Evidence for Atmospheric Deposition Impacts On the Enchytraeid Worm Population of Uk Upland Ombrotrophic Peats

The results of four experiments on acidification effects upon the Enchytraeid worm populations of ombrotrophic peats are reported. in the first, populations were measured in peats from Calluna vulgaris-dominated microcosms collected from along a gradient in N deposition in the UK and subjected for 18 months to simulated precipitation with a solute composition appropriate for their site of collection. There was a significant decline in Enchytraeid population along the N deposition gradient for Calluna-dominant microcosms, but when grasses took over from the Calluna, Enchytraeid numbers increased significantly. in the second experiment, two sets of peat moorland microcosms from a single site, supporting Calluna and Calluna-grass mixed vegetation, were subjected for 12 months to ambient and 2- and 6-times the ambient N deposition. Additional N was added in two forms, as ammonium sulphate and as nitric acid. the high N treatments significantly reduced the Enchytraeid populations for both vegetation types. in a third experiment, the pH preference for the Enchytraeids was assessed using interconnected tubes of peat covering the pH range 2.2-8.7. the preferred pH range after 8 months was 2.7-3.7. in the final experiment, it was found that recolonization with Enchytraeids after initial removal was more rapid under grass dominant vegetation than under Calluna dominant vegetation.     

Evidence for Atmospheric Deposition Impacts On the Enchytraeid Worm Population of Uk Upland Ombrotrophic Peats

The results of four experiments on acidification effects upon the Enchytraeid worm populations of ombrotrophic peats are reported. in the first, populations were measured in peats from Calluna vulgaris-dominated microcosms collected from along a gradient in N deposition in the UK and subjected for 18 months to simulated precipitation with a solute composition appropriate for their site of collection. There was a significant decline in Enchytraeid population along the N deposition gradient for Calluna-dominant microcosms, but when grasses took over from the Calluna, Enchytraeid numbers increased significantly. in the second experiment, two sets of peat moorland microcosms from a single site, supporting Calluna and Calluna-grass mixed vegetation, were subjected for 12 months to ambient and 2- and 6-times the ambient N deposition. Additional N was added in two forms, as ammonium sulphate and as nitric acid. the high N treatments significantly reduced the Enchytraeid populations for both vegetation types. in a third experiment, the pH preference for the Enchytraeids was assessed using interconnected tubes of peat covering the pH range 2.2–8.7. the preferred pH range after 8 months was 2.7–3.7. in the final experiment, it was found that recolonization with Enchytraeids after initial removal was more rapid under grass dominant vegetation than under Calluna dominant vegetation.     

Evidence for Ph Insensitivity in Some Insects Inhabiting Peat Pools in the Loch Fleet Catchment

The impact of liming on the insects associated with peat pools was studied in the Loch Fleet catchment in 1991 and 1992. Fifty-six taxa were identified from 121 timed samples. Despite the raised pH associated with liming in 1986, the population densities of Odonata, Hemiptera and Coleoptera appeared to be unaffected when compared with those of untreated peat pools in the same area. the study demonstrated the existence of two main types of community, that of the steep-sided edges of pools, dominated by odonate nymphs and large species of beetles, and that of the shallower pools, dominated by Hydroporus species (Col., Dytiscidae).     

Tolerance of calluna vulgaris and peatland plant communities to sulphuric acid deposition

Critical loads offer a unique way of evaluating impacts of acid deposition by quantifying environmental sensitivity. The critical loads of acidity for UK peat soils have been based upon an arbitrary reduction in pH of 0.2 units. This chemical shift needs to be better related to adverse effects on sensitive biological receptors. It is known that effective precipitation pH equates closely to soil solution pH, and the latter is directly linkable to biotic effects of pH change. On continuation of a long-term experiment assessing impacts of simulated acid rain on peat microcosms in a realistic outdoor environment, Calluna vulgaris continued to flourish at acid deposition loads well above the existing critical load. Calluna plants were harvested and analysed, and acid deposition treatments to the microcosms continued to allow natural vegetation to regenerate. A diverse mixture of moorland plants and bryophytes established at acidity treatments well above the existing critical load, and only a very high acid load resulted in no natural regeneration. A critical effective rain pH value of 3.6 is suggested as a basis for setting critical loads. At this pH, Calluna grows well, and a healthy diverse vegetation community re-establishes when harvested. It is suggested that the peat critical load should be set at the acid load that, at any specific site, would result in a mean effective precipitation pH of 3.6.     

改良剂对红蛋植物修复污染土壤重金属铅和镉效果的影响

通过盆栽试验研究了在重度重金属混合污染土壤上,施用不同配比的石灰和泥炭（T1,泥炭0 g·kg^-1土,石灰2 g·kg^-1土;T2,泥炭30 g·kg^-1土,石灰0 g·kg^-1土;T3,泥炭50 g·kg^-1土,石灰0g·kg^-1土;T4,泥炭30 g·kg^-1土,石灰2g·kg^-1土;T5,泥炭50 g·kg^-1土,石灰2g·kg^-1土）对红蛋（Echinodorus osiris）生长及其去除污染土壤铅、镉量的影响,探讨了化学修复和植物提取修复技术相结合修复重金属污染土壤的可能性。研究结果表明,施用石灰显著提高了土壤pH,施用泥炭不显著;施用石灰和泥炭后土壤中交换态铅、镉含量较CK显著降低,红蛋地上部和地下部铅、镉含量较CK有不同程度降低,T4、T5处理降低不显著;T3、T4、T5处理显著地提高了红蛋的铅单株迁移量和年迁移量,年迁移量分别为CK的2.1倍、2.6倍和2.8倍;T1、T2、T3、T4、T5处理显著地提高了红蛋的镉单株迁移量和年迁移量,年迁移量分别为CK的1.8倍、2.9倍、2.9倍、2.8倍和2.9倍,其主要原因在于施用土壤改良剂改善了红蛋的生长,显著增加了地上部生物量。结合经济效益方面因素考虑,以施用泥炭30g·kg^-1土和石灰2g·kg^-1土的处理更适合推广运用。     

泥炭生物脱臭技术研究

本文介绍生物脱臭的应用及其原理；并以自采的泥炭为载体，以硫化氢氧为试验气体，进行原始泥炭以及经过各种处理后泥炭臭性能的对比试验，由试验证明泥 一种比较理想的脱臭生物载体。     

Effects of Simulated Sulphuric Acid Deposition On Calluna Vulgaris/Peat Microcosms and Associated Soil Solutions

Calluna vulgaris/peat microcosms have been used in an outdoor simulated acid rain experiment to test a series of hypotheses about sulphuric acid deposition effects upon the growth of Calluna on peat soil, namely: (1) Initially, enhanced acid input will enhance base cation and ammonium concentrations in soil solution. This may enhance uptake of these species, increasing foliar concentrations of base cations and nitrogen, and possibly foliar chlorophyll a and b concentrations. (2) If changes are induced in nutritional status, they may influence plant growth. (3) in the longer term, enhanced ammonium and base cation solubility occurring as a consequence of cation exchange reactions will lead, especially in winter months, to enhanced leaching losses. Hence any positive effects upon plant nutrition will not be sustainable. (4) the peat will acidify significantly over two years, in the shorter term primarily as a consequence of an enhanced mobile anion effect. (5) Acidification may reduce the rate of mineralisation of organic phosphorus and, in a phosphorus-deficient peat soil, this may lead to reduced foliar phosphate concentration and possibly induce phosphorus deficiency.

Most of these hypotheses were supported to some extent by the experimental results. the peat soil solution pH fell immediately in response to the acid treatments, and longer-term acidification continued progressively over the two years of the experiment. in the first year, the treatments significantly influenced the calcium, magnesium, phosphorus and nitrogen status of the leaves from Calluna new shoots, whereas in the second year calcium, potassium and phosphorus were influenced. However, in both years foliar phosphate concentration was enhanced, rather than reduced, in response to increased acid load. Foliar carbon and nitrogen concentrations fell with increasing acidity of     

Evidence for Ph Insensitivity in Some Insects Inhabiting Peat Pools in the Loch Fleet Catchment

The impact of liming on the insects associated with peat pools was studied in the Loch Fleet catchment in 1991 and 1992. Fifty-six taxa were identified from 121 timed samples. Despite the raised pH associated with liming in 1986, the population densities of Odonata, Hemiptera and Coleoptera appeared to be unaffected when compared with those of untreated peat pools in the same area. the study demonstrated the existence of two main types of community, that of the steep-sided edges of pools, dominated by odonate nymphs and large species of beetles, and that of the shallower pools, dominated by Hydroporus species (Col., Dytiscidae).     

Variation of salts and available nutrients in salt-affected soil during leaching process under the influence of organic ameliorators

ABSTRACT

This study investigated the potential influence of three organic ameliorators (peat, biochar and leonardite) on salts and nutrients in salt-affected soils during intermittent leaching. Results showed that nearly 90% of salt was removed from columns in the leaching process and sodium adsorption ratio (SAR) of the soil after leaching was reduced by 67.3% (control, CK), 62.9% (peat), 70.1% (biochar) and 55.0% (leonardite). Total N loss declined by 26.2% (peat), 11.7% (biochar) and 55.5% (leonardite) compared with CK in the process of leaching. The maintaining N (NH₄⁺ and NO₃^?) of soil after leaching was 8.25, 7.31, 11.31 and 14.48?mg/kg for CK, peat, biochar and leonardite treatments. Final P loss was 0.47, 0.31, 0.54, 0.27?mg/column in leaching for CK, peat, biochar and leonardite treatments. Soluble P of soil after leaching was measured as 6.95 (CK), 5.62 (peat), 8.52 (biochar) and 3.33 (leonardite) mg/kg. Leaching could remove the salt effectively but with nutrient loss in the process. The findings of this study suggest that organic ameliorators (biochar, peat or leonardite) play an important role in retaining nutrients during leaching as well as supplying nutrients after leaching to offer practical assistance for the amendment of salt-affected soil in the Yellow River Delta.     

Effects of previous drying of sediment on root functional traits and rhizoperformance of emerged macrophytes

• Sediment desiccation alters morphological characteristics of aquatic sediment. • Alternation in morphological properties of sediment limiting root characteristics. • Fibrous-rooted macrophytes root properties extra favor nutrients removal. • Thick-rooted macrophytes exhibit higher life-span in two sediment types. Purpose of the current study was to investigate the effects of constantly wet and dried-rewetted sediments on root functional traits of emerged macrophytes and their nutrients removal abilities. It is based on the hypothesis that root characteristics and nutrients removal abilities of plants will be altered in the course of sediment desiccation. Four emerged macrophytes including two fibrous-root plants (Canna indica and Acorus calamus) and two thick-root plants (Alocasia cucullata and Aglaonema commutatum) were investigated for their root functional traits and rhizoperformance in both wet and dried-rewetted sediments. Results showed that sediment desiccation followed by rewetting substantially altered the root functional traits (root surface area, radial oxygen loss, and root activity) of plants due to adverse changes in morphological characteristics (porosity, bulk density, particle density) of dried-rewetted sediments than by wet sediments. Consequently, limited plants growth and removal of nitrogen (N), phosphorus (P) and dissolved organic carbon (DOC) were recorded in dried-rewetted sediments and their pore water than in wet sediments. Radial oxygen loss from plant roots correlated positively with root functional traits, plants growth, and removal of N, P and DOC from pore water and sediment in both sediment types. Among the macrophyte species, the fibrous-root plants having advantages root functional traits, greatly influenced the rhizospheric conditions (pH, dissolved oxygen and redox potential), and demonstrated higher N, P and DOC reduction from both sediment types. While, the thick-rooted plants with thick diameter roots (D > 1 mm) and higher rhizome exhibited longer life-span in both sediment types.     

可溶性有机质对芘在泥炭和高岭土上吸附和解吸的影响

为掌握可溶性有机质(DOM)对憎水性有机污染物吸附和解吸行为的影响,本研究选取四环多环芳烃——芘作为目标污染物,通过批平衡实验研究了不同分子量组分DOM对芘在泥炭和高岭土上吸附和解吸的影响.结果表明,吸附和解吸数据均可以用Freundlich模型很好地拟合(R²>0.93).DOM的添加抑制了泥炭对芘的吸附,并且分子量越大的DOM产生的抑制效应越明显,主要是由于DOM与芘分子的竞争、增溶作用及泥炭表面微孔的堵塞引起的.与之相反,DOM促进了芘在高岭土上的吸附,DOM分子量越大,促进效应越强,这是由于DOM与芘分子之间通过累积吸附或共吸附增加高岭土对芘的吸附.DOM促进了芘在泥炭和高岭土上的解吸,并且促进效应随分子量的增加而增强.此外,芘在泥炭和高岭土上的解吸均存在迟滞现象,均在低浓度时表现出更明显的效应.DOM_bulk和DOM_(>14000 Da)增加了芘在泥炭上的解吸迟滞现象,但降低了其在高岭土上的解吸迟滞现象.     

石灰泥炭对镉铅锌污染土壤上小白菜生长和元素吸收的影响

采用盆栽方法研究了在镉、铅、锌污染土壤上,石灰和泥炭对小白菜生长状况及对污染元素(Ｃｄ,Ｐｂ,Ｚｎ)和养分元素(Ｎ,Ｐ,Ｋ,Ｃｕ,Ｍｎ,Ｆｅ)吸收的影响。结果表明,石灰消除了重金属的毒害症状．显著促进小白菜的生长、显著抑制小白菜对镉、铅、锌的吸收。石灰对氮、钾、铜、锰的吸收也有显著抑制作用。泥炭对小白菜生长的改善效果及对铜、铅、锌吸收的抑制效果较石灰差。提高酸性土壤ｐＨ值是减少作物对重金属吸收的有效方法。     

A new conceptual model for the fate of lignin in decomposing plant litter

Lignin is a main component of plant litter. Its degradation is thought to be critical for litter decomposition rates and the build-up of soil organic matter. We studied the relationships between lignin degradation and the production of dissolved organic carbon (DOC) and of CO2 during litter decomposition. Needle or leaf litter of five species (Norway spruce, Scots pine, mountain ash, European beech, sycamore maple) and of different decomposition stage (freshly fallen and up to 27 months of field exposure) was incubated in the laboratory for two years. Lignin degradation was followed with the CuO method. Strong lignin degradation occurred during the first 200 incubation days, as revealed by decreasing yields of lignin-derived phenols. Thereafter lignin degradation leveled off. This pattern was similar for fresh and decomposed litter, and it stands in contrast to the common view of limited lignin degradation in fresh litter. Dissolved organic carbon and CO2 also peaked in the first period of the incubation but were not interrelated. In the later phase of incubation, CO2 production was positively correlated with DOC amounts, suggesting that bioavailable, soluble compounds became a limiting factor for CO2 production. Lignin degradation occurred only when CO2 production was high, and not limited by bioavailable carbon. Thus carbon availability was the most important control on lignin degradation. In turn, lignin degradation could not explain differences in DOC and CO2 production over the study period. Our results challenge the traditional view regarding the fate and role of lignin during litter decomposition. Lignin degradation is controlled by the availability of easily decomposable carbon sources. Consequently, it occurs particularly in the initial phase of litter decomposition and is hampered at later stages if easily decomposable resources decline.     

Changes in nutrient content and stable isotope ratios of C and N during decomposition of seagrasses and mangrove leaves along a nutrient availability gradient in Florida Bay, USA

The decomposition of the mangrove Rhizophora mangle and the seagrass Thalassia testudinum was examined using litterbags along a natural gradient in nutrient availability. Seagrass leaves had a higher fraction of their biomass in the labile pool (57%), compared to mangrove leaves (36%) and seagrass rhizomes (29%); the overall decomposition rates of the starting material reflected the fractionation into labile and refractory components. There was no relationship between the N or P content of the starting material and the decomposition rate.

Nutrient availability had no influence on decomposition rate, and mass was lost at the same rate from litterbags that were buried in the sediment and litterbags that were left on the sediment surface. The dynamics of N and P content during decomposition varied as a function of starting material and burial state. N content of decomposing mangrove leaves increased, but seagrass rhizomes decreased in N content during decomposition while there was no change in seagrass leaf N content. These same general patterns held for P content, but buried seagrass leaves increased in P content while surficial leaves decreased. δ¹³C and δ¹⁵N changed by as much as 2‰ during decomposition.     

磐石等四种泥炭脱除硫化氢能力的研究

本文介绍用自采的磐石等四种泥炭，以硫化氢为试验气体，用同一套试验设备，在相同条件下进行脱臭能力为比的试验研究。并由试验中总结出影响泥炭脱臭能力的物理及化学因素。     

1995年以来国外泥炭及泥炭地研究进展

自1995年以来国外科技工作者对泥炭及泥炭地进行了大量研究。其中，泥炭的基本物理及化学性质、泥炭中环境污染物质如硫化物、甲基汞、泥炭酸碱性、有机物的迁移转化，泥炭地对重金属、有机污染物环境污染物质的吸收、生物过滤和降解、泥炭地对C02、CH4的排放，泥炭地对古环境特征的记录、泥炭与泥炭地的开发利用，是近年来的主要研究内容，这些领域的研究取得了较大的进展。     

Seven Years of Change Following Liming of Sphagnum Communities in Sector Vii of the Loch Fleet Catchment

In 1986, application of lime within the upper wetland area of sector VII of the Loch Fleet catchment initiated numerous unscheduled small-scale experiments on the vegetation of this heterogeneous terrain. Vegetation changes and erosion were monitored in permanent or relocated plots established in 1987 and 1989 and re-surveyed in 1993, seven years after liming.

The most striking early effect, possibly occurring within a few weeks of lime application, was the death of Sphagnum papillosum carpet in soakways within the 2.5 ha area. Some patches of dead material were washed away, but bare surfaces were generally colonised by vascular plants, notably Juncus bulbosus. Effects in moorland and bog communities with dwarf shurbs were more subtle, involving reduction in Sphagnum cover and expansion of Erica teralix, Molinia caerulea, sedges and Narthecium ossifragum, but little change in the frequency of occurrence of Calluna vulgaris.     

Determination of chemical characterizations of activated carbons from various raw materials

The objectives of this research were to identify the surface chemical features of activated carbons made of peat, bituminous coal and coconut shell, as well as examine the specific relationship of these properties by using statistical analyses. The results showed that the peat carbons contained much more amounts of Ca, S, P and Mg; however, the bituminous carbons possessed higher contents of Si, Al and Fe. In addition, the content ratios of Al to Si exhibited the Al enrichment phenomenon occurred after the heat treatment. A nonlinear correlation between the pH value and the difference in the amounts of basic and acidic groups was developed. Unfortunately, there were no specific mass ratios found among the acidic functional groups. The results of correspondence analysis (CA) gave a promising confirmation about the EDXRF analysis; moreover, the results of factor analysis (FA) fairly agreed with the findings suggested by CA. Both could explain the specific chemical features of activated carbons made from different materials, especially the CA could differentiate each other in detail.     

Litter decomposition and nitrogen mineralization from an annual to a monthly model

The forest litter decomposition model (FLDM) described in this paper provides an important basis for assessing the impacts of forest management on seasonal stream water quality and export of dissolved organic carbon (DOC). By definition, models with annual time steps are unable to capture seasonal, within-year variation. In order to simulate seasonal variation in litter decomposition and DOC production and export, we have modified an existing annual FLDM to account for monthly dynamics of decomposition and residual mass in experimental litterbags placed in 21 different forests across Canada.The original annual FLDM was formulated with three main litter pools (fast, slow, and very slow decomposing litter) to address the fact that forest litter is naturally composed of a mixture of organic compounds that decompose at different rates. The annual FLDM was shown to provide better simulations than more complex models like CENTURY and SOMM.The revised monthly model retains the original structure of the annual FLDM, but separates litter decomposition from nitrogen (N) mineralization. In the model, monthly soil temperature, soil moisture, and mean January soil temperature are shown to be the most important controlling variables of within-year variation in decomposition. Use of the three variables in a process-based definition of litter decomposition is a significant departure from the empirical definition in the annual model. The revised model is shown to give similar calculations of residual mass and N concentration as the annual model (r² = 0.91, 0.78), despite producing very different timeseries of decomposition over six years. It is shown from a modelling perspective that (i) forest litter decomposition is independent of N mineralization, whereas N mineralization is dependent on litter decomposition, and (ii) mean January soil temperature defines litter decomposition in the summer because of winter-temperatures’ role in modifying forest-floor microorganism community composition and functioning in the following summer.     

三江平原泥炭地微量元素垂直分布特征

采用冬季采样，现场分层的方法，系统地研究了三江平原河床-河漫滩型泥炭地和谷底洼地型泥炭地微量营养元素和有益元素的垂直分布特征。结果表明，微量营养元素Cu、Zn、Fe、Mn、B和有益元素Ni、Sr、Ti、V、Co均有在G层急剧积累的趋势，Fe、Mn、B、Zn、Ti、Sr质量分数在Ase层明显高于泥炭层，某些微量元素间具有显著的相关性。