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141.
Site index is an important forest inventory attribute that relates productivity and growth expectation of forests over time. In forest inventory programs, site index is used in conjunction with other forest inventory attributes (i.e., height, age) for the estimation of stand volume. In turn, stand volumes are used to estimate biomass (and biomass components) and enable conversion to carbon. In this research, we explore the implications and consequences of different estimates of site index on carbon stock characterization for a 2,500-ha Douglas-fir-dominated landscape located on Eastern Vancouver Island, British Columbia, Canada. We compared site index estimates from an existing forest inventory to estimates generated from a combination of forest inventory and light detection and ranging (LIDAR)-derived attributes and then examined the resultant differences in biomass estimates generated from a carbon budget model (Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3)). Significant differences were found between the original and LIDAR-derived site indices for all species types and for the resulting 5-m site classes (p?<?0.001). The LIDAR-derived site class was greater than the original site class for 42% of stands; however, 77% of stands were within ±1 site class of the original class. Differences in biomass estimates between the model scenarios were significant for both total stand biomass and biomass per hectare (p?<?0.001); differences for Douglas-fir-dominated stands (representing 85% of all stands) were not significant (p?=?0.288). Overall, the relationship between the two biomass estimates was strong (R 2?=?0.92, p?<?0.001), suggesting that in certain circumstances, LIDAR may have a role to play in site index estimation and biomass mapping.  相似文献   
142.

BOOKS

The Handbook of Environmental Chemistry Founded by: Otto Hutzinger – Publisher: Springer – Editors-in-chief: Damià Barceló · Andrey G. Kostianoy – ISSN: 1867-979X  相似文献   
143.
Cape hakes, Merluccius paradoxus and M. capensis, are important gadoid fish that are commercially harvested in the Benguela Current system off Namibia and South Africa. The aim of this study was to elucidate the nutritional condition and feeding preferences of their larvae. Hake eggs and larvae were sampled in austral spring of two consecutive years, 2007 and 2008, off the west coast of South Africa. They were identified to species using genetics, and total lipid content and fatty acid (FA) composition were analysed for each individual egg and larva to compare the condition of different early life stages of both hake species. Higher abundances of M. paradoxus eggs and larvae were consistently found compared to M. capensis. In both species, eggs contained wax esters (WE) and had significantly higher lipid content per dry mass than larvae. Lipid content as well as FA composition changed with the developmental stage of larvae. Quantities of essential fatty acid (EFA) increased with feeding of larvae due to dietary lipid incorporation. In 2007, yolk-sac larvae contained significantly lower total lipids than in 2008. It is argued that this was due to reduced lipid transfer by the spawning females to the eggs. These findings indicate that maternal effects are important in determining condition of hake larvae and that this may have an effect on their survival and subsequent recruitment.  相似文献   
144.
Residential satisfaction is a significant topic in environmental psychology yet there is little research on residential satisfaction among elders. This research aims to identify the cognitive structure of residential satisfaction of elderly persons living in their own dwellings and to identify demographic and psychological variables related to this residential satisfaction. One hundred and three participants, ranging in age from 72 to 86 years old and living at home in the central France, answered (a) a purpose-developed questionnaire to measure their residential satisfaction, (b) an environmental quality questionnaire aimed at evaluating both the physical and social environments, and (c) several psychological variables including: the ESV, a French adaptation of the Satisfaction with Life Scale which examines the general well-being of aging people; and three single well-being items assessing financial well-being, perceived health, and perception of oneself as active. The results indicated that in this sample, residential satisfaction corresponds to a four-dimension structure organized by physical location rather than psychological or behavioral aspects. The four components were the local area, access to services, relations with neighbors, and the home itself. Satisfaction with each component was related to different predictors, supporting the idea that elders hold complex and nuanced views of their homes and neighborhoods.  相似文献   
145.
Over 400tons of Pb enters Swiss soils annually at some 2000 military shooting ranges (MSRs). We measured elements in the leaves of 10 plant species and associated rhizospheric soil on the stop butt of a disused MSR. The geometric mean concentrations of Pb, Sb, Cu, Ni in rhizospheric soils were 10,171mg/kg, 5067mg/kg, 4125mg/kg and 917mg/kg. Some species contained Pb, Cu and Ni, above concentrations (30mg/kg, 25mg/kg and 50mg/kg) shown to be toxic to livestock. Most contaminants in leaves resulted from surface deposition. However, at soil Pb concentrations >60,000mg/kg, Equisetum arvense and Tussilago farfara took up >1000mg/kg Pb into the leaves. These plants are not hyperaccumulators, having <100mg/kg Pb in leaves at lower soil concentrations. Removal of soil with more than 30,000 Pb, from which one could smelt this metal to offset remediation costs, followed by revegetation, would minimise dust and hence leaf-borne contaminants.  相似文献   
146.
GOAL, SCOPE AND BACKGROUND: Exogenic endocrine-active substances are also called 'Endocrine Disrupting Chemicals' (EDC). They imitate or hinder the function of natural endogenic hormones or disturb the synthesis or the metabolism of hormones or of hormone receptors. The Enzyme-Linked Receptor Assay (ELRA) can detect estrogenic and anti-estrogenic effects at the level of receptor binding and is a useful tool for the integrative detection of contaminant effects. Although the test system has been used repeatedly in sediment assessments, the questions have remained concerning how it responds to variations in the physico-chemical matrix. For some bioassays, the salinity of the sample is a critical factor. This is especially relevant when testing wastewater samples or when sediment-associated samples in the tidal reaches of rivers are tested. Sediments in the tidal reaches of rivers change their salinity several times a day. Against this background, it would be beneficial to have a test procedure of known salinity tolerance. On account of this, the salinity tolerance of the ELRA was tested, assessed with reference substances at several salinity levels, and compared with the E-Screen method and a Yeast Estrogen Screen (YES), which are also frequently applied in environmental testing. The aim of this paper was to explore when the salinity limits within these test procedures are applicable. The trials should reveal the working range to be expected, characterize the salinity-dependent variations in sensitivity of the test, and provide options for methodological adjustments to improve the stability against increased salinity. METHODS: The ELRA was carried out with the human Estrogen Receptor alpha. (ER) using the same principle like a competitive immunoassay based on ligand-protein interaction. However, an essential difference is the use of a physiologically relevant receptor instead of an antibody as a linking protein. The ELRA measures the competition of sample estrogens and anti-estrogens against estradiol supplied as a BSA-coating conjugate for the binding site of dissolved ER. Estradiol or xeno-estrogen binding is quantified by a biotynilated anti-ER antibody and the subsequent measurement of peroxidase activity by a streptavidin-POD-biotin complex. The E-Screen was performed with the human breast cancer cell line MCF-7, which expresses the estrogen receptor constitutively. Cell proliferation depends on binding of estrogens or xeno-estrogens with the receptor. After incubation, estrogen-dependent cell growth was measured by sulforhodamin B staining. The YES was performed with a recombinant yeast strain, transfected with a receptor and a reporter plasmid bearing the estrogen receptor and a vitellogenin gene fused with the reporter gene lacZ. Estrogen or xeno-estrogen-dependent gene induction was measured indirectly by LacZ activity. The salinity levels were simulated in varying concentrations with NaCl from 0 to 40 per thousand or Artificial Sea Water (ASW) from 0 to 32 per thousand. RESULTS: The study characterized the factor 'salinity' for the prospective application fields of the ELRA. With reference substances such as 17-beta-estradiol, the ELRA showed classical sigmoidal concentration-effect relations in a range from 0.05 to 100 microg/l under physiological conditions. After a methodological adjustment to compensate decreasing receptor-binding affinity of estrogens and xeno-estrogens at higher salinity levels, the ELRA became applicable under salinity conditions up to concentrations of 20.5 per thousand. In tests, the ELRA reached under the influence of salinity a mean limit of detection of 0.062 microg/l 17-beta-estradiol. The mean relative inter-test error was around 11%. Above concentrations of 20.5 per thousand there is a risk of false negative assessment. Compared with the E-Screen method using the MCF7 cell line and the yeast estrogen test system (YES), the ELRA shows a lower sensitivity to 17-beta-estradiol. In the E-Screen, the cell proliferation was strongly reduced by sodium chloride induced cytotoxicity. In comparison with the E-Screen, the salinity tolerance of the YES and YAS methods is significantly higher. DISCUSSION: Despite adaption, total salinity tolerance could not be achieved with the ELRA. Freshwater samples were generally appraisable. Higher salinity levels above 20.5 per thousand would tend towards false negative results. The low inter-test error of 11% makes the ELRA suitable for the detection of estrogenic and anti-estrogenic potentials of single substances, substance mixtures, and of environmental samples. CONCLUSIONS: The ELRA is very fast and reproducible, it can be used for high-throughput screening in a microplate format at low cost, it is robust to microbial contamination, and is less susceptible to cytotoxic interferences than cell culture methods. RECOMMENDATIONS AND PERSPECTIVES: In their established form, the YES and the E-Screen methods are not applicable for liquid phase testing at higher salinity conditions. The salinity-adapted test version of the ELRA described here shows a broader working range for samples. Native water samples of more or less brackish origin or high-salinity effluent samples are testable. Results of tests with sediment associated samples of different salinity will be subject of a forthcoming publication.  相似文献   
147.
An effects-directed strategy was applied to bed sediments of a polluted tributary in order to isolate and identify the major estrogenic chemicals it discharges into the River Po, the principal Italian watercourse. Sediment extract was concentrated by solid phase extraction and then fractioned into 10 fractions by reversed phase high performance liquid chromatography (RP-HPLC). Estrogenic activity of whole extract and fractions were determined using a recombinant yeast assay containing the human estrogen receptor (YES). The 10 fractions and whole extract were analysed for target compounds, e.g. estrone (E1), 17beta-estradiol (E2), estriol (E3), 4-nonylphenol (NP), 4-tert-octylphenol (t-OP), bisphenol A (BPA), using both liquid chromatography-tandem mass spectrometry (LC-MS/MS) and non-competitive enzyme-linked immunosorbent assays (ELISA). The YES assay determined high estrogenic activity in whole sediment (15.6 ng/g EE2 equivalents), and positive results for fractions nr 1, 2, 6, 7 and 8. E1, E3 and NP were the main estrogenic chemicals, however, other unidentified compounds contributed to sediment estrogenicity, particularly for polar fractions nr 1 and 2. A GC-MS screening performed in scan mode identified other potential contributors such as phthalates (DBP, BBP), and OP isomers. A next sampling campaign extended to other tributaries and receiving stretches of the River Po confirmed E1, E3 and NP as major estrogenic chemicals potentially threatening other sites of the main river. In general, target compound ELISAs have been shown to be suitable tools for a rapid screening of wide areas or large numbers of environmental samples for estrogenic risk. The potential for interferences suggests however to use cautiously the concentration values obtained from some of the immunoassays.  相似文献   
148.

Background

Soil is one of our most important resources and fulfills many ecological functions such as storage and filtration of water and nutrients, transformation of chemical compounds and nutrients, biomass production, and carbon storage. Such soil functions support ecosystem services provided by soils, which need to be protected to protect soil fertility. However, European soils often contain elevated concentrations of contaminants, putting biodiversity of soil organisms as well as the ecological functions and services at risk. To promote soil ecotoxicology in Switzerland, the Swiss Centre for Applied Ecotoxicology together with the Federal Office for Environment and the Federal Office for Agriculture organized a stakeholder workshop on 7 June 2018 with participants from research, governmental bodies, and associations. One goal of this workshop was to inform participants about currently available risk assessment approaches for soil, the soil risk assessment for plant protection products in Europe, available bioassays and bioindicators, and results of research projects on soil contaminants in Switzerland. Another goal was to discuss the needs for research in soil ecotoxicology in Switzerland and to identify next steps, potential projects, and future collaborations.

Results

The main needs identified during the workshop were the establishment of (bio)indicators to measure soil fertility, functional parameters to determine soil functions, and the preservation of soil biodiversity. Another priority listed was the formation of a working group, which addresses the issue of the development of environmental quality standards for soil. The need for experimental field sites for implementing and testing new approaches or tools for assessing soil quality was also discussed.

Conclusion

The next steps planned are two workshops with national and international experts in soil ecotoxicology to develop a soil monitoring concept for Switzerland and to find suitable bioindicators to evaluate soil fertility. Additionally, a literature review will be performed summarizing the current ecotoxicological state of the art with regard to the development of bioindicators in relation to the monitoring of plant protection products in Swiss soil, to evaluate their effects on soil fertility. Furthermore, all attendees agreed on the need for annual meetings or workshops where experts can present scientific results, participants can exchange information, and future projects and collaborations can be developed.
  相似文献   
149.
150.
It has been confirmed that the NOx-concentration in air is highest over industrial areas and that it decreases by more than 75%, parallel to traffic density, over urban areas as related to forested areas. A significant correlation excists between NO2-concentration and the parameters of “traffic density,” followed by “road density” and “number of inhabitants/km2” in urban areas. No positive correlation was found with the number of “registered cars” and the parameters of “land use”. In forested areas, the traffic density correlated with the NO2-concentration, but the correlation was not significant. The other parameters had no positive correlation with NO2-concentration. In forest, urban- and industrial-areas, the NOx-concentration in the air had a fairly constant ratio to traffic density.  相似文献   
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