Uptake of Macro- and Micro-Nutrients into Leaf,Woody, and Root Tissue of Populus after Irrigation with Landfill Leachate

ABSTRACT

Information about macro- and micro-nutrient uptake and distribution into tissues of Populus irrigated with landfill leachate helps to maximize biomass production and understand impacts of leachate chemistry on tree health. We irrigated eight Populus clones (NC 13460, NCI4O18, NC14104, NC14106, DM115, DN5, NM2, NM6) with fertilized (N, P, K) well water(control) or municipal solid waste landfill leachate weekly during 2005 and 2006 in Rhinelander, Wisconsin, USA. During Aug. 2006, we tested for differences in total N, P, K, Ca, Mg, S, Zn, B, Mn, Fe, Cu, Al, and Pb concentration in preplanting and harvest soils; and in leaf, woody (stems?+?branches), and root tissue. Other than N, leachate did not increase the soil concentration of elements relative to preplanting levels. There was broad genotypic variation for tissue concentrations, with clone-specific uptake for most elements. Nitrogen, P, K, Ca, Mg, S, B, and Mn concentrations were greatest in leaves and least in woody tissue, while those of Fe, Cu, and Al were greatest in roots and least in leaves and woody tissue. Overall, successful uptake of nutrients without impacts to tree health validated the use of landfill leachate as an irrigation and fertilization source for Populus.     

凡纳滨对虾精养池养殖水体的富营养状况时空差异

监测了凡纳滨对虾养殖全过程精养虾池养殖水体中溶解态无机氮(DIN)、溶解态活性磷酸盐(DIP)、水体的化学需氧量(COD)、pH、溶解氧(DO)、营养状态综合指数(E)等理化指标的变化,以及养殖后期水体中各理化因子的水平、垂直分布。结果表明:在凡纳滨对虾养殖过程中,DIN质量浓度为(0.093±0.076)～(1.736±1.134)mg·L–1,DIP质量浓度为(0.062±0.271)～(0.380±0.276)mg·L–1,COD质量浓度为(0.940±0.934)～(9.653±1.317)mg·L–1,E:(1.198±4.250)～(1267.537±68.534),富营养化程度随着养殖时间的增加逐渐增强,20d时各项指标均达到较大值,之后逐渐降低,到养殖后期又逐渐增强,营养状态综合指数(E)达到最大值;养殖后期,富营养化程度在水平方向随着靠近排污口的方向逐渐增强,营养状态综合指数(E):(343.230±1.659)～(2786.072±55.241),在垂直方向随着靠近池底的方向逐渐增强,营养状态综合指数(E):(2046.687±5.568)～(2789.524±7.166)。     

萘普生栓联合吗啡硬膜外镇痛用于剖宫产术后镇痛的临床观察

目的观察萘普生栓联合吗啡硬膜外镇痛在剖宫产术后镇痛效果。方法将123例剖宫产产妇随机分成萘普生栓联合吗啡硬膜外镇痛组(NM组,61例)和单纯吗啡硬膜外镇痛组(M组,62例),比较两组间术后4、8、12、24hVAS评分、以及24h内镇痛泵按压次数和不良反应发生情况。结果 NM组术后4、8、12、24hVAS评分、以及24h内镇痛泵按压次数均明显低于M组(P<0.01或0.05),两组间不良反应差异无统计学意义(P>0.05)。结论萘普生栓联合吗啡硬膜外镇痛在剖宫产术后镇痛效果明显,值得临床应用。     

湖南城市土地集约利用与“两型城市”耦合协调发展时空特征分析

采用多因素综合分析法结合主成分分析法和熵值法对城市土地集约利用及“两型城市”建设进行综合评价,运用耦合协调度模型从时序和空间角度对两系统之间的耦合协调发展进行测度。结果显示:(1)2007-2011年湖南城市土地集约利用和“两型城市”建设综合水平不高,但呈逐年上升态势,“两型城市”建设落后于城市土地集约利用;(2)2007-2011年两系统之间的耦合发展处于颉颃阶段,协调发展水平逐年上升,但与优质协调差距较大;(3)湘东和湘北城市在城市土地集约利用、“两型城市”建设及两系统耦合协调发展三方面均优于湘南、湘西和湘中城市。依据两系统耦合协调发展的具体情况,提出了相应的对策建议,即增加土地利用强度;加快产业转型;加强湘南、湘西和湘中城市土地集约利用和“两型城市”建设;在“两型城市”建设中,将城市土地集约利用放在核心位置。     

安徽省城乡统筹发展与农村土地集约利用的因果关系研究

运用Granger因果关系检验方法检验了安徽省城乡统筹发展度与农村土地集约利用水平之间的关系,结果表明,在滞后1期和2期,安徽省城乡统筹发展与农村土地集约利用之间存在双向的因果关系。这表明,城乡统筹发展促进了安徽省农村土地集约利用;同时,农村土地集约利用水平的提高,也加快了城乡统筹发展的步伐,提升了城乡统筹发展的内涵。     

绿色农业与农业人文关怀的浅议

中国农业大发展养育16亿人口,在中国工业大发展时期出现人与自然,科技与人文的双重非良性互动。由此农业发展进程中出现了农业的生态环境严重受到破坏,农产品的质量受到威胁。在供求矛盾之下,发展绿色农业是对人类的长久的思考。     

建设“两型”社会,全面推进节约集约用地——临沂市兰山区节约集约用地的成功经验

临沂市兰山区在土地利用实践中总结形成了"节地八法",走出了一条立足存量抓挖潜、节约集约促发展的新路子。对省、市每年下达的新增用地指标,兰山区严格规划调控和用地标准,从源头上保障城乡各项建设都能节约集约利用土地。同时,完善的管理机制保障了各项节地措施的贯彻执行。     

规模化养鸡场CDM项目减排及经济效益估算

该文以山东民和集约化养鸡场为案例,利用《气候变化框架公约》清洁发展机制理事会批准的方法（ACM0010）,分析了沼气池处理鸡场粪便及污水、利用沼气发电替代以燃煤为主的电网电能和减少温室气体排放的潜力。项目每年可减排温室气体为84666 t CO2-e。公司每年售电获利767万元,减排获益593万元。由于有CDM项目的额外收入,使项目的投资年限由原来的19.7 a缩短为6.0 a。因此,在规模化养殖场建设沼气池并利用沼气发电,不仅减少粪便对周边环境的污染、充分利用可再生能源和减少化石燃料的使用,还能减少温室气体的排放,获得额外的减排收益,在很大程度上提高了企业建设大型沼气工程的积极性。     

Regional surface flux of CO2 inferred from changes in the advected CO2 column density

A Lagrangian experiment was conducted over Iowa during the daytime (9:00–17:30 LT) on June 19, 2007 as part of the North American Carbon Program's Mid-Continent Intensive using a light-weight and operationally flexible aircraft to measure a net drawdown of CO₂ concentration within the boundary layer. The drawdown can be related to net ecosystem exchange when anthropogenic emissions are estimated using a combination of the Vulcan fossil fuel emissions inventory coupled with a source contribution analysis using HYSPLIT. Results show a temporally and spatially averaged net CO₂ flux of −9.0 ± 2.4 μmol m⁻² s⁻¹ measured from the aircraft data. The average flux from anthropogenic emissions over the measurement area was 0.3 ± 0.1 μmol CO₂ m⁻² s⁻¹. Large-scale subsidence occurred during the experiment, entraining 1.0 ± 0.2 μmol CO₂ m⁻² s⁻¹ into the boundary layer. Thus, the CO₂ flux attributable to the vegetation and soils is −10.3 ± 2.4 μmol m⁻² s⁻¹. The magnitude of the calculated daytime biospheric flux is consistent with tower-based eddy covariance fluxes over corn and soybeans given existing land-use estimates for this agricultural region. Flux values are relatively insensitive to the choice of integration height above the boundary layer and emission footprint area. Flux uncertainties are relatively small compared to the biospheric fluxes, though the measurements were conducted at the height of the growing season.     

不同集约经营年限对雷竹林土壤磷形态的影响

为研究不同集约经营年限下雷竹林土壤的磷形态特征,采集分别经营3,9,15年的雷竹林上层(0—20cm)和下层(20—40cm)土壤样品,测定土壤pH、有机碳、全磷(TP)、Olsen P、Mehlich-3P等理化性质,并采用改进的Hedley分级法分析土壤中不同形态磷的含量。结果表明:在集约经营9,15年后,上层土壤pH低于雷竹正常生长范围,且有酸化深层化现象;土壤有机碳主要在上层土壤中积累,经营15年为各处理中最高,较3年提高了183%。上、下层土壤TP、Olsen P、Mehlich-3P、活性磷(H2O-P+NaHCO3-Pi+NaHCO3-Po)和中稳性磷(NaOH-Pi+NaOH-Po)含量均随经营时间逐渐增加。与3年相比,集约经营15年后活性磷和中稳性磷占总磷百分比在上层土壤中提高了63%和83%,在下层土壤中提高了88%和128%;而上、下层土壤难溶性磷(HCl-P+Res-P)所占百分比则分别从58%和66%降低至26%和29%,难溶性磷的含量基本不变。由此可见,持续、大量施用磷肥提高了雷竹林土壤中活性磷和中稳性磷比例。此外,Mehlich-3P-H2O-P拟合方程推测上、下层土壤均有可能已发生磷酸盐流失。因此,雷竹林集约经营过程中应注意合理施肥,以免造成磷流失。