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1.
Zenon Lukaszewski Ryszard Siwecki Jadwiga Opydo Wlodzimierz Zembrzuski 《Trees - Structure and Function》1993,7(3):169-174
Summary The patterns of radial distribution of copper, lead, zinc and cadmium in two species of poplar, growing under polluted conditions near a copper smelter, were investigated. Populus marilandica is very resistant to such pollution, but P. balsamifera is sensitive. Soils were examined for concentrations of these metals, and only a surface layer of soil was polluted with copper and lead. P. balsamifera absorbed much more cadmium than P. marilandica under the same conditions. P. marilandica shows a pattern of copper radial distribution with significantly increased concentration of the meral in the layers in the middle of the trunk compared to P. balsamifera. Zinc and cadmium have a pattern with increased metal concentration from the bark towards the pith of the tree. In the case of copper and lead the pattern indicates increased concentrations of these metals in the rings adjacent to the pith while the pattern in other parts of the tree remains unconfirmed due to poor precision. Poplar xylem seems to accumulate zinc and cadmium while the content of lead in xylem is much lower than in the adjacent soil.This paper is dedicated to the memory of Professor Stefan Bialobok, Institute of Dendrology, Polish Academy of Sciences in Kornik 相似文献
2.
Report cards are an increasingly popular method for summarising and communicating relative environmental performance and ecosystem health, including in aquatic environments. They are usually underpinned by an Ecosystem Health Index (EHI) that combines various individual indicators to produce an overall ecosystem health “score”. As a result of public water quality concerns, an integrated means of monitoring and reporting on aquatic ecosystem health was needed for the Fitzroy Basin in central Queensland, Australia. The Fitzroy Partnership for River Health was formed to address this need, and developed an EHI and report card for the Basin using existing monitoring data collected from various third parties including regulated companies operations and government. At 142,000 square kilometres, the Fitzroy Basin is the largest catchment draining to the World Heritage Listed Great Barrier Reef. The Fitzroy Basin provides an example of how to deliver an effective aquatic ecosystem health reporting system in a large and complex river basin. We describe the methodology used to develop an adaptive EHI for the Fitzroy Basin that addresses variability, complexity and scale issues associated with reporting across large areas. As well, we report how to manage the design and reporting stages given limitations in data collection and scientific understanding. 相似文献
3.
Karachi is one of the most populated urban agglomerations in the world. No categorical study has yet discussed the geochemical baseline concentrations of metals in the urban soil of Karachi. The main objectives of this study were to establish geochemical baseline values and to assess the pollution status of different heavy metals. Geochemical baseline concentrations of heavy metals were estimated using the cumulative frequency distribution (CDF) curves. The estimated baseline concentrations of Pb, Cr, Cu, Zn and Fe were 56.23, 12.9, 36.31, 123.03 and 11,776 mg kg−1, respectively. The pollution status of heavy metals in urban soils was evaluated using different quantitative indices (enrichment factor–EF, Geo-accumulation Index–Igeo, and pollution index–PI). Enrichments factors of the selected heavy metals determined by using Fe as a normalizer showed that metal contamination was the product of anthropogenic activities. The urban soils of Karachi were found to have a moderate to moderately severe enrichment with Pb, whereas Cr and Cu has moderate and Zn has minor enrichment. Igeo results indicated moderate soil contamination by Pb at some of the sampling locations. PI for Pb, Cr, Cu and Zn was found in the range of 0.04–3.42, 0.19–1.55, 0.27–2.45 and 0.32–1.57, respectively. Large variations in PI values of Pb revealed that soil in those areas of the city which are influenced by intensive anthropogenic activities have exceptionally high concentrations of Pb. The findings of this study would contribute to the environmental database of the soil of the region and would also facilitate both at the local and the international scales, in a more accurate global environmental monitoring, which will eventually facilitate the development of management and remediation strategies for heavy metal contaminated urban soil. 相似文献
4.
5.
《Science activities》2013,50(2):73-76
The purpose of this activity was to help students understand the percentage of cloud cover and make more accurate cloud cover observations. Students estimated the percentage of cloud cover represented by simulated clouds and assigned a cloud cover classification to those simulations. 相似文献
6.
《Archives of animal nutrition》2013,67(2-3):225-231
Domesticated animals all over the world are subjected to a wide variety of environmental conditions and challenges. Any deviation from “normal”; may result in adaptive behavior of which changes in feed intake or feed intake pattern is by far the most important. Adaptive behavior may further include influences on passage rate of feed residues through the digestive tract, resulting in changes in digestibility. Adaptive behavior may also result in changes in heat production, either to maintain body temperature constant, or as a result of an elevated body temperature. Important environmental challenges are infectious diseases. Mild (sub‐clinical) infections usually result in reduced performance, without affecting feed intake or digestibility. Severe infections may disrupt the barriers between the internal metabolism and the respiratory and/or digestive tract, resulting in severe losses of energy and protein. This situation is notably apparent in severe infections with parasites of the gastrointestinal tract and may be associated with severe protein losses. Feeding high protein diets may partly alleviate the negative effects. Contamination of air, water and feed may occasionally cause problems in farm animals. Such contamination may include pathogenic microbes, toxic secondary fungal metabolites and heavy metals. Negative effects associated with such contamination often show an impaired reproductive efficiency, but their influence on the utilization of energy and nutrients is not well documented. 相似文献
7.
1-MCP和CO2对‘南果梨’冷藏后货架期能量代谢特性的影响 总被引:2,自引:0,他引:2
分别对‘南果梨’果实采用0.75μL/L 1-甲基环丙烯(1-MCP)在20℃熏蒸20h后装入保鲜袋(0.02mm)、用2%CO2充气果实包装袋(0.04mm)、以保鲜袋果实为对照,各处理组果实均置于(0±1)℃贮藏5个月后移至室温下(18℃±3℃),测定各处理果实在货架期间的褐变度以及果实线粒体蛋白含量、MDA含量、ATP含量,以明确1-MCP和CO2对南果梨冷藏后果实货架期的能量代谢特性。结果显示:(1)1-MCP和CO2处理可不同程度延缓南果梨冷藏后货架期果实果心褐变指数和褐变度,且1-MCP处理效果更好,但CO2处理在货架后期反而使果实褐变度较对照提高。(2)1-MCP和CO2处理可有效抑制果实MDA含量增加,延缓细胞膜透性的升高,保持细胞完整性。(3)1-MCP处理有利于提高货架前期果实中线粒体蛋白质含量,能够在货架后期保持较高的ATP含量和能荷水平,而CO2处理在货架前期果实内含有较高水平的ATP,促进了果实内的能荷水平。研究发现,1-MCP和CO2处理均可以通过影响南果梨果实的能量代谢特性从而影响果实的成熟衰老进程,且1-MCP处理可以抑制货架前期的ATP含量和能量供应,有利于保持细胞膜完整性,抑制果心褐变的发生,延缓果实成熟衰老进程;而2%CO2处理与对照相比对果实能量代谢特性的影响不大。 相似文献
8.
In this study, autometallography and immunohistochemistry were used to localize and quantify cadmium and metallothionein (MT) levels, respectively, in cellular compartments of turbot liver on exposure to cadmium for 7 days and further depuration treatment for 14 days. Metals weakly bound to proteins (i.e. MTs) in hepatocyte lysosomes were visualized as black silver deposits (BSDs) using a light microscope. With the aid of a newly developed immunohistochemical procedure, MTs were localized and semi-quantified in both the cytosolic and the lysosomal compartments of hepatocytes. The BSD extent in the lysosomes of hepatocytes increased significantly as a result of cadmium exposure. This response was evidenced after 1h. Further, a progressive increase in the volume density of BSDs occurred up to the seventh day. Total MT immunohistochemical levels increased at a lower rate, starting after 1 day of cadmium exposure. BSD extent values recovered after depuration, whilst MT levels remain unchanged. It is possible that the detoxification rate of metals via lysosomes was diminished, whilst MT levels remained unchanged, at least after 14 days of depuration. It can be concluded that autometallography and MT immunohistochemistry are good tools for clarifying metal and metal-MT trafficking routes in hepatocytes, and also that BSD extent and MT immunohistochemical levels in the lysosomes and cytosol of fish hepatocytes can be considered to be useful biomarkers of metal exposure. 相似文献
9.
Increasing economic growth and industrial development in China is starting to impact even remote areas such as the Shennongjia nature reserve, where nitrogen pollution is becoming a major environmental threat. The epiphytic lichen flora is particularly rich in this area and is one of the components of this habitat most sensitive to nitrogen pollution. Since lichens represent an important food resource for the endangered monkey species Rhinopithecus roxellana, a reduction in lichen availability would have harmful consequences for the conservation of its habitat in the Shennongjia Mountains. To investigate the effects of increased nitrogen availability on the local lichen communities, so far scarcely considered, we conducted a one-year field experiment measuring growth, survival, and phosphomonoesterase activity of the widespread species Usnea luridorufa in response to nitrogen (up to 50 kg N ha−1 year−1 deposition) and phosphorus supply. Growth and survival of thalli and propagules of U. luridorufa decreased when treated with N deposition >12.05 kg N ha−1 year−1 and >2.14 kg N ha−1 year−1, respectively. The important role of phosphorus availability in relation to nitrogen supply was demonstrated by the increase in phosphomonoesterase activity with increasing nitrogen availability until a nitrogen toxicity threshold was reached. However, the high concentration of phosphorus in rainwater showed that phosphorus is not a limiting nutrient in the area.The results make a contribution to the knowledge of the negative effects of increased N deposition in the Shennongjia forest ecosystem. 相似文献
10.
Heidrun Anke 《Mycologist》2006,20(3):83-89
White-rot fungi possess a unique oxidative mechanism by which the recalcitrant lignin component of wood is mineralised. The activity of lignin-degrading enzymes, chiefly lignin and manganese peroxidases, depends on several small organic molecules. Some of these (e.g. chloroanisyl alcohols) are chloroaromatics and may act as environmental pollutants in the forest soil, whereas the synthesis of others (e.g. veratryl alcohol) requires chloromethane. Certain white-rot genera, notably Phellinus and Inonotus, release excess quantities of chloromethane into the atmosphere where it acts as a greenhouse gas. On the other hand, their powerful ligninolytic system enables white-rot fungi to degrade a wide range of man-made environmental pollutants, including recalcitrant chloroaromatics such as DDT, PCP, 2,4-D and 2,4,5-T. This review describes the multifarious interactions of white-rot fungi with their environment via the chlorine cycle. 相似文献