Monitoring shallow methane‐derived authigenic carbonate: Insights from a UK Marine Protected Area

1. Methane‐derived authigenic carbonate (MDAC) is a biogenic rocky substrate formed by microbial assemblages below the seabed. It performs important ecosystem functions, including the provision of reef‐like habitats on soft sediments and the sequestration of carbon.
2. The protection of MDAC is limited at the global scale; however, 27 marine protected areas (MPAs) have been designated in European waters for ‘cold seep’ MDAC, mainly in shallow waters (<200 m). Few studies have been conducted on these habitats from a conservation perspective.
3. The effective management of MDAC structures requires an understanding of their ecology and physical characteristics in a healthy condition. This is best achieved using a multidisciplinary approach to provide evidence on predefined aspects of MDAC structures, termed feature attributes, which can be assessed to determine habitat condition over time.
4. This article presents the first UK effort to develop a multidisciplinary approach to monitoring shallow MDAC feature attributes, using the Croker Carbonate Slabs Special Area of Conservation (SAC) as a case study. A range of remote and physical survey methods were used to characterize the MDAC and associated relatively unimpacted and healthy biological communities.
5. The data confirm that the SAC contains the largest known area of shallow MDAC in European waters, that methane release is ongoing, and that MDAC is still likely to be forming. Specialized chemoautotrophic fauna were not recorded, possibly due to the dominance of fauna that derive carbon (ultimately) from photosynthesis. Five epifaunal taxa were found to be associated with MDAC, but not with the surrounding sediments.
6. The broad multidisciplinary survey allowed a detailed characterization of shallow MDAC but was resource intensive. We recommend a low‐resource monitoring strategy to deliver cost‐effective and robust evidence for condition assessment and suggest further studies to contextualize future interpretations of change.

     

聚碳酸乙烯酯代替乙二醇碳酸酯液化玉米秸秆的效果研究

通过催化液化技术和环状碳酸酯的开环聚合技术的结合，提高秸秆液化产率以及改进液化产物在交联成大分子后存在的生物降解缓慢问题。研究采用Lewis酸盐作催化剂，对乙二醇碳酸酯(EC)进行开环聚合，并利用聚合产物——聚碳酸乙烯酯(PEC)代替传统液化剂EC对玉米秸秆进行了液化。对液化产物的定量分析表明，该新工艺固定液化剂中碳酸酯基团从而将液化产率提高了31.4%。同时，新的液化产物的化学结构中引进了脂肪族碳酸酯，其聚氨酯产品的生物降解速率得到较大提高。     

Clay illuviation and calcium carbonate accumulation along a precipitation gradient in Kansas

One of the significant features of loess-derived soils in Kansas is the occurrence of clay-rich subsurface horizons above a layer enriched with pedogenic carbonates. In order to examine the extent of clay increase and pedogenic carbonate enrichment in a precipitation gradient, ten soil profiles from three different precipitation regions were studied using micromorphological and mineralogical techniques. The precipitation gradient was divided into three groups: 400–550 mm, 550–750 mm, and 750–1100 mm regions. The objectives were to (1) understand the cause of clay orientation in clay-rich horizons (2) investigate the reasons for the clay increase, and (3) observe the interaction of clay and pedogenic carbonate accumulation features along a precipitation gradient in Kansas. Although clay films were identified in the field for soils in the 400–550 mm regions, illuvial clay films were not observed in thin section analysis. The clay accumulations mostly occurred as grain coatings. The rest of the clay accumulations observed were very thin, striated, and mostly associated with voids. The argillic horizons had a granostriated b-fabric, which indicates stress orientation of micromass caused by high shrink–swell activity. Thick and continuous illuvial coatings were observed in the buried horizons of paleosols. In the other two regions where precipitation exceeds 550 mm, illuvial clay coatings with strong orientation were observed along with thin and striated stress-oriented clay. Both types of clay orientations exceeded 1% of the cross-sectional area for the thin section. Although illuvial clay features and pedogenic carbonates were observed in all soils at approximately the same depth, complete obliteration of clay coatings was not observed in these horizons. In-situ weathering of biotite was one of the reasons for the clay increase in all soil profiles. In all soils studied, the clay increase and cause of clay orientation cannot be attributed to a single genetic process or event. Both illuviation and shrink–swell activity were involved in the orientation of clay. Although orientation of clay and pedogenic carbonates were observed in all soils at approximately the same depth, the decomposition of clay coatings was not observed in these horizons.     

利用烧失量方法精确测定土壤有机质

Wet oxidation procedure,i.e.,Walkley-Black (WB) method,is a routine,relatively accurate,and popular method for the determination of soil organic matter (SOM) but it is time-consuming,costly and also has a high potential to cause environmental pollution because of disposal of chromium and strong acids used in this analysis.Therefore,loss-on-ignition (LOI) procedure,a simple and cheap method for SOM estimation,which also avoids chromic acid wastes,deserves more attention.The aims of this research were to study the statistical relationships between SOM determined with the LOI (SOMLOI) and WB (SOMWB) methods to compare the spatial variability of SOM in two major plains,Shahrekord and Koohrang plains,of Chaharmahal-va-Bakhtiari Province,Iran.Fifty surface soil samples (0-25 cm) were randomly collected in each plain to determine SOM using the WB method and the LOI procedure at 300,360,400,500 and 550 ℃ for 2 h.The samples covered wide ranges of soil texture and calcium carbonate equivalent (CCE).The general linear form of the regression equation was calculated to estimate SOM LOI from SOM obtained by the WB method for both overall samples and individual plains.Forty soil samples were also randomly selected to compare the SOM and CCE before and after ignition at each temperature.Overall accuracy of the continuous maps generated for the LOI and WB methods was considered to determine the accordance of two procedures.Results showed a significant positive linear relationship between SOM LOI and SOM WB.Coefficients of determination (R2) of the equations for individual plains were higher than that of the overall equation.Coefficients of determination and line slopes decreased and root mean square error (RMSE) increased with increasing ignition temperature,which may be due to the mineral structural water loss and destruction of carbonates at higher temperatures.A temperature around 360 ℃ was identified as optimum as it burnt most organic carbon,destroyed less inorganic carbon,caused less clay structural water loss,and used less electrical energy.Although the trends of SOM in the kriged maps by the two procedures accorded well,low overall accuracy was observed for the maps obtained by the two methods.While not suitable for determination where high accuracy is required,determination of organic carbon through LOI is likely suitable for exploratory soil surveys where rough estimation of organic matter is required.     

碳酸钠、碳酸氢钠和山梨酸钾对柑橘采后酸腐病菌的抑制作用

利用一定浓度的碳酸钠、碳酸氢钠和山梨酸钾对柑橘酸腐病菌进行处理,以体外试验筛选对柑橘酸腐病菌有抑制作用的物质.结果表明:在一定的浓度范围内,碳酸钠、碳酸氢钠和山梨酸钾对柑橘酸腐病菌的生长有抑制作用,并且随着培养基中浓度的增加,对柑橘酸腐病的病斑大小抑制效果越好.当培养基中碳酸钠和山梨酸钾浓度分别为16、8 g/L时,菌丝生长受到完全抑制.表明碳酸钠、碳酸氢钠和山梨酸钾对柑橘酸腐病有很好的防治潜力.     

杀螺药物研究──碳酸酯、氨基甲酸酯类化合物的合成及其构效关系初步探讨

合成了碳酸酯类化合物23个和苯氨基甲酸苯酯类化合物7个。杀螺初筛试验发现，8个碳酸酯化合物具有杀螺活性，其中，化合物I1和I11，10ppm的杀螺率为100％和96．7％。碳酸苯酯的苯环上，用硝基或3个以上的氯原子取代，有利于增强该类化合物的杀螺作用。杀螺效果较好的三氯苯碳酸酯改变成同电异素体类似物，苯氨基甲酸酯后，杀螺作用明显下降。     

山东省青州市典型碳酸盐岩区山楂和柿子对硒的富集规律初步研究

山东省青州市西南部碳酸盐岩区的山楂、柿子种植历史悠久且果实品质上乘,通过系统配套采集山楂和柿子果实及其根系土,探究其含硒水平、富集规律及其影响因素,以期为后续富硒产业开发提供科学依据。研究结果表明：（1）研究区内山楂和柿子根系土中Se元素相对富集,其与有机质密切相关,由于有机质的吸附固化,易利用态硒含量低。（2）山楂和柿子果实中硒含量较低,富集系数也较低,山楂富硒率为17.65%,柿子均未达到富硒。（3）柿子和山楂中硒富集系数与根系土中有机质、硒含量均呈强负相关。（4）有机质吸附固化硒,虽提高了土壤硒含量,但降低了硒的生物可利用性,有机质是影响硒有效性的关键因素。     

LIMESTONE PARTICLE SIZE AND RESIDUAL LIME CONCENTRATION AFFECT PH BUFFERING IN CONTAINER SUBSTRATES

The objective was to quantify how the concentration and particle size of unreacted “residual” limestone affected pH buffering capacity for ten commercial and nine research container substrates that varied in residual calcium carbonate equivalents (CCE) from 0.3 to 4.9 g CCE·L^?1. The nine research substrates contained 70% peat:30% perlite (by volume) with dolomitic hydrated lime at 2.1 g·L^?1, followed by incorporation of one of four particle size fractions [850 to 2000 μm (10 to 20 US mesh), 250 to 850 μm (20 to 60 US mesh), 150 to 250 μm (60 to 100 US mesh), or 75 to 150 μm (100 to 200 US mesh)] of a dolomitic carbonate limestone at 0, 1.5 or 3.0 g·L^?1. Substrate-pH buffering was quantified by measuring the pH change following either (a) mineral acid drenches without plants, or (b) a greenhouse experiment where an ammonium-based (acidic) or nitrate-based (basic) fertilizer was applied to Impatiens wallerana Hook. F. Increasing residual CCE in commercial substrates was correlated with greater pH buffering following either the hydrochloric acid (HCl) drench or impatiens growth with an ammonium-based fertilizer. Research substrates with high applied lime rate (3.0 kg·m^?3) had greater pH buffering than at 0 or 1.5 g·L^?1. At 3 g·L^?1, the intermediate limestone particle size fractions of 250 to 850 μm and 150 to 250 (20 to 60 or 60 to 100 US mesh) provided the greatest pH-buffering with impatiens. Particle fractions finer than 150 μm reacted quickly over time, whereas buffering by particles coarser than 850 μm was limited because of the excessively slow reaction rate during the experimental periods. Addition of acid from either an ammonium-based fertilizer or HCl reduced residual CCE over time. Dosage with 40 meq acid from HCl per liter of substrate or titration with HCl acid to substrate-pH of 4.5 were well-correlated with pH buffering in the greenhouse trials and may be useful laboratory protocols to compare pH buffering of substrates. With nitrate fertilizer application, residual CCE did not affect buffering against increasing pH. Residual limestone is an important substrate property that should be considered for pH management in greenhouse crop production under acidic conditions.     

采用碳酸钾活化法制备油茶壳活性炭

以油茶壳为原料,采用碳酸钾活化法制备活性炭.探讨了活化温度、浸渍比和保温时间对活性炭吸附性能的影响.结果表明,随着活化温度的提高和保温时间的延长,活性炭的得率不断下降,吸附性能呈先升后降的趋势.N2吸附-脱附等温线分析结果表明,活性炭具有发达的微孔结构,活化温度升高有利于中孔结构的发达.在较佳的实验条件下,活性炭的比表面积为1033.2 m2·g-1,总孔容积、微孔容积和中孔容积分别为0.662、0.500、0.162 cm3·g-1.     

Calcium Sulphate versus Lime as Fertilizer Filler: Effects on Ammonium and Nitrate Uptake by Perennial Ryegrass

Abstract

The recovery of ¹⁵N‐labelled nitrogen (N) by perennial ryegrass can be significantly increased by mixing gypsum (CaSO₄ · 2H₂O) into soil rooting medium at rates equivalent to 0.7 t ha^?1. Similar improvements in fertilizer N efficiency might be achieved, at less cost and more conveniently, by applying smaller amounts of CaSO₄ anhydrite more strategically to fertilizer microsites as a fertilizer filler or diluting agent, in calcium ammonium nitrate (CAN), in place of CaCO₃. With this in mind, two complementary pot experiments were conducted under simulated spring conditions in a controlled environment chamber. Use of CaSO₄ as diluting agent, in place of CaCO₃, appreciably enhanced (>30%) the uptake of labeled N by perennial ryegrass plants within the second week of regrowth, but thereafter, because losses of ¹⁵N‐labeled NO₃ ^?‐N from pots by denitrification or leaching had been minimal, plants in both treatments eventually recovered equal amounts of this N form from the soil.