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1.
镉和铁及其交互作用对植物生长的影响   总被引:19,自引:2,他引:19  
镉是植物的非必需元素,而铁是植物生长发育过程中必不可少的元素。虽然这两种元素对植物的作用是截然相反的,但是它们在植物体内存在着交互作用关系,相互影响着对方功能的发挥。供给植物足够的铁可极大地缓解植物的镉污染毒害,利于植物合成更多的叶绿素,促进光合作用进行,降低镉对氨基酸、蛋白质合成以及酶活性的影响。相反,镉污染将诱导植物的铁营养缺乏。渍水植物根表形成的铁氧化物胶膜可促进植物对镉的吸收。  相似文献   

2.
This article presents a short overview of selected recent papers using nuclear magnetic resonance (NMR) to investigate interactions between organic pollutants and soil components such as organic matter, clays, whole soils, and sediments. First, we describe solid state cross polarisation magic angle spinning (CP-MAS) experiments as the main tools to investigate covalent bonds. Second, we report NMR approaches allowing us to assess molecule mobility and to characterise non-covalent interactions. Those approaches include correlations between K oc values and soil organic matter functions determined by CP-MAS, 2H NMR fingerprints, relaxation time measurements, 19F and 1H high resolution (HR)-MAS experiments.  相似文献   

3.

Environmental and ecological degradation can be monitored by biological indicators such as plants, yet little research has been done using subterranean organisms such as collembola, especially in cities. Collembola, a soil fauna group, can be used to assess soil quality and to decipher assembly rules of soil organisms in cities. Here, we review 75 articles on soil collembola in an urban context. We found that soil properties and landscape characteristics influenced soil communities. There is a need for more connectivity between green urban spaces to allow the dispersion of collembola. Little information is available on the assembly of collembola communities, on biotic interactions and on dynamics of colonisation.

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4.
It is increasingly recognised that interactions between geomorphological and biotic processes control the functioning of many ecosystem types as described e.g. by the ecological theory of ecosystem engineering. Consequently, the need for specific bio-geomorphological research methods is growing recently. Much research on bio-geomorphological processes is done in coastal marshes. These areas provide clear examples of ecosystem engineering as well as other bio-geomorphological processes: Marsh vegetation slows down tidal currents and hence stimulates the process of sedimentation, while vice versa, the sedimentation controls ecological processes like vegetation succession. This review is meant to give insights in the various available methods to measure sedimentation, with special attention to their suitability to quantify bio-geomorphological interactions. The choice of method used to measure sedimentation is important to obtain the correct parameters to understand the biogeomorphology of tidal salt marshes. This review, therefore, aims to be a tool for decision making regarding the processes to be measured and the methods to be used. We, subdivide the methods into those measuring suspended sediment concentration (A), sediment deposition (B), accretion (C) and surface-elevation change (D). With this review, we would like to further encourage interdisciplinary studies in the fields of ecology and geomorphology.  相似文献   

5.
Uncommon heavy metals,metalloids and their plant toxicity: a review   总被引:4,自引:0,他引:4  
Heavy metals still represent a group of dangerous pollutants, to which close attention is paid. Many heavy metals are essential as important constituents of pigments and enzymes, mainly zinc, nickel and copper. However, all metals, especially cadmium, lead, mercury and copper, are toxic at high concentration because of disrupting enzyme functions, replacing essential metals in pigments or producing reactive oxygen species. The toxicity of less common heavy metals and metalloids, such as thallium, arsenic, chromium, antimony, selenium and bismuth, has been investigated. Here, we review the phytotoxicity of thallium, chromium, antimony, selenium, bismuth, and other rare heavy metals and metalloids such as tellurium, germanium, gallium, scandium, gold, platinum group metals (palladium, platinum and rhodium), technetium, tungsten, uranium, thorium, and rare earth elements yttrium and lanthanum, and the 14 lanthanides cerium, dysprosium, erbium, europium, gadolinium, holmium, lutetium, neodymium, promethium, praseodymium, samarium, terbium, thulium and ytterbium.  相似文献   

6.
In the past decade, environmental forensics has emerged as a discipline directed toward determining parties liable for causing spills of contaminants into the environment. Such investigations, while geared toward determining the guilty parties in order to recover costs of the cleanup and remediation, require various questions to be addressed. These include determination of the nature of the product; Where did it come from?; Extent of weathering, if any; How long has it been there?; and Is it degrading naturally? Traditionally, these studies have been addressed through utilization of techniques such as gas chromatography (GC) and gas chromatography–mass spectrometry (GCMS). However, in recent years, stable isotopes, primarily determined through the use of combined gas chromatography–isotope ratio mass spectrometry (GCIRMS), have emerged as an equally important tool in environmental forensics. For relatively low molecular, volatile compounds such as MTBE, BTEX, or chlorinated solvents, the isotopes, primarily carbon and hydrogen, have been used extensively for evaluating the onset of natural attenuation. For larger molecules such as PCBs or PAHs, in which the effects of biodegradation on the isotope composition of these molecules is minimal, the isotopic fingerprints of the individual compounds can be used for correlation purposes. In this paper, a brief introduction to isotope geochemistry will be given, followed by a review of applications of stable isotopes to a variety of environmental problems. While the review may not necessarily be exhaustive, it will provide a comprehensive overview of areas where isotopes have been used and potential applications for the future. Most of the review is concerned with carbon and hydrogen isotopes, although a brief overview of the emerging area of chlorine isotopes will also be discussed.  相似文献   

7.
湿地服务价值评估的复杂性及研究进展   总被引:7,自引:0,他引:7  
王建华  吕宪国 《生态环境》2007,16(3):1058-1062
湿地服务价值评估具有重要的理论意义和应用价值。由于湿地具有类型多样、分布广泛和过程复杂等特点,湿地服务价值评估极具复杂性。主要表现为:湿地科学是一门年轻的科学,其过程与功能研究有待深入;对生态系统服务及其价值认识上还存在分歧;湿地服务价值研究具有多学科交叉的特点等。近年来,国内外湿地服务价值评估发展很快,取得了丰硕的研究成果,但也存在着一些问题与不足,如对湿地研究成果的利用不够充分;评估理论和方法有待完善;评估标准和评估结果差异较大等。因此,今后湿地服务价值评估研究应该将重点放在理论探索和方法完善方面,对应用研究加强引导和规范。从湿地生态系统过程与功能的机理入手,认真研究和改进湿地服务价值评估的手段、方法和技术,使湿地服务价值评估结果更具说服力、可比性和实用性,为湿地的科学管理,生态补偿机制的制定以及社会经济可持续发展提供有力支持。  相似文献   

8.
Environmental Chemistry Letters - Nanoparticles synthesis under green conditions has been performed using natural resources to diminish the use of toxic chemicals. For instance, microbial synthesis...  相似文献   

9.
The incidence of diabetes has increased dramatically in recent decades and become one of the leading health problems worldwide. Lifestyle and dietary changes alone cannot account for the dramatic rise of diabetes, while an increasing number of publications have reported the possible relationships between exposure to environmental pollutants and risk of diabetes. In the present review, our objective was to summarize the human studies on environmental pollutants, which includes persistent organic pollutants, pesticides (not on the Stockholm Convention list), bisphenol A, and phthalates, and the risk of diabetes. Currently published results suggest a positive relationship between certain persistent organic pollutants (dichlorodiphenyldichloroethene, dichlorodiphenyltrichloroethane, hexachlorobenzene, and polychlorinated biphenyls) and bisphenol A exposure and risk of diabetes. For pyrethroids, organophosphates, carbamates, and phthalates, there are insufficient studies to reach conclusions and therefore more studies, especially prospective studies, are needed along with in vivo and in vitro studies to understand the underlying mechanisms.  相似文献   

10.
Environmental Chemistry Letters - Nanotechnology has revolutionized the field of biomedical sciences with smart approaches of imaging and treatment. This transformation has led to the development...  相似文献   

11.
多环芳烃(polycyclic aromatic hydrocarbons,PAHs)作为典型的持久性有机污染物(persistent organic pollutants,POPs)中的重要类别,具有半挥发性、生物蓄积性、长期残留性和明显的毒性(包括致癌、致畸、致突变)等特点,因此是环境中的一类重要污染物.PAHs衍...  相似文献   

12.
Dust and Sand Storms (DSS) originating in deserts in arid and semi-arid regions are events raising global public concern. An important component of atmospheric aerosols, dust aerosols play a key role in climatic and environmental changes at the regional and the global scale. Deserts and semi-deserts are the main source of dust and sand, but regions that undergo vegetation deterioration and desertification due to climate change and human activities also contribute significantly to DSS. Dust aerosols are mainly composed of dust particles with an average diameter of 2 mm, which can be transported over thousands of kilometers. Dust aerosols influence the radiation budget of the earthatmosphere system by scattering solar short-wave radiation and absorbing surface long-wave radiation. They can also change albedo and rainfall patterns because they can act as cloud condensation nuclei (CCN) or ice nuclei (IN). Dust deposition is an important source of both marine nutrients and contaminants. Dust aerosols that enter marine ecosystems after long-distance transport influence phytoplankton biomass in the oceans, and thus global climate by altering the amount of CO2 absorbed by phytoplankton. In addition, the carbonates carried by dust aerosols are an important source of carbon for the alkaline carbon pool, which can buffer atmospheric acidity and increase the alkalinity of seawater. DSS have both positive and negative impacts on human society: they can exert adverse impacts on human’s living environment, but can also contribute to the mitigation of global warming and the reduction of atmospheric acidity.
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13.
Polyphenols in plants can protect proteins from degradation and improve the efficiency of conversion of plant protein to animal protein (meat and milk), but can this be achieved in a way that is environmentally sustainable, profitable to the livestock farmer and is consistent with aspirations for improved livestock nutrition, health, welfare and product quality? Given that grazed and conserved forage is the bedrock of sustainable ruminant production, this paper attempts to consider what challenges are ahead in terms of enhancing productive efficiency, reducing the polluting footprint of livestock agriculture and alleviating the endemic parasitism that occurs with grazing animals.  相似文献   

14.
This work presents an overall introduction to the Station for Observing Regional Processes of the Earth System–SORPES in Nanjing, East China, and gives an overview about main scientific findings in studies of air pollution-weather/climate interactions obtained since 2011. The main results summarized in this paper include overall characteristics of trace gases and aerosols, chemical transformation mechanisms for secondary pollutants like O3, HONO and secondary inorganic aerosols, and the air pollution–weather/climate interactions and feedbacks in mixed air pollution plumes from sources like fossil fuel combustion, biomass burning and dust storms. The future outlook of the development plan on instrumentation, networking and data-sharing for the SORPES station is also discussed.
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15.
Cahill JF  Elle E  Smith GR  Shore BH 《Ecology》2008,89(7):1791-1801
Plants engage in diverse and intimate interactions with unrelated taxa. For example, aboveground floral visitors provide pollination services, while belowground arbuscular mycorrhizal fungi (AMF) enhance nutrient capture. Traditionally in ecology, these processes were studied in isolation, reinforcing the prevailing assumption that these above- and belowground processes were also functionally distinct. More recently, there has been a growing realization that the soil surface is not a barrier to many ecological interactions, particularly those involving plants (who live simultaneously above and below ground). Because of the potentially large impact that mycorrhizae and floral visitors can have on plant performance and community dynamics, we designed an experiment to test whether these multi-species mutualisms were interdependent under field conditions. Using benomyl, a widely used fungicide, we suppressed AMF in a native grassland, measuring plant, fungal, and floral-visitor responses after three years of fungal suppression. AMF suppression caused a shift in the community of floral visitors from large-bodied bees to small-bodied bees and flies, and reduced the total number of floral visits per flowering stem 67% across the 23 flowering species found in the plots. Fungal suppression has species-specific effects on floral visits for the six most common flowering plants in this experiment. Exploratory analyses suggest these results were due to changes in floral-visitor behavior due to altered patch-level floral display, rather than through direct effects of AMF suppression on floral morphology. Our findings indicate that AMF are an important, and overlooked, driver of floral-visitor community structure with the potential to affect pollination services. These results support the growing body of research indicating that interactions among ecological interactions can be of meaningful effect size under natural field conditions and may influence individual performance, population dynamics, and community structure.  相似文献   

16.
There are multiple lines of compelling evidence, mostly from population-based studies, supporting that green tea consumption is associated with reduced risk of several human malignancies. Epigallocatechin gallate (EGCG) is a major antioxidant present in green tea. Chemopreventive effects of EGCG have been extensively investigated and well documented. These include inhibition of metabolic activation of carcinogens and/or stimulation of their detoxification, scavenging of reactive oxygen species, induction of apoptosis or differentiation of malignant or transformed cells, suppression of tumor promotion, inhibition of angiogenesis or metastasis, etc. EGCG targets many intracellular signaling molecules and events responsible for malignant transformation or abnormal cell proliferation, and NF-κB and AP-1 appear to be two of most potential targets of EGCG in its exerting chemopreventive activities.  相似文献   

17.
Environmental Chemistry Letters - Nanoplastics are emerging contaminants of concern for living organisms and ecosystems, yet nanoplastics are difficult to extract and analyse. Once released into...  相似文献   

18.
Environmental Chemistry Letters - Climate change and the unsustainability of fossil fuels are calling for cleaner energies such as methanol as a fuel. Methanol is one of the simplest molecules for...  相似文献   

19.

Microplastic pollution is becoming a major issue for human health due to the recent discovery of microplastics in most ecosystems. Here, we review the sources, formation, occurrence, toxicity and remediation methods of microplastics. We distinguish ocean-based and land-based sources of microplastics. Microplastics have been found in biological samples such as faeces, sputum, saliva, blood and placenta. Cancer, intestinal, pulmonary, cardiovascular, infectious and inflammatory diseases are induced or mediated by microplastics. Microplastic exposure during pregnancy and maternal period is also discussed. Remediation methods include coagulation, membrane bioreactors, sand filtration, adsorption, photocatalytic degradation, electrocoagulation and magnetic separation. Control strategies comprise reducing plastic usage, behavioural change, and using biodegradable plastics. Global plastic production has risen dramatically over the past 70 years to reach 359 million tonnes. China is the world's top producer, contributing 17.5% to global production, while Turkey generates the most plastic waste in the Mediterranean region, at 144 tonnes per day. Microplastics comprise 75% of marine waste, with land-based sources responsible for 80–90% of pollution, while ocean-based sources account for only 10–20%. Microplastics induce toxic effects on humans and animals, such as cytotoxicity, immune response, oxidative stress, barrier attributes, and genotoxicity, even at minimal dosages of 10 μg/mL. Ingestion of microplastics by marine animals results in alterations in gastrointestinal tract physiology, immune system depression, oxidative stress, cytotoxicity, differential gene expression, and growth inhibition. Furthermore, bioaccumulation of microplastics in the tissues of aquatic organisms can have adverse effects on the aquatic ecosystem, with potential transmission of microplastics to humans and birds. Changing individual behaviours and governmental actions, such as implementing bans, taxes, or pricing on plastic carrier bags, has significantly reduced plastic consumption to 8–85% in various countries worldwide. The microplastic minimisation approach follows an upside-down pyramid, starting with prevention, followed by reducing, reusing, recycling, recovering, and ending with disposal as the least preferable option.

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20.
短链氯化石蜡(SCCPs)是持久性有机污染物,已于2017年5月被正式列入《关于持久性有机污染物的斯德哥尔摩公约》附件A的受控名单.中链氯化石蜡(MCCPs)具有相似的性质.由于氯化石蜡(CPs)大量生产以及广泛应用,其在环境介质中的含量处于较高水平.本文综述了 SCCPs和MCCPs的生产和排放,以及2016年以后文...  相似文献   

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