公别拉河流域三类湿地水化学特征研究

选择公别拉河流域有代表性的丛苔草湿地、臌囊苔草-细叶沼柳湿地和沼泽皱蒴藓-柴桦湿地为研究对象,分别对其水化学特征进行研究和分析.结果表明,三类湿地水中的阴离子以HCO₃^-为主,占阴离子总量的81.91％～85.46％,阳离子以Ca₂⁺为主,占阳离子总量的56.80％～69.32％,其水化学类型为重碳酸盐类钙型水.三类湿地水pH为6.2～7.1,矿化度为112.56～461.23 mg·L^-1,总硬度为14.31～148.53 mg·L^-1.三类湿地水的各项指标基本符合国家I、II类水质标准,但Fe、Mn含量超标,在一定程度上影响本区水资源质量.从时间和空间角度分析了三类湿地水的水化学特征变化规律,并对湿地水微量元素含量进行了分析.     

上海地区大气氮湿沉降及其对湿地水环境的影响

根据1998～2003年上海地区雨水中NO₃^--N、NH₄⁺-N浓度,采用单因子评估模式评价了降雨对湿地水环境的影响,并结合降雨量数据,研究了大气湿沉降氮通量.结果表明,上海地区雨水中氮浓度较高,6年雨水平均硝态氮浓度为259 mg·L^-1,铵态氮浓度为2.16 mg·L^-1,总无机氮（TIN）浓度474 mg·L^-1,远大于水体富营养水中氮浓度阀值（0.2 mg·L^-1）,依据降水中的氮浓度,降水已达到地表水V类、劣V类水平.6年湿沉降氮通量平均值为58.1 kg·hm^-2·yr^-1,其中NO₃^--N占54%.大气氮沉降对湿地水体富营养化影响值得关注.     

不同森林群落类型溪流水化学特征的季节动态

以小兴安岭凉水自然保护区内的阔叶红松林、云冷杉林和落叶松人工林为研究对象, 于2006年3—10月, 分析了其溪流水化学特征的动态变化. 结果表明: 不同月份3种森林群落溪流水的主要阳离子含量均表现为 Ca²⁺>Na⁺>K⁺>Mg²⁺, 主要阴离子含量均为HCO₃^->SO₄^2->NO₃^->Cl^-;不同群落类型的主要离子含量影响显著, 3种森林群落溪流水中Na⁺、Ca²⁺、Mg²⁺、Fe²⁺和Fe³⁺平均含量为云冷杉林>落叶松人工林>阔叶红松林, 而K⁺为落叶松人工林>云冷杉林>阔叶红松林; 主要阴离子平均含量均以落叶松人工林溪流水中为最高.     

濒危植物珙桐的组织培养与植株再生

以珙桐冬芽为材料进行组织培养和植株再生研究,结果表明：珙桐冬芽直接诱导丛生芽的最适培养基为WPM+NAA 0.2 mg·L^-1+6-BA 3.0 mg·L^-1+AC 2.0 g·L^-1;珙桐带芽茎段增殖的适宜培养基为WPM+NAA 0.05 mg·L^-1+6-BA 1.0 mg·L^-1+GA₃ 2.0 mg·L^-1+AC 2.0 g·L^-1;生根最佳培养基为White+IBA3.0 mg·L^-1+6-BA 1.0 mg·L^-1+AC 2.0 g·L^-1,在此条件下,根发育良好,植株健壮;组培苗炼苗后移栽,成活率可达80%。     

孝顺竹愈伤组织增殖培养基优化研究

为筛选适宜孝顺竹愈伤组织继代增殖培养基,控制褐变发生,提高再生体系效率,对培养基组成如5种基本培养基、6种有机添加物、7种糖类和5种大量元素等因子进行试验分析。结果表明：培养20 d,基本培养基以MS效果较好,愈伤组织增殖2.8倍,白至淡黄色,致密;有机添加物以1.0 g·L^-1脯氨酸效果较显著,愈伤组织增殖3.64倍,淡黄色,致密均一;碳源以30 g·L^-1麦芽糖效果较好,愈伤组织增殖2.96倍,白至淡黄色,致密。5种大量元素中NH₄NO₃对孝顺竹愈伤组织增殖的影响达到显著水平,以825 mg·L^-1为较佳浓度,培养29 d愈伤组织增殖可达5倍以上,部分出现根分化;适宜孝顺竹愈伤组织培养的大量元素组合为：KNO₃ 475 mg·L^-1+NH₄NO₃ 825 mg·L^-1+MgSO₄·7H₂O 185 mg·L^-1+KH₂PO₄ 340 mg·L^-1+CaCl₂·7H₂O 440 mg·L^-1。     

氮磷营养因子对赤潮异弯藻生长的影响

研究了N、P营养浓度对赤潮异弯藻(Heterosigma akashiwo)生长的影响.结果表明,该藻的生长速率与N、P营养因子浓度的关系符合Monod公式.在NO₃^--N浓度达到7.5 mg·L^-1时,赤潮异弯藻开始生长;浓度为3.75～75 mg·L^-1时,赤潮异弯藻的比生长速率与NO₃^--N浓度成正比关系.N营养充足时,赤潮异弯藻的最大生长速率μ_m-n=0.3475·d^-1,K_s-n=18.91 mg·L^-1.PO₄^--P浓度为0～1.0 mg·L^-1时,赤潮异弯藻的比生长速率与P浓度成正比关系;P营养充足时,赤潮异弯藻的最大生长速率μ_m-p=0.3024·d^-1,K_s-p=0.4086 mg·L^-1.N/P达到25后藻细胞浓度达到最大,表明N/P为25时最适合赤潮异弯藻生长.赤潮异弯藻最适合在N 37.5～225.0 mg·L^-1、P 5.0～50.0 mg·L^-1、N/P=25条件下生长.     

野葛叶片和茎段高频再生体系的建立

探讨几种因子对野葛叶片和茎段高频再生体系建立的影响。采用植物组织培养、正交实验和单因子实验的方法。野葛叶片和茎段的最佳消毒方式为70%酒精处理30 s后再用0.1%HgCl₂处理15 min；野葛叶片愈伤组织诱导的最佳培养基为MS+NAA 1.0 mg·L^-1+2,4-D 2 mg·L^-1，野葛茎段愈伤组织诱导的最佳培养基为MS+NAA 0.5 mg·L^-1+6-BA 1.0 mg·L^-1+2,4-D 2 mg·L^-1；暗培养更有利于野葛愈伤组织的诱导；野葛叶片和茎段愈伤组织诱导的最佳蔗糖浓度均为30 g·L^-1；野葛叶片愈伤组织的最佳出芽培养基为MS+NAA 1.0 mg·L^-1+6-BA 3.0 mg·L^-1，而野葛茎段愈伤组织的最佳出芽培养基为MS+ NAA 0.5 mg·L^-1+KT 2 mg·L^-1；光照培养更有利于野葛叶片和茎段愈伤组织芽的再分化；野葛叶片愈伤组织再生芽生根的最佳培养基为MS+NAA 0.5 mg·L^-1+PP₃₃₃ 0.5 mg·L^-1，而野葛茎段愈伤组织再生芽生根的最佳培养基为MS+NAA 0.5 mg·L^-1+PP₃₃₃ 3.0 mg·L^-1；野葛叶片和茎段愈伤组织再生芽生根的最佳蔗糖浓度均为30 g·L^-1；叶片再生苗移栽的最佳PP₃₃₃浓度为1.0 mg·L^-1，茎段再生苗移栽的最佳PP₃₃₃浓度为3.0 mg·L^-1；叶片和茎段再生苗的最佳移栽基质均为蛭石:珍珠岩（2:1）。     

表层岩溶动力系统中土壤水分及其岩溶效应

对广西弄拉表层岩溶动力系统中森林和灌丛的土壤容重、非毛管孔隙度等物理性质以及土壤CO₂、土壤水和泉水水化学特征进行了研究.结果表明：森林和灌丛环境下的土壤物理性质存在显著性差异,影响土壤含水量.土壤水固定CO₂浓度和土壤CO₂之间存在显著的负相关关系.森林土壤水中游离CO₂浓度为0,灌丛为5.33×10³ mg·m^-3.土壤水和泉水中pH、Ca^2＋、Mg²⁺ 、Cl^-浓度存在一定的负相关关系,其K⁺、Na^＋、HCO₃^-浓度和有机碳含量存在正相关关系.经过雨水的淋溶,土壤层各离子浓度均大幅度增加,其溶蚀能力大大增强.森林环境下的岩溶作用稳定但强度大,灌丛环境下的岩溶作用活跃但强度小.     

马蔺组织培养快繁技术体系研究

以成熟且具活力的马蔺种子为外植体,以MS为基本培养基,与不同浓度比例的2,4-D、BA、NAA、KT等植物生长调节剂构成愈伤组织诱导、分化、生根等培养基的组合方案,对马蔺组织培养快繁技术开展系统研究。结果表明,不同植物生长调节剂组合的培养基对愈伤组织的诱导率有显著影响,MS+2,4-D 4 mg·L^-1+BA2 mg·L^-1、MS+2,4-D 4 mg·L^-1+BA5 mg·L^-1和MS+2,4-D 2 mg·L^-1+KT1.5 mg·L^-1为最佳诱导培养基,诱导出愈率均在58%以上,显著高于其它培养基组合方案（p<0.05）;最佳分化培养基为MS+BA4 mg·L^-1和MS+BA1 mg·L^-1+NAA0.15 mg·L^-1,绿苗分化率高达100%,生长势好,状态叶和分化芽丛质量好;适宜继代增殖培养基为MS+BA2 mg·L^-1+NAA0.1 mg·L^-1、MS+BA1 mg·L^-1+NAA0.2 mg·L^-1;1/2MS为最适宜的生根培养基,1/2MS+IBA0.5 mg·L^-1、1/2MS+IBA0.5 mg·L^-1+NAA0.5 mg·L^-1两种组合也相对较好;试管苗不需炼苗可直接出瓶移栽于V_田土∶V_河沙=2∶1的土壤基质,成活率在95%以上。从而为马蔺提供了一套从“成熟种胚—诱导愈伤组织—绿苗分化—继代增殖—生根—试管苗移栽”等整个过程中各环节的最佳培养基和操作规程的组培快繁体系。     

施用坡缕石对黄绵土中尿素氮的挥发和淋溶损失的影响

通过室内模拟试验,采用吸收法和土柱淋溶法研究了施用坡缕石对黄绵土中尿素氮的挥发和淋溶的影响.结果表明：施用坡缕石+尿素处理能降低尿素氨挥发高峰期的挥发速率,比单施尿素处理的氨挥发损失减少了13.6%～15.0%.坡缕石施用量为0.3和0.6 g·kg^-1时,降低了NH₄⁺-N和NO₃^--N的淋溶速率,无机氮淋溶损失比单施尿素处理分别减少13.7%和13.6%;而坡缕石施用量为0.9 g·kg^-1时,加快了NH₄⁺-N和NO₃^--N的淋溶速率,无机氮淋溶损失比单施尿素处理增加了6.1%.施用低量（0.3 g·kg^-1）坡缕石+尿素处理土壤的NH₄⁺-N含量比单施尿素处理提高了0.20 mg·kg^-1,而施用高量（0.9 g·kg^-1）坡缕石+尿素处理土壤的NH₄⁺-N含量比单施尿素处理降低了0.42 mg·kg^-1;施用坡缕石+尿素处理土壤的NO₃^--N含量比单施尿素处理增加1.24～2.52 mg·kg^-1.表明施用坡缕石能减少土壤中尿素氨的挥发损失,在一定用量范围内能降低NH₄⁺-N和NO₃^--N的淋失,提高土壤NH₄⁺-N和NO₃^--N含量.     

酸雨对温州三土羊湿地水体氮营养盐数量的影响

为了解酸雨对温州三羊湿地水体氮营养盐数量的影响,本文测定了三土羊湿地水体中不同形态氮的含量,其中氨氮2.90～10.75 mg·L^-1,平均538 mg·L^-1、硝态氮0.16～0.44 mg·L^-1,平均0.31 mg·L^-1;总氮34.04～63.20 mg·L^-1,平均55.75 mg·L^-1和水体的pH值,6.1～6.5,平均6.4;并测算了近两年通过降水输入到三羊湿地和三羊湿地水体中不同形态氮的数量及其占湿地现有水体中各形态氮的比例,其中输入到三羊湿地氨氮、硝态氮和总氮的量分别为2.48～2.86×10⁴ kg、2.87×10⁴～4.96×10⁴ kg和5.35×10⁴～7.82×10⁴ kg,分别占湿地水体现有量的56%～64%、11.21～19.38倍和12%～17%;直接输送到三羊湿地水体各形态氮的数量0.72×10⁴～0.84×10⁴ kg、0.83×10⁴～1.44×10⁴ kg和1.55×10⁴～2.27×10⁴,分别占现有量的16%～19%,3.24～5.63倍和3%～5%.结果表明,酸雨是三,羊湿地水体氮污染的主要来源之一,对三羊湿地水体富营养化产生重要影响.     

Effect of level and origin of rumen degradable nitrogen on rumen microbial growth and nitrogen utilisation efficiency of animals fed maize silage at maintenance.

Isoenergetic maize silage diets, fed at maintenance to 24 suckling cows (Exp. 1) and to 3 (Exp. 2) or 4 (Exp. 3) rumen fistulated sheep, were compared with a urea and controlled release NPN diet (Exps. 1 and 2) and with a protein-N supplemented diet (Exp. 3). Supplementation increased blood urea concentrations (44.7 +/- 22.3 vs. 97.6 +/- 23.7 mg urea-N x L(-1)) (Exp. 1) and renal urea excretion (2.5 +/- 1.1 vs. 7.6 +/- 1.8 g urea-N x d(-1)) (Exps. 2 and 3), whereas blood allantoin concentrations (286.7 +/- 77.0 micromol x L(-1)) (Exp. 1) and renal excretion of purine derivatives (357.6 +/- 90.7 mg purine-N x d(-1)) (Exps. 2 and 3) were not affected, indicating additional N supplementation did not improve rumen microbial growth. However, some deficiency of rumen degradable N might occur in non supplemented diets as suggested by the reduced rumen NH3-N and RNA concentrations (868 +/- 270 vs. 1466 +/- 466 mg RNA x kg(-1) rumen contents).     

北京西山不同人工林枯落物层的水化学性质

通过采集降雨经枯落物后的水样,初步研究了北京西山地区油松林和栓皮栎林林下枯落物层的水化学性质.结果表明:大气降水经过林冠进入枯落物层后,油松林和栓皮栎林林下不同元素的浓度发生明显变化.枯落物水中K 、Na 、Ca2 、Mg2 、NH4 -N和NO3--N的浓度随时间的变化趋势基本一致.穿透雨经过枯落物层后,水中K 、Na 、Ca2 和Mg2 的平均浓度增加,而NH4 -N、NO3--N的平均浓度减小.其中,栓皮栎林和油松林中Ca2 浓度分别增加了7.54和5.27mg.L-1.栓皮栎林下枯落物层中K 、Na 、Ca2 、Mg2 的平均浓度高于油松林,而NH4 -N、NO3--N的平均浓度则低于油松林;经降水淋溶作用后,栓皮栎林和油松林林下枯落物归还林地的养分分别为41.59和58.12kg.hm-2,其中归还林地较多的是Ca2 ,其次是K .     

Associations between smoking, GST genotypes and N7-methylguanine levels in DNA extracted from bronchial lavage cells

N7-Methylguanine (N7-MeG) DNA adducts are markers of human exposure to methylating agents including tobacco-specific nitrosamines (TSNAs). Repair of this adduct is poor, so levels in lung tissue should reflect variation in both intensity of exposure and in metabolism. N7-MeG adducts in lung DNA from bronchial lavage samples were measured to determine whether levels were higher in smokers than non-smokers, and if levels were modified by genetic variation in carcinogen-metabolising enzymes. Adducts were detected in 38 out of 44 DNA samples by 32P post-labelling of the N7-methyldeoxyguanosine-3'-monophosphate (N7-MedGp) isolated from DNA digests by two-stage HPLC. N7-MeG adduct levels were higher in smokers than in never smokers ((9.99 +/-20.3)x10(-7) versus (0.58+/-0.50)x10(-7) N7-MedGp/deoxyguanosine-3'-monophosphate (dGp); P=0.02) and intermediate in ex-smokers ((5.59+/-15.6)x10(-7) N7-MedGp/dGp). Adduct levels tended to be higher in individuals with GSTM1 null, GSTT1 null or GSTP1 ile/ile genotypes. When genotypes were combined, N7-MedGp levels among GSTM1 null/GSTT1 null individuals (n=6) were higher than among those having at least one wild-type allele of these two genes ((26.1+/-38.0)x10(-7) versus (2.73+/-4.07)x10(-7) N7-MedGp/dGp), although the results were not statistically significant (P=0.13). Adduct levels were highest in individuals with three unfavourable genotypes (GSTM1 null/GSTT1 null and GSTP1 ile/ile) compared with others ((74.5+/-13.1)x10(-7) versus (2.64+/-3.89)x10(-7) N7-MedGp/dGp, P=0.02). N7-MeG adduct levels in DNA isolated from lung tissue thus reflect exposure to cigarette smoke, and genetic variation in carcinogen-metabolising enzymes may modify these levels.     

Nitrogen dynamics of storm runoff in the riparian zone of a forested watershed

The influence of storm runoff processes on stream nitrogen dynamics was investigated in a headwater riparian swamp on the Oak Ridges moraine in southern Ontario. Hydrologic data were combined with analysis of an isotopic tracer (¹⁸0) and nitrogen (NH ₄ ⁺ , NO ₃ ^– ) concentrations in saturation overland flow and stream discharge. Storm runoff was separated into its event and pre-event components using¹⁸O in order to examine the effect of water source on nitrogen chemistry. Laboratory experiments were also used to study nitrogen transformation associated with storm runoff-surface substrate interactions in the swamp. In most storms N0₃-N and NH₄-N concentrations in the initial 3–4 mm throughfall increment were 10–20x and 20–100x higher respectively than stream base flow concentrations. Maximum stream N0₃-N concentrations were < 2x to 6x higher than base flow concentrations and preceded or coincided with peak stream discharge. Storm-to-storm variations in stream N0₃-N behaviour also occurred during the hydrograph recession phase. NH₄-N concentrations attained an initial peak on the rising hydrograph limb, or at peak stream discharge. A second NH₄-N increase occurred during the late recession phase 3–5 h after maximum stream discharge. Inorganic-N concentrations in surface runoff were similar to peak streamflow.The close agreement between observed N0₃-N concentrations and values predicted from a chemical mixing model indicate that stream N0₃-N variations were controlled mainly by the mixture of throughfall and groundwater in surface stormflow from the swamp. Laboratory experiments also indicated that N0₃-N in surface runoff behaved conservatively when mixed with swamp substrates. With the exception of the late hydrograph recession phase, observed stream NH₄-N concentrations were much lower than concentrations predicted by the chemical mixing model. The rapid loss of NH₄-N from mixtures of surface stormflow and swamp substrates in laboratory experiments and the absence of uptake in sterilized substrates indicated that NH₄-N retention in surface storm runoff was due to biotic processes.     

凉水和帽儿山地区低级溪流生境和水质状况

为研究不同植被景观土地利用下低级溪流的生境状况和水质差异,对凉水国家级自然保护区红松原始林内和帽儿山国家森林公园境内天然次生林植被和农田背景下各3条溪流生境和水质状况进行调查。对溪流生物特性（悬浮藻、附着藻）和理化性质（温度、混浊度、溶解氧（DO）、pH、NH4^＋-N、NO3^-N、PO4^3-P、总氮（TN）和总磷（11P））以及细小颗粒有机物质（FPOM）和粗大有机物质（CPOM））进行测定。研究结果表明,凉水地区原始林溪流的生境状况好于帽儿山地区的次生林,帽儿山地区农田溪流生境最差。原始林溪流具有稳定的溪底生物生活基质,稳水区和急流区均匀分布,稳水区尺度变化大,受淀积物沉降干扰小,河道较弯曲,河岸稳定,河岸植被覆盖度高;次生林溪流以急流区为主,稳定基质相对较差,并受到一定程度的淀积物沉降干扰,河岸尚稳定,有一定程度的人为干扰;农田溪流基质不稳定,受到强烈淀积物沉降影响,渠道化严重,河岸带植被严重破坏。3种景观背景下溪流总磷（11P）、溶解氧（DO）、混浊度、温度、氮磷比值（N／P）（P〈0．05）存在显著差异。原始林溪流NH4^＋、DO、TP、TN、悬浮藻浓度和pH较高、附着藻数量较多,温度较低、FPOM和CPOM的数量较少;次生林溪流的NO3^--N、N／P和TDIN较高。 浊度较低;农田溪流浊度、温度、PO4^3--P较高,DO和pH较低,附着藻数量较少。景观尺度上的土地利用对溪流生境具有深刻的影响,同时决定溪流的水质状况。     

不同营养状态下金鱼藻的生理响应

通过静态模拟实验,比较研究了不同营养水平（中营养、富营养、重富营养和Hoagland植物培养液）下培养的金鱼藻（Ceratophyllum demersum）的蛋白质、叶绿素含量,过氧化物酶（POD）及超氧化物酶（SOD）活性变化.研究发现,总N、总P 的变化会影响金鱼藻的生物合成,当水环境总氮浓度低于1 mg·L^-1,总磷浓度低于0.1 mg·L^-1时,金鱼藻茎叶的叶绿素合成较低,其茎蛋白含量迅速下降.金鱼藻在富营养水平（1 mg TN·L^-1, 0.1 mg TP·L^-1）下抗氧化防御酶活跃,POD、SOD活性增高.研究表明,金鱼藻较适应于富营养水环境,水体营养盐继续增加对金鱼藻有胁迫作用,过高营养盐浓度（重富营养和Hoagland培养液）影响金鱼藻的抗逆能力.     

Potential of constructed wetlands in treating the eutrophic water: evidence from Taihu Lake of China

Three parallel units of pilot-scale constructed wetlands (CWs), i.e., vertical subsurface flow (VSF), horizontal subsurface flow (HSF) and free water surface flow (FWS) wetland were experimented to assess their capabilities in purifying eutrophic water of Taihu Lake, China. Lake water was continuously pumped into the CWs at a hydraulic loading rate of 0.64 m d(-1) for each treatment. One year's performance displayed that average removal rates of chemical oxygen demand (COD), ammonia nitrogen (NH(4)(+)-N), nitrate nitrogen (NO(3)(-)-N), total nitrogen (TN) and total phosphorous (TP) were 17-40%, 23-46%, 34-65%, 20-52% and 35-66%, respectively. The VSF and HSF showed statistically similar high potential for nutrients removal except NH(4)(+)-N, with the former being 14% higher than that of the latter. However, the FWS wetland showed the least effect compared to the VSF and HSF at the high hydraulic loading rate. Mean effluent TP concentrations in VSF (0.056 mg L(-1)) and HSF (0.052 mg L(-1)) nearly reached Grade III (0.05 mg L(-1) for lakes and reserviors) water quality standard of China. Wetland plants (Typha angustifolia) grew well in the three CWs. We noted that plant uptake and storage were both important factors responsible for nitrogen and phosphorous removal in the three CWs. However, harvesting of the above ground biomass contributed 20% N and 57% P of the total N and P removed in FWS wetland, whereas it accounted for only 5% and 7% N, and 14% and 17% P of the total N and P removed in VSF and HSF CWs, respectively. Our findings suggest that the constructed wetlands could well treat the eutrophic lake waters in Taihu. If land limiting is considered, VSF and HSF are more appropriate than FWS under higher hydraulic loading rate.