Carbon footprints of rice production in five typical rice districts in China

Five provinces located in the five main rice-growing regions in China were selected as study areas, which were Jiangsu, Heilongjiang, Sichuan, Guangdong and Hunan province respectively in the middle and lower reaches of the Yangtze River, northern, southwest, southern and central rice districts. Carbon footprints of rice production in these five provinces were calculated through the life cycle assessment method using governmental statistical data, industrial standards and relevant technical data separately. Material and energy consumptions were estimated, key stages of energy consumptions and carbon emissions were identified as well. Moreover, improving measurements had been suggested correspondingly. The results indicated that: the energy consumptions of rice production in these five provinces ranked as following (high to low): Guangdong, Heilongjiang, Hunan, Sichuan and Jiangsu. The carbon footprints of rice production were 2504.20 kg carbon dioxide equation per ton rice (kgCO₂-eq./t) (Guangdong province), 2326.47 kgCO₂-eq./t (Hunan province), 1889.97 kgCO₂-eq./t (Heilongjiang province), 1538.90 kgCO₂-eq./t (Sichuan province) and 1344.92 kgCO₂-eq./t (Jiangsu province) respectively. Reducing the quantities of urea and using the intermittent irrigation method could decrease energy consumption as well as carbon footprint.     

Decouple indicators on the CO2 emission-economic growth linkage: The Jiangsu Province case

Jiangsu Province has become one of the most developed regions in China. Economic growth in Jiangsu has occurred along with rising energy-related CO₂ emission levels. Thus, the link between economic activity and environmental pressure represents a risk to the global efforts toward CO₂ emission reductions. This paper examines the occurrence of a decoupling between the growth rates in economic activity and CO₂ emission from energy consumption in Jiangsu from 1995 to 2009. The results indicate that: (1) Along with the rapid economic development, CO₂ emission in Jiangsu rose from 18,781.46 × 10⁴ t in 1995 to 52,029.24 × 10⁴ t in 2009, with an average annual growth rate of 7.54%. Our results also show that CO₂ emission in Jiangsu Province is dominated by the secondary, which accounts for about 80% of total CO₂ emission. (2) During the study period, the whole Jiangsu economy experienced weak decoupling and strong decoupling except 2003–2005. However the decoupling states for the secondary and tertiary industries are similar to that of the whole economy.     

农地利用碳强度及可持续性动态变化——以山东省平度市为例

以中国东部山东省平度市为案例区,通过识别重要的农地利用碳排放源和构建碳排放测算体系,包括农用化学物质投入间接碳排放、耗能碳排放、氮肥施用后导致的土壤直接N_2O释放、秸秆燃烧碳排放和牲畜养殖CH_4和N_2O排放,测算了1995—2013年农地利用的碳排放量;结合农产品产值分析了农地利用碳强度变化特征,结合农作物碳吸收分析了农地利用的碳可持续指数的变化规律。研究得出:(1)1995—2013年平度年均碳排放量的次序是:农资投入22.50万t牲畜养殖17.41万t秸秆燃烧6.62万t,其中秸秆燃烧碳排放呈逐年增加态势,而农资投入和畜牧养殖均呈逐年减少趋势。(2)平度农地利用碳强度变化结果表明,农产品产值增加速度超过农地利用碳排放速度,单位产值碳排放已从1995年的1.24 t/元降至2013年的0.35 t/元。(3)碳可持续性指数变化特征表明,平度农地利用过程中碳吸收大于碳排放,且碳可持续性指数以年均7.12%速率增长,故平度农作物生产期的碳吸收能够完全消纳农地利用过程中所产生碳排放。该研究不仅为中小尺度以及我国东部区域的农地利用碳排放及可持续发展提供科学依据,而且有益于推进我国农业的碳减排,并为国际全球环境变化人文因素计划中LUCC、碳循环等重大问题的研究提供基本素材。     

Dynamic assessment of the value of vegetation carbon fixation and oxygen release services in Qinghai Lake basin

Studies on ecosystem service function have an important significance for analyzing and understanding global warming. With the introduction of geographic information system (GIS) and remote sensing (RS) technologies for the evaluation of ecosystem service function, the scope for analysis has been widening. Increasing number of researchers use these technologies to quantify the value of ecosystem service functions and reveal their spatial-temporal variability. By using the data for the interpretation of five RS images and net primary productivity (NPP) in Qinghai Lake basin, we assessed the value of vegetation carbon fixation and oxygen release services and revealed their dynamic variation in this basin. The result suggested that the average values of vegetation carbon fixation and oxygen release services in Qinghai Lake basin between 1987 and 2010 were spatially distributed in a ring shape around the Qinghai Lake and decreased from southeastern to the north and northwestern regions; the northwestern areas had the lowest value. The vegetation carbon fixation value between 1987 and 2010 was on an average 28.87 × 10⁸ yuan/a in Qinghai Lake basin, whereas the oxygen release value was 64.41 × 10⁸ yuan/a. Alpine meadow ecosystem showed the highest value of vegetation carbon fixation and oxygen release services function in Qinghai Lake basin, with average values of 18.28 × 10⁸ yuan/a and 40.79 × 10⁸ yuan/a, respectively, followed by those of temperate steppe and sparse vegetation. The vegetation carbon fixation and oxygen release values in Qinghai Lake basin gradually increased from 1987 to 2010, with the maximum value in 2010. By the end of 2010, the values increased by 7.19 × 10⁸ yuan and 16.04 × 10⁸ yuan, respectively. The values slightly decreased in barren land, lakeside marsh, river valley swamp, and sandy areas, but increased to different degrees in other ecosystems. Among them, the largest increase was noted in alpine meadow (4.38 × 10⁸ yuan and 9.78 × 10⁸ yuan, respectively), followed by those in temperate steppe with increased values of 1.12 × 10⁸ yuan and 2.49 × 10⁸ yuan, respectively.     

Delinking indicators on regional industry development and carbon emissions: Beijing–Tianjin–Hebei economic band case

Based on the two-level Logarithmic Mean Divisia Index (LMDI) method and Tapio index, this paper constructed an expanded decomposition model for decoupling elasticity and effort index of industrial carbon emissions, and further quantitatively analyzed the delinking indicators on industry growth and environmental pressures in Beijing–Tianjin–Hebei (BTH) economic band from 1996 to 2010. The results indicate that: (1) together with the rapid economic growth, industrial energy-related carbon emissions in BTH region rose from 44477.43 × 10⁴ t in 1996 to 105602.33 × 10⁴ t in 2006 and then declined to 64426.71 × 10⁴ t in 2010, with an average annual growth rate of 2.94%. Our results also show that carbon emissions in BTH region were dominated by the secondary industry, which accounted for about 80% of total carbon emissions. (2) “Weak decoupling” was the main characteristic during the 9th Five-Year Plan period (1996–2000) and 11th Five-Year Plan period (2006–2010), particularly “strong decoupling” in 2007; while “weak coupling” was the main characteristic during the 10th Five-Year Plan period (2001–2005). (3) The rapid economic growth was the main factor responsible for industrial decoupling blocking. The energy structure and energy intensity made significant contributions to the industrial decoupling progress. The industrial structure effect had varied considerably over the years without showing a clear trend.     

Optimizing coffee cultivation and its impact on economic growth and export earnings of the producing countries: The case of Saudi Arabia

Coffee is one of the historical socioeconomic crops. It has received an increasing attention at the global level, due to its positive interlinkage with the economic growth and on the gross domestic product for most of the producing countries, particularly, developing and least developed countries. Saudi Arabia is one of the coffee producing countries that has a relative comparative advantage of coffee cultivation. Yet, coffee cultivation has not received as much attention in Saudi Arabia as that of producing countries around the world. This study aims to assess the current state of coffee cultivation in Saudi Arabia and to investigate the potential to optimize coffee cultivation in Saudi Arabia that maximizes the net national economic return and export earnings, given limitation of cultivated areas, local market activities, and international trade activities. The study statistically analyzed primary data collected from around (65) coffee farms and traders in the study regions at the south and southwest Saudi Arabia, and optimized coffee cultivation in Saudi Arabia using LINGO optimization software. Empirical results of the study revealed the great potential of Saudi Arabia to expand coffee cultivation at south and southwest regions to meet the escalating local demand and to increase its share at the world market up to 2%. Optimization of coffee cultivation in Saudi Arabia showed a high potential to meet the local demand for coffee by producing 80.07 thousand tons grown over 2861.78 hectares and to generate a net return equivalent to $395.72 million a year, which is equivalent to $138.28 thousand per hectare and $4.94 thousand per ton of coffee. Optimizing coffee cultivation will play a substantial role to increase market share of Saudi Arabia to about 1–2% of the world market by increasing its export volume, respectively, to about 69.66 and 112.56 thousand tons, the national net economic return by about $395.86 and $395.95 million a year, and the export earnings of coffee by about $219.43–354.57 million a year, which in turns, will serve the national strategic trend to diversify the economic base and lower the dependency of incomes generated from oil exportation.     

Impacts of human activity on environment in the high-cold pasturing area: A case of Gannan pasturing area

Identifying the specific forces driving environmental impact is a hot topic in the field of sustainable development in the pasturing area. In the paper, the ecological footprint was taken as the index of environmental impact, and a series of index like population quality, prosperous, using intensity, livelihood tactics are considered as the main human factors. Using the STIRPAT model and temporal series data from 1980 to 2007, the author analyzes the effects of the human driving forces of environmental impact.
The ecological footprint method presents a simple framework for national natural capital accounting, and it has been used as a comprehensive index of human activity impact, which indirectly reflect human activity’s pressure on the environment. Our analyses showed that the ecological footprint increased from 238736.9 to 877716.1 ha and per capital ecological footprint also increased from 0.854 to 1.961 ha/per during 1980–2007 in Gannan pasturing area. However, in the meantime, the ecological footprint intensity was inclined from 25.396 to 3.025 ha/ten thousand yuan.
With a view of dismantling the human driving forces of ecological footprint, the modified IPAT-called STIRPAT has been employed as a common analytic framework. Our analyses showed that population quantity and using intensity was a major driver of ecological footprint, their coefficients were greater than 1.0 in model (1); In addition, promoting the prosperous lever and the primary industry proportion, the impact of environment will be increased, but their coefficients are less than 1.0 in model (1). At the same time, the technological eco-efficiency of sample regions was discussed in details, the range ability of the technological eco-efficiency was wider, and 15 years went beyond the average level, but the other was less than the average level. Another important finding in the empirical study is that there are some evidences of an environmental Kuznets curve for ecological footprint within the range of calculated data. Some potential improvements in some further researches and suggestions to alleviate the environment pressure, and it is put forward in the last section.     

Using assessment of net ecosystem services to promote sustainability of golf course in China

Golf courses have been shown to have a positive impact on local biodiversity, quality of life and the economy. However, the impacts of golf courses on local environment, including ecosystem services and dis-services are not clearly understood. To explore this relationship, we took two golf courses in Beijing (a links course and a parkland course) to develop an assessment framework and present estimates of economic values of net ecosystem services, in aspects of ecosystem goods, carbon fixation, soil retention, flood storage, recreation, water consumption and nonpoint-source pollution. The results showed that the two golf courses have provided remarkable net ecosystem services values (links 51.58 × 10⁴ yuan/ha/yr, parkland 42.60 × 10⁴ yuan/ha/yr, 6.19 yuan = 1 US$ in 2013). Over 95% of this value is generated by three services: recreation, ecosystem goods and flood storage. Our results indicate that the parkland course has better performance in sustainable supply of ecosystem services than the links course. In addition, this study provides useful improvements for golf course design and management concerning positive environmental externalities optimizing, including the scaling of non-playing areas to maximize golf course ecosystem services supply capacity, appropriate grass species selecting and irrigation with recycled water. Moreover, a policy analysis suggests that the development of public golf course in China is a necessary complement to resolve the mismatch between private and public benefits and let more people enjoy the ecosystem services.     

基于IPSO-BP神经网络模型的山东省碳排放预测及生态经济分析

在低碳经济发展背景下,针对山东省碳排放数据更新迟缓、以往预测模型难以满足现实需求的问题,统计相关数据,根据政府间气候变化专门委员会(IPCC)推荐方法测算山东省2000—2017年碳排放量和排放强度,并借助脱钩分析、碳承载力和碳赤字探究碳排放的动态变化趋势;基于5项最重要的碳排放影响因素,建立改进的粒子群算法(IPSO...     

Quantification of the water,energy and carbon footprints of wastewater treatment plants in China considering a water–energy nexus perspective

Water and energy are closely connected and both are very important for human development. Wastewater treatment plants (WWTPs) are central to water–energy interactions as they consume energy to remove pollutants and thus reduce the human gray water footprint on the natural water environment. In this work, we quantified energy consumption in 9 different WWTPs in south China, with different treatment processes, objects, and capacities. The energy intensity in most of these WWTPs is in the range of 0.4–0.5 kWh/m³ in 2014. Footprint methodologies were used in this paper to provide insight into the environmental changes that result from WWTPs. A new indicator “gray water footprint reduction” is proposed based on the notion of gray water footprint to better assess the role of WWTPs in reducing human impacts on water resources. We find that higher capacity and appropriate technology of the WWTPs will result in higher gray water footprint reduction. On average, 6.78 m³ gray water footprint is reduced when 1 m³ domestic sewage is treated in WWTPs in China. 13.38 L freshwater are required to produce the 0.4 kWh electrical input needed for treating 1 m³ domestic wastewater, and 0.23 kg CO₂ is emitted during this process. The wastewater characteristics, treatment technologies as well as management systems have a major impact on the efficiency of energy utilization in reducing gray water footprint via these WWTPs. The additional climate impact associated with wastewater treatment should be considered in China due to the enormous annual wastewater discharge. Policy suggestions are provided based on results in this work and the features of China's energy and water distribution.     

区域生态足迹盈亏测算及其空间特征——以江苏省为例

生态足迹分析法能够通过计算生物生产性土地和水域的产量,估算人类对自然资本的消耗和自然资本的供给情况,进而对区域发展的可持续发展状态进行定量评估。论文在改进国家公顷生态足迹模型的基础上,对江苏省及其13个地级市生态足迹盈亏进行测算,进而揭示其空间演化特征。研究结果表明:(1)2015年江苏省的人均生态足迹为1.7890 hm2/人,人均生态承载力为0.2991 hm2/人,生态赤字为-1.4899 hm2/人,万元GDP生态足迹为0.2033 hm2/万元;(2)地级市中,人均生态足迹上,常州市最高为2.9317 hm2/人,宿迁市最低为1.7348 hm2/人;人均生态承载力上,盐城市最高为0.6111 hm2/人,苏州市最低为0.0812 hm2/人;人均生态赤字上,常州市最高为-2.8115 hm2/人,盐城市最低为-1.1503 hm2/人;万元GDP生态足迹上,宿迁市最高为0.3956 hm2/万元,无锡市最低为0.1651 hm2/万元;(3)江苏省及其苏南、苏中地区的人均建筑用地生态足迹和化石能源用地生态足迹所占比例较大,苏北地区人均耕地生态足迹和草地生态足迹所占比例较大;(4)人均生态足迹和生态赤字在空间分布上较为一致,呈现出南高北低的特征,而人均生态承载力呈现北高南低的分布特征;万元GDP生态足迹空间分布北高南低,整体上与人均地区生产总值成反比。研究结果能够为江苏省区域协调发展、生态文明建设提供理论指导和定量参考。     

The influence of rapid urbanization and land use changes on terrestrial carbon sources/sinks in Guangzhou,China

Complex changes in carbon sources and sinks caused by rapid urbanization have been observed with extensive changes in the quantity, structure, and spatial pattern of land use types. Based on the modified Carnegie-Ames-Stanford Approach model and on gray relational analysis, we analyzed the influence of land use changes on carbon sinks and emissions in Guangzhou from 2000 to 2012. The aim was to identify suitable options for built-up land expansion that would allow for minimal carbon losses. The key results were as follows: (1) Built-up land increased by 118.91% in Guangzhou city over the study period, with this expansion taking the form of concentric circles extending around the old Yuexiu district. (2) Carbon emissions over the period of analysis significantly exceeded carbon sink capabilities. The total carbon sink decreased by 30.02%, from 535.40 × 10³ t to 374.6 × 10³ t. Total carbon emissions increased by 1.89 times, from 13.73 × 10⁶ t to 39.67 × 10⁶ t; 80% of carbon emissions were derived from energy consumption. (3) There were large differences in the extent of carbon sink losses at different scales of built-up land expansion and land use change. In Guangzhou, the loss of carbon sink is small when cultivated land (though not prime farmland) and water bodies are converted to built-up land on a small scale. The loss of carbon sink is much smaller when grasslands are converted to built-up land on a large scale. However, forested land, which has excellent carbon sink functions, should not be converted. (4) Changes in carbon sinks were mainly affected by natural factors and land urbanization. Changes in carbon emissions were mainly affected by population urbanization, economic urbanization, and land urbanization. (5) To achieve “economical and intensive use of land”, “urban growth boundary” and “ecological red lines” should be determined for government policies on land use management. These factors have great significance for “increasing carbon sinks and reducing carbon emissions” in urban ecological systems.     

江西省能耗碳排放时空特征、脱钩关系及其驱动因素

查明碳排放时空演变成因、经济发展脱钩情形及其影响因素,对协调区域经济发展同时更好进行碳减排具有指导意义。以欠发达江西省为例,基于2002-2016年规模以上工业主要能源消费数据,用IPCC碳核算方法、Tapio脱钩模型及对数平均迪氏指数分解法（Logarithmic Mean Divisia Index,LMDI）对该域能耗碳排放时空演变特征、与经济发展脱钩关系及其驱动因素进行了分析。结果表明：（1）江西省碳排放量前期快速增长、中后期增长减缓,由2002年的6248.57×10⁴ t增加到2016年的18680.47×10⁴ t,增长率高达198.96%。碳排放强度处于前中期快速下降,后期缓慢下降的趋势,由5.604 t/万元降为0.552 t/万元。碳排放量和碳排放强度大体呈现着西北高东南低的空间分布特征。（2）2002-2009年和2009-2016年江西省经济增长与碳排放总体上呈现弱脱钩,脱钩弹性分别为0.177和0.105。2002-2009年江西省南部和北部地区脱钩情况不够理想;2009-2016年江西省除上饶市以外的东北部地区脱钩状况较差。（3）2002-2009年,能源结构对江西省碳排放脱钩有微弱的抑制作用,2009-2016年转变为微弱的促进作用,其对各地市碳排放脱钩的驱动方向有所不同。能源强度对碳排放脱钩起主导性作用,其在两个阶段的脱钩弹性分别为-0.329和-0.481。经济水平对碳排放脱钩有主要的抑制作用,在两个阶段的脱钩弹性分别为0.377和0.475。人口对碳排放脱钩具有较小的抑制作用。因此,江西省碳减排的重点在于改善能源结构与提高能效,推动新余、九江和萍乡等城市的传统工业转型升级,促进江西西北地区与东南地区城市的绿色协同发展。     

Denitrification capacity in response to increasing nitrate loads and decreasing organic carbon contents in injected leachate of a simulated landfill reactor

Ex situ nitrification followed by denitrification inside the landfill has been recommended to remove ammonia from leachate. The effects of increasing nitrate load and decreasing organic carbon content in the injected leachate on the denitrifying capacity of municipal solid waste (MSW) were investigated. Results showed that MSW possesses a high denitrification capacity. Nitrate reduction could be initiated within 48 h after the first addition of nitrate. Nitrate reduction rate increased with the increasing nitrate loading concentration. When the nitrate loading concentration was increased to 850 mg L^?1, nitrate reduction rate reached up to 35 mg L^?1 h^?1. Nitrite accumulation could be found after the addition of nitrate in each test. However, the maximum nitrite accumulation efficiency declined with increased nitrate load. Organic carbon played an important role in the reduction of nitrate, and both endogenous and exogenous organic materials could act as electron donors.     

Enhancement of growth rate and β-galactosidase activity,and variation in organic acid profile of Bifidobacterium animalis subsp. lactis Bb 12

The behavior of Bifidobacterium animalis subsp. lactis Bb 12 under batch cultivation, after continuous culturing for up to 12 d, was monitored in skim milk-based media. Previous continuous culture for longer than 6 d affected the physiology of said microorganism. The minimum inhibitory concentrations of lactic and acetic acids increased from 18 to 26 g/l, whereas the molar ratio of acetic to lactic acid increased from 0.8 to 1.55, when the previous continuous culture increased its duration from 1 to 12 d. The specific lactose consumption rate decreased from 0.94 to 0.77 g_lactose/g_{cell dry mass}/h within the batch culture timeframe; this was concomitant with greater amounts of acetic and formic acids, and lower amounts of lactic acid produced. The β-galactosidase activity increased as continuous culturing time increased, and reached 446 units/ml by 12 d; however, the rate of enzyme synthesis decreased concomitantly. Succinic acid was produced during the exponential growth and stationary phases of the batch culture, but the former at exponential growth phase was higher as the continuous culturing time was longer. For comparison purposes, batch cultivation of samples taken from continuous cultures by 1 and 12 d was done using a semi-synthetic medium with glucose as carbon source; a pattern similar to that observed when using skim milk-based media was observed.     

Optimization of an ultra-fast silicon detector for proton and carbon beams using GEANT4 Monte Carlo toolkit

AimThe purpose of this study was to investigate the crosstalk effects between adjacent pixels in a thin silicon detector with 50 um thickness.BackgroundThere are some limitations in the applications of detectors in hadron therapy. So it is necessary to have a detector with concurrent excellent time and resolution. In this work, the GEANT4 toolkit was applied to estimate the best value for energy cutoff in the thin silicon detector in order to optimize the detector.Materials and MethodsGEANT4 toolkit was applied to simulate the transport and interactions of particles. Calculations were performed for a thin silicon detector (2 cm × 2 cm×0.005 cm) irradiated by proton and carbon ion beams. A two-dimensional array of silicon pixels in the x-y plane with 100 um × 100 um × 50 um dimensions build the whole detector. In the end, the ROOT package is used to interpret and analyze the resultsResultsIt is seen that by the presence of energy cutoff, pixels with small deposited energy are ignored. The best values for energy cutoff are 0.01 MeV and 0.7 MeV for proton and carbon ion beams, respectively. By applying these energy cutoff values, efficiency and purity values are maximized and also minimum output errors are achieved.ConclusionsThe results are reasonable, good and useful to optimize the geometry of future silicon detectors in order to be used as beam monitoring in hadron therapy applications.     

Effect of functional electrical stimulation on the effort and walking speed,surface electromyography activity,and metabolic responses in stroke subjects

ObjectiveTo investigate the effects of functional electrical stimulation (FES) combined with conventional rehabilitation program on the effort and speed of walking, the surface electromyographic (sEMG) activity and metabolic responses in the management of drop foot in stroke subjects.MethodsFifteen patients with a drop foot resulting from stroke at least 3 months prior to the start of the trial took part in this study. All subjects were treated 1 h a day, 5 days a week, for 12 weeks, including conventional stroke rehabilitation program and received 30 min of FES to the tibialis anterior (TA) muscle of the paretic leg in clinical settings. Baseline and post-treatment measurements were made for temporal and spectral EMG parameters of TA muscle, walking speed, the effort of walking as measured by physiological cost index (PCI) and metabolic responses.ResultsThe experimental results showed a significant improvement in mean-absolute-value (21.7%), root-mean-square (66.3%) and median frequency (10.6%) of TA muscle EMG signal, which reflects increased muscle strength. Mean increase in walking speed was 38.7%, and a reduction in PCI of 34.6% between the beginning and at end of the trial. Improvements were also found in cardiorespiratory responses with reduction in oxygen consumption (24.3%), carbon dioxide production (19.9%), heart rate (7.8%) and energy cost (22.5%) while walking with FES device.ConclusionsThe results indicate that the FES may be a useful therapeutic tool combined with conventional rehabilitation program to improve the muscle strength, walking ability and metabolic responses in the management of drop foot with stroke patients.     

Influence of management and precipitation on carbon fluxes in great plains grasslands

Suitable management and sufficient precipitation on grasslands can provide carbon sinks. The net carbon accumulation of a site from the atmosphere, modeled as the Net Ecosystem Productivity (NEP), is a useful means to gauge carbon balance. Previous research has developed methods to integrate flux tower data with satellite biophysical datasets to estimate NEP across large regions. A related method uses the Ecosystem Performance Anomaly (EPA) as a satellite-derived indicator of disturbance intensity (e.g., livestock stocking rate, fire, and insect damage). To better understand the interactions among management, climate, and carbon dynamics, we evaluated the relationship between EPA and NEP data at the 250 m scale for grasslands in the Central Great Plains, USA (ranging from semi-arid to mesic). We also used weekly estimates of NEP to evaluate the phenology of carbon dynamics, classified by EPA (i.e., by level of disturbance impact). Results show that the cumulative carbon balance over these grasslands from 2000 to 2008 was a weak net sink of 13.7 g C m⁻² yr⁻¹. Overall, NEP increased with precipitation (R² = 0.39, P < 0.05) from west to east. Disturbance influenced NEP phenology; however, climate and biophysical conditions were usually more important. The NEP response to disturbance varies by ecoregion, and more generally by grassland type, where the shortgrass prairie NEP is most sensitive to disturbance, the mixed-grass prairie displays a moderate response, and tallgrass prairie is the least impacted by disturbance (as measured by EPA). Sustainable management practices in the tallgrass and mixed-grass prairie may potentially induce a period of average net carbon sink until a new equilibrium soil organic carbon is achieved. In the shortgrass prairie, management should be considered sustainable if carbon stocks are simply maintained. The consideration of site carbon balance adds to the already difficult task of managing grasslands appropriately to site conditions. Results clarify the seasonal and interannual dynamics of NEP, specifically the influence of disturbance and moisture availability.     

The effect of internal capacitance on power quality and energy efficiency in a tubular microbial fuel cell

The pseudo-capacitive behaviour of a high surface area carbon veil electrode in a tubular microbial fuel cell (MFC) was investigated as a mechanism to enhance power quality and energy efficiency. Accumulated charge and energy from the anodic biofilm after prolonged open circuit times (1–120 min) were compared against equivalent periods of steady state loading (R = 100–3000 Ω). A significant difference in the amount of accumulated charge with different loads was observed, resulting in 1.051 C (R = 100 Ω) compared to 0.006 C (R = 3 kΩ). The automated application of short open and closed circuit (0.5–10 s) cycles resulted in an increase of power/current production (closed circuit alone), but presented lower efficiency considering entire open and closed period. The cumulative charge on the carbon veil electrode with biofilm was 39,807 C m⁻² at 100 Ω. Electrochemical Impedance Spectroscopy (EIS) showed that the Helmholtz layer presented a double layer capacitance of more than ten times the biofilm on electrode. The results indicate that the capacitive behaviour could be utilized to increase the power quality, i.e. its availability/applicability with respect to the operation of low power consuming devices.     

Multi-source and multi-date mapping of deforestation in Central India (1935-2010) and its implication on standing phytomass carbon pool

Information on the historical distribution of Indian forest cover change and carbon stocks is scarce and far from comprehensive. Geospatial methods were used to study changes in forest cover and above ground carbon stocks over seven decades in Central India, which covers over a tenth of India (13.5%) and accounts for almost a fifth of its forest cover (19.27%). Changes in the above ground phytomass carbon pool were computed. There is a significant contribution of deforestation to the reduction in the C pool. The overall loss of forest cover was 2.5 Mha (16%), while the reduction in carbon stock was 343.5 Tg C (42%) since 1935. The overall rate of deforestation in Central India (0.23 from 1935 to 2010), has been on decline in recent years. In order to increase the amount of carbon accumulation, open forests which are occupying about 45.8% of forest area must be considered for improvement of carbon stocks. The above results indicate that the forests of central India could act as important carbon sinks in India.