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城市土地利用下的植物物种资源特征分析 总被引:14,自引:0,他引:14
根据对前联邦德国卡尔斯鲁厄市城市自生植被的调查资料,分析了城市植物区系的特征及其与人类活动影响的关系。结论为:①城市植物区系在优势科组成和生态特征方面与其所在地区自然植被明显不同,并在城市之间表现出较大的相似性;②人类活动和城市热岛效应对城市植物区系及其生态特征的作用明显;③城市土地利用和城市绿地管理对许多物种的生存构成威胁 相似文献
23.
外源性稀土La和Ce对几种淡水微藻生长影响的研究 总被引:7,自引:0,他引:7
通过模拟培养实验,研究了不同质量浓度的稀土元素La3+和Ce3+对2种产地的微囊藻以及月牙藻增殖的影响.结果表明低质量浓度的La3+和Ce3+对2种微囊藻的刺激作用明显大于对月牙藻的刺激作用,说明稀土元素La3+和Ce3+在湖泊中的富集可能改变湖泊种群结构,有利于微囊藻在湖泊中形成优势种;高质量浓度的La3+和Ce3+对3种藻均有抑制生长的作用,当La3+和Ce3+的质量浓度为50.0 mg/L时,微囊藻的生长繁殖完全被抑制. 相似文献
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Wu Jin Wang Anpu Huang Yanchu Ma ciguang Y. Ii S. Daishim K. Furuy T. Kikuchi H. Matsushit K. Tanabe 《环境科学学报(英文版)》1990,2(1):27-39
A study has been made on elements organic constituents, TSP, SO2,NO2 of atmospheric pollutants in Beijing. 17 elements, and some PAHs, e. g. B(a)P, B(b, j, k)P, and B(g, h, i)P, in airborne particles by X-ray fluorescence spectroscopy and HPLC, GC/MS, have been determined respectively. It has been shown that the elements Pb, Zn, S and Cu were more enriched in fine particles and different valence states of sulfur at various sites. It was found that the concentrations of S6+ and S2-were more than 85% and less than 15% of the total sulfur respectively. Concentrations of major PAHs and sulfur-containing compounds increased in winter and in urban area. High values for Pb and Zn in city, Fe and Mn at industrial area and Cu, Al rural sites were obtained respectively. This implies the functions of different elemental sources of various sites. Thus, elements can be from distingushed anthropogenic and natural sources.The main contribution of SO2 was found of to have same seasonal variation as the anthropogenic el 相似文献
26.
长江铜陵段表层水中重金属含量及存在形态分布研究 总被引:11,自引:0,他引:11
通过测定长江铜陵段枯、丰水期江水中cu、Pb、Zn和cd不同形态的含量,分析了4种金属在江水中的存在形态分布,不同水期含量变化,水中悬浮物对金属吸附能力大小,以及近20年来含量的变化情况。结果表明,长江铜陵段江水中各重金属总量丰水期时大于枯水期,重金属各形态含量之间均有差异:丰水期时,各金属会被悬浮物以不同的方式携带进入水体中,cu、zn、Pb以活跃态和稳定态为主,Cd以活跃态为主;枯水期时,Zn主要以溶解态和稳定态为主,Pb以稳定态方式被携带,而80%的Cu、Cd是以溶解态形式存于水中。悬浮物(丰水期)对重金属的吸附能力大小顺序为Pb>Cu>Zn>Cd。与近20年江水中的重金属背景值比较,长江铜陵段重金属含量有普遍升高的趋势。 相似文献
27.
Nada Horvatinčić José Luis Briansó Bogomil Obelić Jadranka Barešić Ines Krajcar Bronić 《Water, Air, & Soil Pollution: Focus》2006,6(5-6):475-485
The process of eutrophication in form of intense plant growth has been observed in some lakes and water streams at the Plitvice
Lakes National Park in central Croatia. Here we investigate whether this phenomenon is a consequence of anthropogenic pollution
or due to naturally produced organic matter in the lakes. We applied chemical analysis of water at two springs and four lakes
(nutrients, dissolved organic carbon (DOC), trace elements) and measurements of surface lake sediments (mineral and organic
fraction analyses, trace elements) in four different lakes/five sites. The chemical composition of water does not indicate
recent anthropogenic pollution of water because the concentrations of most trace elements are below detection limits. The
concentrations of DOC and nutrients are slightly higher in the area of increased eutrophication-plant growth. Also the content
of organic matter in the sediment is at the highest level in areas with highest C/N ratio indicating that the organic fraction of this sediment is mainly of terrestrial origin. There is no significant difference
among the trace element concentration in the upper segment of all cores, deposited approximately during last 50 years when
higher anthropogenic influence is expected due to development and touristic activity, and the lower part of the cores, corresponding
to the period approximately 100–200 years before present. The content of trace elements and organic matter in sediments decreases
from the uppermost lake downstream. According to our results there is no indication of recent anthropogenic pollution in water
and sediment. Higher concentrations of DOC in water as well as phosphorus and some other elements in the lake sediment can
be a consequence of input of natural organic matter to the lake water. 相似文献
28.
黄荆自然保护区植物区系的初步研究 总被引:3,自引:0,他引:3
黄荆自然保护区地处四川盆地与云贵高原的过渡地带,地带性植被为亚热带偏湿性常绿阔叶林,有种子植物165科745属1521种,其中裸子植物9科19属24种,被子植物156科726属1497种.该区特殊的自然条件和复杂的地质构造,使其成为多种植物地理成分的汇集地,并成为我国乃至全世界亚热带(同纬度)地区保存较好的常绿阔叶林植被群落,具有极高的研究价值和生态价值.根据近年来的科学考察,认为黄荆自然保护区植物区系的种类丰富、珍稀特有植物较多、起源古老、区系成分复杂,显示出多方植物交汇的特点. 相似文献
29.
Pierre Hennebert Hans A. van der Sloot Flore Rebischung Reinhilde Weltens Lieve Geerts Ole Hjelmar 《Waste management (New York, N.Y.)》2014,34(10):1739-1751
Hazard classification of waste is a necessity, but the hazard properties (named “H” and soon “HP”) are still not all defined in a practical and operational manner at EU level. Following discussion of subsequent draft proposals from the Commission there is still no final decision. Methods to implement the proposals have recently been proposed: tests methods for physical risks, test batteries for aquatic and terrestrial ecotoxicity, an analytical package for exhaustive determination of organic substances and mineral elements, surrogate methods for the speciation of mineral elements in mineral substances in waste, and calculation methods for human toxicity and ecotoxicity with M factors.In this paper the different proposed methods have been applied to a large assortment of solid and liquid wastes (>1 0 0).Data for 45 wastes – documented with extensive chemical analysis and flammability test – were assessed in terms of the different HP criteria and results were compared to LoW for lack of an independent classification. For most waste streams the classification matches with the designation provided in the LoW. This indicates that the criteria used by LoW are similar to the HP limit values.This data set showed HP 14 ‘Ecotoxic chronic’ is the most discriminating HP. All wastes classified as acute ecotoxic are also chronic ecotoxic and the assessment of acute ecotoxicity separately is therefore not needed. The high number of HP 14 classified wastes is due to the very low limit values when stringent M factors are applied to total concentrations (worst case method). With M factor set to 1 the classification method is not sufficiently discriminating between hazardous and non-hazardous materials. The second most frequent hazard is HP 7 ‘Carcinogenic’. The third most frequent hazard is HP 10 ‘Toxic for reproduction’ and the fourth most frequent hazard is HP 4 “Irritant – skin irritation and eye damage”. In a stepwise approach, it seems relevant to assess HP 14 first, then, if the waste is not classified as hazardous, to assess subsequently HP 7, HP 10 and HP 4, and then if still not classified as hazardous, to assess the remaining properties.The elements triggering the HP 14 classification in order of importance are Zn, Cu, Pb, Cr, Cd and Hg. Progress in the speciation of Zn and Cu is essential for HP 14. Organics were quantified by the proposed method (AFNOR XP X30-489) and need no speciation. Organics can contribute significantly to intrinsic toxicity in many waste materials, but they are only of minor importance for the assessment of HP 14 as the metal concentrations are the main HP 14 classifiers. Organic compounds are however responsible for other toxicological characteristics (hormone disturbance, genotoxicity, reprotoxicity…) and shall be taken into account when the waste is not HP 14 classified. 相似文献
30.
Plant conservation initiatives lag behind and receive considerably less funding than animal conservation projects. We explored a potential reason for this bias: a tendency among humans to neither notice nor value plants in the environment. Experimental research and surveys have demonstrated higher preference for, superior recall of, and better visual detection of animals compared with plants. This bias has been attributed to perceptual factors such as lack of motion by plants and the tendency of plants to visually blend together but also to cultural factors such as a greater focus on animals in formal biological education. In contrast, ethnographic research reveals that many social groups have strong bonds with plants, including nonhierarchical kinship relationships. We argue that plant blindness is common, but not inevitable. If immersed in a plant‐affiliated culture, the individual will experience language and practices that enhance capacity to detect, recall, and value plants, something less likely to occur in zoocentric societies. Therefore, conservation programs can contribute to reducing this bias. We considered strategies that might reduce this bias and encourage plant conservation behavior. Psychological research demonstrates that people are more likely to support conservation of species that have human‐like characteristics and that support for conservation can be increased by encouraging people to practice empathy and anthropomorphism of nonhuman species. We argue that support for plant conservation may be garnered through strategies that promote identification and empathy with plants. 相似文献