Incipient Forest Decline in the Province of Trento (Northern Italy). Preliminary Sem Observations and Consideration of Inorganic Components of Leaves and Roots

One year old needles of both healthy and damaged silver fir and Norway spruce from the area of Trento (Northern Italy) were observed by SEM. Needles of damaged trees show quite evident structural alterations of epidermis, expecially epicuticular waxes. Roots and needles of both fir and spruce are also tested for their metal content. Evidence is reported of an increasing concentration of Fe, Mg and Ca in roots of plants grown on alkali soil. Ca, and to a lesser extent Fe, Al and Pb, appears to be more present in old needles, whereas K and Mg exhibit higher amounts in young needles. Some indications are found between damage and the content of some metals such as Mg and Mn in needles.     

The Nutrient Status of Some Graminaceous Species in Britain. 2. Deschampsia Flexuosa (L.) Trin

Above-ground biomass of Deschampsia flexuosa from 40 sites throughout Britain was analysed for concentrations of elements (N, P, K, Ca, Mg, Fe, Mn, Cu, Zn and Na), with matching analyses of nutrient levels in the soils, together with pH and LOI. Seasonal variation in the nutrients was also studied in detail at one of the sites. the grass was found on acid sites ranging between pH 3.1 and 4.7. the soil humus content varied widely, and there were significant correlations between that and elements (N, P, K, Ca, Mg, Zn and Na) in the soil. Concentrations of zinc and manganese in the plant material were the only elements that significantly correlated with extractable levels in the soils. Tissue concentrations of nitrogen, phosphorus, and potassium declined throughout the growing season, whereas the other elements showed a tendency to build up until the end of September. Calcium, magnesium and manganese concentrations then declined as growth ceased. the results are compared with above-ground concentrations of minerals in other plants and the growth strategy of this perennial grass.     

化工行业中小企业安全生产现状与对策——以江苏省某市为例

随着国民经济的不断发展,化工行业中小企业呈现出较强的增长势头,安全生产出现了许多新问题.通过对江苏省某市化工行业中小企业的全面调查和典型企业重点调研,对其安全生产基础状况、安全资金投入状况和事故发生情况进行了分析,并针对存在的具体问题,提出了进一步加强化工行业中小企业安全管理的对策建议.     

The Need to Rationalize and Prioritize Threatening Processes Used to Determine Threat Status in the IUCN Red List

Abstract: Thorough evaluation has made the International Union for Conservation of Nature (IUCN) Red List the most widely used and accepted authority on the conservation status of biodiversity. Although the system used to determine risk of extinction is rigorously and objectively applied, the list of threatening processes affecting a species is far more subjectively determined and has not had adequate review. I reviewed the threats listed in the IUCN Red List for randomly selected groups within the three most threatened orders of mammals: Artiodactyla, Carnivora, and Primates. These groups are taxonomically related and often ecologically similar, so I expected they would suffer relatively similar threats. Hominoid primates and all other terrestrial fauna faced similar threats, except for bovine artiodactyls and large, predatory carnivores, which faced significantly different threats. Although the status of bovines and hominoids and the number of threats affecting them were correlated, this was not the case for large carnivores. Most notable, however, was the great variation in the threats affecting individual members of each group. For example, the endangered European bison (Bison bonasus) has no threatening processes listed for it, and the lion (Panthera leo) is the only large predator listed as threatened with extinction by civil war. Some threatening processes appear spurious for the conservation of the species, whereas other seemingly important factors are not recorded as threats. The subjective nature of listing threatening processes, via expert opinion, results in substantial biases that may be allayed by independent peer review, use of technical manuals, consensus among multiple assessors, incorporation of probability modeling via decision‐tree analysis, and adequate coordination among evaluators. The primary focus should be on species‐level threats rather than population‐level threats because the IUCN Red List is a global assessment and smaller‐scale threats are more appropriate for national status assessments. Until conservationists agree on the threats affecting species and their relative importance, conservation action and success will be hampered by scattering scarce resources too widely and often by implementing conflicting strategies.     

湖北省工业污染现状分析及防治对策

对湖北省工业污染排放现状进行了评价,提出了污染防治对策。     

Physiological and Morphological Response Patterns of <Emphasis Type="Italic">Populus deltoides</Emphasis> to Alluvial Groundwater Pumping

We examined the physiological and morphological response patterns of plains cottonwood [Populus deltoides subsp. monilifera (Aiton) Eck.] to acute water stress imposed by groundwater pumping. Between 3 and 27 July 1996, four large pumps were used to withdraw alluvial groundwater from a cottonwood forest along the South Platte River, near Denver, Colorado, USA. The study was designed as a stand-level, split-plot experiment with factorial treatments including two soil types (a gravel soil and a loam topsoil over gravel), two water table drawdown depths (∼0.5 m and >1.0 m), and one water table control (no drawdown) per soil type. Measurements of water table depth, soil water potential (Ψ_s), predawn and midday shoot water potential (Ψ_pd and Ψ_md), and D/H (deuterium/hydrogen) ratios of different water sources were made in each of six 600-m² plots prior to, during, and immediately following pumping. Two additional plots were established and measured to examine the extent to which surface irrigation could be used to mitigate the effects of deep drawdown on P. deltoides for each soil type. Recovery of tree water status following pumping was evaluated by measuring stomatal conductance (g _s ) and xylem water potential (Ψ_xp) on approximately hourly time steps from before dawn to mid-afternoon on 11 August 1996 in watered and unwatered, deep-drawdown plots on gravel soils. P. deltoides responded to abrupt alluvial water table decline with decreased shoot water potential followed by leaf mortality. Ψ_pd and percent leaf loss were significantly related to the magnitude of water table declines. The onset and course of these responses were influenced by short-term variability in surface and ground water levels, acting in concert with physiological and morphological adjustments. Decreases in Ψ_pd corresponded with increases in Ψ_md, suggesting shoot water status improved in response to stomatal closure and crown dieback. Crown dieback caused by xylem cavitation likely occurred when Ψ_pd reached −0.4 to −0.8 MPa. The application of surface irrigation allowed trees to maintain favorable water status with little or no apparent cavitation, even in deep-drawdown plots. Two weeks after the partial canopy dieback and cessation of pumping, g _s and Ψ_xp measurements indicated that water stress persisted in unwatered P. deltoides in deep-drawdown plots.     

Physiological Rearrangements in the Progeny of White Rats in the Zone of the Chernobyl Accident

Studies on six generations of white rats kept at the experimental station in Chernobyl showed that the dynamics of hormonal rearrangements and endocrine responses evoked by additional stress (hypokinesia) were generation- and sex-dependent. The male rats of the first five generations were characterized by hypercorticoidism, early involutional shifts, and decreased reactivity in response to hypokinesia. By the sixth and seventh generations, the hormonal profiles shifted toward an increase in the background level of sex hormones and their role in the response to hypokinesia. In female rats, the hormonal indices and reactivity changed less significantly.     

环境慢性镉危害早期判断标准的研究──沈阳张士灌区妇女的慢性镉危害

本文根据张士灌区镉的环境污染对居民健康影响的多年研究，提出了镉的内、外暴露水平和对人群肾小管损伤的＂临界值＂以及镉与尿低分子蛋白等多项生化指标的健康效应关系，并通过超＂临界值＂频率和接触归因危险性评价提出了环境慢性镉危害早期判断标准的初步建议．     

藻类爆发危害及其控制技术研究进展

在简要介绍国内外富营养化现状的基础上,阐述了水域中藻类爆发及伴随藻毒素带来的各种危害;分别对水源水控藻除藻技术(限制营养盐控藻、直接除藻灭藻、生物技术与生态工程)和水厂水中控藻除藻技术(预氧化、混凝沉淀、膜滤、直接过滤、气浮、联合处理工艺)的国内外研究现状和应用动态进行了全面评述;指出了各种工艺技术中存在的问题。为今后实现含藻水的标本兼治及有效控藻除藻提供技术借鉴。     

城镇化对四川盆地丘陵区生态环境的影响研究——以南充市为例

通过寻访调查,信息收集、文献查阅等形式对南充市城镇化进程中生态环境现状进行调查,阐述了城镇化进程中存在的环境问题,包括面源污染、大气污染、水污染和噪声污染,总结了南充市生态环境保护已取得的工作进展.为此,从环保意识、资金、规划、产业、政策与法制、科技等方面提出了南充城镇化与生态环境协调发展的途径.