Reproduction of the Siberian spruce in the timberline ecotone of the Iremel’ Massif

Quantitative and qualitative characteristics of cones and seeds and the emergence and survival of seedlings in the Siberian spruce (Picea obovata Ledeb.) were studied in different parts of the timberline ecotone on the Iremel’ Massif, the Southern Urals, from 2003 to 2006. In the productive year 2003, a decrease in the number of cones (from 110000 to 3000 per hectare), the yield of seeds (from 13 × 10⁶ to 0.09 × 10⁶ per hectare), and their laboratory germination rate (from 34 to 14%) with an increase in elevation above sea level was recorded. In 2004, significant differences in the number of seedlings per hectare were revealed between the lower, middle, and upper parts of the ecotone (85 200, 19 800, and 0–400 ind., respectively). It has been shown that the greater part of seedlings (76–96%) perish during the first cold period. New generations of spruce trees are formed only after productive years. Seed production and seedling mortality in spruce apparently depend not only on air temperature and soil moistening but also on snow depth and soil temperature, which change more abruptly along the altitudinal gradient.     

Modeling the Effects of Potential Salinity Shifts on the Recovery of Striped Bass in the Savannah River Estuary,Georgia–South Carolina,United States

Increased salinity in spawning and nursery grounds in the Savannah River estuary was cited as the primary cause of a 97% decrease in adult striped bass (Morone saxatilis) and a concomitant 96% decrease in striped bass egg production. Restoration efforts focused on environmental remediation and stock enhancement have resulted in restored salinity patterns and increased egg and adult abundances. However, future water needs or harbor development may preclude further recovery by reducing freshwater inflow or increasing salinity intrusion. To assess the effect of potential changes in the salinity regime, we developed models relating discharge, tidal phase, and salinity to striped bass egg and early larval survival and re-cast these in a quantitative Bayesian belief network. The model indicated that a small upstream shift (≤1.67 km) in the salinity regime would have the least impact on striped bass early life history survival, whereas shifts >1.67 km would have progressively larger impacts, with a 8.33-km shift potentially reducing our estimated survival probability by >28%. Such an impact could have cumulative and long-term detrimental effects on the recovery of the Savannah River striped bass population. The available salinity data were collected during average and low flows, so our model represents some typical and some extreme conditions during a striped bass spawning season. Our model is a relatively simplistic, “first-order” attempt at evaluating potential effects of changes in the Savannah River estuarine salinity regime and points to areas of concern and potential future research.     

Using Mediterranean shrubs for the phytoremediation of a soil impacted by pyritic wastes in Southern Spain: a field experiment

Re-vegetation is the main aim of ecological restoration projects, and in Mediterranean environments native plants are desirable to achieve successful restoration. In 1998, the burst of a tailings dam flooded the Guadiamar river valley downstream from Aznalcóllar (Southern Spain) with sludges that contained elevated concentrations of metals and metalloids, polluting soils and waters. A phytoremediation experiment to assess the potential use of native shrub species for the restoration of soils affected by the spillage was performed from 2005 to 2007, with soils divided into two groups: pH < 5 and pH > 5. Four native shrubs (Myrtus communis, Retama sphaerocarpa, Rosmarinus officinalis and Tamarix gallica) were planted and left to grow without intervention. Trace element concentrations in soils and plants, their extractability in soils, transfer factors and plant survival were used to identify the most-interesting species for phytoremediation. Total As was higher in soils with pH < 5. Ammonium sulphate-extractable zinc, copper, cadmium and aluminium concentrations were higher in very-acid soils, but arsenic was extracted more efficiently when soil pH was >5. Unlike As, which was either fixed by Fe oxides or retained as sulphide, the extractable metals showed significant relationships with the corresponding total soil metal concentration and inverse relationships with soil pH. T. gallica, R. officinalis and R. sphaerocarpa survived better in soils with pH > 5, while M. communis had better survival at pH < 5. R. sphaerocarpa showed the highest survival (30%) in all soils. Trace element transfer from soil to harvestable parts was low for all species and elements, and some species may have been able to decrease trace element availability in the soil. Our results suggest that R. sphaerocarpa is an adequate plant species for phytostabilising these soils, although more research is needed to address the self-sustainability of this remediation technique and the associated environmental changes.     

ClO2和碳水化合物水平对中国明对虾存活和生长的影响

研究了盐度为5条件下,ClO2和碳水化合物水平对中国明对虾(Fenneropenaeus chinensis)存活和生长的影响,共两个实验:实验1研究了ClO2(0、1、4、7、10、13、16、19和22 mg/L)对中国明对虾存活的影响,发现随ClO2浓度的升高,对虾存活率呈下降趋势;在24、48、72和96 h,LC50分别为21.04、13.32、10.91和8.26 mg/L,安全浓度为1.60 mg/L.实验2研究了ClO2(0.0、0.2、0.4和0.6 mg/L)和饲料中碳水化合物水平(13.89和41.76%)对中国明对虾存活和生长的影响,发现在两个碳水化合物水平,随ClO2浓度的升高,对虾存活率、特定生长率、摄食量和吸收效率均呈下降趋势,而饲料系数呈上升趋势;在四个ClO2水平,摄食13.89%碳水化合物对虾的特定生长率、摄食量和吸收效率均高于摄食41.76%碳水化合物的对虾,而摄食13.89%碳水化合物对虾的饲料系数低于摄食41.76%碳水化合物的对虾.     

Toxicity assessing for chlorpyrifos-contaminated soil with three different earthworm test methods

Earthworm toxicity tests are useful tools for terrestrial risk assessment but require a hierarchy of test designs that differ in effect levels (behavior, sublethal, lethal). In this study, the toxicity of chlorpyrifos contaminated soil on earthworms was assessed. In addition to the acute and chronic tests, an avoidance response test was applied. Earthworms were exposed to sublethal and lethal concentration of chlorpyrifos, and evaluated for acute toxicity, growth, fecundity and avoidance response after a certain exposure period. The test methods covered all important ecological relevant endpoints (acute, chronic, behavioral). Concentration of 78.91 mg/kg, chlorpyrifos caused significant toxic effects in all test methods, but at lower test concentrations, only significant chronic toxic effects could be observed. In the present study, chlorpyrifos had adverse effect on growth and fecundity in earthworm exposed to 5 mg/kg chlorpyrifos after eight weeks. The avoidance response test, however, showed significant repellent effects concentration of 40 mg/kg chlorpyrifos. For chlorpyrifos, concentration affecting avoidance response was far greater than growth and fecundity, it seemed likely that earthworms were not able to escape from pesticide-contaminated soil into the clean soil in field and hence were exposed continuously to elevated concentrations of pesticides.     

葫芦岛市沿海潮间带无脊椎生物生存状况调查

对葫芦岛市沿海潮间带常见无脊椎生物的种类、种群密度和生物量进行了调查分析，采用生物多样性指数和均匀度指数两项指标对近岸海域环境进行了评价。研究了环境污染对沿海潮间带常见无脊椎生物生存状况的影响，并根据当地情况提出了保护水质的建议。     

Application of compost in agricultural practice could potentially cause contamination of foodstuffs with pathogenic bacteria such as Escherichia coli O157:H7. This study investigated pathogenic bacteria in compost collected from the compost facilities, an

IntroductionIncreasing public interests have been concerned onsafety foods and the environmental aspects recently,especially on the so-called organic foods , which are madefromcrops grown with organic fertilizers or compost but notchemical fertilizers .Pu…     

丝栗栲种群生命过程及谱分析

以种群生命表及生存分析理论为基础，编制丝栗栲种群静态生命表，绘制存活曲线，死亡率曲线，亏损度曲线，死亡密度函数曲线。积累死亡函数曲线和危险率函数曲线，分析种群生命过程。结果表明，丝栗栲有2个死亡高峰，存活曲线趋于Deevey-Ⅱ型。并应用谱分析方法研究丝栗栲种群动态，结果表明，在丝栗栲种群自然更新过程中存在着明显的周期性。     

柠檬醛对赤子爱胜蚓(Eisenia fetida)再生的影响

用不同浓度柠檬醛处理不同部位剪切的蚯蚓,和处理剪切后不同时间段的蚯蚓体段,探讨了柠檬醛对赤子爱胜蚓再生作用的体段、作用浓度和敏感时间段.结果表明,柠檬醛对蚯蚓再生有明显影响,但这种作用依不同体段而异,以体段P7和P25作用最显著,而A25,A90和P60的受柠檬醛影响较小; 柠檬醛影响蚯蚓头部再生,而不影响尾部再生;对再生有影响的柠檬醛浓度为1mmolkg-1, 0. 1mmolkg-1和0. 01mmolkg-1 (土壤),对蚯蚓再生作用的时间为切后0. 5~1d.试验显示,柠檬醛干扰蚯蚓再生头部形成而且还影响再生头尾体轴形成;内源视黄酸在蚯蚓头尾轴再生图式形成中有重要作用. 图4表4参18     

土壤水分对沙棘成活率及抗逆生理特性的影响

为提高沙棘在滩涂区，半干旱区造林的成活率，对不同土壤水分下沙棘的生理学特性进行了分析。结果表明：（1）在不同土壤水分处理下，随土壤含水量降低及处理时间的延长，沙棘叶片脯氨酸（Pro)含量升高，POD活性增强，可溶性糖含量升高；水淹情况下，沙棘叶片Pro含量明显上升，POD活性增强，可溶性糖含量升高。（2）土壤含水量在15%-30%之间，沙棘苗木成活率最高（100%），生长最好；35%和40%处理下，沙棘苗木成活率较高（66.7%)，生长良好；5%，10%处理水平和水淹情况下，沙棘苗木成活率低（33.3%)，生长不良，（3）不同处理下，随土壤含水量的降低，沙棘叶片的相对电导度增大，沙棘受伤害的程度加剧，且淹水对沙棘的伤害最重。