我国工业“三废”的环境库兹涅茨曲线实证研究

选取我国1996~2008年共13年的人均GDP与工业"三废"排放量的统计数据,借助SPSS系统软件,建立计量经济学模型,分析了工业"三废"排放量的环境库兹涅茨曲线特征及其成因。研究发现:我国工业固体废物排放量的环境库兹涅茨曲线呈现出一条递增的直线;工业废水排放量的环境库兹涅茨曲线呈现出一条"倒N型"("U型"+"倒U型")曲线;工业废气排放量环境库兹涅茨曲线近似"倒U型"曲线的左半段。也就是说,除工业废水排放量回归曲线出现拐点外,工业固体废物产生量与工业废气排放量仍处于上升期。     

初始氨氮浓度对钝顶螺旋藻生长及其去除率的影响

螺旋藻是一种经济价值很高的微藻,研究氨氮对钝顶螺旋藻生长及其去除水中氨氮效率的影响,探讨其在废水处理中的可行性具有重要意义。结果表明,以硫酸铵作为氮源时,钝顶螺旋藻的对数期一般在4～6 d,随着氨氮浓度的升高对数期略有提前。钝顶螺旋藻对硫酸氨的耐受浓度为0.5 g/L,相应的氨氮浓度为106 mg/L。培养4～6 d时氨氮浓度下降幅度最大,培养结束时氨氮去除率为67.7%～82.5%,当硫酸铵投加量为0.4 g/L时,氨氮去除率最高,达82.6%。因此,螺旋藻可用于去除废水中的氨氮,具有很好的应用前景。     

Survival and growth of transplants of laboratory raised axenic seedlings of Enhalus acoroides (L.f.) Royle and field-collected plants of Syringodium isoetifolium (Aschers.) Dandy, Thalassia hemprichii (Ehrenb.) Aschers. and Halodule pinifolia (Miki) den Hartog

Experimental transplantation investigations, using laboratory raised axenic seedlings of Enhalus acoroides and natural populations of Syringodium isoetifolium, Thalassia hemprichii and Halodule pinifolia in the Gulf of Mannar Marine Biosphere Reserve, found that the denuded seagrass ecosystem of this Gulf can effectively be restored with plug and turfs methods of seagrass transplantation. Axenically developed E. acoroides, transplanted by the staples method, established by adapting to the prevailing environmental conditions. 0% seedlings “washed ashore” when the staples method was adopted using ‘L’ shaped bamboo sticks for transplanting E. acoroides and S. isoetifolium seedlings. This suggests that the seagrass transplantation using “L” shaped bamboo sticks, as staples will be technically feasible and eco-friendly for future seagrass transplantation programmes. Substratum type, duration of low tide exposure and environmental parameters like surface water temperature and turbidity are key parameters determining the success of the transplantation attempts.     

Tug-of-war over reproduction in a cooperatively breeding cichlid

In group-living animals, dominants may suppress subordinate reproduction directly and indirectly, thereby skewing reproduction in their favour. In this study, we show experimentally that this ability (‘power’) is influenced by resource distribution and the body size difference between unrelated dominants and subordinates in the cichlid Neolamprologus pulcher. Reproduction was strongly skewed towards the dominant female, due to these females producing more and larger clutches and those clutches surviving egg eating better than those of subordinate females, but was not so when subordinates defended a patch. If breeding shelters were provided in two patches, subordinate females were more likely to exclusively defend a patch against the dominant female and breed, compared to when the same breeding resource was provided in one patch. Relatively large subordinate females were more likely to defend a patch and reproduce. Females also directly interfered with each other’s reproduction by eating the competitors’ eggs, at which dominants were more successful. Although dominant females benefited from subordinate females due to alloparental care and an increase in egg mass, they also showed costs due to reduced growth in the presence of subordinates. The results support the view that the dominant’s power to control subordinate reproduction determines reproductive partitioning, in agreement with the predictions from tug-of-war models of reproductive skew.     

十二烷基苯磺酸钠的微生物降解

从长期受十二烷基苯磺酸钠(sodiumdodecylbenzenesulfonate,SDBS)污染的土壤中,筛选到3株对SDBS降解能力很强的细菌,分别为荧光假单胞杆菌(PseudomonasfluorescensP-11)、芽孢杆菌(Bacilussp.B-24)、气单胞菌(Aeromanassp.A-2)。3株细菌均属中温细菌,最适生长温度为30℃,最适生长pH为7.0,在低浓度SDBS中生长比在高浓度中生长好。在选定的最适条件下,测定了3株菌对SDBS的降解能力,在含40mg/LSDBS的培养基上,于28℃生长72h,SDBS的降解率均超过95%,其中P-11达100%。      

Assessment of growth and stemwood quality of Scots pine on territory influenced by alkaline industrial dust

Long-term influence of alkaline dust (pH 12.3–12.7) pollution emitted over 40 years from a cement plant in Estonia was the reason of alkalisation (pH 6.7–7.9) and high concentrations of K, Ca and Mg in the soil of affected territories. Although dust emission has diminished during the last 10 years, the disbalances in nutrition substrate and their influence on the growth of trees are notable up to now. The study of morphological and physical properties of 70–80-year-old Scots pine (Pinus sylvestris L.) crown, stems and stemwood from three different air pollution zones showed serious deviations in comparison with a relatively healthy forest in an unpolluted area. The specimens from polluted trees, if compared to reference site, showed significantly smaller height growth, radial increment and width of annual rings of sapwood. In heartwood wider annual rings were found in polluted areas. In the period of heartwood formation the dust pollution level emitted from the plant was relatively modest and cement dust, which contains elements necessary for mineral nutrition of trees, may have acted as fertiliser. The moisture content in sapwood and heartwood, especially in the upper layers of stems, was lower in the polluted area than in reference site trees. Regression analysis revealed a strong dependence between latewood percentage and sapwood or heartwood in stems of Scots pine in all sample plots.     

Combined effects of lanthanum ion and acid rain on growth, photosynthesis and chloroplast ultrastructure in soybean seedlings

Rare earth elements (REEs) have been accumulated in the agricultural environment. Acid rain is a serious environmental issue. In the present work, the effects of lanthanum ion (La³⁺) and acid rain on the growth, photosynthesis and chloroplast ultrastructure in soybean seedlings were investigated using the gas exchange measurements system, chlorophyll fluorometer, transmission electron microscopy and some biochemical techniques. It was found that although the growth and photosynthesis of soybean seedlings treated with the low concentration of La³⁺ was improved, the growth and photosynthesis of soybean seedlings were obviously inhibited in the combined treatment with the low concentration of La³⁺ and acid rain. At the same time, the chloroplast ultrastructure in the cell of soybean seedlings was destroyed. Under the combined treatment with the high concentration of La³⁺ and acid rain, the chloroplast ultrastructure in the cell of soybean seedlings was seriously destroyed, and the growth and of photosynthesis were greatly decreased compared with those of the control, the single treatment with the high concentration of La³⁺ and the single treatment with acid rain, respectively. The degree of decrease and destruction on chloroplast ultrastructure depended on the increases in the concentration of La³⁺ and acid rain (H⁺). In conclusion, the combined pollution of La³⁺ and acid rain obviously destroyed the chloroplast ultrastructure of cell and aggravated the harmful effect of the single La³⁺ and acid rain on soybean seedlings. As a new combined pollutant, the harmful effect of REEs ions and acid rain on plant should be paid attention to.     

Effects of sub-lethal glyphosate concentrations on growth and photosynthetic performance of non-target species Bolboschoenus maritimus

Glyphosate use has increased over the last decades for the control of invasive plant species in wetland ecosystems. Although glyphosate has been considered ‘environmentally’ safe, its repeated use could increase the toxicological risk derived from diffuse pollution of surface and groundwater on non-target vegetation. A glasshouse study was designed to determine the effect produced by the addition of different sub-lethal doses of glyphosate herbicides (5–30 mg L⁻¹) to the nutrient solution on the growth and photosynthetic apparatus of Bolboschoenus maritimus. Although B. maritimus plants were able to grow and survive after 20 d of exposure to glyphosate, the presence of this herbicide affected their growth, through a direct interaction with the root system. Particularly, at 30 mg L⁻¹ glyphosate, B. maritimus showed ca. 30% of biomass decrease. The reduction in B. maritimus growth was due to a decrease in net photosynthetic rate (A), which ranged between values ca. 11.5 and 5.5 μmol m⁻² s⁻¹ CO₂ for the control and the highest glyphosate treatment, respectively. The response of A to glyphosate could be largely accounted for by non-stomatal limitations, since stomatal conductance was similar in all glyphosate treatments. Thus, A decrease was prompted by the negative impact of herbicide on photochemical (PSII) apparatus, the reduction in the absorption of essential nutrients, the reduction of photosynthetic pigments and possibly the reduction in Rubisco carboxilation capacity. Moreover, glyphosate excess caused photoinhibitory damage. In conclusion, in this study we have shown that herbicide water pollution could be a source of indirect phytotoxicity for B. maritimus.     

The Combination of Zinc Compounds and Acidic pH Limits Aerobic Growth of a Salmonella typhimurium Poultry Marker Strain in Rich and Minimal Media

Abstract

The objective of the present study was to examine the combined effects of zinc compounds with different acidic pH levels on the aerobic growth of a S. typhimurium poultry isolate in either rich or minimal media. When overall main effects of pH levels of medium or concentrations of Zn compounds were compared, growth rates of the S. typhimurium poultry isolate were significantly ( p < 0.05) decreased by stepwise increase of pH levels of medium (pH 4, 5, 6, and 7) or concentrations (0.67, 3.35, and 6.03%) of Zn compounds (Zn acetate and Zn sulfate). In general growth rates of S. typhimurium poultry isolate appeared to be more reduced by Zn acetate than by Zn sulfate and more reduced in minimal media compared to rich media.     

Slow growth of Empetrum nigrum in industrial barrens: combined effect of pollution and age of extant plants

We studied the impact of industrial pollution on population demography (age structure), growth and reproduction of crowberry, Empetrum nigrum L. Crowberry growing in severely polluted sites near non-ferrous smelters (at Harjavalta, Monchegorsk and Nikel) was on average twice as old as in unpolluted habitats, as indicated by the number of annual rings at root collar. Shoot length decreased both with plant ageing and due to pollution impact, while neither the proportion of generative plants nor berry production was affected by pollution or plant age. Our results suggest that death of the extant individuals of E. nigrum near the non-ferrous smelters is to a large extent explained by age-related damage of the main stem accelerated by pollution. Since vegetative propagation, seed germination and seedling establishment are hampered by soil toxicity, E. nigrum populations near the smelters continue to decline with ageing in spite of the gradual decline of emissions.