碱性矿化水灌溉对土壤溶质运移的影响

经过连续几年的灌溉试验可知,应用2.5 g稬-1以下的低矿化水灌溉是安全的,超过此值土壤积盐和碱化明显。灌溉后,土壤中溶质运移受多因素影响。在阳离子分布中,水平方向Na+随灌溉水矿化度增大而增多,Ca2+、Mg2+变化不大;土壤剖面上,从表层至60 cm土层,先以Ca2+、Mg2+为主,过渡到Na+、Ca2+、Mg2+共同占优,再发展为以Na+占优。阴离子的分布中,水平方向,随灌溉水矿化度增大HCO3-增多;土壤剖面上,从表向里,先以Cl-或SO42-为主,过渡到C1-、SO42-、HCO3-均分局面,再发展以HCO3-占优。灌溉后土壤pH值在0~20 cm变化不明显,大于20 cm土层有一定增加。土壤中的SAR和ESP均以大于1.5 g稬-1的碱性低矿化水灌溉后增加明显,碱化层由下向上抬升,小麦田碱化速度快于玉米田。     

微咸水淋洗对苏打盐渍土土壤理化性状的影响

在轻度盐碱化和中度盐碱化2种苏打盐渍土上,分别设置对照、补充灌溉、低额淋洗和高额淋洗4个处理,对经微咸水淋洗的苏打盐渍土的土壤渗透性、土壤容重以及土壤盐碱含量的分析结果表明,在高额淋洗区,微咸水在中度苏打盐渍土中渗透速率约为对照区的3倍,在轻度苏打盐渍土中约为对照区的2倍。与对照区相比,中度和轻度苏打盐渍土高额淋洗区土壤容重分别降低10.1%和9.5%。在高额淋洗区,中度苏打盐渍土60 cm深度内的含盐量降至1.0 g.kg-1,碱化度降低17.4百分点;轻度苏打盐渍土120 cm深度内含盐量均降至0.6 g.kg-1以下,碱化度也降低7.9百分点。苏打盐渍土土壤理化性状得到明显改善。认为适合中、轻度苏打盐渍土的淋洗定额分别为400和150 mm。     

苏打盐碱胁迫下水稻体内的Na＋、K＋响应

土地盐碱化是限制农业发展的主要因素之一.实践证明,盐碱地种植水稻(Oryza sativa L.)是土壤盐碱化治理、改良、利用的有效途径.土壤盐碱对水稻的影响表现为生长抑制、产量降低和生理异常等.深刻认识盐碱胁迫下水稻生理响应机制对耐盐碱水稻种质资源筛选、耐盐碱性鉴定和培育耐盐碱水稻品种具有重要意义.以不同比例的苏打盐碱土和非盐碱旱田土充分混合配制不同盐碱梯度的实验土壤.根据苏打盐碱土的特殊性,采用土壤ESP作为胁迫指标因子,观察不同生育期水稻植株对Na 、K 的吸收、运输和分配,分析植株体内的离子响应及植物与盐碱作用关系.结果表明:在分蘖期,Na 在根、叶和叶鞘中浓度的次序从高到低依次为根>叶鞘>叶.随着盐碱胁迫的增强,叶和叶鞘的Na /K 升高更加显著.水稻分蘖期叶片Na /K 与土壤ESP相关性更好,可以采用分蘖期叶片Na /K 来指示水稻对盐碱胁迫的离子响应.水稻生殖生长阶段,Na 的累积以根为主.Na 、K 在穗部、籽粒和颖壳中的浓度,在不同盐碱胁迫强度间差异不明显.     

盐碱胁迫对水稻花粉扫描特征和生活力的影响

盐碱胁迫导致水稻结实率降低是盐碱地水稻生产中的主要问题之一.以非盐碱土壤为对照,将不同比例的盐碱土和非盐碱土壤充分混合,设置5个土壤盐碱胁迫梯度,根据苏打盐碱土的特殊性,以土壤碱化度(ESP)为胁迫指标因子,用盆栽实验研究了盐碱胁迫下水稻花粉表面形态特征、花粉生活力和柱头对花粉的接受能力等.结果表明,盐碱胁迫下,水稻花粉表面形态结构表现出明显差异,盐碱胁迫处理的花粉表面凸凹程度较浅,雕纹不明显,相对平滑,而对照(SS0)花粉粒雕纹较深,SS4盐碱胁迫下只有孔环没有孔盖.盐碱胁迫对水稻花粉生活力产生了影响,随着盐碱胁迫的增强,水稻花粉在离体培养基上的萌发率呈下降趋势,品种‘吉农大10号’花粉萌发率在SS4和SS2处理分别比对照(SS0)降低34.4%和15.5%,对盐碱胁迫反应比‘吉优1号’更为敏感.盐碱胁迫下,水稻柱头对有萌发力的花粉的接受程度依胁迫强度的增大而降低,在轻、中度盐碱胁迫(SS1、SS2)下,‘吉优1号’柱头对花粉的接受能力强于‘吉农大10号’品种,而在重度盐碱胁迫(SS3、SS4)下则相反.盐碱胁迫下柱头对花粉的接受能力对水稻结实具有重要意义.     

脱硫石膏改良中度苏打盐渍土施用量的研究

采用盆栽试验和田间试验相结合的方法,通过种植油葵(Helianthus annus),进行了脱硫石膏施用量的试验.结果表明,施用脱硫石膏能够有效降低土壤碱化度、总碱度和pH值,但却增加了土壤全盐量;施用脱硫石膏可显著提高油葵出苗率和产量,但施用量过高会抑制油葵的生长发育.施用11 250 kg·hm-2脱硫石膏对中度苏打盐渍土改良效果最佳,最有利于油葵的生长发育,耕作层土壤碱化度、总碱度和pH值分别降至6%、0.2 cmol·kg-1和8.5以下,油葵出苗率达到70%以上,田间试验中油葵产量高达2 031 kg·hm-2,与不施脱硫石膏处理相比,增产率达到16.2%.     

有机-无机土壤改良剂对滨海盐渍土降盐防碱的效果

以脱硫石膏为主要材料添加天然有机类物质制成的土壤改良剂,在碱性淡水淋盐过程中应用达到盐渍化土壤迅速脱盐防止碱化的效果.盆栽试验采取3因素3水平组合设计,2种质地土壤,3个灌水量,3个改良剂施用量,3次重复,以不施改良处理为对照,试验作物为油菜(Brassica campestris L.)"傲绿101".结果表明:灌水淋洗可以使盐渍化土壤迅速脱盐,灌水量525 m3·hm2、750 m3·hm-22种质地土壤全盐量分别由0.34%和0.54%下降至0.15%～0.309%和0.16%～0.38%.施用改良剂能够改变土壤盐分组成,降低土壤碱化度,与对照相比,土壤ESP和交换性Na+分别下降25.02%～64.86%和23.95%～57.83%.土壤HCO3-、Cl-与改良剂施用量呈负相关,土壤SO42-、Ca2+与改良剂施用量呈正相关.综合结果分析,重壤质土壤灌水量525 m3·hm2与改良剂施用量1 500 kg·hm-2组合、灌水量750 kg·hm3与改良剂施用量1 500kg·hm-2组合;中壤质土壤灌水量525m3·hm-2与改良剂施用量3 000 kg·hm-2七组合为首选.     

新疆盐渍化土壤氮肥氨挥发损失特征初步研究

在室温下应用“静态吸收法”,研究不同盐渍化程度的盐化土壤和碱化土壤上氮肥氨挥发损失特征。结果表明:(1)除碱土外碱化土壤上氮肥氨挥发量随时间延长呈现下降趋势,在盐化土壤上氨挥发量随时间呈现先上升后下降趋势。(2)供试9个典型盐渍化土壤样品上氮肥氨挥发量(Y)与时间(t)关系均符合Y=at2 bt c动力学方程,相关性呈极显著水平。(3)氨挥发总量(Y)、氨挥发速率(Yi)与土壤含盐量(x)呈极显著正相关;氨挥发持续时间随着盐渍化程度的增加而延长。(4)氨挥发总量、挥发速率与盐渍土pH相关性未达到显著水平;盐渍土上pH值对氨挥发的影响需要进一步研究。以上结果表明,盐渍化耕作土壤上氮肥氨挥发的控制要依据盐渍化类型的不同而制定相应的措施。     

脱硫石膏改良碱化土壤种植水稻施用量研究

选择具有典型代表性的宁夏西大滩碱化土壤,采用拉丁方田间试验设计进行脱硫石膏改良碱化土壤种植水稻(Oryza sativa)的施用量研究.试验研究表明施用脱硫石膏能够降低土壤碱化度、总碱度和pH值,提高水稻的出苗率和产量.但是,脱硫石膏施用量不同,土壤碱化度、总碱度和pH值降低的值不同.根据脱硫石膏施用量与土壤碱化度、总碱度、pH值降低的模拟曲线关系,当脱硫石膏施用量为2.8～3.1kg·m~(-2)时,土壤碱化度、总碱度、pH值降低的值达到最大.同时,根据脱硫石膏施用量与水稻出苗率和产量的模拟曲线关系,当脱硫石膏施用量为2.86kg·m~(-2),水稻出苗率达到最大,为84.7%;当脱硫石膏施用量为2.79kg·m~(-2)时,水稻产量达到最大,为0.75kg·m~(-2).因此,建议脱硫石膏改良碱化土壤种植水稻的施用量为2.8～3.1kg·m~(-2).     

岩溶石灰土微生物丰度的影响因素及其指示意义

应用荧光定量PCR技术检测广西两种典型石灰土(黄色石灰土和红色石灰土)不同层位(0~10、10~20、20~40、40~60、60~80和80~100 cm)土壤细菌与真菌丰度的变化规律,以揭示影响土壤细菌、真菌丰度的关键因子并利用其剖面特征指示土壤质量。结果表明:细菌丰度与土壤类型呈显著正相关(F=4.413,P=0.041),与土层呈极显著正相关(F=7.225,P=0.000);真菌丰度与土壤类型在0.05水平上无显著相关性,与土层呈显著正相关(F=2.732,P=0.030)。RDA结果显示,土壤有机碳、全氮和速效磷对微生物丰度影响的解释率分别为31.8%、27.2%和21.1%,3种土壤因子累计解释率为80.1%,说明3种土壤因子是影响微生物丰度的主要因子。由于两种石灰土的微生物丰度受土壤有机碳、全氮以及速效磷等土壤因子影响显著,而研究区土层间土壤因子差异性强于土壤类型,所以微生物丰度表现出对土层的响应强于土壤类型。细菌丰度与土壤有机碳、速效磷、全氮的相关性强于真菌丰度,说明细菌对环境变化更为敏感,可作为指示土壤质量的指标。此外,细菌在石灰土土壤演化与养分循环过程中也具有重要作用。     

黑河中游地区水循环过程对土壤盐分特征的影响

干旱、半干旱区的土壤盐渍化是重要的生态环境问题。黑河流域是我国第二大内陆河流域,研究该地区的土壤盐渍化问题对于我国西部地区的可持续发展具有重要意义。黑河的中游地区集中了流域内绝大部分人口和经济活动(以农业生产为主)。该研究对黑河中游地区表层土壤进行了全面采样,测定了土壤含盐量及其离子构成;并通过主成分分析确定了表征盐渍化程度的第一主成分和表征碱化程度的第二主成分。结合地表-地下水耦合模拟的结果,探讨了研究区水循环过程对土壤盐分特征的影响。研究结果表明,黑河中游表层土壤的盐渍化程度较高,高台-金塔一带盐渍化最严重,含盐量最高可达31.4%,其次为酒泉北部和张掖南部地区,含盐量在0.20%~0.37%之间。黑河中游土壤的盐渍化程度与地下水埋深密切相关。总体而言,地下水埋深越浅,土壤含盐量的均值越高,而标准差越大。研究区土壤主要呈原生盐渍化,次生盐渍化现象不显著。黑河中游土壤碱化程度较轻,碱化程度和盐渍化程度的空间分布呈反向关系。黑河中游的灌溉活动未造成显著的次生盐渍化,但一定程度上提高了土壤的碱化程度。与以往研究相比,该研究更全面地覆盖了黑河中游地区的代表性地点,并定量分析了区域水循环与土壤盐渍化之间的联系,研究结果对于我国西部地区水土资源的可持续开发利用具有重要参考价值。     

Induction of metamorphosis of two species of sea urchin from Sea of Japan

The induction of metamorphosis in mature larvae by selected chemical compounds and natural substrata was investigated in two species of sea urchins from the Sea of Japan, Strongylocentrotus intermedius and Scaphechinus mirabilis. Glutamine in crystalline form was added directly to water containing mature larvae, and this compound, at a final concentration of 10 g ml^-1, was an inducer of metamorphosis in S. intermedius (100% activity) and S. mirabilis (50% activity). Gutamine, or its natural mimetic molecules, may be an active component of the exogenous cue that induces metamorphosis of S. intermedius larvae. This exogenous cue was produced by the epiphytic calcareous algae, Melobesia spp. that colonized the older sea grass Zostera marina. Glutamic acid was also used as an inducer of metamorphosis for S. intermedius and S. mirabilis larvae (50 to 60% activity), but it was toxic to the larvae.     

1株微小杆菌对4种蓝藻的生长影响

利用过滤的天然珍珠养殖水参照BG11配制加富培养液,将1株能促进鱼害微囊藻生长的微小杆菌属菌株(Exiguobacterium sp.013,简写为E.sp.013)进行纯化扩大培养后与铜绿微囊藻(Microcystis aeruginosa)、水华微囊藻(Microcystis flosaquae)、平裂藻(Merismopedia sp.)和惠氏微囊藻(Microcystis wesenbergii)按一定菌、藻密度比例同时接种后进行为期24 d的培养试验,利用特定生长率和细胞密度等指标观察并检验E.sp.013菌株对4种蓝藻生长的影响,同时检测培养液中优势菌群的数量变化趋势.结果表明:E.sp.013菌对铜绿微囊藻、水华微囊藻和惠氏微囊藻具有显著促生长和延长稳定生长期作用,对平裂藻不具有显著促生长作用,但对延长其稳定生长期具有显著效果;试验培养过程中E.sp.013菌落数量占所有菌落总数的比例始终高于46％,处于绝对优势地位,表明E.sp.013菌具有调控其他菌群的能力.     

南京城市西部遗产廊道规划

南京城市西部历史时期是城市的重要边界,现在逐渐演变成老城与新区之间的核心地带,成为公共活动的重要地区,保护其自然、文化遗产和生态环境具有非常重要的意义。在对其现状调查分析的基础上,梳理遗产点的历史概况、现状及其分布情况,提出规划遗产廊道的意义,探讨规划的具体思路,为南京遗产保护提供了新的视角。     

《生态毒理学报》主编简介

<正>王子健,男,1953年10月出生,博士,研究员,博士生导师．1976年中国科技大学毕业后到中科院生态环境研究中心工作．1983-1985年在瑞士留学,从事水质污染化学规律研究;1987年在日本从事生物样品生理活性物质分析方法研究． 1992-2000年担任中科院生态环境研究中心环境水化学国家重点实验室副主任、主任,兼环境模拟与污染控制国家重点联合实验室学术委员会委员,国家863计划污染控制技术主题专家组副组长,国家自然科学基金委员会地球科学部第二届咨询专家委员会委员,国际环境地球化学与健康学会亚太分会理事,全球环境基金专家库成员等．同时担任环境科学学报(副主编)、过程工程学报、环境化学、湿地研究、地球与环境、美国Environmental Science and Health(A)等杂志的编委．王子健领导的研究小组主要研究天然水体和水处理过程中的水质转化、相关毒性和毒理变化以及健康和生态风险．内容包括发展新的环境监测技术,离体和活体生物毒性测试方法,污染物水体多介质过程,水质安全性评价以及水污染的健康和生态风险的指标和方法．在开发新型生物模拟采样技术和生物毒性测试方法体系、生活饮用水和再生水的安全性评价、持久性有毒污染物污染及其生态与健康影响等方面取得了丰硕的成果,相当一部分成果得到推广应用．     

Evaluation of adsorption potential of adsorbents: a case of uptake of cationic dyes

Adsorption potential of a commercial activated carbon (FS300) has been evaluated for the uptake of cationic dyes namely methylene blue (MB) and rhodamine B (RB). Though, there are numerous studies in literature which report the sorption of MB (more than 40 studies) and RB (more than 10), however none of these use a common parameter to report the capacity of the sorbent. A protocol, based on the equilibrium dye concentration has been proposed to measure the sorption potential of a sorbent. The Langmuir model can very well describe the experimental equilibrium data for both dyes (coefficient of correlation > 0.999). MB (Qm = 312.5 mg g(-1)) is more adsorbable than the RB (Qm = 144.9 mg g(-1)). Molecular weight and chemical structure of dye molecules seem to affect the dye uptake. The effect of pH on dye uptake has also been evaluated by varyingpH from 3 to 11. Uptake of MB increases with pH, wherein RB removal decreases with pH. Dyes could not be desorbed either by distilled water (0.06 and 0.11% for MB and RB respectively), or by 0.1 NHCl (0.136 and 3.0% for MB and RB respectively) indicating, chemical adsorption type of adsorbent-adsorbate interactions.     

利用回归分析确定降水入渗补给量

目前常用降水量乘以降水入渗补给系数的方法计算降水入渗补给量,此法不能表现降水特征、蒸发等因素对降水入渗补给的影响．为解决不同时间尺度、不同降水特征和蒸发情况下的降水入渗补给量,在分析郑州地下水均衡试验场地中渗透仪实测入渗量、降水和蒸发资料的基础上,利用均匀设计法选取最优的与降水入渗补给量关系密切的前期降水量和蒸发量的期次,然后利用回归分析建立各岩性和埋深的年、月和日尺度上的降水入渗函数,可以比较准确的计算降水入渗补给量．表3,参9．     

洞庭湖生态环境承载力分析

洞庭湖湖内冬枯水季节，有芦苇面积530km^2，草地面积800余km^2，泥滩地面积367km^2，天然水域面积约993km^2。湖洲之间隔水相望，河沟水系纵横交错，具“水浸皆湖，水落为洲”的地貌特征，呈现出支离破碎的形态面貌和典型的自然湿地景观。文章在大量调查的基础上，从自然和人文两个方面对洞庭湖的生态环境承载力或环境压力进行分析。     

接种污泥源对厌氧氨氧化启动效能的影响

厌氧氨氧化(anaerobic ammonium oxidation,ANAMMOX)菌生长缓慢是影响其实际应用的主要问题之一,选取合适的接种污泥十分重要.本研究采用好氧污泥、厌氧颗粒污泥和厌氧消化污泥3种接种污泥,分别经过61、70和85 d的运行均实现了厌氧氨氧化过程,氨氮去除率分别为82%、92%和91%,总氮去除率达76%、82%和80%.分别接种3种污泥源的厌氧序批式反应器(ASBR)R1、R2、1t3出水pH值最终稳定在8.4、8.5、8.5.好氧污泥呈絮状,但沉降性比接种前好,厌氧颗粒污泥解体后最终形成粒径集中在0.5～1.0 mm的污泥,厌氧消化污泥则呈沙化状态,有细小颗粒出现.根据厌氧氨氧化细胞产率系数及NH4+-N、NO2--N去除量和NO3--N生成量之间的计量学关系,估算出厌氧氨氧化菌产率系数(以1 mol NH4+产生的CH2O0.5N0.15量计)分别为0.080、0.105和0.114 mol·mol-1,说明反应器内厌氧氨氧化菌有不同程度的衰减.总体而言,厌氧颗粒污泥是富集厌氧氨氧化菌的最适污泥源.     

Effects of contrasting modes of larval development on the genetic structures of populations of three species of prosobranch gastropods

 In south-eastern Australia, the prosobranch gastropods Morula marginalba (Blainville), Cominella lineolata (Lamarck) and Bedeva hanleyi (Angas) have similar fine-scale distributions, but appear to possess very different dispersal capabilities due to contrasting modes of larval development. M.marginalba produce planktonic larvae, whereas C. lineolata and B. hanleyi undergo direct development in benthic egg capsules and emerge as crawling juveniles. To test for possible effects of contrasting life histories on levels of genetic variation within and among populations, a survey was conducted of allozyme variation at six polymorphic loci in 8 to 9 local populations of each species. Collections of snails were made between June 1992 and November 1993. Sampling ranges spanned between 162 and 180 km of coast. Regardless of larval type, proportions of single-locus genotypes in each collection were consistent with the recruitment of offspring which had been generated through random mating. However, genotypic diversity was lower in those species that undergo direct development. Loci surveyed in C. lineolata and B. hanleyi were polymorphic (i.e. frequency of most common allele <95%) in fewer populations than those examined for M.␣marginalba (P <0.001) and, where polymorphisms occurred, also possessed significantly fewer alleles (P <0.001). Consequently, average levels of expected heterozygosity were greater in populations of M. marginalba than in those of either of the other species (P <0.001). Genetic variation among populations, expressed as the standardised variance in allele frequencies (F _ST ), was inversely related to expected larval dispersal capability. The nine collections of M. marginalba showed little overall differentiation (F _ST  = 0.017; P <0.001), reflecting the ability of planktonic larvae to interconnect local populations, and so limit divergence due to drift and natural selection. In contrast, there were high levels of allelic heterogeneity among the nine collections of C. lineolata (F _ST  = 0.523; P <0.001) and eight collections of B. hanleyi (F _ST  = 0.140; P <0.001). These data imply that for species which undergo direct development, local populations are effectively closed and evolve largely independent of one another. Received: 3 May 1996 / Accepted: 12 July 1996     

Comparative study of the effects of temperature,salinity and oxygen tension on the rates of oxygen consumption of nauplii of different strains of Artemia

The effects of temperature, salinity and oxygen tension on the rates of oxygen consumption of three different strains of Artemia nauplii have been studied. When acclimated to a salinity of 30, nauplii from each of the three strains were able to maintain approximately constant rates of oxygen consumption over a wide range of oxygen tension. The ability to maintain respiratory independence during hypoxia was reduced, however, with an increase in either temperature or salinity. Nauplii of two of the strains (parthenogenetic diploid and tetraploid) showed a progressive increase in the rate of oxygen consumption with increasing temperature up to 35°C. Nauplii of the bisexual strain appeared to be less tolerant of exposure to temperatures >30°C, since at higher temperatures their oxygen consumption declined slightly. The differences between the nauplii of the different strains in their physiological responses to changing environmental conditions appear to correlate well with their seasonal occurrence in the field.