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Kirchner TB Webb JL Webb SB Arimoto R Schoep DA Stewart BD 《Journal of environmental radioactivity》2002,60(3):275-291
Concentrations of radionuclides were measured in soils from a grid of locations surrounding the US Department of Energy Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico and from a grid on a reference site approximately 20 km southeast of the WIPP site. Each of the two grids has 16 sampling locations (grid nodes) systematically distributed within an area of 16.580 ha. Sampling was conducted prior to the arrival of the first waste shipment at WIPP. Thus, the 137Cs and 23,240Pu in the soil are expected to have been deposited as global fallout, although the Gnome Site, 8.8 km southwest of the WIPP, is also a potential source of 239,240Pu and fission products. The reference grid has significantly higher concentrations of fallout and natural radionuclides than the WIPP grid. Up to 80% of the total variability in radionuclide concentrations across the two grids is attributable to differences between grid nodes. Differences between replicates within a location account for 44-50% of the variability in concentrations of the uranium isotopes, but only 11-17% of the variability in the concentrations of the other radionuclides. Samples having similar abundance of radionuclides were spatially aggregated across the terrain. The activity concentrations of the radionuclides were strongly correlated with the concentrations of Al and Pb, and with the percentages of sand, silt and clay in the soil. Normalizing radionuclide concentrations to the concentration of Al or percent fine particles can help adjust for differences in soil textures among samples and facilitate the detection of gradients or temporal changes in soil concentrations. 相似文献
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园林绿化树种香樟叶片的含硫量动态分析 总被引:1,自引:0,他引:1
植物对一定浓度范围内的大气污染物,具有一定程度的抵抗及吸收净化作用。为了解南京市主要园林绿化树种香樟(Cinnamomum camphora)叶片吸收净化SO2的能力,选择在5个不同污染靶区,以3个不同胸径级的香樟叶片为研究对象,采用硫酸钡比浊法测定了不同季节香樟叶片的含硫量。结果表明:香樟叶片对SO2具有一定的吸收净化能力,其叶片含硫量平均为0.2160%,且其含量随分布区、生长季节及个体胸径不同差异显著;并与异域大气中SO2污染指数成一定的正相关;与个体胸径大小成显著负相关;季节间呈现出"先降后升再降"的动态趋势,于春秋季较高,而夏冬季较低。 相似文献
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为认知水源地型水库异味发生风险及其规律,本研究于异味风险高危期(夏季),对江苏17个省级水源地型水库开展了水质、浮游生物和异味物质状况调查.结果表明,本次调查的17个水库普遍存在富营养化程度偏高(如藻类生物量偏大和水体透明度偏低)的问题,约三分之一的水库出现部分水层异味物质2-甲基异莰醇(MIB)浓度超标,MIB平均浓度为(13. 7±20. 7) ng·L-1,表明江苏省水库型水源地普遍存在MIB风险;多个水库检出土臭素(GSM),但其浓度均没有超过10ng·L-1的饮用水标准浓度(最大浓度为4. 6 ng·L-1);同步水质调查及统计分析表明,MIB浓度和水体叶绿素a浓度、水体透明度、悬浮颗粒物浓度、富营养化指数等重要水质指标及浮游植物生物量(特别是蓝藻生物量)相关性显著(P 0. 05),其中MIB与叶绿素a、富营养化指数呈极显著的相关关系(P 0. 01).因此,水源地型水库的异味物质风险与水库的富营养化密切相关;实施营养盐外源输入削减、提高流域植被覆盖度、科学调控渔业养殖规模等水体富营养化控制措施是水库异味物质控制的关键. 相似文献
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以著名钢铁企业上海宝钢为例,基于厂区植被调查、航片数字化解释、优势种生物量测定及模型建立,对宝钢厂区植被碳储量和固碳能力进行估算,并通过碳税法对其固碳效益进行评价,以期为城市工业区绿地群落配置和绿化树种选择、企业绿化建设的费用效益分析提供更为科学的依据。结果表明:宝钢厂区植被总碳储量为3992.99~4736.17 t,固碳效益为13507.33~16185.85万元;平均碳密度为45.82~53.27 t/hm2,固碳能力为5.91~6.87t/(hm2.a),高于上海城市森林平均值,但小于中国森林平均值,一定程度上受平均胸径、郁闭度及群落密度等因素影响。厂区在进行绿化建设时,应考虑选择防污且固碳能力强的植物,构建防污固碳兼有型群落,发挥植被的多元功能。 相似文献
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对城市绿地进行科学评价有助于人们正确认识和改造城市绿地建设,为城市绿地规划和管理提供参考。以2007—2016年嘉峪关市城市绿地为研究对象,从数量、结构、功能三个方面构建评价指标体系,通过障碍度模型,识别影响城市绿地生态水平的障碍因子。结果表明:(1)10 a来嘉峪关市城市绿地生态水平整体呈波动上升趋势,级别由较低等级提高到高等级,但目前城市绿地生态水平属于低层次、不稳定的高等级阶段,城市绿地建设工作压力还很大。(2)从准则层看,嘉峪关市城市绿地生态水平的主要威胁变化较为明显,数量指标和结构指标是主要障碍因子;从指标层看,各年份主要障碍因子不尽相同,最大障碍因子历经了从人均公园绿地面积、树种丰富度到净化空气能力的演变。 相似文献
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THOR HANSON THOMAS M. BROOKS†‡§ GUSTAVO A. B. DA FONSECA†† MICHAEL HOFFMANN‡‡§§ JOHN F. LAMOREUX‡‡ GARY MACHLIS CRISTINA G. MITTERMEIER††† RUSSELL A. MITTERMEIER† JOHN D. PILGRIM‡‡‡ 《Conservation biology》2009,23(3):578-587
Abstract: Conservation efforts are only as sustainable as the social and political context within which they take place. The weakening or collapse of sociopolitical frameworks during wartime can lead to habitat destruction and the erosion of conservation policies, but in some cases, may also confer ecological benefits through altered settlement patterns and reduced resource exploitation. Over 90% of the major armed conflicts between 1950 and 2000 occurred within countries containing biodiversity hotspots, and more than 80% took place directly within hotspot areas. Less than one-third of the 34 recognized hotspots escaped significant conflict during this period, and most suffered repeated episodes of violence. This pattern was remarkably consistent over these 5 decades. Evidence from the war-torn Eastern Afromontane hotspot suggests that biodiversity conservation is improved when international nongovernmental organizations support local protected area staff and remain engaged throughout the conflict. With biodiversity hotspots concentrated in politically volatile regions, the conservation community must maintain continuous involvement during periods of war, and biodiversity conservation should be incorporated into military, reconstruction, and humanitarian programs in the world's conflict zones. 相似文献
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猪粪堆肥中一株溶磷菌的筛选鉴定及溶磷能力初步测定 总被引:2,自引:0,他引:2
从猪粪堆肥中分离纯化得到一株具有较强溶磷能力的菌株PSM-1,进行了形态学和分子生物学鉴定,研究了其溶磷能力和遗传稳定性.结果表明:通过菌落形态和ITS基因序列分析鉴定,菌株PSM-1为产黄青霉(Penicillium chrysogenum);在3种不同无机磷源液体培养基中其溶磷量依次为Ca3(PO4)2(138.36 mg·L-1)Fe PO4(117.38 mg·L-1)Al PO4(113.76 mg·L-1),且PSM-1的溶磷量均与培养液p H值呈现出显著负相关性;以葡萄糖为碳源、硝酸铵为氮源时,菌株PSM-1的溶磷量最高可达195.67 mg·L-1,比初始有效磷高141.42%;该菌株对碳源和氮源的利用效率分别依次为:葡糖糖蔗糖麦芽糖淀粉,硝酸铵硝酸钾硫酸铵草酸铵;经过20次传代培养后PSM-1的溶磷量保持在(124.54±3.50)mg·L-1,说明其溶磷遗传稳定性良好.研究表明:PSM-1菌株具有良好的溶解无机磷的能力,在土壤微生态改良方面具有重要的应用潜力. 相似文献