单甲脒农药对草型塘模型生态系统影响的初步研究

在室外中等规模草型塘模型生态系统（Ｖ＝３ｍ＾３）中，实验研究了国产新农药单甲脒盐酸盐水剂对池塘生态系统结构与功能的影响，在１２．５、２５．０和５０．０ｍｇ／Ｌ的农药浓度下１周左右，大型水生植物，浮游植物，浮游动物，底栖动物均受到不同程度的损伤的破坏，种类，密度，多样性指数下降，高浓度组中浮游生物全部消亡；水层中的好氧异养菌数量则明显增加，单甲脒浓度越高异养菌数量加越多，与此同时，群落产氧量减少，呼     

酚类环境雌激素对水生生物毒性效应的研究进展

已有研究发现多种酚类化合物可以干扰水生生物正常内分泌代谢,对生物生殖系统、神经系统、免疫系统等产生毒性效应,进而通过食物链的生物放大作用对人体产生危害。酚类化合物对生物体的内分泌干扰效应已经成为了近年来的研究热点。结合近年来国内外毒理学研究进展,在详细概述酚类化合物对水生生物的毒性效应及作用机制的基础上,并对目前研究中存在的问题以及未来的研究方向进行了探讨和展望。     

基于混合效应模型的京津冀地区PM2.5日浓度估算

利用2016年182d的MODIS 3km AOD数据与地面监测数据,评估了混合效应模型不同参数组合的模拟性能,得出模型在解释AOD-PM_2.5关系时,对时间序列变异的解释能力要比空间差异更佳.在此基础上,利用混合效应模型建立京津冀地区每日的AOD-PM_2.5关系,模型拟合R²为0.92,交叉验证调整R²为0.85,均方根误差（RMSE）为12.30 μg/m³,平均绝对误差（MAE）为9.73 μg/m³,说明模型拟合精度较高.基于此模型估算的2016年京津冀地区年均PM_2.5浓度为42.98 μg/m³,暖季（4月1日~10月31日）为43.35 μg/m³,冷季（11月1日~3月31日）为38.52 μg/m³,与同时期的地面监测数据差值分别为0.59,0.7,5.29 μg/m³.空间上,京津冀地区的PM_2.5浓度呈现南高北低的特征,有一条明显的西南-东北走向的高值区.研究结果表明,基于每日混合效应模型可以准确评估京津冀地区的地面PM_2.5浓度,且模型估算的PM_2.5浓度分布状况为区域大气污染防治提供了基础的数据支撑.     

Phytotoxicity of cadmium on protein, proline and antioxidant enzyme activities in growing Arachis hypogaea L. seedlings

Phytotoxicity of cadmium on growing Arachis hypogaea L. seedlings was studied. Seeds were exposed to 25, 50, and 100 μmol/L CdCl2 concentrations, for a period of 10, 15, 20 and 25 d. The extent of damage to chlorophyll, protein, proline, nitrate and nitrite reductase, antioxidant enzyme activity in leaves and roots were evaluated after 10 d of cadmium stress. The higher concentration of cadmium （100 μmol/L） resulted （leaves and roots） total chlorophyll 91.01%, protein 79.51%, 83.61%, nitrate reductase 79.39%, 80.72% and nitrite reductase 77.07%, 75.88% activity decreased with increase in cadmium concentrations and exposure periods. Cadmium caused significant changes in the activity of antioxidative enzymes. Contrastingly Cd treated plant tissues showed an increase in proline 159.87%, 239.6%, gluthion reductase （GR） 337.72%, 306.14%, superoxide disumutase （SOD） 688.56%, 381.72%, ascorbate peroxidase （APX） 226.47%, 252.14%, peroxidase （POD） 72.19%, 60.29% and catalase （CAT） 228.96%, 214.74% as compared to control. Cadmium stress caused a significant increase in the rate of SOD activity in leaves and roots of plant species. Results show the crop A. hypogaea is highly sensitive even at very low cadmium concentrations.     

Critical factors for the recovery of marine mammals

{en} Over the past decades, much research has focused on understanding the critical factors for marine extinctions with the aim of preventing further species losses in the oceans. Although conservation and management strategies are enabling several species and populations to recover, others remain at low abundance levels or continue to decline. To understand these discrepancies, we used a published database on abundance trends of 137 populations of marine mammals worldwide and compiled data on 28 potentially critical factors for recovery. We then applied random forests and additive mixed models to determine which intrinsic and extrinsic factors are critical for the recovery of marine mammals. A mix of life‐history characteristics, ecological traits, phylogenetic relatedness, population size, geographic range, human impacts, and management efforts explained why populations recovered or not. Consistently, species with lower age at maturity and intermediate habitat area were more likely to recover, which is consistent with life‐history and ecological theory. Body size, trophic level, social interactions, dominant habitat, ocean basin, and habitat disturbance also explained some differences in recovery patterns. Overall, a variety of intrinsic and extrinsic factors were important for species’ recovery, pointing to cumulative effects. Our results provide insight for improving conservation and management strategies to enhance recoveries in the future.     

空气中超细颗粒物检测方法的研究进展

颗粒物的健康损害效应已得到广泛的关注。尤其近年来,国内外学者们针对PM2.5等大颗粒开展了大量的人群流行病学和毒理学研究,健康损害效应的因果关系得到基本确认。然而比PM2.5粒径更小但数量更多的超细颗粒物(UFPs),其暴露特征及对健康影响的贡献值尚不清楚,缺乏统一的检测方法及策略是影响其健康评估的关键因素。因此,本文根据国内外文献,综述了目前超细颗粒物的检测方法、仪器及策略,总结了超细颗粒物评价方法的影响因素及其存在的不足,为超细颗粒物检测方法的进一步研究提供建议和帮助。     

Exploration of relationships between phytoplankton biomass and related environmental variables using multivariate statistic analysis in a eutrophic shallow lake： A S-year study

Understanding the process of the changing phytoplankton patterns can be particularly useful in water quality improvement and management decisions. However, it is generally not easy to illustrate the interactions between phytoplankton biomass and related environmental variables given their high spatial and temporal heterogeneity. To elucidate relationships between them, in a eutrophic shallow lake, Taihu Lake, relative long-term data set of biotic and abiotic parameters of water quality in the lake were conducted using multivariate statistical analysis within seasonal periodicity. The results indicate that water temperature and total phosphorus （TP） played governing roles in phytoplankton dynamics in most seasons （i.e. temperature in winter, spring and summer; TP in spring, summer and autumn）; COD （chemical oxygen demand） and BOD （biological oxygen demand） presented significant positive relationships with phytoplankton biomass in spring, summer and autumn. However, a complex interplay was found between phytoplankton biomass and nitrogen considering significant positive relationships occurring between them in spring and autumn, and conversely negative ones in summer. As the predatory factor, zooplankton presented significant grazing-pressure on phytoplankton biomass during summer in view of negative relationship between them in the season. Significant feedback effects of phytoplankton development were identified in summer and autumn in view that significant relationships were obser,qed between phytoplankton biomass and pH, Trans （transparency of water） and DO. The results indicate that interactions between phyto：plankton biomass and related environmental variables are highly sensitive to seasonal periodicity, which improves understanding of different roles of biotic and abiotic variables upon phytoplankton variability, and hence, advances management methods for eutrophic lakes.     

缘管浒苔对利玛原甲藻生长的克生作用

研究了缘管浒苔(Ulva linza)新鲜组织、干粉末、培养水过滤液和抽提液对利玛原甲藻(Prorocentrum lima)生长的克生效应。试验结果表明,缘管浒苔新鲜组织和干粉末对利玛原甲藻均有强烈的克生作用。利玛原甲藻以半连续培养法在缘管浒苔培养水过滤液中的生长受到明显抑制;以一次性培养法在缘管浒苔培养水过滤液中的生长未受到明显抑制;而煮沸的培养水过滤液对利玛原甲藻的生长无抑制作用。这表明,克生效应的产生需要克生物质的连续分泌,且克生物质在高温中易被分解。抽提液的克生作用表现为:甲醇抽提液大于水溶性抽提液大于氯仿抽提液,这表明缘管浒苔组织内的生长抑制活性物质具有相对较高的极性。     

Two-dimensional numerical and eco-toxicological modeling of chemical spills

The effects of chemical spills on aquatic nontarget organisms were evaluated in this study. Based on a review of three types of current eco-toxicological models of chemicals, i.e., ACQUATOX model of the US-EPA, Hudson River Model of PCBs, and critical body residual (CBR) model and dynamic energy budget (DEBtox) model, this paper presents an uncoupled numerical ecotoxicological model. The transport and transformation of spilled chemicals were simulated by a chemical transport model (including flow and sediment transport), and the mortalities of an organism caused by the chemicals were simulated by the extended threshold damage model, separately. Due to extreme scarcity of data, this model was applied to two hypothetical cases of chemical spills happening upstream of a lake. Theoretical analysis and simulated results indicated that this model is capable of reasonably predicting the acute effects of chemical spills on aquatic ecosystems or organism killings.     

云南省凤眼莲入侵现状及其引种得失分析

大规模外来种的引入是生物多样性下降主要原因之一,外来种的入侵已经引起了一系列的生态、经济、社会问题。从云南省凤眼莲入侵的现状,分析了入侵植物风眼莲引种的得失。对于风眼莲的控制及其治理主要有物理、化学以及生物方法,认为目前对风眼莲等入侵生物应采取综合治理的方法。同时引进植物外来种时,要对引进种的行为特性进行调查研究,注意其安全性。