A preliminary assessment of socio-ecological metabolism for three neighborhoods within a rust belt urban ecosystem

Rust belt cities of the northeastern United States are plagued by flat or declining economies and the accompanying social fallout from lack of employment. Advocates of green fuels, green infrastructure and green jobs have proposed these nature-based technologies as means to revitalize the economies of cities. Before making public and private investment a baseline analysis of the relative magnitude of existing energy production and energy respiration at the neighborhood scale is useful in order to understand what the potential for green infrastructure might be. Because the urban canopy and other green infrastructure can enhance urban socio-ecological metabolism, we measured the flows of natural energy produced (P) by the urban forest versus the industrial or fossil energy currently consumed or respired (R) in three economically and demographically distinct neighborhoods of a typical rust-belt city, Syracuse, NY. Our objectives were to (1) understand the potential for green energy to replace fossil fuels in general, (2) assess the degree to which different socio-demographic communities are receiving the ecosystem benefits of existing urban “green” infrastructure (i.e. forest primary production), and (3) identify where local (in-city) biotic energy resources could be enhanced or fossil fuel consumption altered to improve overall urban socio-ecological metabolism. We found that (1) the fossil energy consumed in all three neighborhoods was 200-700 times higher than the biotic “green” energy produced; (2) that to produce this much energy from willow biomass grown in the region would require at least between 0.3 and 0.7 ha of bio-energy production per person depending on affluence, density of living, transportation mix and home fuel mix; (3) that although the more affluent neighborhood used, per residence and per person, almost twice as much energy as that of the downtown more densely settled and poorer neighborhood, its R:P ratio was still the lowest due to the high primary productivity of its neighborhood tree canopy. As a first assessment our findings identify several opportunities for enhancement of the socio-ecological metabolism of these neighborhoods, and the city at large, through conversion of heating units in poorer neighborhoods away from expensive electricity, and toward tree planting, solar installations, and per capita energy use reductions.     

Accounting for Cadmium: Tracking Emissions of Cadmium From the Global Economy

This paper examines the flow of cadmium through the global economy, with the aim of quantifying emissions of cadmium into the environment as a result of anthropogenic activities. First, a materials balance methodology is presented as the most appropriate means of assessing cadmium emissions from a wide range of anthropogenic sources. This is then applied to the best available data, from a variety of sources, to arrive at estimated flows of cadmium. Results are presented for 10 geo-political world regions and for a range of economic activities including non-ferrous metals production, iron and steel production, combustion of fossil fuels, fertilizer manufacture and use, cement production and the manufacture, use and disposal of cadmium containing products. Initially, this analysis partitions the total flow of cadmium into three major categories: atmospheric emissions, water-borne effluents and solid or bulked waste arisings. the paper then suggests a probable further partition of the initial emissions into different environmental media.     

Protein Metabolic Response to Carbon Tetrachloride in A Freshwater Fish, Sarotherodon Mossambicus

Exposure of a freshwater teleost, Sarotherodon mossambicus, to a sublethal concentration (26 ppm) of carbon tetrachloride for periods up to 30 days led to significant changes in the soluble protein fractions (albumin and globulins) and free amino acid content. the decrease in total protein content was greater in liver than in muscle. the protein loss was expected due to the impairement of protein synthetic activity during stress conditions.     

高效异养硝化-好氧反硝化菌Glutamicibacter sp.WS1低温下对多种氮源的脱氮特性及氮代谢机制

针对污水处理厂冬季生物脱氮效率低、出水水质不达标的问题,从活性污泥中分离出1株耐低温异养硝化-好氧反硝化菌株Glutamicibacter sp.WS1.采用PCR技术扩增该菌株的脱氮功能基因,研究其对不同氮源的低温脱氮效能,通过单因素实验探究环境因子对其低温好氧反硝化性能的影响,并利用氮平衡解析其氮代谢路径.结果表明,菌株WS1含有氮代谢相关的功能基因amoA、napA、nirS和nirK;在15℃低温条件下,菌株WS1在以NH₄⁺-N、NO₃^--N、NO₂^--N+NO₃^--N和NH₄⁺-N+NO₃^--N为氮源时,对各无机氮的去除率分别为100%、98.10%、99.87%+100%和100%+94.92%;菌株WS1的最佳反硝化条件：柠檬酸钠为碳源、C/N为16、pH为8、ρ（DO）为4.5~6.8 mg ·L^-1和温度为30℃;在低温（15℃）和低C/N （10）条件下,菌株WS1对NO₃^--N的去除率达到92.50%;异养硝化-好氧反硝化/好氧反硝化和同化作用是菌株WS1去除不同氮源底物的主要途径,其中大部分的无机氮（47%~56%）通过异养硝化-好氧反硝化/好氧反硝化作用转化为了气态氮.菌株WS1在低温污水脱氮领域具有广阔的应用前景.     

基于酶化学计量法探究有机无机肥配施调控果园土壤微生物碳、磷代谢机制

土壤微生物的C、N、P养分需求和代谢限制与环境养分的有效性有着密切关系.然而,有机无机肥配施如何影响苹果园土壤微生物C、N、P代谢限制亟待进一步研究.因此,基于2008年建立的苹果园长期定位试验,应用土壤酶化学计量学理论与方法,系统研究有机无机肥配施对土壤C、N和P周转相关的酶活性（β-1,4-葡萄糖苷酶,BG;β-1,4-N-乙酰基氨基葡萄糖苷酶,NAG;L-亮氨酸氨基肽酶,LAP;碱性磷酸酶,PHOS）及其化学计量特征的影响,并分析其与环境因子和微生物碳利用率之间的关系.试验共设4个处理,分别为不施肥（CK）、单施氮磷钾化肥（NPK）、单施有机肥（M）和化肥配施有机肥（MNPK）.结果表明：①在果树各生育期,施用有机肥处理（MNPK和M）的微生物量碳（microC）含量显著高于不施有机肥处理（CK和NPK）;微生物量氮（microN）含量,在萌芽期NPK、MNPK和M处理比CK处理分别增加了89%、269%和213%（P<0.05）.②CK处理在萌芽期有较高的叶片ω（N）和ω（P）（29.8 g ·kg^-1和2.17 g ·kg^-1）,并且仅果树萌芽期的叶片P含量与土壤有效磷（AP）含量呈显著负相关.③土壤酶化学计量分析的所有数据点均在1 ：1线以上,表现为微生物群落存在较强的P限制;果树生长期,矢量长度和角度的变化范围分别为0.56~0.79和59.3°~67.7°,且研究中矢量角度均>45°,也体现了微生物存在较强的磷限制.④RDA和随机森林模型分析结果表明,有机碳和速效氮（AN）是影响矢量长度的主要理化因子,AP、AN和土壤含水量是影响矢量角度的主要理化因子;SEM分析表明,AN和可溶性有机碳（DOC）直接影响microC和microN,AP直接影响microP和microN,DOC和AP直接影响矢量长度,AP和microN直接影响矢量角度;微生物碳利用率与矢量长度呈显著正相关,与矢量角度呈显著负相关.综上所述,有机无机肥配施通过影响果树不同生育期土壤碳和磷含量,调控微生物碳、磷代谢进而影响微生物碳利用率,为有机无机肥配施提升土壤质量、维持土壤健康提供科学依据.     

脱氮菌剂在低溶解氧黑臭水体中氮代谢特征

研究在低溶解氧浓度下氨化细菌、硝化细菌、反硝化细菌氮代谢能力,明确不同菌剂脱氮效率和氮转化关系,为大湾区黑臭水体治理提供理论依据.通过不同菌剂浓度和不同底物浓度,检测筛选出的氨化细菌(Staphylococcus sp. Ay)、硝化细菌(Microbacterium sp. Xw)和反硝化细菌(Arthrobacter sp. Fy)制成的菌剂在污水处理厂排放的水中的氮代谢特征;然后在低溶解氧条件下,研究不同Ay、Xw和Fy菌剂浓度在同浓度黑臭水体中氮代谢变化情况、以及相同菌剂浓度在不同浓度黑臭水体中的氮代谢特征.结果表明:Ay菌剂细菌浓度增加3倍,氨化效率没有成倍增加,说明增加氨化细菌浓度不是增加氨化速率的最佳方法; Xw菌剂对硝态氮浓度变化影响显著,低菌剂浓度条件下60 h硝态氮浓度增加180%,高菌剂浓度为231%,Fy反硝化效率较高,在较低浓度下能很快去除硝态氮.总氮浓度的适当提高可以增加Ay菌剂的氨化效率,过高会抑制Ay菌剂的氮氮代谢效率.Xw菌剂硝态氮的生成率在总氮浓度25 mg·L~(-1)条件下达到最好效果,浓度提高3 736%; Fy菌剂对氨氮去除效果不明显.总氮浓度为25 mg·L~(-1)时,Fy菌剂对硝态氮的去除达到最好效果.得出:氨化细菌和反硝化细菌原菌剂直接投加,氮代谢速率较高,硝化细菌菌剂浓度增加,可以提高硝态氮生成速率.在一定范围内,增加底物浓度可以增加菌剂氮代谢效率,浓度过高将抑制氮代谢效果,可为大湾区黑臭水体问题的解决提供数据支持.     

河口陆基养虾塘沉积物铁的含量和形态

为研究河口陆基养殖塘底泥中铁的迁移和转化机制,本文测定了福建省3个河口养虾塘养殖期表层和亚表层底泥沉积物中活性铁含量及间隙水的常见组分.结果表明,不同站点间晶质Fe（III）、非硫Fe（II）、有机铁、铁硫化物含量存在显著差异.间隙水SO₄^2-和Cl^-可能是影响不同站点间Fe的形态和分布存在异质性的主要环境影响因子之一.盐度较高的养虾塘,铁的硫化物含量较高,有机铁和晶质Fe（III）含量较少.陆基养虾塘底泥沉积物中活性铁含量按固相Fe（III） > 铁硫化物 > 非硫Fe（II） > 有机铁的顺序排列.养虾塘亚表层沉积物铁硫化物（FeS和FeS₂）含量高于表层沉积物,而表层沉积物有机铁含量与间隙水SO₄^2-和NH₄⁺浓度高于亚表层沉积物.铁硫化物的生成一定程度上降低河口陆基养虾塘沉积物营养盐污染的潜在风险.     

Assessment of physical economy through economy-wide material flow analysis in developing Uzbekistan

In this paper, we assess the physical dimensions of Uzbekistan's economy during 1992–2011 by using the economy-wide material flow analysis (EW-MFA) method, which is an internationally recognized tool for such assessments. There have been a number of studies using methodological standardization of EW-MFA, but to the best of our knowledge, it has never been used to assess the metabolism of Central Asian economies, especially, in this case, the Republic of Uzbekistan.Our analysis strives to empirically evaluate macroscopic economic activities by considering the accounting of material flows. The material flows data-set comprises of consistent data for domestic extraction, imports, and exports, as well as other derived MFA-based indicators.The derived indicators are internationally compared for further evaluation of national economic development performance in a given period. The indicators of direct material input (DMI) and total material requirements (TMR) showed a slight increase in 1992–2011 with an average annual increase of 2.79% and 2.34%. The trends of TMR, DMI, domestic material consumption (DMC) and material efficiency, which is indicated by GDP/DMI, displayed lower values than other industrialized countries referenced in the international comparison. Although national economic performance data showed particularly remarkable success, indicators measuring material inputs and DMC reveal an insignificant increase during the period of study. During the second decade of study period, relative decoupling has occurred which indicated that the economic indicator (GDP) grows faster than DMC and other macro indicators grow.     

Turnover of dissolved organic carbon fuels nocturnal CO2 emissions from a headwater catchment reservoir, Southeastern China: Effects of ecosystem metabolism on source partitioning of CO2 emissions

Dam reservoirs in headwater catchments, as critical zones for their proximity to terrestrial sources, play important roles in dissolved organic carbon (DOC) cycling. However, the effects of ecosystem metabolism (EM) on DOC cycling are not well known. Here, in-situ diurnal and monthly observations were conducted to measure EM (including gross primary production (GPP), ecosystem respiration (ER) and heterotrophic respiration (HR)), DOC turnover and CO₂ emissions in a headwater catchment reservoir in Southeastern China in 2020. Our study showed the nocturnal CO₂ emission rate was about twice as high as in daytime, and was strongly driven by EM. The values for DOC turnover velocity ranged from 0.10 to 1.59 m/day, and the average DOC turnover rate was 0.13 day⁻¹, with the average removal efficiency of 12%. The contribution of respired DOC to daily CO₂ emissions ranged from 17% to 61%. The accumulated efficiencies were estimated to be 13% for the selected 15 reservoirs throughout the Changjiang River network, corresponding to about 0.34 Tg C/year of the respired DOC. The modified CO₂ flux was 0.75 Tg C/year, and respired DOC accounted for about 45% of total emitted CO₂ from the 15 larger reservoirs. Our research emphasizes the necessity of incorporating the effects of EM into studies of reservoir DOC removal and CO₂ emissions.     

铝胁迫下不同耐铝小麦品种活性氧代谢差异及与小麦耐铝性的关系

逆境条件下植物体内产生并累积活性氧从而破坏植物组织结构与功能,同时植物也可以通过改变活性氧代谢相关酶活性清除活性氧而减轻活性氧伤害以适应环境胁迫。为研究铝胁迫下不同耐铝小麦品种（TriticumaestivumL．）在活性氧代谢上的差异及与小麦耐铝性的关系,本试验选用小麦品种ET8（耐铝型）、ES8（铝敏感型）为试验材料研究了不同耐铝小麦品种活性氧代谢变化上的差异。结果表明,50μmol·L-1铝处理24h,ET8和ES8活性氧含量显著升高,O2产生速率增幅分别为10．5％和20．4％,H202含量增幅分别为3．3％和7．6％。ET8和ES8超氧化物歧化酶（SOD）活性增幅分别为11．9％和41．6％,过氧化物酶（POD）活性增幅为51．8％和77．8％,抗坏血酸过氧化物酶（APX）活性增幅为54．4％和29．1％,过氧化氢酶（CAT）活性增幅为32．9％和38．4％,谷胱甘肽还原酶（GR）活性增幅为83．1％和85．5％。虽然抗氧化酶活性增加后会清除一部分活性氧,但活性氧的累积仍然造成了膜脂的过氧化,ET8和ES8丙二醛（MDA）含量分别增加18．2％和50．0％,质膜透性也随着MDA含量的升高而增加,增幅分别为1．25倍和1．36倍。综上所述,不同耐铝品种间活性氧代谢的差异是小麦品种耐铝性差异显著的原因之一。