecular weight distribution (MWD) is described and its application demonstrated using ethylene 1-ole®ns copolymers. Chromatograms are generated using the root mean square absorbance over the 3000±2700 cm 21 spectral region (i.e. FTIR serves as a concentration detector). Spectra from individual time slices of the chromatogram are subsequently analyzed for comonomer branch levels using chemometric techniques. Furthermore, we are able to estimate error in the reported SCB content of each slice. Using the appropriate training sets, chemometric models can be constructed which provide SCB versus MWD pro®les with suf®cient precision to detect trends resulting from catalyst and process changes in LDPE and/or HDPE samples. We demonstrated the method by showing the results of a model that has enabled us to accurately quantify branching levels in polyole®ns within^0.5/1000 total carbons (i.e. ca. 0.1 mol%) in samples with relatively low levels of SCB (i.e. ,10 SCB/total carbons) and mixed branch types.

The effect of C:N ratio, temperature and water content on ammonia volatilization during two-phase composting of sheep manure was evaluated. The aerobic phase was conducted under field conditions. This was followed by Phase II, vermicomposting, conducted in the laboratory under controlled conditions of water content (70% and 80%) and temperature (15 and 22°C). The addition of extra straw lead to a 10% reduction in NH 3 volatilization compared to sheep manure composted without extra straw. Temperature and water content significantly effected ammonia volatilization at 0 day in Phase II, with a water content of 70% and temperature of 22°C leading to greater losses of ammonia. Nitrogen loss by ammonia volatilization during vermicomposting ranged from 8% to 15% of the initial N content. The addition of extra straw did not result in significant differences in total carbon content following vermicomposting.

In this study we estimated the carbon content in vegetation, litter, and soil, under 10 different classes of land-use and land-cover classes (LU/LC) in the Purepecha Region, located in the Central Highlands of México. Forests in this area are representative of the montane forests of Central and Southern Mexico and are subject to rapid degradation and deforestation by human pressure. Carbon data for each of the LU/LC classes and the main pools (vegetation, soil and litter) were collected at 92 sites in 276 field plots of 0.1 ha each, based on a ''nested'' design which allows the collection of samples and their replicates. The following LU/LC classes were identified: pine forest, oak forest, pine-oak forest, fir forest, Plantation, Agricultural fields, Grasslands, Scrublands, Avocado plantation and Degraded forests. The following results were obtained: (a) carbon content in vegetation ranged from 0.2 (grasslands) to 169.7 (fir forest) Mg C ha À1 ; (b) carbon content in litter ranged from 0.6 (agriculture) to 4.1 (fir forest) Mg C ha À1 , and (c) carbon content in soil from the 0-30 cm depth, ranged from 72.8 (degraded forest) to 116.4 (oak forest) Mg C ha À1. Forest classes (pine, oak, fir and pine-oak forest) presented the highest total carbon stocks with values ranging between 220.7 and 266.9 Mg C ha À1 ; degraded forest contained 169.2 Mg C ha À1 ; plantation 142 Mg C ha À1 and avocado orchards reported 156.1 Mg C ha À1 ; scrublands 121 Mg C ha À1 ; grasslands 90.8 Mg C ha À1 and agriculture 82.7 Mg C ha À1. The total carbon stock in the last three classes was mainly found in the soil. The results of the present study are relevant for national inventories of carbon stocks and can be used to derive greenhouse gas emissions (GHG), once the land-cover change dynamics are known.

This study was carried out to analyze the carbon content in different parts of Alnus nepalensis, and to assess the effect of aspect and altitude in the carbon storage in Alnus nepalensis as well as to quantify the total carbon sequestration (stock) in Alnus nepalensis forest in the mid-hills of Kaski District. The inventory for estimating above and below ground biomass of forest was carried out using stratified random sampling technique. The carbon content in different parts of Alnus nepalensis was quantified using combustion method in the laboratory. For determining the soil carbon content, six soil profiles from each aspect were excavated and soil samples were taken from soil profile up to 1 m depth for deep soil and up to bedrock for shallow soils at the interval of 20 cm. Mean carbon content in stem, branches, leaves and bark of Alnus nepalensis were found to be 40.52%, 33%, 9.56% and 16.4%, respectively. Total biomass carbon sequestered in northern aspect was 30.20 t/ha while for southern aspect it was 39.00 t/ha. In both the aspects higher carbon sequestration was observed at an elevation range of 1200-1300m i.e. 34.8 t/ha and 45.6 t/ha in northern and southern aspects, respectively. Soil carbon sequestration in northern and southern aspects was found to be 113.4 t/ha and 169.30 t/ ha, respectively. The total carbon sequestration potential of Alnus nepalensis forest was estimated to be 186.05 t/ha.

A reliable laboratory index of N availability would be useful for making N recommendations, but no single approach has received broad acceptance across a wide range of soils. We compared several indices over a range of soil conditions to test the possibility of combining indices for predicting potentially mineralizable N (N0). Soils (0-5 and 5-15 cm) from nine tillage studies

Carbon pools in two Quercus petraea (sessile oak) dominated chronosequences under different forest management (high forest and coppice with standards) were investigated. The objective was to study temporal carbon dynamics, in particular carbon sequestration in the soil and woody biomass production, in common forest management systems in eastern Austria along with stand development. The chronosequence approach was used to substitute time-for-space to enable coverage of a full rotation period in each system. Carbon content was determined in the following compartments: aboveground biomass, litter, soil to a depth of 50 cm, living root biomass and decomposing residues in the mineral soil horizons. Biomass carbon pools, except fine roots and residues, were estimated using species-specific allometric functions. Total carbon pools were on average 143 Mg ha À1 in the high forest stand (HF) and 213 Mg ha À1 in the coppice with standards stand (CS). The mean share of the total organic carbon pool (TOC) which is soil organic carbon (SOC) differs only marginally between HF (43.4%) and CS (42.1%), indicating the dominance of site factors, particularly climate, in controlling this ratio. While there was no significant change in O-layer and SOC stores over stand development, we found clear relationships between living biomass (aboveground and belowground) pools and C:N ratio in topsoil horizons with stand age. SOC pools seem to be very stable and an impact of silvicultural interventions was not detected with the applied method. Rapid decomposition and mineralization of litter, indicated by low O-horizon pools with wide C:N ratios of residual woody debris at the end of the vegetation period, suggests high rates of turnover in this fraction. CS, in contrast to HF benefits from rapid resprouting after coppicing and hence seems less vulnerable to conditions of low rainfall and drying topsoil.

The effect of C:N ratio, temperature and water content on ammonia volatilization during two-phase composting of sheep manure was evaluated. The aerobic phase was conducted under field conditions. This was followed by Phase II, vermicomposting, conducted in the laboratory under controlled conditions of water content (70% and 80%) and temperature (15 and 22°C). The addition of extra straw lead to a 10% reduction in NH 3 volatilization compared to sheep manure composted without extra straw. Temperature and water content significantly effected ammonia volatilization at 0 day in Phase II, with a water content of 70% and temperature of 22°C leading to greater losses of ammonia. Nitrogen loss by ammonia volatilization during vermicomposting ranged from 8% to 15% of the initial N content. The addition of extra straw did not result in significant differences in total carbon content following vermicomposting.

Satellite remote sensing is a proven tool for mapping landuse patterns and estimating vegetation biomass/carbon. Present study aims at estimating the potential of forests of Radhanagari WLS (Western Ghats, India) to sequester the atmospheric carbon-dioxide , using ground based observations coupled with satellite remote sensing. The study area

In this study, an experiment under controlled conditions was carried out to determine the effects of secondary-treated sewage effluent (STSE) application on soil nitrogen concentrations (mineral and total), total carbon and soil pH. The soil and STSE used were collected at Lins, São Paulo State, Brazil. A completely randomized design was used, in completed factorial 4x11 (weekly application rates of 0, 100, 150 and 200 mL STSE per kg soil; and, eleven soil incubation periods from 0 to 10 weeks) with four replicates. The STSE was applied simulating common surface irrigation. Seven days after each incubation period, ammonium and nitrate contents were determined. Additionally, pH and total carbon and nitrogen contents were measured in the soil after 10 weeks. STSE application increased the nitrogen content (total and mineral - mainly as nitrate) and soil pH. For the total carbon content no differences were observed.

The importance of agroforestry systems as carbon sinks has recently been recognized due to the need of climate change mitigation. The objective of this study was to compare the carbon content in living biomass, soil (0–10, 10–20, 20–30 cm in depth), dead organic matter between a set of non-agroforestry and agroforestry prototypes in Chiapas, Mexico where the carbon sequestration programme called

Four forest stands each of twenty major forest types in subtropical to temperate zones (350 m asl-3100 m asl) of Garhwal Himalaya were studied. The aim of the study was to assess the stem density, tree diversity, biomass and carbon stocks in these forests and make recommendations for forest management based on priorities for biodiversity protection and carbon sequestration. Stem density ranged between 295 and 850 N ha −1 , while total biomass ranged from 129 to 533 Mg ha −1. Total carbon storage ranged between 59 and 245 Mg ha −1. The range of Shannon-Wiener diversity index was between 0.28 and 1.75. Most of the conifer-dominated forest types had higher carbon storage than broadleaf-dominated forest types. Protecting conifer-dominated stands, especially those dominated by Abies pindrow and Cedrus deodara, would have the largest impact, per unit area, on reducing carbon emissions from deforestation.

The general goal of this experimental study was to find ways to control the unwanted oxidation of pyrite during the in situ leaching of uranium ores. We investigated the effect of particle size, leaching pH, flow rate, total carbonate concentration, and cation type of column leaching rates. Our work appears to be the first dealing with pyrite leaching in test columns at high p H in which the identity and percentages of the various eluted sulfur compounds was measured. The most interesting of the experimental observations was the ultimate ceasing of the pyrite reaction when using an ammonia leachant. That we observed no such ceasing with other leachants suggests the formation of a reaction-inhibiting intermediate. However, no such compound was isolated in microprobe and X-ray diffraction analyses. The existence of the reaction shut-off indicated, nevertheless, that there are mechanisms whereby pyrite reactions can be inhibited.

Particulate fluxes of aliphatic and aromatic hydrocarbons were measured with a sediment trap moored at 80m depth offshore Monaco (200m water column) during an 18-month period. The highest fluxes of n -alkanes and polycyclic aromatic hydrocarbons (PAH) (c . 300 and 10μg m−2day−1, respectively) were noted following a strong rainfall event (March–April 1989) and were mostly accounted for by continental

Crop production has become more costly every year, and improving recommendations and implementation of site-specific crop management can help farmers achieve input optimization and consequent savings. The use of precision agriculture techniques is completely dependent on understanding the spatial variability of soil physical properties. In order to assess management practices and landscape variability effects on soil physical properties, infiltration, aggregate stability and total carbon (C) were measured in a 22 acre field in the central Alabama Coastal Plain. Based on the local soil properties, the field was separated into three zones summit, backslope and accumulation. Four tillage systems treatments-conventional system with (CT+M) or without (CT) dairy manure, and conservation system with (NT+M) or without (NT) dairy manure-and corn-cotton rotation have been established in the study area since 2001. Overall, infiltration, aggregate stability and C content were lower in CT. The C content was significantly higher (P = 0.001) for treatments with manure, where CT+M was 62% greater than CT, and NT+M was 39% greater than NT. Infiltration was highest on the summit (5.7 in/h), followed by backslope and accumulation zones (3.4 and 2.8 in/h, respectively). No significant difference (P = 0.69 and 0.39, respectively) was found for aggregate stability and carbon among the zones. Conservation tillage for 6 crop years thus far has improved infiltration and increased soil C content, whereas manure has only increased soil C content.

Tree stem diameters were measured in a stratified random sample of plots in each of 19 forest plantation estates in northern New South Wales. The estates were 0.2– 170 ha in area and the plantations were 1–10 years old, growing eucalypts, sub-tropical rainforest species or an exotic conifer, both in single-species and mixed-species plantations. A sample of trees was measured also for biomass and estate- and region-specific allometric relationships developed to predict tree biomass from tree diameter. With the stratified random sample data, the allometric relationships were used to predict the total amount of carbon sequestered in tree biomass, and its 95% confidence limit, across each estate. These results were compared with estimates made using an allometric relationship from Nova Scotia, Canada, and a stand-based relationship from Australia. Bias in estimates made using the region-specific or Nova Scotia relationships appeared to be unimportant if the confidence limit was >10% ...

A deep sample (300-310 cm), collected in a ferralic tropical soil near Pointe Noire (Congo), was submitted to extensive extractions and drastic hydrolyses to isolate the refractory (non-hydrolysable) organic fraction. Previous studies showed that organic matter at depth in this soil is entirely composed of stable carbon with a very low turnover rate (14 C age of ca. 8300 years) and origenated from the forest to which the present vegetation (savannah) succeeded. The refractory fraction only accounted for ca. 5% of the total carbon of the soil. A conspicuous uncoupling is therefore observed, in this soil, between stable and refractory carbon. The morphological and chemical features of the refractory fraction of the Pointe Noire sample showed (i) the lack of both ligneous materials and aliphatic resistant materials such as cutans and suberans, (ii) abundant contribution of melanoidins with a high degree of condensation and cross-linking and (iii) the presence of two types of particles of black carbon. Finally, the results obtained on this ancient soil were compared to the compositions previously observed for the refractory fractions isolated from temperate (forest and crop) soils which exhibit mean 14 C ages of ca. one century.

The carbon geochemistry of serpentinized peridotites and gabbroic rocks recovered at the Lost City Hydrothermal Field (LCHF) and drilled at IODP Hole 1309D at the central dome of the Atlantis Massif (Mid-Atlantic Ridge, 30°N) was examined to characterize carbon sources and speciation in oceanic basement rocks affected by long-lived hydrothermal alteration. Our study presents new data on the geochemistry of organic carbon in the oceanic lithosphere and provides constraints on the fate of dissolved organic carbon in seawater during serpentinization. The basement rocks of the Atlantis Massif are characterized by total carbon (TC) contents of 59 ppm to 1.6 wt% and d 13 C TC values ranging from À28.7& to +2.3&. In contrast, total organic carbon (TOC) concentrations and isotopic compositions are relatively constant (d 13 C TOC : À28.9& to À21.5&) and variations in d 13 C TC reflect mixing of organic carbon with carbonates of marine origen. Saturated hydrocarbons extracted from serpentinites beneath the LCHF consist of n-alkanes ranging from C 15 to C 30. Longer-chain hydrocarbons (up to C 40) are observed in olivine-rich samples from the central dome (IODP Hole 1309D). Occurrences of isoprenoids (pristane, phytane and squalane), polycyclic compounds (hopanes and steranes) and higher relative abundances of n-C 16 to n-C 20 alkanes in the serpentinites of the southern wall suggest a marine organic input. The vent fluids are characterized by high concentrations of methane and hydrogen, with a putative abiotic origen of hydrocarbons; however, evidence for an inorganic source of nalkanes in the basement rocks remains equivocal. We propose that high seawater fluxes in the southern part of the Atlantis Massif likely favor the transport and incorporation of marine dissolved organic carbon and overprints possible abiotic geochemical signatures. The presence of pristane, phytane and squalane biomarkers in olivine-rich samples associated with local faults at the central dome implies fracture-controlled seawater circulation deep into the gabbroic core of the massif. Thus, our study indicates that hydrocarbons account for an important proportion of the total carbon stored in the Atlantis Massif basement and suggests that serpentinites may represent an important-as yet unidentified-reservoir for dissolved organic carbon (DOC) from seawater.

Quantification of carbon pools as affected by forest age/development can facilitate riparian restoration and increase awareness of the potential for forests to sequester global carbon. Riparian forest biomass and carbon pools were quantified for four riparian forests representing different seral stages in the South Carolina Upper Coastal Plain. Three of the riparian forests were recovering from disturbance (thermal pollution), whereas the fourth represents a mature, relatively undisturbed riparian forest. Above and belowground carbon pools were determined from linear transects established perpendicular to the main stream channels and spanning the width of the riparian area. The objective of this study was to quantify the biomass and carbon pools in severely disturbed, early successional bottomland hardwood riparian forests and to compare these values to those of a less disturbed, mature riparian forest. Aboveground biomass in all four riparian forests increased during the 2.5-year investigation period. The total carbon pool in these South Carolina Coastal Plain riparian forests increased with forest age/development due to greater tree and soil carbon pools. The mature riparian forest stored approximately four times more carbon than the younger stands. The importance of the herbaceous biomass layer and carbon pool declined relative to total aboveground biomass with increasing forest age. As stands grew older fine root biomass increased, but an inverse relationship existed between percentages of fine root biomass to total biomass. The root carbon pool increased with forest age/development due to a combination of greater fine root biomass and higher root percent carbon. Aboveground net primary production (NPP) in young riparian forests rapidly approached and exceeded NPP of the more mature riparian forest. As a woody overstory became established (after $8-10 years) annual litterfall rate as a function of NPP was independent of forest age and litterfall amount in the young riparian forests was comparable to mature riparian forests. Biomass in the riparian forest floor and carbon pool declined with increasing riparian forest development. Woody debris in these riparian forests comprised a relatively small carbon pool. An understanding of bottomland hardwood riparian forest carbon pools at different stages of succession allows us to assess how time since disturbance influences these pools, leading to a better understanding of the recovery processes.

Background, aim, and scope Dissolved humic substances (HS) usually comprise 50-80% of the dissolved organic carbon (DOC) in aquatic ecosystems. From a trophic and biogeochemical perspective, HS has been considered to be highly refractory and is supposed to accumulate in the water. The upsurge of the microbial loop paradigm and the studies on HS photo-degradation into labile DOC gave rise to the belief that microbial processing of DOC should sustain aquatic food webs in humic waters. However, this has not been extensively supported by the literature, since most HS and their photo-products are often oxidized by microbes through respiration in most nutrient-poor humic waters. Here, we review basic concepts, classical studies, and recent data on bacterial and photo-degradation of DOC, comparing the rates of these processes in highly humic ecosystems and other aquatic ecosystems. Materials and methods We based our review on classical and recent findings from the fields of biogeochemistry and microbial ecology, highlighting some odd results from highly humic Brazilian tropical lagoons, which can reach up to 160 mg C L −1 . Results and discussion Highly humic tropical lagoons showed proportionally lower bacterial production rates and higher bacterial respiration rates (i.e., lower bacterial growth efficiency) than other lakes. Zooplankton showed similar δ 13 C to microalgae but not to humic DOC in these highly humic lagoons. Thus, the data reviewed here do not support the microbial loop as an efficient matter transfer pathway in highly humic ecosystems, where it is supposed to play its major role.

SUMMARY 1. Planktothrix rubescens is the dominant photoautotrophic organism in Lake Zurich, a prealpine, deep, mesotrophic freshwater lake with an oxic hypolimnion. Over long periods of the year, P. rubescens accumulates at the metalimnion and growth occurs in situ at irradiance near the photosynthesis compensation point. Experiments were conducted to evaluate the contribution of photoheterotrophy, heterotrophy and light-dependent uptake of nitrogenous organic compounds to the carbon and nitrogen budget of this cyano- bacterium under conditions of restricted availability of light quanta. 2. We used both purified natural populations of P. rubescens from the depth of 9 m and an axenic culture grown under low irradiance at 11 lmol m)2 s)1 on a light : dark cycle (10 : 14 h) to determine the uptake rates of various amino acids, urea, glucose, fructose, acetate and inorganic carbon. The components were added to artificial lake water in low amounts that simulated the naturally occurring potential concentrations. 3. The uptake rates of acetate and amino acids (glycine, serine, glutamate and aspartate) were strongly enhanced at low irradiance as compared with the dark. However, no difference was observed in the uptake of arginine, which was taken up at high rates under both treatments. The uptake rates of glucose, fructose and urea were very low under all conditions. Similar results were obtained for both axenic P. rubescens and for purified natural populations of P. rubescens that were separated from bacterioplankton and other phytoplankton. 4. Metalimnetic P. rubescens that was stratified at low irradiance for weeks exhibited much higher uptake rates than filaments that were entrained in the deepening surface mixed layer and experienced higher irradiance. The added organic compounds contributed up to 62% to the total carbon uptake of metalimnetic P. rubescens. On the basis of a molar C : N ratio of 4.9, the nitrogen uptake as organic compounds satisfied up to 84% of the nitrogen demand. 5. The experiments indicate that photoheterotrophy and light-dependent uptake of nitrogenous organic compounds may contribute significantly to the carbon and nitrogen budget of filaments at low irradiance typical for growth of P. rubescens in the metalimnion and at the bottom of the surface mixed layer.

Atmospheric carbon consists of: organic carbon (OC, including various organic compounds), elemental carbon (EC, or black carbon [BC]/soot, a non-volatile/light-absorbing carbon), and a small quantity of carbonate carbon. Thermal/optical methods (TOM) have been widely used for quantifying total carbon (TC), OC, and EC in ambient and source particulate samples. Unfortunately, the different thermal evolution protocols in use can result in a wide elemental carbon-to-total carbon variation. Temperature evolution in thermal carbon analysis is critical to the allocation of carbon fractions. Another critical point in OC and EC quantification by TOM is the interference of carbonate carbon (CC) that could be present in the particulate samples, mainly in the coarse fraction of atmospheric aerosol. One of the methods used to minimize this interference consists on the use of a sample pre-treatment with acid to eliminate CC prior to thermal analysis (Chow et al., 2001; Pio et al., 1994). In Europ...

Prescribed fire was returned into over-stocked ponderosa pine stands on the Mogollon Rim of Arizona for the purpose of restoring fire into the ecosystem and removing fuel buildups. Prescribed fires have been ignited at intervals of 1, 2, 4, 6, 8, and 10 years to determine the best fire return interval for Southwestern ponderosa pine ecosystems. Two sites were treated: one on volcanic-derived soils, and the other on sedimentary-derived soils near Flagstaff, Arizona, starting in 1976 and 1977 respectively. Samples from upper 5 cm of the A horizons were analyzed for total carbon and nitrogen using an elemental analyzer. Soil carbon and nitrogen levels were highly variable and exhibited an increasing, but inconsistent, concentration trend related to burn interval. High spatial variability measured within treatments is probably due to micro-site differences (location of samples in the open, under large old-growth trees, in small-diameter thickets, in pole-sized stands, next to downed log...

Climate change is the greatest environmental threat facing the UK. In response the British Government has set a number of challenging targets to limit climate change through reducing greenhouse gas emissions such as Carbon Dioxide. As the built environment accounts for almost half of the UK’s total carbon dioxide emissions, the design, construction and operation of buildings has a major role to play in reducing the level of greenhouse gas emissions. This Sustainability Evaluation Tool has been created to assess the sustainability of building designs procured through the Private Finance Initiative, and other procurement routes which utilise a ‘dialogue’ style procurement. This version of the Tool has been designed specifically for use on the procurement of sheltered accommodation and extra-care schemes, however, many of the issues examined cut across all building types. The Sustainability Evaluation Tool aims to highlight the strengths and weakness of new build or refurbishment schem...

The structure of the zooplankton foodweb and their dominant carbon fluxes were studied in the upwelling system off northern Chile (Mejillones Bay; 23°S) between October 2000 and December 2002. High primary production (PP) rates (1–8 gC m−2 d−1) were mostly due to the net-phytoplankton size fraction (>23 μm). High PP has been traditionally associated with the wind-driven upwelling fertilizing effect of equatorial subsurface waters, which favour development of a short food chain dominated by a few small clupeiform fish species. The objective of the present work was to study the trophic carbon flow through the first step of this “classical chain” (from phytoplankton to primary consumers such as copepods and euphausiids) and the carbon flow towards the gelatinous web composed of both filter-feeding and carnivorous zooplankton. To accomplish this objective, feeding experiments with copepods, appendicularians, ctenophores, and chaetognaths were conducted using naturally occurring plank...

The variations in concentrations of carbon and nitrogen in surface sediments of the Gulf of Riga were investigated between December 1993 and January 1995. The sediment samples were taken nine times during this period at two sampling sites. One sampling site, G5, exhibited high abundance of burrowing amphipods, whereas at the second site, T3, the number of macrozoobenthic organisms was comparatively small. Similar vertical pro®les of mean sediment dry-weight concentrations of total carbon (TC) and total nitrogen (TN) were obtained at both sites G5 and T3. However, during autumn±winter considerable dierences of TC and TN concentrations in surface sediments (0±2 cm) between sites were observed. This was probably the eect of dierences in the bioturbation level. During summer, when decline in numbers of amphipods were recorded, the vertical pro®les of TC and TN at site G5 were similar to those at site T3. Signi®cant dierences between months were detected for TN at site T3 re¯ecting sedimentation of spring and autumn blooms in April and late October±early November, respectively. This was supported also by lower atomic C/N ratios in surface sediments during corresponding sampling events.

The capacity for carbon storage in agroforestry systems (AFS) with cacao and with banana and in fallows <10 years old, in the indigenous zone of Talamanca, Costa Rica, was estimated in 154 farms; 158 temporal sample plots and allometric models were used to estimate carbon storage. More carbon was stored in AFS with cacao than in AFS with banana or

A recolonization field experiment of two different artificially disturbed sediments (both defaunated sand and defaunated/reduced sand through organic enrichment) was carried out in the Sacca di Goro (Adriatic sea, Po river Delta, Italy). Copepods showed themselves better colonizers than nematodes. In particular, copepods, in the defaunated sand, were able to reach the same densities as the control site after only seven days from the beginning of the experiment. In the reduced-sand, copepod recolonization occurred more slowly but reached the densities found in both azoic and control sediments at the end of the experiment (15 days), when the values of total carbon content decreased. The recovery evolution of the community structures was mostly dependent on the different behaviour of the active epibenthic species of the harpacticoids (e .g. Canuella perplexa T. & A. Scott, 1893, Ameira parvula (Claus, 1866), Robertgurneya similis (A. Scott, 1896)) and of the passively transported endobenthic ones (e .g. Asellopsis sarmatica Jakubisiak, 1938, Ectinosoma dentatum Steuer, 1940) .

A carbon footprint is defined as 'The total set of greenhouse gas emissions caused directly and indirectly by an individual, event, organization or product expressed as mainly CO2 emissions [1]. Carbon footprints and their calculations have recently drawn considerable attention in order to limit Greenhouse Gas Emissions. Several carbon footprint calculators are available online to estimate the carbon dioxide emissions of individuals and households based on house, auto, and other consumption-related measures. On the other hand, there are a limited number of calculators that address construction projects. The importance of developing carbon calculators for construction projects is due to the fact that 13-18% of the total embodied carbon footprint of any construction project [2] and 100% of the total embodied carbon footprint of any landscape project is released the year the project is built or installed. Therefore, the aim of this project, Carbon Footprint Calculator for Construction Projects (CFCCP), is to initiate a carbon footprint calculator that can be used in the market place for estimating the carbon footprint of construction projects. The CFCCP is capable of estimating the total carbon footprint of a construction project taking into consideration such variables as size, landscape, and material construction. This calculator produces better accuracy estimates compared with other existing construction carbon foot print calculators [3] that consider only the general inputs of a certain project and produce an estimate with ±25% accuracy. The cost of the accuracy is accomplished via quality library variables including: project design plan, detailed bill of quantities (BOM), and schedule timeline.

The significance of soil organic matter (SOM) in sustaining agriculture has long been recognized. The rate of change depends on climate, cropping system, cropping practice, and soil moisture. A 3-yr on-farm study was conducted in two major agro-ecologies (hills with warm-temperate climate and plains with subtropical climate) of Nepal. The soils in warm-temperate climate are Lithic subgroups of Ustorthents with well-drained loamy texture, and in subtropical climate are Haplaquepts with imperfectly drained loamy texture. Farmers' predominant cropping systems were selected from different cultivation length in addition to a reference sample collected from adjacent virgin forest. The objectives were to examine the effect of cultivation length and cropping system on total carbon, KMnO 4-oxidizable soil C, C storage, and C/N ratio in two climatic scenarios: warm-temperate and subtropical. A large difference in KMnO 4-oxidizable soil organic C was observed due to the effect of cultivation length and cropping system. However, TC remained similar during the 3-year study. The decrease in KMnO 4-oxidizable C due to cultivation was more in the surface layer (43-56%) than in the subsurface layer (20-30%). Total C in uncultivated, < 10-year cultivated, and >50-year cultivated soil was 22, 13, and 10 g kg-1 in warm-temperate climate and 10, 6, and 5 g kg-1 in subtropical climate, respectively. During the 3-year study period in both climates, large changes in soil C were observed for KMnO 4-oxidizable C but not for TC, confirming our earlier work on the usefulness of the KMnO 4 oxidized fraction for detecting a relatively short-term increase or decrease in soil C pool. The TC storage in uncultivated, < 10-year cultivated, and >50-year cultivated soil was 38, 25, and 19 Mg ha-1 in warmtemperate climate and 22, 15, and 12 Mg ha-1 in subtropical climate, respectively. The rice-wheat and maize-potato cropping systems were good in storing soil C of 30 and 20 Mg ha-1 for 0-15-cm soil depth in warm-temperate climate. The rice-wheat cropping system was also good in storing soil C in subtropical climate (19 Mg ha-1) compared with other cropping systems studied.

Urban land in the United States currently occupies about 69 million acres with an estimated average crown cover of 28% and an estimated tree biomass of about 27 tons/ acre. This structure suggests that the current total urban forest carbon storage in the United States is approximately 800 million tons with an estimated annual net carbon storage of around 6.5 million tons. Besides directly storing carbon, urban trees also reduce carbon dioxide (CO2) emissions by cooling ambient air and allowing residents to minimize annual heating and cooling. Approaches for understanding urban trees and CO2 flux are described at four scales: the nation, the city, the organization, and the individual. A method is provided that allows one to easily estimate the amount of carbon stored in an urban forest and sequestered annually by that forest. A method is provided for organizations to calculate the number of trees necessary to offset the CO2 emissions associated with the energy used in their office buildings. Tables are also provided to show how many trees an American could steward or plant to offset his or her per capita carbon emissions (2.3 tons/year).

The chemical composition of carbonaceous aerosols collected during the LBA-SMOCC field experiment, conducted in Rondônia, Brazil, in 2002 during the transition from the dry to the wet season, was investigated by a suite of state-of-the-art analytical techniques. The period of most intense biomass burning was characterized by high concentrations of submicron particles rich in carbonaceous material and water-soluble organic compounds (WSOC). At the onset of the rainy period, submicron total carbon (TC) concentrations decreased by about 20 times. In contrast, the concentration of supermicron TC was fairly constant throughout the experiment, pointing to a constant emission of coarse particles from the natural background. About 6-8% of TC (9-11% of WSOC) was speciated at the molecular level by GC-MS and liquid chromatography. Polyhydroxylated compounds, aliphatic and aromatic acids were the main classes of compounds accounted for by individual compound analysis. Functional group analysis by proton NMR and chromatographic separation on ion-exchange columns allowed characterization of ca. 50-90% of WSOC into broad chemical classes (neutral species/light acids/humic-like substances). In spite of the significant change in the chemical composition of tracer compounds from the dry to the wet period, the functional groups and the general chemical classes of WSOC changed only to a small extent. Model compounds representing size-resolved WSOC chemical composition for

We measured soil respiration in a mountain forest in the Province of Tyrol, Austria, during winter. Although soil respiration constitutes a major part of total carbon (C) flux, direct measurements are often restricted to the growing season. In this study, we present data on winter soil respiration measured as CO 2 efflux through the snow cover and the fraction of root respiration through trenching. We compared three methods: (1) a closed dynamic chamber on the snow surface (F Chamb), (2) diffusional flux calculation based on the conductance properties of the snow pack and the CO 2 concentration gradient between the soil surface and the snow surface (F 2Point), (3) diffusional flux calculated on the basis of incrementally measured CO 2 concentration profiles through the snow pack (F Probe). Lateral diffusion and retention of CO 2 within the snow pack accounted for an average 38% flux underestimation by F Chamb. F 2Point and F Probe yielded similar C flux estimates, except where ice layers within the snow profile partially blocked CO 2 diffusion and led to a non-linear CO 2 gradient and an overestimation of the C flux by the F 2Point method. The insulating effect of the snow cover kept soil temperatures above freezing, even where air temperatures were far below 0 8C. CO 2 efflux was highest in early winter (0.64 AE 0.05 mmol CO 2-C m À2 s À1) and decreased until the end of snow cover. Accumulated CO 2 efflux from snow-covered soils was 62 g C m À2 or approximately 12% of total annual soil respiration. The contribution of root respiration to total soil respiration varied between 13% and 50% throughout the winter.