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1.
Virgin olive oils from percolation (first extraction) have been compared with the corresponding oils from centrifugation (second extraction). The former were characterized by (i) higher contents of total phenols, o-diphenols, hydroxytyrosol, tyrosol-aglycons, tocopherols, trans-2-hexenal, total volatiles, and waxes; (ii) higher values of resistance to autoxidation and of turbidity; (iii) higher sensory scores; (iv) higher ratios of campesterol/stigmasterol, trans-2-hexenal/hexanal, and trans-2-hexenal/total volatiles; (v) lower contents of chlorophylls, pheophytins, sterols, and aliphatic and triterpene alcohols; (vi) lower alcoholic index and color indices; (vii) similar values of acidity, peroxide index, and UV (ultraviolet) spectrophotometric indices; (viii) similar percentages of saturated and unsaturated fatty acids, triglycerides, and diglycerides; and (ix) similar values of glyceridic indices. Stigmastadienes, trans-oleic, trans-linoleic, and trans-linolenic acid isomers were not detected in the two genuine oil kinds. Hence, the qualitative level of the first extraction oil was superior to the second extraction one.  相似文献   

2.
To enable the estimation of production and consumption rates of free glycine in soils through 15N isotope dilution experiments, an isotope dilution mass spectrometric method was developed. The method, which enabled high precision N isotope ratio determination of glycine in soil extracts at δ15N levels up to 4000‰ and concentrations from approximately 2 μM, is based on the following steps: (i) addition of glycine spike to the soil extract, (ii) removal of humic substances and pre-concentration of glycine using solid phase extraction, (iii) derivatization of amino acids, (iv) separation of the derivatives using gas chromatography (GC), (v) their combustion to yield sample N2 gas, and (vi) finally the use of N isotope ratio mass spectrometry (IRMS). Judging by uncertainty budget calculations, the precision obtained (SD=0.01-0.06 at% 15N) is sufficient for detecting differences in N isotopic ratios obtained in 15N isotope dilution experiments.  相似文献   

3.
We isolated the non‐hydrolysable macromolecular organic fraction (insoluble fraction resistant to drastic laboratory hydrolyses) from a temperate, loamy, forest soil (Lacadée, France) and from the soil of an adjacent plot cleared 35 years ago and continuously cropped with maize. The quantitative, morphological (light, scanning and transmission electron microscopy) and isotopic (bulk δ13C, individual compound δ13C and radiocarbon dating) features of these two non‐hydrolysable fractions were determined and compared. It appeared that: (i) extensive degradation of the non‐hydrolysable material inherited from the forest soil occurred upon cropping, revealing that its resistance to drastic laboratory hydrolyses is not paralleled by a great resistance to natural biodegradation triggered by change in land use; (ii) only small inputs of maize‐derived compounds occurred in the non‐hydrolysable fraction of the cultivated soil so that, in spite of extensive degradation, the forest‐inherited carbon still predominates; (iii) the non‐hydrolysable fractions of both soils comprise the same components (wood debris, spores, pollen, and, predominantly, granular organic aggregates), which correlate with the previously identified chemical components (charcoal, aliphatic lipid components and melanoidin‐like components); (iv) the non‐hydrolysable fraction of the cropped soil shows a greater contribution of aliphatic moieties, reflecting differential degradation of the components of the non‐hydrolysable material inherited from the forest soil; (v) this degradation resulted in enrichment in the oldest components; and (vi) no relationship is observed, in the two Lacadée soils, between resistance to drastic laboratory hydrolyses, on the one hand, and stability towards biodegradation in situ, on the other. These observations, added to recent ones on other types of soils, suggest that such a conspicuous uncoupling between non‐hydrolysable and stable carbon is probably a general feature of organic matter in soil as opposed to sedimentary organic matter.  相似文献   

4.
Irrigation with treated wastewater (TWW) may affect soil structure and stability and the characteristics of dissolved organic matter (DOM) of the soil solution. The objectives of our study were (i) to evaluate the impact of TWW irrigation, as compared with fresh water (FW) irrigation, on aggregate stability and saturated hydraulic conductivity (indices of soil structure stability) and (ii) to determine whether these indices can be associated with the chromophoric indicators of water‐extractable DOM in TWW‐ and FW‐irrigated soils. We studied aggregate stability and soil hydraulic conductivity (HC) of four different soil types irrigated with either TWW (for at least 5 years) or FW. The results were linked to earlier published data on the concentration scores of fluorescent chromophoric DOM components (obtained from excitation‐emission matrices of flouorescence coupled with parallel factor analysis), dissolved organic carbon (DOC) concentration and absorbance at 254 nm (Abs254). These were all obtained from water extracts of the same soils as those used in the current study. Irrigation with TWW decreased aggregate stability, in comparison to irrigation with FW, in the sandy clay and clay soils, while in the loamy sand TWW increased aggregate stability. The apparent steady state HCs in the TWW‐irrigated samples in the loamy sand, sandy clay and clay soils were similar to, or significantly less than, those obtained in the FW‐irrigated samples. In the sandy loam the opposite trend was noted. Results of principal component and classification analyses showed that the aggregate stability indices were directly associated with soil organic matter and DOM attributes in the coarse‐textured soils, while in the fine‐textured soils inverse associations were noted. Only in the fine‐textured soils were the HC attributes associated (directly) with some of the DOM characteristics. Our results suggest that structural indices of fine‐textured soils are more sensitive than those of coarse‐textured soils to the composition of water extractable DOM.  相似文献   

5.
Many tropical soils include sesquioxides, which influence the stability of soil organic matter (OM) and aggregation to an extent that is not fully characterized. The present study was carried out on a range of 18 topsoil samples (0–10 cm) from low-activity clay (LAC) soils from sub-Saharan Africa and Brazil, and aimed: (i) at characterizing the size distributions of water-stable aggregates and organic constituents, (ii) at studying how these distributions were affected by texture and sesquioxides, and (iii) how they interacted.The distributions of stable aggregates were generally dominated by macroaggregates (> 200 μm), and those of organic constituents by fine OM (< 20 μm). Aggregation was not clearly affected by soil texture, while total soil carbon (Ct) and the amount of carbon (C) as fine OM increased with soil content in clay plus fine silts (< 20 μm). Stable macroaggregation correlated with Ct and with C amount as fine OM, but each of them correlated more closely with citrate-bicarbonate-dithionite-extractable aluminium (Al), which was not expected. Stable macroaggregation also correlated with C amounts as coarse- and medium-sized OM (> 200 and 20–200 μm, respectively), but each of them correlated more closely with oxalate-extracted Al. These results suggested that for the LAC tropical soils under study OM and aggregate stability depended closely on Al-containing sesquioxides, on Al-substituted crystalline hematite and goethite especially. These sesquioxides also seemed to play a dominant role in the relations between aggregation and OM. As far as soils rich in sesquioxides are concerned, this confirmed that OM is not the main aggregating agent, and suggested that physical protection within aggregates is not necessarily the main mechanism for OM stabilization. However, as soil sesquioxide content cannot be managed easily, the effect of land use on soil OM and aggregation was determinant at the local scale: indeed, for a given location, stable macroaggregation, Ct and C amount as fine OM generally decreased with land use intensification (i.e. cultivation, tillage, reduced surface cover).  相似文献   

6.
Stability and resilience of a variety of soil properties and processes are emerging as key components of soil quality. We applied recently developed measures of biological and physical resilience to soils from an experimental site treated with metal‐contaminated sewage sludge. Soils treated with cadmium‐, copper‐ or zinc‐contaminated, digested or undigested sewage sludge were studied. Biological stability and resilience indices were: (i) the time‐dependent effects of either a transient stress (heating to 40°C for 18 hours) or a persistent stress (amendment with CuSO4) on decomposition, and (ii) the mineralization of dissolved organic carbon (DOC) released by drying–rewetting cycles. Physical stability and resilience measures were: (i) compression and expansion indices of the soils, and (ii) resistance to prolonged wetting and structural regeneration through drying–rewetting cycles. Soil total carbon and DOC levels were greater in the sludge‐amended soils, but there were no differential effects due to metal contamination of the sewage sludge. Effects of metals on physical resilience were greater than effects on soil C, there being marked reductions in the expansion indices with Cd‐ and Cu‐contaminated sludge, and pointed to changes in soil aggregation. The rate of mineralization of DOC released by drying and wetting was reduced by Zn contamination, while biological resilience was increased in the Zn‐contaminated soil and reduced by Cd contamination. We argue that physical and biological resilience are potentially coupled through the microbial community. This needs to be tested in a wider range of soils, but demonstrates the benefits from a combined approach to the biological and physical resilience of soils.  相似文献   

7.
Biosolids compost is a good organic amendment but immature compost can exhibit phytotoxic behavior which can be attributed to different toxic substances. Our objective was to determine the phytotoxicity of: i) Biosolids; ii) Mix of biosolids and wood sawdust sampled a day after composting started; iii) The same material sampled at the end of the thermophilic stage; iv) cured compost; v) cow manure and vi) horse manure A germination bioassay was carried out using Lolium perenne (ryegrass) seeds: germination and root growth percentage were determined as well as electrical conductivity, pH, phenol content and volatile organic acids. In three treatments, Ni, Pb, Zn, Cu and Cd were also determined. Ammonia volatilization was determined during biosolids composting. The germination percentage varied from 67% to 95% but the inhibition of root growth appears to be a more sensitive phytotoxicity indicator (18% to 74%. Phytotoxic effects on germinating ryegrass were mainly related to extract pH and electrical conductivity. Potentially toxic elements, volatile organic acids, phenolic compounds and ammonia were not related to germination.  相似文献   

8.
The stability of biochar in soils is the cornerstone of the burgeoning worldwide interest in the potential of the pyrolysis/biochar platform for carbon (C) sequestration. While biochar is more recalcitrant in soil than the original organic feedstock, an increasing number of studies report greater C‐mineralization in soils amended with biochar than in unamended soils. Soil organisms are believed to play a central role in this process. In this review, the variety of interactions that occur between soil micro‐, meso‐ and macroorganisms and biochar stability are assessed. In addition, different factors reported to influence biochar stability, such as biochar physico‐chemical characteristics, soil type, soil organic carbon (SOC) content and agricultural management practices are evaluated. A meta‐analysis of data in the literature revealed that biochar‐C mineralization rates decreased with increasing pyrolysis temperature, biochar‐C content and time. Enhanced release of CO2 after biochar addition to soil may result from (i) priming of native SOC pools, (ii) biodegradation of biochar components from direct or indirect stimulation of soil organisms by biochar or (iii) abiotic release of biochar‐C (from carbonates or chemi‐sorbed CO2). Observed biphasic mineralization rates suggest rapid mineralization of labile biochar compounds by microorganisms, with stable aromatic components decomposed at a slower rate. Comparatively little information is available on the impact of soil fauna on biochar stability in soil, although they may decrease biochar particle size and enhance its dispersion in the soil. Elucidating the impacts of soil fauna directly and indirectly on biochar stability is a top research priority.  相似文献   

9.
Abstract

A new method is introduced to measure water stability of soil aggregates. The wrist‐action shaker is a simple, inexpensive tool that provides highly accurate data for the assessment of soil erodibility. Three soils from Hawaii (two Oxisols and one Vertisol) with different mineralogies, management histories, and potassium (K)‐factors were examined in this study. Six indices of water stable aggregation were determined after rapid immersion of air‐dry aggregates, followed by gentle wet‐sieving. Single‐sieve indices of percent water stable aggregates (WSA) < 0.063 mm, > 0.25 mm, and > 1.00 mm, were highly correlated. Additionally, these indices were highly correlated with three multiple sieve indices, namely geometric mean aggregate diameter (GMAD), arithmetic mean aggregate mass diameter (MAMD), and the coarse‐to‐fine index (CFI = % WSA > 1.00 mm / % WSA < 0.063 mm). Analysis of WSA data indicated that the relative soil erodibility ranking, from high to low, would be: Lualualei Vertisol > Molokai Oxisol > Kaneloa Oxisol. Discriminant analysis using GMAD and % WSA > 1.00 mm correctly classified 55 of 56 soil samples into their respective soil series.  相似文献   

10.
Olive oil, a traditional food product with thousands of years of history, is continually evolving toward a more competitive global market. Being one of the most studied foods across different disciplines, olive oil still needs intensive research activity to face some vulnerabilities and challenges. This perspective describes some of them and shows a vision of research on olive oil for the near future, bringing together those aspects that are more relevant for better understanding and protection of this edible oil. To accomplish the most urgent challenges, some possible strategies are outlined, taking advantage of the latest analytical advances, considering six areas: (i) olive growing; (ii) processing, byproduct, and environmental issues; (iii) virgin olive oil sensory quality; (iv) purity, authentication, and traceability; (v) health and nutrition; (vi) consumers. The coming research, besides achieving those challenges, would increase the understanding of some aspects that are still the subject of debate and controversy among scientists focused on olive oil.  相似文献   

11.
As an important component of organic fertilizers, animal faeces require methods for determining diet effects on their microbial quality to improve nutrient use efficiency in soil and to decrease gaseous greenhouse emissions to the environment. The objectives of the present study were (i) to apply the chloroform fumigation extraction (CFE) method for determining microbial biomass in cattle faeces, (ii) to determine the fungal cell-membrane component ergosterol, and (iii) to measure the cell-wall components fungal glucosamine and bacterial muramic acid as indices for the microbial community structure. Additionally, ergosterol and amino sugar data provide independent control values for the reliability of the microbial biomass range obtained by the CFE method. A variety of extractant solutions were tested for the CFE method to obtain stable extracts and reproducible microbial biomass C and N values, leading to the replacement of the original 0.5 M K2SO4 extractant for 0.05 M CuSO4. The plausibility of the data was assessed in a 28-day incubation study at 25 °C with cattle faeces of one heifer, where microbial biomass C and N were repeatedly measured together with ergosterol. Here, the microbial biomass indices showed dynamic characteristics and possible shifts in the microbial community. In faeces of five different heifers, the mean microbial biomass C/N ratio was 5.6, the mean microbial biomass to organic C ratio was 2.2%, and the mean ergosterol to microbial biomass C ratio was 1.1‰. Ergosterol and amino sugar analysis revealed a significant contribution of fungi, with a percentage of more than 40% to the microbial community. All three methods are expected to be suitable tools for analysing the quality of cattle faeces.  相似文献   

12.
Abstract

Ion exchangers have proven to be a useful tool in the study of metal speciation in aquatic environments, but have seen little application in the study of metal behavior in soil environments. The labile metal species in polluted soils were evaluated by equilibrating soil suspensions with ion exchange resin membranes of different types at pH values ranging from 3 to 9. The total soluble metal content of cadmium (Cd), chromium (Cr), nickel (Ni), and lead (Pb) contaminated Western Canadian soils was subdivided into (i) low‐pH labile, (ii) weak‐acid labile, (iii) weak‐base labile, (iv) high‐pH labile, and (v) non‐adsorbable forms using cation and anion exchange membranes. Soil suspension is mixed overnight with different types of resin membranes and the cations transferred from the soil are subsequently eluted from the membranes using 1N HCl. The HCl extract is then analyzed for Cd, Cr, Ni, and Pb. The aqueous phase remaining in contact with the soil residue is considered the amount of released non‐labile, non‐adsorbable species. The low‐pH labile fraction constituted the largest proportion of the added metal in poorly buffered (sandy) soils. Weak‐acid and base labile fractions were typically highest in highly buffered soils. Clearly, metal contaminated soils most likely to cause environmental damage are sandy textured soils subject to acidification, although the production of chelating substances by roots and microorganisms may also mobilize considerable quantities of metal in soils of high clay content.  相似文献   

13.
Goal, Scope and Background  In terrestrial ecotoxicology, standardised test methods using plants, earthworms and insects are available for the evaluation of effects induced by heavy metals, organic chemicals and, in particular, pesticides. Currently, these tests are performed either by using so-called Artificial Soils or (more or less) arbitrarily selected natural soils. Consequently, the test results depend not only on the intrinsic physico-chemical properties of the test chemical, but are also significantly influenced by the variable properties of the chosen soil In order to standardise the. test conditions and, at the same time, to relate the test results to representative soil types within the EU, it is proposed to modify the EURO-Soil concept for testing purposes. Main Features  The EURO-Soil concept, i.e. the selection of a limited number of soils that are representative for Europe, was originally developed for the performance of standardised environmental fate tests. Despite many problems in detail, soils from six sites all over Europe were identified that cover a wide range of soil properties (e.g. texture, pH, organic matter content) and, therefore, very different conditions concerning the bioavailability and, in turn, the effects of chemicals. Obviously, the routine use of EURO-Soils as a control or test substrate would require large amounts of soil. Therefore, it is proposed to modify this concept in such a way that all soils similar to one of the six EUROSoils can be used for ecotoxicological tests. Results and Discussion  It is assumed that the six EURO-Soils are representative for wide areas of the European Union, but at the same time it is neglected that some soils typical for, e.g. Northern Scandinavia, have to be identified in the future. All soils having similar properties (i.e. texture, pH, C/N ratio, and organic matter content) as one of the original EURO-Soils are called SIM-Soils. In this contribution, ‘ranges’ are proposed for four main properties and the six EUROSoils, thus allowing the identification of the SIM-Soils. However, since these properties cover a continuum, soils cannot be classified easily into a small number of classes; expert knowledge is required in order to decide whether a natural soil belongs to a certain SIM-Soil class or not. In the long run, this classification must take biological parameters like their suitability for standard test organisms into account as well. Recommendation and Outlook  The soils selected so far (at least one for each EURO-Soil) are actually tested using different biological test methods. Further tests are necessary in order to decide which tests can be done in which soil and whether new test systems, e.g. covering acid soils, have to be developed. However, it is already clear that the standard test species differ distinctly regarding their sensitivity towards soil properties. It is recommended to use the SIMSoils in order to provide the authorities with more field-relevant, data when assessing chemicals in the terrestrial environment.  相似文献   

14.
Two adjacent soils with contrasting sulfate sorption were examined in terms of (i) water-soluble and ion-exchangeable Al, Fe, Ca, Mg, K, Mn and Zn, (ii), water- and bicarbonate-extractable sulfate, (iii) Truog-extractable P, (iv) dithionite-extractable Al, Mn and Fe and (v) treatment response to irrigation with simulated acid precipitation. The biomass of 8 year old black spruce saplings growing on the soils, and the distributions of Al, Fe, Ca, Mg, K, Mn, P and Zn within these plants, were also examined. The soils were well to moderately-well drained, with the mineral soil exposed by site preparation prior to planting. The exposed soil underneath individual saplings was treated with acid sulfate solutions (75 mm containing 2 to 50 mg L?1 H2SO4) applied during each of three consecutive growing seasons. The results indicate that Al, much like Fe, Ca, Mn and Zn, accumulated with time in the foliage, but K, Mg and P were highest in young plant tissues. Much of Al and Fe taken up remained in the fine roots. Aluminum uptake increased with the amount of dithionite-extractable Al (free Al oxide) in the soil. Growth of the black spruce saplings was not visibly affected by readily accessed Al in each soil, or by acid irrigation.Instead, growth was restricted by factors other than soil Al and acid irrigation in spite of (i) low soil pH, (ii) high levels of exchangeable Al, and (iii) high levels of Al in fine roots. Sulfate retention across and within the two soils was positively correlated with free Al oxide. The two soils responded to acid irrigation by accelerated silicate weathering and enhanced ion leaching. Sulfate sorption reduced these effects.  相似文献   

15.
Laboratory‐based aggregate stability (AS) tests should be applied to material wetted to a moisture content comparable with that of a field soil. We have improved our original laser granulometer (LG)‐based AS test published in this journal by including a pre‐wetting stage. Our method estimates disaggregation reduction (DR; µm) for a soil sample (1–2‐mm diameter aggregates). Soils with more stable aggregates have larger DR values. We apply the new technique to soils from 60 cultivated sites across eastern England, with ten samples from each of six different parent material (PM) types encompassing a wide range of soil organic carbon (SOC) concentrations (1.2–7.0%). There are large differences between the median DR values (rescaled to < 500 µm) for soils over the PM types, which when used as a predictor (in combination with SOC concentration) accounted for 53% of the variation in DR. There was no evidence for including an interaction term between PM class and SOC concentration for the prediction of DR. After applying the aggregate stability tests with the 60 regional soil samples, they were stored for 9 months and the tests were repeated, resulting in a small but statistically significant increase in DR for samples from some, but not all, PM types. We show how a palaeosol excavated from a site in southern England can be used as an aggregate reference material (RM) to monitor the reproducibility of our technique. It has been suggested that soil quality, measured by critical soil physical properties, may decline if the organic carbon concentration is less than a critical threshold. Our results show that, for aggregate stability, any such thresholds are specific to the PM.  相似文献   

16.
近20年来，国际上兴起的“地球关键带”研究，为重新审视地球表层系统内水、土、气、生、岩等各要素的功能及其内在关联提供了新思路。通过搜集2001—2021年间国内外地球关键带研究，应用引文空间（CiteSpace）技术进行文献计量分析，梳理地球关键带的研究历史与现状，为自然资源综合管理和国土空间生态修复提供理论依据和决策支持。文献分析表明：地球关键带受到欧美发达国家和中国学界的普遍关注；三个发展阶段（萌芽、初期和快速发展）的研究重点差异明显；土壤是联结地表和地下过程的纽带与核心；地球物理技术成为理解地球关键带结构与过程的重要工具；联网观测和模型模拟是下一阶段的重要方向；地球关键带功能和服务的量化、权衡与提升有望成为重要的决策支持工具。未来仍需在五个方面深化研究：加强基础设施建设，构建更具包容性的地球关键带观测站网络；加强学科交叉和人才队伍建设，培养新一代地球关键带科学家；服务面向可持续发展的社会需求，在实践中应用和发展地球关键带科学；开发新技术、新方法，完善理论、模型和方法体系；揭示地球关键带过程的耦合机制及其环境效应，加强人类活动对水土过程、物质循环与能量交换影响的研究。  相似文献   

17.
《Geoderma》2001,99(1-2):123-145
The quantification and interpretation of aggregate stability depend on internal soil properties and external factors such as measurement method and aggregate size. The objectives of this study were to: (i) determine the aggregate stability in Ultisols from subtropical China applying the Le Bisssonais Method; (ii) determine the effect of initial aggregate size on its stability, and (iii) interpret mechanisms of aggregate stabilization in the soils. Three aggregate-size ranges (5–3, 3–2 and 2–1 mm) were obtained by dry sieving. After the wetting treatments, the dominant fraction of fragments for each soil was 2–1 mm or 0.63–0.2 mm. The mechanisms of aggregate breakdown was in the order, slaking>mechanical breakdown>micro-cracking. They differed with soil type and composition. The normalized mean weight diameter (NMWD) of the aggregates after fast wetting and wet stirring were more correlated with soil properties, such as degree of micro-aggregation (DOA), cation exchange capacity (CEC), K2O, Fe2O3 or Al2O3 rather than clay and soil organic carbon (SOC) content. The binding force by soil organic matter was smaller than the force caused by entrapped air or the force of combination of mechanical stress by stirring and differential swelling of minerals.The smaller the aggregate, the larger was the aggregate stability according to NMWD. The rankings of the soils differed with the soil aggregate sizes and the wetting treatments. Sandy loams from sandstone (Sc and Sw) were the weakest soils while the purple mudstone (Pp) was the strongest. All the cultivated soils decreased in aggregate stability compared with the comparable uncultivated soils or parent materials irrespective of the cultivation time and the changes in SOC content after cultivation.  相似文献   

18.
Abstract

We developed a simple and rapid method suitable for on‐site determination of gravimetric water content of soil samples. The proposed procedure was as follows; i) take 10–20 g of a soil sample in a tared mortar and weigh with a portable electronic balance, ii) add glycerol at a soil:glycerol ratio of 1 to 2 and weigh again, iii) mix the soil and glycerol thoroughly to ‘extract’ soil water into the added glycerol, iv) measure the refractive index of the ‘extract’ passed trough a filter placed on a refractometer, and vi) calculate the water content of the soil sample from a calibration curve relating the refractive index to water content of glycerol and the weights of the soil sample and glycerol. We tested the method on four soils at various moisture levels and found that the water contents from the proposed method were close to those from the standard oven‐drying method with slight downward deviations.  相似文献   

19.
A new survey taken in the East Mediterranean island of Cyprus showed an increase in the number of earthworm species (from the six recorded earlier to 16). These species belong to two earthworm families: Lumbricidae (15 species) and Acanthodrilidae (one species). The majority of these species are autochthonous (57–64%) and five to seven species (36–44%) were introduced. The autochthonous species are (i) endemic of the Levant (Dendrobaena semitica), (ii) distributed in Anatolia and the Caucasus (D. pentheri), (iii) distributed from Europe up to Anatolia (Allolobophora nematogena, D. pantaleonis, Proctodrilus tuberculatus) (iv) distributed from Europe up to the Levant (Murchieona minuscula), (v) distributed in the Transcaucasian region and in the East Mediterranean (Helodrilus patriarchalis), or (vi) widely distributed along the Mediterranean basin (D. byblica, Eiseniella neapolitana, and Octodrilus complanatus). The data obtained indicate that the Cypriote earthworm fauna is significantly richer in species than previously thought and that it has more zoogeographic affinities with the Anatolian fauna than with those of Levant.  相似文献   

20.
Ecotoxicological tests are often recommended for the environmental risk assessment (ERA) of contaminated soils. In comparison to chemical residue analysis that focuses on individual contaminants, ecotoxicological tests are able to integrate the effects of the overall contamination, including interactions between individual contaminants, as well as between the contaminants and the various soil properties. However, their use is limited by the fact that the most sensitive tests are chronic tests such as the earthworm reproduction test which lasts 56 days. In order to promote the use of ecotoxicological tests for the routine assessment of contaminated test soils, the usage of short-term earthworm avoidance tests were investigated in the German project ERNTE. According to the International Organization for Standardization (ISO) guideline no. 17512-1, such a test has a duration of just 48 h which, although less than chronic tests, is still quite long in comparison to modern methods of chemical analysis whereby results are often available within 24 h (“on-site analysis”). Therefore, we assessed the effects of shortening the duration of the earthworm avoidance test from 48 to 24 h on the resulting ecotoxicological data. Eight uncontaminated natural soils and 22 contaminated natural soils containing a wide range of chemicals were tested concurrently for 24 and 48 h. Additionally, seven of the uncontaminated natural soils (one was excluded due to its low pH) plus Organization for Economic Co-operation and Development (OECD) artificial soil or LUFA (Landwirtschaftliche Untersuchungs- und Forschungsanstalt, Speyer, Germany) St. 2.2 soil were spiked with two model chemicals (zinc nitrate-tetrahydrate and tributyltin-oxide (TBT-O)) and tested accordingly. It was also investigated whether the results would differ when using either standard LUFA St. 2.2 or OECD artificial soil as a control when contaminated natural soils were tested. Statistical analysis of the data indicates that a decrease in test duration in general did not result in a different assessment of the test soils. In view of the fact that an ERA of contaminated soils is increasingly starting with an on-site analysis (i.e. data are available within 24 h) it is recommended to change the existing ISO guideline, i.e. to decrease the test duration from 48 to 24 h. In doing so, the use of a multi-concentration design increases the robustness of the test results. Both OECD and LUFA St. 2.2 soils are equally suitable as controls.  相似文献   

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