大连市复州河流域2011年水质评价

复州河发源于普兰店市同益乡老帽山南麓,干流全长137 km,干流上有大型水库2座,中型水库1座,支流上有中型水库2座,瓦房店市城镇生活及工农业用水主要来自该河。通过对大连市复州河流域2011年的水质监测资料进行评价,了解复州河流域主要水功能区监测断面的水质状况,为该流域的水功能区水质达标提供了理论依据,并提出了合理建议。     

漕桥河小流域平原河网地区水环境污染分析

作为太湖主要入湖河流的漕桥河流域,地势平缓,河浜密布,是典型小流域平原河网地区。该文通过对流域内污染物来源和污染物特征进行了源解析,得出如下规律：化学需氧量（COD）主要来源于农村生活污染和工业污染;总氮（TN）主要来源于农业种植业和干湿沉降;NH4-N来源于干湿沉降、农业种植业、工业污染和农村生活污染;总磷（TP）主要来源于种植业和城镇生活污染。4个常规监测断面水质污染指标评价结果表明：丰水期河网地区水质可达到国标Ⅳ类水质标准,平水期、枯水期的水质为劣Ⅴ类;来自武宜运河的客水主要影响上游地区水质,来自太滆运河的客水主要影响下游地区水质。37条主要河浜的等标污染负荷排序结果为：总氮（TN）对漕桥河污染负荷最大,其次为NH4-N。该研究对于漕桥河流域河网水利整治与水环境生态修复规划有一定的指导作用,对中国南方河网地区的水利整治有一定的借鉴参考价值。     

吕梁市三川河水质分析评价

采用单因子评价法和综合污染指数法,对三川河四个水质监测断面2015-2019年水质情况进行了分析。结果表明:三川河上游河段水质较好,均达到了Ⅲ类及以上;中下游河段水质较差,水体水质多为劣Ⅴ类,水体污染严重。从污染指数年际变化分析可知,水体水质总体上呈明显好转趋势。     

汾河运城段河流水质评价

基于长期的水质监测数据,应用水质标识指数法,对汾河运城段2005—2009年的水质进行了评价,得出了新绛站监测断面和河津大桥监测断面的地表水环境质量级别。结果表明,该河段COD,BOD5和氨氮这3项因子超标严重,且氨氮的污染指数最大,不能满足相应的水环境功能要求,水质不能达到地表水环境质量标准。总体来看,须对汾河运城段的COD,BOD5和氨氮等污染物加以严格控制。研究结果可为运城市地表水资源规划、管理与保护提供科学依据。     

基于综合水质标识指数法的大凌河中游水体污染季节性变化特征研究

为了对大凌河中游水体污染季节性变化特征进行评价,在大凌河中游段设置10个水质监测断面。基于不同时期(丰、平、枯)氨氮、pH、电导率、总氮、总磷的水质断面监测数据,应用综合水质标识指数法,对大凌河中游水体污染季节性变化特征进行评价,并识别主要污染源。此外结合上、下断面监测数据对大凌河中游水体污染沿程变化进行分析。结果表明:丰水期,大凌河中游水体总体评价为II类水标准,轻度污染,在枯水期,水体呈现中度污染,总体达到III类水质标准,但水体pH全年可稳定在6.12~7.49,对水生生物的生长较为适宜;生活污染排放是大凌河中游主要污染源,主要污染指标为氨氮;从上游到下游监测断面,水体沿程污染指数逐步加重。     

浑太河流域水环境质量综合分析与评价

以浑太河流域为研究对象,选取流域88个监测站点,在2009,2010,2012年对河流高锰酸盐指数、总氮、氨氮、总磷等9项指标进行监测,并对河流水质的时空异质性进行了分析。选择高锰酸盐指数、总氮、氨氮和总磷作为主要评价因子,采用单因子和综合水质标识指数法对该地区主要河流水污染特征进行分析及评价。结果表明,水质因子具有明显的时空异质性。单因子评价结果表明,非汛期总氮和氨氮为主要污染物,汛期总磷和总氮为主要污染物,非汛期的水质状况较汛期好,说明非点源是造成其污染的主要原因。河流水质综合评价中,小汤河上游、太子河南支、太子河北支所有点位的水质评价结果均为最好。所有站点中,海城河的支流（五道里河、运梁河、南沙河下游）区域的水质最差,达到劣Ⅴ类水质,且出现黑臭现象。研究结果对指导浑太河流域水污染防治及水资源管理具有重要意义。     

沱江流域地表水水质的模糊综合评价

沱江是长江上游的一个重要支流,其水质安全对维持成都平原及周边地区正常的生产生活起着至关重要的作用。采用模糊综合评价的方法,对沱江流域15个地表水监测断面的水质状况进行了综合评价,结果表明：在15个监测断面中,处于清洁状态的有6个,占40%;处于未污染的有4个,约占26.7%;处于轻污染和中污染的各有1个,分别约占6.7%;处于重污染的有3个,占20%。处于清洁和未污染的断面主要位于沱江流域的中游,其水质状况较好;处于中污染和重污染的断面主要位于沱江流域的上游和下游,水质状况较差。需要加强流域综合治理尤其是对沱江上游和下游的治理,以确保沱江流域的水质安全。     

基于综合评价法的天津市主要排污河流水质评价

为了研究天津市主要排污河流的水质污染情况,利用综合评价法对天津市的5条主要排污河流：津河、南运河、海河、北运河、子牙河2009年12个月的水质监测数据进行了监测和评价。结果表明：从单项污染指数来看,海河的污染指数总磷〉氨氮〉总氮〉化学需氧量〉氟化物〉1,说明海河的富营养化比较严重;海河的综合污染指数为12.15最高,津河和南运河的综合污染指数较低分别为2.76和2.37;污染分担率方面看,海河的总氮污染分担率也较高,达到了16.62%。最终水质污染程度（P）分析表明,海河P〉0.5属于中度污染,其他4条河流P〈0.5属于轻度污染。     

阜新市地表水功能区水质变化趋势分析

以阜新市为例,对2016—2020年地表水功能区水质变化趋势利用季节性Kendall检验法进行分析.结果表明:柳河、细河水质较好,小清沟河、苇塘河水质呈好转趋势,东沙河、新开河的CODMn呈明显上升趋势,饶阳河、养息牧河、伊马图河水质变化趋于稳定.通过综合调研上游、两岸陆上来水,明确了农田面源污染是断面水质恶化的主要原...     

2016—2021年黄土高原马莲河干流水质时空变化特征及其成因

[目的] 分析黄土高原马莲河干流水质时空变化特征,揭示水质污染状况及成因,为该流域内生态文明建设和水环境治理提供科学依据。[方法] 基于黄土高原马莲河干流2016—2021年甘肃省庆阳市境内5个断面水质逐月监测数据,结合单因子污染指数法、综合污染指数法对水质进行评价,利用线性趋势法对水质演变趋势进行分析。[结果] ①2016—2021年庆阳市境内马莲河水质整体较差,属于Ⅴ类水范畴,综合污染指数较高,主要污染因子为高锰酸盐指数、化学需氧量(COD)、5日生化需氧量(BOD₅)、氨氮(NH₃-N)、总磷、氟化物及六价铬,下游水质优于上游。②庆阳市境内马莲河干流水质季节变化特征显著,综合表现为夏、秋季优于春、冬季。具体表现为秋季最优,冬季最差。[结论] 2016年以来,庆阳市境内马莲河水质趋势稳定向好,尤其是2017年以后,向好趋势表现明显;受入境水质及流域地质条件影响,马莲河水污染治理任务依然任重而道远。     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。     

Biodiversity and ecogeography of wild Lactuca spp. in some European countries

Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.     

Properties of anaerobically digested and composted municipal solid waste assessed by linking soil mesofauna dynamics and nitrogen modelling

We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.