pH和添加有机物料对3种酸性土壤中磷吸附-解吸的影响

研究了pH和添加有机物料对红壤、砖红壤和水稻土中磷吸附-解吸的影响。结果表明,砖红壤和水稻土中磷的吸附量和解吸量均随pH的升高而降低,pH对红壤中磷吸附和解吸的影响很小。土壤阳离子交换量(CEC),铁、铝氧化物含量和有机质含量是影响磷吸附的主要因素。红壤的CEC和有机质含量很低,铁、铝氧化物含量高,因而对磷的吸附量最高。砖红壤和水稻土CEC较高,土壤表面对磷的排斥作用较大,而且较高含量的有机质覆盖了土壤表面的磷吸附位,因此这2种土壤对磷的吸附量低于红壤。添加稻草并进行恒温培养可使红壤和水稻土对磷的吸附量显著减少,但对砖红壤中磷吸附的影响较小。添加稻草使土壤磷的解吸量和解吸率增加,从而增加了土壤中吸附性磷的活性。     

Impact of fishing methods on conservation of ichthyofauna of river Relli in Darjeeling Himalaya of West Bengal

Impact of fishing methods and gears used on fish faunal diversity in spring-fed torrential river Relli in Darjeeling hill area of West Bengal was investigated in the present study. The fish species available in the river provide nutrition and recreation (rarely income generating) fora large number of people residing along the river bank and nearby villages and towns. The fishing methods observed therein have been categorized as, i) Scientific fishing methods, that is, collection of required number and size of fish so that sufficient population of fish remains balanced in the nature. ii) Unscientific fishing methods, that is, indiscriminate killing of large number of fish which adversely affect the water quality of rivers. Ten types of fishing methods are practiced in this area, for example, diversion of river channel, cast netting, scoop netting, angling, fish spearing, rock striking or hammering, dynamiting, electric fishing, river poisoning and traps utilized. Over the years uncontrolled and often indiscriminate fishing in the unmanaged hill-stream has resulted in a sharp decline in fish resources. The study gives a clear picture on the anthropogenic pressure on the river Relli and provides baseline data which may be helpful for conservation and management of the fish species and also formulating new fishery policy.     

菹草生长对沉积物间隙水中各形态磷浓度的影响

通过人工构建湖泊生态系统,用湖泊沉积物的上层泥和下层泥分别代表清淤前后的2种基质,研究菹草(Potamogeton crispus)生长对沉积物不同层次间隙水中各形态磷浓度的影响.垂直方向上,将2种基质中的间隙水分为表层、中层和底层3个层次.结果表明,菹草生长能够不同程度地降低各层间隙水中磷浓度,上层泥和下层泥2种基质均表现为表层间隙水溶解性总磷(DTP)和溶解性活性磷(SRP)含量降低幅度最大,DTP含量分别降低68.97％和83.09％,SRP含量分别降低54.57％和96.02％.菹草的吸收作用使得各层间隙水中磷浓度均低于无沉水植物的对照组.试验结束时,2种沉积物中TP含量降低幅度差异不显著,说明疏浚前后种植菹草均可有效控制湖泊内源磷污染.     

Effect of weed extracts on seedling growth of some varieties of wheat

Allelopathic effect ofAvena fatua L., Cyperus rotundus L., Polygonum hydropiper L., and Solanum nigrum L. were examined on seedling growth of certain commonly used varieties of wheat (Triticum aestivum L.) in the Tarai region of U.P. state. The weed extracts inhibited the length of plumule in all the varieties (100%) with Solanum and it was in 12 (92%), 10 (77%) and 06 (46%) varieties with Polygonum, Avena and Cyperus, respectively. In radicle length, it was in 92% with both Polygonum and Solanum; and 85% and 69% of the varieties with Avena and Cyperus, respectively. However, all the four weed extracts reduced the dry weight of plumule, radicle and total seedling in all the varieties (100%) of wheat except in HD--2329 with Cyperus, in which it was positive. The percent reduction (percentage of control) was more than 50% in 92%, 77%, 54% and 39% of the varieties, respectively with Solanum, Polygonum, Avena and Cyperus. Among the weed extracts, the inhibitory effect on seedling growth in different varieties followed the order: Solanum > Polygonum > Avena and > Cyperus. On the basis of the present results, UP--2003 and WH--542 followed by PBW--226, Sangam and HD--248 were more susceptible to all the four weed extracts compared to the rest of the varieties of wheat.     

不同温度对沉水植物保护酶活性的影响

富营养化导致了湖泊沉水植被消亡,是我国众多湖泊存在的普遍现象.在富营养化未能有效控制的前提下,采用人工措施重建沉水植被,已被水环境工作者普遍关注.然而,受水体温度、透明度、营养盐以及适宜的物种等限制,沉水植被的有效重建面临诸多困难.本研究着眼于温度对沉水植被重建的影响,设置了5、10、15、25、30、35℃6个温度处理,在人工气候箱培养条件下,对黑藻Hydrilla verticillata和马来眼子菜Potamogeton malaianus在5 h、10h、14h和7d处理后的蛋白质含量、过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性进行了测试.同时考察了实验前后植物生物量积累的情况,比较了不同温度胁迫下,两种植物生物量的净积累与抗氧化酶活性和可溶性蛋白含量的关系,试图为沉水植被的恢复提供理论依据和经验借鉴.结果表明,25℃是两种植物生物量净积累的最佳温度,此温度下,各种酶活性和可溶性蛋白未随处理时间的延长而显著变化.高于或低于25℃的处理,生物量净积累显著下降.并且,表现为短期胁迫5～14h内,各种酶活性和可溶性蛋白随处理时间的延长呈上升或下降的趋势,7 d长期胁迫后上述指标均低于25℃处理.结果表明,25℃外,其它处理均不同程度受到了温度的胁迫.短期胁迫,各处理的酶活性和可溶性蛋白表现了激烈的响应,以清除和维持植物体内活性氧的平衡和植物细胞较低的渗透势,保持植物正常的代谢活动.随着胁迫时间的延续,抗氧化酶系统受损,可溶性蛋白降低,植物正常的代谢紊乱,最终导致实验结束时,各处理植物生物量的积累存在较大差异.     

Patterns of Rarity in the Birds of the Atlantic Forest of Brazil

Patterns of rarity in species are generally explained by several factors: evolutionary history, spatial distribution, and genetic structure of each taxon. Human intervention also leads to or increases rarity in species. The discernment of causes of rarity is essential to the understanding of extinction patterns, and thus to devising conservation strategies. I examine patterns of rarity among bird species in the Atlantic forest region in Brazil, one of the most threatened ecosystems in the world. I assigned bird species to one of eight possible categories that differ in degree of vulnerability and that are based on three parameters of rarity: geographic distribution, habitat specificity, and population size. The Atlantic forest avifauna is a highly endangered group; 68% of the species are rare. Patterns of rarity among the birds in the region likely result from their specific ecologies or evolutionary histories. In addition, human alteration of natural habitats and hunting pressures have undoubtedly influenced rarity for a number of species.     

Chromatographic measurement of molecular markers of sources of atmospheric aerosol particles

Various organic compounds in aerosol particles in ambient air near a coniferous forest fire in Boulder, Colorado were identified as molecular markers of wood burning and forest fires. Particle samples were collected by filtering small volumes of air. The samples were analysed using thermal desorption followed by gas chromatographic separation and detection, a highly sensitive analytical method. Several compounds unique to softwood combustion were identified in the samples. Additionally, a predominance of odd-carbon-numbered n-alkanes over the corresponding even-carbon-numbered n-alkanes was observed. This predominance is a well-documented molecular pattern indicative of epicutical waxes in plants.     

Sampling biological characteristics of krill: Effect of heterogeneous nature of swarms

An effect of the very patchy distribution of Antarctic krill (Euphausia superba Dana) in various forms of aggregation is that a single swarm may not provide an unbiased estimate of population parameters such as mean length of krill in the local area. Here, we analyse the number of samples required to estimate the characteristics of a local population as precisely as if there were no differences between krill swarms in terms of their biological composition. Krill were intensively sampled over different spatial and temporal scales around South Georgia in 1981 and 1982, and in the Bransfield Strait in 1985. These varied from replicate hauls at a single station over 24 h and repeat sampling in restricted areas over periods of 6 to 14 d to regional surveys around South Georgia and in the Bransfield Strait. Various biological characteristics were measured such as length, maturity, moult stage and feeding state. Depending upon the biological characteristic examined and the area covered by the sampling programme, the number of samples needed to obtain the same degree of precision as would be found in the absence of heterogeneity varied from 3 to > 80 samples. This has important implications for the design of net-sampling programme for monitoring krill populations.     

方位及冠层对厚朴果实和种子形态变异的影响

为从方位及冠层的角度探讨光照对厚朴(Magnolia officinalis)果实和种子形态变异的影响,分别从植株的不同方位和冠层采集果实、种子,并测定其形态指标。结果表明,方位对厚朴果实和种子的形态变异影响显著,不同方位厚朴果实和种子的表型性状表现为南方位和东方位优于西方位,南、东和西3个方位均优于北方位;冠层对厚朴果实和种子的形态变异影响显著,不同冠层果实和种子性状表现为中冠层优于上冠层,上冠层优于下冠层;方位和冠层对厚朴果实和种子多项形态指标的协同作用不显著。与果实相比,种子的表型性状更稳定。     

重庆市蔬菜基地土壤中重金属含量及污染特征

重庆市蔬菜基地土壤中重金属的平均含量分别为Hg0.185mg/kg．CdO.231mg/kg.Pb21.09mg/kg.As.As7.03mg/kg,Cr47.92mg/kg;部分基地的土壤受到污染．主要污染物为Hg和Cd。由于城市区划的不同,土壤污染程度为近郊区＞工矿区＞远郊区。     

How the diversity of human concepts of nature affects conservation of biodiversity

Protecting nature has become a global concern. However, the very idea of nature is problematic. We examined the etymological and semantic diversity of the word used to translate nature in a conservation context in 76 of the primary languages of the world to identify the different relationships between humankind and nature. Surprisingly, the number of morphemes (distinct etymological roots) used by 7 billion people was low. Different linguistic superfamilies shared the same etymon across large cultural areas that correlate with the distribution of major religions. However, we found large differences in etymological meanings among these words, echoing the semantic differences and historical ambiguity of the contemporary European concept of nature. The principal current Western meaning of nature in environmental public policy, conservation science, and environmental ethics–that which is not a human artifact–appears to be relatively rare and recent and to contradict the vision of nature in most other cultures, including those of pre-Christian Europe. To avoid implicit cultural bias and hegemony–and thus to be globally intelligible and effective–it behooves nature conservationists to take into account this semantic diversity when proposing conservation policies and implementing conservation practices.     

我国农田土壤碳氮耦合特征的区域差异

利用中国第2次土壤普查数据,分析了稻作和旱作方式下农田耕层土壤有机碳和全氮特征及其区域差异。结果表明,水田土壤有机碳和全氮含量分别为旱地的147.8%和145.5%,但水田碳氮含量的区域变异低于旱地。全国水田和旱地土壤有机碳氮比值分别为10.8和9.9,各区域水田土壤碳氮比值普遍高于旱地,其中东北水田最高,而华东旱地和西北旱地最低。旱地碳氮比值的区域变异显著,水田则不显著。农田耕层土壤有机碳和全氮含量呈显著正相关,除华北地区外,各区域无论水田还是旱地其碳氮含量之间相关系数都超过0.8,达极显著水平。由此可见,我国农田耕层土壤有机碳和全氮含量之间存在显著耦合关系,而且不同利用方式和区域之间差异显著;相同氮水平下,水田土壤可能储存更多的有机碳。     

基于RS和GIS的嫩江下游土地沙漠化景观格局变化特征分析

以2004、2008年的MODIS数据为主要数据源,在ArcGIS 9.0、ERDAS IMAGE 9.0等软件支持下,利用FRAGSTATS软件分析土地沙漠化的景观格局变化.结果表明,研究区域沙漠化土地以轻度和中度沙漠化土地为主;各景观要素的边缘密度和斑块密度呈现一致性的减少,表明斑块形状趋向简单,景观整体破碎化程度降低,边缘效应影响减小;除水域景观外,其他景观要素的形状指数和分维数都呈现一致性的下降,表明整体景观的形状都向着简单化和稳定性方向发展,各景观要素的散布与并列指数和聚集度指数都呈现一致性的增加,反映出各要素斑块趋向大型化发展,景观整体连接度增强,破碎化程度降低,景观相互作用和空间关系增强.     

广州市饮用水中挥发性有机物的研究

饮用水中的挥发性有机化合物（VOCs）来源于水源水受到的环境污染或是在净化消毒工艺处理工程中反应产生的副产物,可对人体健康造成极大的危害。改革开放以来,广州人口和经济得到突飞猛进的发展,也带来了包括饮用水安全在内的诸多严重的社会和环境问题。虽然饮用水中VOCs的研究已经得到越来越多的重视,但是目前对广州市饮用水中挥发性有机物的研究还鲜有报道。本文在广州市中心城区选取15个不同位置的采样点进行了自来水水样采集,并利用吹扫-捕集-气相色谱-质谱（GC-MS）联用系统分析技术测定水中 VOCs 的种类和三卤甲烷的质量浓度。结果表明,广州市中心城区的自来水中VOCs有20种,以三卤甲烷（THMs）和芳香烃类为主,占了所检出的物质总量的78%以上。THMs中四种化合物（氯仿、一溴二氯甲烷、二溴一氯甲烷、溴仿）的检出率达100%,总三卤甲烷的平均质量浓度为46.46μg· L-1,最大值为53.31μg· L-1,最小值39.91μg· L-1。根据2006版国家饮用水标准,四种三卤甲烷质量浓度均低于标准限值,符合标准要求。对市面上一般的瓶装水的研究发现,瓶装水中三卤甲烷的质量浓度非常低,总三卤甲烷平均质量浓度仅为1.47μg·L-1,约是自来水中质量浓度的1/30。为了解温度及煮沸对自来水中 THMs 质量浓度的影响,本研究设计了实验进行探究。结果发现加热至沸腾过程中,THMs质量浓度随温度升高而升高,而沸腾后THMs骤降,煮沸5 min可降低水中约95%的THMs,接近瓶装水中THMs质量浓度。     

Assessment of the degree of mercury contamination of marine fish around Bonaire

Many reports indicate that the levels of mercury (Hg) contamination of marine fish in other regions are above the United States Food and Drug Administration safe limit (0.5μg/g). No such studies were conducted on fish in the Dutch Caribbean region. Local fish are significant in the diet of the people of Bonaire. Mercury accumulates through the food web and would be expected to be greatest in the top predators. Four species of fish (wahoo, mahi mahi, black fin tuna and barracuda) that are caught for human consumption and occupy top predator positions within the food web were sampled and analyzed for their degree of contamination with Hg. Mercury concentrations were analyzed using semi-quantitative kits and the results verified by a private analytical lab in South Africa. There were no significant differences between the species. Black fin tuna showed the highest Hg concentrations, wahoo and mahi mahi showed lower levels and barracuda the lowest. These levels compare favorably with data published elsewhere. Uncontrolled illegal gold mining in Brazil and Venezuela contaminates ground and river water with Hg. This ultimately reaches the Atlantic where prevailing currents bring it past the Bonaire region. Bonairean fish's Hg levels are not a concern at present, but this may change with time.     

河蚬(Corbicula fluminea)在生态毒理学研究中的应用与评价

河蚬是大型底栖双壳类生物,广泛分布于我国淡水水域。它具有个体小、分布广、来源方便、易于实验室驯养等特点,常被作为受试生物用于毒理学研究中,为评价污染物毒性作用提供有价值信息。从河蚬对各化学品的行为响应、耐受性以及生理生化指标响应三个方面详细阐述了其在生态毒理学中的研究现状。最后指出将河蚬应用于毒理学研究领域的过程中存在的待完善之处,并对其研究前景进行了展望。总结出其可用于中国淡水水质基准制定、化学品毒性评价以及生物监测领域,具有广阔的研究前景。     

小麦秸秆生物质炭对水稻产量及晚稻氮素利用率的影响

选择湖南长沙红黄泥水稻土和江西进贤红壤性水稻土为供试土壤,研究小麦秸秆制生物质炭在20、40t.hm-2施入量水平下与氮肥配施对早、晚稻产量及晚稻氮素利用率的影响。结果表明,生物质炭与氮肥配施情况下,2个试验点不同生物质炭施用量处理间早稻产量均无显著差异,但进贤试验点生物质炭施用量为20和40t.hm-2处理晚稻产量分别比未施生物质炭对照提高5.18%和7.95%,而长沙试验点3个处理间晚稻产量无显著差异。在相同氮素水平下,当生物质炭施用量为40 t.hm-2时,2个试验点土壤有机碳含量与未施生物质炭对照相比最高增幅均在55%以上;施用生物质炭可提高酸性或弱酸性土壤pH值,降低土壤容重;施用生物质炭也可显著提高水稻氮肥利用率,在40 t.hm-2施用水平下,长沙和进贤试验点水稻氮肥吸收利用率分别提高20.33和17.58百分点,进贤试验点氮肥农学效率提高39.81%。在酸性土壤中施用生物质炭可提高氮肥利用率,保持水稻产量稳定或有一定的增产效果。     

Evaluation of initiation activity of dimethylarsinic acid: Initiation potential of rat hepatocarcinogenesis

There is a dearth of data on the initiation activity of dimethylarsinic acid (DMA (V)), a major metabolite of the ubiquitous environmental and occupational carcinogen and toxicant, arsenic (As). The initiation activity of DMA (V) was investigated on rat hepatocarcinogenesis with liver being a major target organ for As-induced carcinogenicity. A total of 50 rats at 10 weeks old were randomly divided in a nine-week medium-term bioassay into four groups. Groups 1 and 2 received 200 ppm of DMA (V) in drinking water for four weeks while groups 3 and 4 drank only tap water until the sixth week when groups 1 and 3 were given 0.01% 2-acetylaminofluorene (2-AAF) in their diet for two weeks in the promotion stage. All animals were subjected to two-third partial hepatectomy (PH) at the seventh week. Quantitative analysis of glutathione S-transferase placental form (GST-P) positive foci in liver, a pre-neoplastic marker of rat hepatocarcinogenesis, demonstrated higher numbers in group 1 (DMA (V) + 2-AAF) than 3 (2-AAF alone) at foci consisting of two–four cells and 15 or a greater number of cells. The numbers of GST-P positive foci consisting of five–nine cells were significantly higher in group 1 than 3. Foci consisting of 10–14 cells were also higher but not significantly different. The GST-P positive foci were apparently similar in groups 2 and 4. Expression of total GST-P positive foci was significantly higher in group 1 compared to 2, 3 or 4. The proliferating cell nuclear antigen (PCNA) test performed to clarify the apparent trend of GST-P data revealed significantly higher PCNA index in group 1. Data indicate weak initiation potential of DMA (V) and for the first time appear to provide evidence for initiation activity in DMA (V)-induced hepatocarcinogenesis in rats.     

沼泽产甲烷能力和途径差异的机制

土壤中甲烷的形成有 2条途径 :乙酸发酵和H2 /CO2 还原。比较而言 ,乙酸发酵产甲烷的能力强于H2 /CO2 还原。在特定环境中 ,何种产甲烷途径占优势取决于底物尤其是活性有机碳含量 ,而新形成的有机碳尤为重要。活性有机碳含量丰富的沼泽 ,甲烷主要由乙酸发酵形成 ,因此产甲烷能力较强。导致沼泽产甲烷能力异同的原因就是有效底物含量差异 ,从而使不同类型沼泽环境中产甲烷菌菌种不同 ,正是底物含量的高低和由此引起的产甲烷菌菌种的不同决定了不同类型沼泽产甲烷潜能的差异     

Geochemical interpretation of cancer maps of Finland

In order to reveal possible cause-and-effect relationships and correlations between geochemical variables and the incidences of various forms of cancer, geochemical maps (soil and groundwater) and cancer maps of Finland are compared using standard methods of correlation analysis. The cancer incidence maps published by the Finnish Cancer Registry and soil and groundwater geochemical maps published by the Geological Survey of Finland, both in colour, were decoded to numerical incidence or concentration values by placing a rectangular grid of 684 evenly spaced observation points over each map representing the entire area of the mainland of Finland,i.e. the points were located at intervals of about 25 kilometres on the ground. Bivariate correlation coefficients were calculated between the variables for cancer incidence and the geochemical data matrices. As a general rule, the results show a low degree of correlation between the variables (r = 0.00 – 0.40), which suggests that the types studied of cancer are not related to the geochemical variables. There are a few possible exceptions, however, such as cancer of the colon in males and females in relation to arsenic and uranium in the soil and hardness of the groundwater, where the Spearman product-moment correlation coefficients are 0.59, 0.55 and 0.51 respectively, so that the cancer case may have a geochemical factor implicated in their aetiology, albeit very vaguely. The relatively high correlation coefficients (0.61, 0.62 and 0.63 respectively) recorded for the dependence of total cancer in females on groundwater hardness and uranium and arsenic in till must be regarded as meaningless in view of the multicausative aetiology of total cancer (all forms combined).