Evaluation of Forest Carbon Budget of Liaoning Province in Recent 50 Years

The interannual variation characteristics of NPP and carbon emission of Liaoning forest in recent 50 years (from 1961 to 2008) were analyzed based on the hydrothermal optimized NPP model and soil respiration Q10 model.The results showed that the total amount of annual NPP was increased in recent 50 years,in which the amount of NPP (83.9 Mt) in 2008 was 2.8 times as high as that in 1961.Amount of NPP per unit area changed with different years,and the maximum value was 36.5% more than the minimum one.The net carbon budget of Liaoning forest was carbon sink,with annual 2.1 t CO2/hm2.

Carbon Budget of Bastard Halibut Paralichthys Olivaceus in Relation to Body Weight and Temperature

The effects of body weight and temperature on the carbon budget of the juvenile bastard halibut,Paralichthys olivaceus, were studied at temperature 13.5, 18, 21.5 and 24 ℃, respectively. The carbon intake, faecal and growth carbon were measured, and the carbon respiration was calculated using the carbon budget equation (C C=G C+F C+R C). The combined relationship between different components of the carbon budget, body weight and temperature could be described by regression equations:C C=1.0206W 0.8126e 0.1483T; G C=0.0042W 1.4096 (-5.11T3+285.90T2-5173.72T+30314.03);F C=0.0485W 0.7711e 0.1624T U C = 1.4333W 0.6715e 0.1487T. Body weight had no significant effect on the carbon absorption efficiency and the conversion efficiency.

Simulating Net Carbon Budget of Forest Ecosystems and Its Response to Climate Change in Northeastern China Using Improved FORCCHN

As dominant biomes,forests play an important and indispensable role in adjusting the global carbon balance under climate change.Therefore,there are scientific and political implications in investigating the carbon budget of forest ecosystems and its response to climate change.Here we synthesized the most recent research progresses on the carbon cycle in terrestrial ecosystems,and applied an individual-based forest ecosystem carbon budget model for China(FORCCHN) to simulate the dynamics of the carbon fluxes of forest ecosystems in the northeastern China.The FORCCHN model was further improved and applied through adding variables and modules of precipitation(rainfall and snowfall) interception by tree crown,understory plants and litter.The results showed that the optimized FORCCHN model had a good performance in simulating the carbon budget of forest ecosystems in the northeastern China.From 1981 to 2002,the forests played a positive role in absorbing carbon dioxide.However,the capability of forest carbon sequestration had been gradually declining during the the same period.As for the average spatial distri-bution of net carbon budget,a majority of the regions were carbon sinks.Several scattered areas in the Heilongjiang Province and the Liaoning Province were identified as carbon sources.The net carbon budget was apparently more sensitive to an increase of air temperature than change of precipitation.

Sensitivity analysis of the De Nitrification and De Composition model for simulating regional carbon budget at the wetlandgrassland area on the Zoige Plateau,China

Although mathematical models(e.g., De Nitrification and De Composition(DNDC) provide a powerful tool to study regional carbon budget, it is still difficult to obtain accurate simulation results because there exists large uncertainties in modeling regional carbon budget. Through the investigation on the sensitivity of model output parameters to the input parameters, sensitivity analysis(SA) has been proved to be able to identify the key sources of uncertainties and be helpful to reduce the model uncertainties. However, some input parameters with discrete values(e.g., land use type and soil type) and the regional effect of the sensitive parameters were rarely examined in SA. In this paper, taking the Zoige Plateau as a case area, we combined the one-factor-ata-time(OAT) with Extended Fourier Amplitude Sensitivity Test(EFAST) to conduct a SA of DNDC for simulating the regional carbon budget, including Gross Primary Productivity(GPP), Net Primary Productivity(NPP), Net Ecosystem Productivity(NEP), autotrophic respiration(Ra), soil microbial heterotrophic respiration(Rh) and ecosystem respiration(Re). The result showed that the combination of OAT and EFAST could test the contribution of the input parameters with discrete values to the output parameters. In DNDC model, land use type and soil type had a significant impact on the regional carbon budget of the Zoige Plateau, and daily temperature was also confirmed to be one of the most important parameters for carbon budget. For the other input parameters, with the change of land use type or soil type at regional scale, the sensitive parameters of carbon budget would vary accordingly. The SA results would provide scientific evidence to optimize DNDC model and they suggested that we should pay attention to the spatial/temporal effect of SA and try to use the appropriate data in simulation of the regional carbon budget.

FOOD SOURCES AND CARBON BUDGET OF CHINESE PRAWN PENAEUS CHINENSIS

This study deals with contribution of artificial food pellet and natural food to Chinese prawn (Penaeus orientalis) growth in a semi-intensive culture pond. The prawn carbon consumption, budget, and the effects of some factors on the budget were investigated. The results showed that 26.2% of P. orientalis growth carbon came from formulated feed at the initial culture stage (when the prawns were 0.06±0.01 g in wet weight), and was 62.5% when the prawns were 9.56±1.04 g. The remaining part of the growth carbon was derived from organic fertilizer and natural food. The highest growth rate occurred at 20×10 -3 salinity. Suitable salinity for culturing Chinese prawn was (20-28)×10 -3 .

Carbon Budget Proposal:An Institutional Framework for an Equitable and Sustainable World Climate Regime

Consensus on reducing greenhouse gas emissions has been reached at the technical and political level.However,as the issue involves economic costs and the right to develop,the international institutional framework for addressing greenhouse gas emissions has consistently failed to balance the demands of impartiality and sustainability.However,a sustainable carbon budget proposal is undoubtedly achievable if the global carbon budget (the total amount of carbon permitted by climate security) is made an absolute constraint.If a preliminary distribution was made among the world's population on a per capita basis,the total limited global carbon budget could not only meet basic needs but also ensure the proposal's equitable.Taking into account historical emission levels and future needs,we should carry out carbon budget transfer payments and devise a corresponding funding mechanism to ensure efficient allocation under the proposal.Unlike the phase-by-phase progress and provisional goals of the Kyoto Protocol,the carbon budget proposal outlined above is a comprehensive and holistic package.Due to the politicization of the climate change issue,however,many technical issues can only be worked out through international political and diplomatic negotiations.

Carbon Budget for Basic Needs:Implications of International Equity and Sustainability

The fundamental way of satisfying the basic needs of human development is to secure the basic needs,limit luxurious and wasteful emissions,and ensure the fulfillment of climate targets,so as to achieve intra-and intergenerational equity.In this paper,the author discusses and analyzes a series of challenges that the development has to face,such as poverty elimination,urbanization,and industrialization,and the problems of increased consumption that is brought about by the improvement of living standards;the author distinguishes the stock emission,which does not need annual updating,and the flow emission of regular consumption;the author also defines the standards of energy consumption and carbon emissions that can meet the basic needs.On this basis,the author proposes the concept and method of carbon budget,compares this method with other means,and in particular,studies and analyzes the implications of international equity and sustainability of carbon budget as part of the international climate regime design.

Studies on carbon budget score remarkable progress

On 23 November, 2006, a key CAS research project on carbon budget passed the review by a panel of experts under the joint

Organic carbon budget in shrimp polyculture enclosure ecosystems

The organic carbon budget in shrimp polyculture ecosystems was studied with five experimental enclosures. The results showed that: (l ) the total Organic carbon income of the ecosystems varied from 4 847. 46 to 6 154. 67 g, averaged (5 646. 94 t 551.09) g, the average ratio among its components, i. e., (phytoplankton production ): (periphyte production ): (feed casted) was 0. 73: 0. 11: 0. 16; (2) the total output of organic carbon varied from 3 310. 28 to 3 974. 79 g, averaged (3 644. 21 281. 44) g, the average ratio among its components, i. e., (plankton community respiration): (periphyton respiration): (benthic community): (culture animal production): (culture animal respiration) was 0. 53: 0. 19: 0. 15: 0. 04:0. 09; (3) the organic carbon accumulation varied from 1 383. 45 to 2 707. 31 g, averaged (2 002. 73 546. 76) g, which was 26% --44 % of the total organic carbon income; the sequence of organic carbon accumulation in the ecosystems of different polyculture types was Y5 (Penaeus chinensis -- Argopecten irradians) > Y7 (P. chinensis -- Taiwan red tilapia) > Y4 (P. chinensis ) > T5 (P. chinensis -- Taiwan red tilapia -- Sinonovacula constricta ) > Y6 (P. chinensis S. constricta ); (4) the average conversion rate of organic carbon income to P. chinensis was (l. 77 0. 62) % (Y6>T5 > Y4 >YS > Y7), and that to total culture animals was (2. 18 0. 79) % (T5 >Y6 > Y5 > Y4 > Y7).

Carbon Budget Dynamics over a Rain-Fed Maize Agricultural Ecosystem in Northeast China and Its Regulation

Based on the eddy-covariance observation data over rain-fed maize agricultural ecosystem during 2005-2011, the dynamics of net ecosystem CO2 exchange (NEE) and its control mechanism were analyzed in the present study. We found that the average carbon budget of non-growing season, growing season and annual were 153.16 - 202.03 g C/m2, −689.36 - −488.17 g C/m2, and −316.96 - −487.33 g C/m2, respectively. Maize carbon content of grain yield was −226.6 - −339.94 g C/m2, accounting for 55.4% of carbon budget in the growing season. From sowing to seven-leaf stage, the carbon budget of this ecosystem was characterized by carbon release, with the rate of 0.028 ±0.0056 mg CO2 m−2⋅s−1. From seven-leaf to mature stage, the carbon budget was characterized by carbon absorption, with the rate of −0.256 ±0.0693 mg CO2 m−2⋅s−1. The key meteorological factors affecting annual carbon budget included daily average temperature (R = −0.81, P = 0.03) and saturated vapor pressure deficit (R = −0.64, P = 0.12). At the same photosynthetically active radiation (PAR) level, CO2 assimilation rate was linearly correlated with leaf area index (P 【0.05), and the slopes increased with PAR, indicating the increase in net ecosystem CO2 exchange in growing season was unlikely to be resulted from the extension of growing season. On the contrary, the carbon sink of rain-fed maize ecosystem in growing season might be decreased by extending the growing season ahead of the sowing date.

Understanding equityeefficiency interaction in the distribution of global carbon budgets

Equity and efficiency are two important factors guiding the mitigation of anthropogenic emissions to achieve the Paris climate goals.Previous studies have proposed a range of allocations of global carbon budgets,but few have quantified the equity-efficiency interaction.Based on an investigation of the existing allocation literature,this study conducts a novel analysis using a‘mixed’allocation‘big-data’framework to understand the equityeefficiency interaction in the distribution of global carbon budgets under 2℃ and 1.5℃ warming targets.At a global scale,a carbon Gini coefficient and aggregate abatement costs are used as quantitative metrics to reflect equity and efficiency,respectively.Results show an equity-efficiency frontier that reflects the opportunity for the international community to co-improve equity and efficiency on top of existing allocations.However,the frontier also features strong trade-offs to further improve equity and efficiency if national allocations are to be achieved individually.Our analysis verifies that such trade-offs are sensitively dependent on the level of global connection and integration.Linking national mitigation actions and potentials can help promote equity-efficiency synergies and contribute to the efficient achievement of the Paris Agreement's temperature and equity goals.

Carbon budget proposal： a framework for an equitable and sustainable international climate regime

A worldwide consensus on reducing greenhouse gas emissions has been reached at the technical and political level. However, as the issue involves economic costs and developmental interests, the international institutional framework for addressing global greenhouse gas emissions has consistently failed to balance the demands of equity and sustainability. But the sustainability of carbon budget proposal is undoubtedly achievable if the total global carbon budget （the total amount of carbon permitted by climate security） is made an absolute constraint. If an initial allocation is made among all members of the global village on a per capita basis, a limited total budget could not only meet basic needs but also ensure equity. Taking into account historical emission levels and future needs, we should implement carbon budget transfer payments and devise a corresponding financial mechanism to ensure efficient allocation. Unlike the phase-by-phase progress and provisional goals of the Kyoto Protocol, the carbon budget proposal presented here is a comprehensive and holistic package. Due to the politicization of the climate change question, however, many technical issues can only be worked out through international political and diplomatic negotiations.

Examining spatio-temporal variations in carbon budget and carbon compensation zoning in Beijing-Tianjin-Hebei urban agglomeration based on major functional zones

Research on the carbon budget and zoning for carbon compensation in major functional zones(MFZs)is important for formulating strategies for low-carbon development for each functional zone,promoting the collaborative governance of the regional ecological environment,and achieving high-quality development.Such work can also contribute to achieving peak emissions and carbon neutrality.This paper constructs a theoretical framework for the carbon budget and carbon compensation from the perspective of the MFZ,uses 157 county-level units of the Beijing-Tianjin-Hebei urban agglomeration(BTHUA)as the study area,and introduces the concentration index,normalized revealed comparative advantage index,and Self Organizing Mapping-K-means(SOM-K-means)model to examine spatio-temporal variations in the carbon budget and carbon compensation zoning for the BTHUA from the perspective of MFZs.The authors propose a scheme for the spatial minimization of carbon emissions as oriented by low-carbon development.The results show that:(1)From 2000 to 2017,the carbon budget exhibited an upward trend of volatility,its centralization index was higher than the“warning line”of 0.4,and large regional differences in it were noted on the whole.(2)There were significant regional differences in the carbon budget,and carbon emissions exhibited a core-periphery spatial pattern,with a high-value center at Beijing-Tianjin-Tangshan that gradually decreased as it moved outward.However,the spatial pattern of carbon absorption tended to be stable,showing an inverted“U-shaped”pattern.It was high in the east,north,and west,and was low in the middle and the south.(3)The carbon budget was consistent with the strategic positioning of the MFZ,and the optimized development zone and key development zone were the main pressure-bearing areas for carbon emissions,while the key ecological functional zone was the dominant zone of carbon absorption.The difference in the centralization index of carbon absorption among the functional zones was smaller than that in the centralization index of carbon emissions.(4)There were 53 payment areas,64 balanced areas,and 40 obtaining areas in the study area.Nine types of carbon compensation zones were finally formed in light of the strategic objectives of the MFZ,and directions and strategies for low-carbon development are proposed for each type.(5)It is important to strengthen research on the carbon balance and horizontal carbon compensation at a microscopic scale,enrich the theoretical framework of regional carbon compensation,integrate it into the carbon trading market,and explore diversified paths for achieving peak emissions and carbon neutrality.

The role of herbivores in the grassland carbon budget for Three-Rivers Headwaters region,Qinghai-Tibetan Plateau,China

Background:An accurate assessment of the carbon budget is a crucial part of projecting future climate change and its impact on ecosystems.Grasslands foster multiple ecological functions including support for wild animals and livestocks.Herbivores intake forage biomass carbon,then digest and metabolize,and finally retain some carbon.The carbon processes have not been well quantified,resulting in uncertainties in the estimation of regional carbon budgets for grassland ecosystems.Methods:An animal metabolic carbon flux model was developed for herbivores in the Three-Rivers Headwaters region of China.The forage intake and metabolic carbon rates were estimated through metabolic body weight and daily digested measures for the main herbivore species.Results:The carbon intake was 5.52 Tg C year−1(45%)from partial aboveground biomass(12.2 Tg C year−1),in which 39.31%was released into the atmosphere by respiration CO_(2),43.77%was returned to the ecosystem as feces and urine,and 16.96%was retained in herbivores for population regeneration or for human well-being.Conclusions:This study,as the first research on this topic,quantified the carbon flux of herbivores and found livestock accounts for a major part of consumed carbon on grasslands,which is important for understanding regional carbon budgets to mitigate and adapt to climate change over grasslands worldwide.

Carbon budgets of three temperate forest ecosystems in Dongling Mt.,Beijing,China

There is a general agreement that forest ecosystems in the NorthernHemisphere function as significant sinks for atmospheric CO_2; however, their magnitude anddistribution remain large uncertainties. In this paper, we report the carbon (C) stock and itschange of vegetation, forest floor detritus, and mineral soil, annual net biomass increment andlitterfall production, and respiration of vegetation and soils between 1992 to 1994, for threetemperate forest ecosystems, birch (Betula platyphylla) forest, oak (Ouercus liaotungensis) forestand pine (Pinus tabulaeformis) plantation in Mt. Dongling, Beijing, China. We then evaluate the Cbudgets of these forest ecosystems. Our results indicated that total C density (organic C perhectare) of these forests ranged from 250 to 300 t C ha^(-1), of which 35—54 t C ha^(-1) fromvegetation biomass C and 209-244 t C ha^(-1) from soil organic C (1 m depth, including forest floordetritus). Biomass C of all three forests showed a net increase, with 1.33—3.55 t C ha^(-1) a^(-1)during the study period. Litterfall production, vegetation autotrophic respiration, and soilheterotrophic respiration were estimated at 1.63—2.34,2.19—6.93, and 1.81 —3.49 t C ha^(-1)a^(-1), respectively. Ecosystem gross primary production fluctuated between 5.39 and 12.82 t Cha^(-1) a^(-1), about half of which (46%-59%, 3.20-5.89 t C ha^(-1) a^(-1)) was converted to netprimary production. Our results suggested that pine forest fixed C of 4.08 t ha^(-1) a^(-1), whereassecondary forests (birch and oak forest) were nearly in balance in CO_2 exchange between theatmosphere and ecosystems.

Forest carbon budgets in Southeast Asia following harvesting and land cover change

Terrestrial ecosystems play an important role in the global carbon (C)cycle. Tropical forests in Southeast Asia are constantly changing as a result of harvesting and conversion to other land cover. As a result of these changes, research on C budgets of forest ecosystems has intensified in the region over thelast few years. This paper reviews and synthesizes the available information. Natural forests in SE Asia typically contain a high C density (up to 500 Mg/ha). Logging activities are responsible for at least 50% decline in forest C density.Complete deforestation (conversion from forest to grassland or annual crops) results in C density of less than 40 Mg/ha. Conversion to tree plantations and other woody perennial crops also reduces C density to less than 50% of the originalC forest stocks. While much information has been generated recently, there are still large gaps of information on C budgets of tropical forests and its conversion to other land uses in SE Asia. There is therefore a need to intensify research in this area.

Modeling Carbon and Water Budgets in the Lushi Basin with Biome-BGC

In this article, annual evapotranspiration(ET) and net primary productivity (NPP) of fourtypes of vegetation were estimated for the Lushi basin,a subbasin of the Yellow River in China. These fourvegetation types include: deciduous broadleaf forest,evergreen needle leaf forest, dwarf shrub and grass.Biome-BGC--a biogeochemical process model wasused to calculate annual ET and NPP for eachvegetation type in the study area from 1954 to 2000.Daily microclimate data of 47 years monitored byLushi meteorological station was extrapolated tocover the basin using MT-CLIM, a mountainmicroclimate simulator. The output files of MT-CLIM were used to feed Biome-BGC. We usedaverage ecophysiological values of each type ofvegetation supplied by Numerical TerradynamicSimulation Group (NTSG) in the University ofMontana as input ecophysiological constants file.The estimates of daily NPP in early July and annualET on these four biome groups were comparedrespectively with field measurements and other studies.Daily gross primary production (GPP) of evergreenneedle leaf forest measurements were very close tothe output of Biome-BGC, but measurements ofbroadleaf forest and dwarf shrub were much smallerthan the simulation result. Simulated annual ET andNPP had a significant correlation with precipitation,indicating precipitation is the major environmentalfactor affecting ET and NPP in the study area.Precipitation also is the key climatic factor for theinterannual ET and NPP variations.

Carbon and nitrogen budget in fish-polychaete integrated aquaculture system

Integrated multi-tropic aquaculture(IMTA)systems have been used in China for many years and have achieved significant economic,social,and ecological benefits.However,there is still a lack of benthic bioremediation species that can effectively utilize the aquaculture particulate organic waste in the system.Polychaete Perinereis aibuhitensis Grube is used as an environmental remediation species for large-scale aquaculture to reduce particulate organic waste,which is of great significance to environmental protection.To improve bio-elements utilization efficiency,P.aibuhitensis was applied for IMTA indoor fish(Hexagrammos otakii)farming.Results showed that in the system,production of 1 kg of the fish discharged 2141-2338 mg of carbon and 529-532 mg of nitrogen,while in the monoculture of the fish,the figures were 3033-3390 mg and 764-794 mg,or 24.84%-35.26%and 30.35%-33.32%less,respectively.This approach promoted IMTA technology that could utilize the particulate organic waste from intensive aquaculture and reduce the adverse environmental effects.

The experimental studies on the carbon and nitrogen budgets of Pseudeuphausia sinica

The carbon and nitrogen budgets were estimated on the adult females, juveniles and post-furcilia larvae of Pseudeuphausia sinica fed on newly hatching nauplii of Artemia salina in the laboratory. It was found that the ingestion rate was linearly related to the food concentration, suggesting high feeding potential. The linear correlation could be established between the respirating rate (carbon consumption rate) and carbon ingestion rate, as well as carbon assimilation rate. The regression coefficients (i.e.specific dynamic action coefficients) were in the range from 9% to 16% (ingested C) or 10% to 17% (assimilated C) respectively, with lower in the post-furcilia larvae. There also existed a linear correlation equation between estimated total nitrogen excretion rate and the rates of nitrogen ingestion and assimilation separately, except for the juveniles. The defecation rates increased with the increase of the ingestion rate; as a result, assimilation efficiency was not related to the ingestion rate, ranging from 0.84 to 0.95. The results inducated that the nitrogen content in food particles was a key factor limiting the growth of P. sinica. The critical ingestion rate was 10 μgN·mg-1 body dry weight per day. Assimilated N was lost mostly by excretion, following allocated to somatic growth. The nitrogen loss by moult only accounted for a minor part. As for carbon budget, respiration and somatic growth also accounted for most of assimilation, but varied with ingestion rates. Moult loss was minor. Estimated reproductive growth (C&N) in the adult females accounted for somewhat higher percent of assimilation than the moult growth. The net growth efficiency (K2) increased with the increase of the ingestion rates, but decreased slightly for juvenile and post-furcilia larvae after the rates up to a certain value.

Large porewater exchange reshapes saltmarsh carbon and greenhouse gas budgets on local and global scales

Saltmarshes are carbon-rich ecosystems that play a role in climate regulation by efficiently sequestrating atmospheric CO_(2).Climate change is a major threat to saltmarshes and will impact saltmarsh carbon sequestration.Notably,porewater-derived carbon outwelling emerges as a crucial pathway for carbon sequestration,but it has been largely overlooked in saltmarshes.Here,we assessed the drivers of dissolved carbon exports and greenhouse gas emissions in a saltmarsh and placed those observations into a global context.In our study site,porewater exchange(PEX)was the major process controlling dissolved carbon and greenhouse gas dynamics.Combining our results with 33 other studies in saltmarshes worldwide,porewater-derived carbon fluxes were equivalent to~48% of average global saltmarsh primary productivity and 2.2 times greater than global organic carbon burial.Hence,our local observations and global upscaling demonstrate the major role played by PEX in saltmarsh carbon budgets.While part of dissolved inorganic carbon returns to the atmosphere as CO_(2),the remaining bicarbonate fraction is stored in the ocean over long time scales.Our findings strengthen global blue carbon assessments and build arguments for the use of saltmarshes as nature-based solutions for global climate change.