An assessment of macroinvertebrate functional feeding groups as water quality indicators in the Buffalo River, eastern Cape Province, South Africa

The aim of this paper was to investigate the potential for using functional feeding groups (FFGs) as indicators of water quality conditions in rivers, using the Buffalo River, South Africa, as a specific example. Multivariate classification and ordination techniques were used to investigate species and FFG distributions in relation to a number of physico-chemical variables at 16 sites from the headwaters to the estuary of the Buffalo River.Two-way indicator species analysis (TWINSPAN) of species composition ranked most of the sites sequentially down the river, irrespective of water quality conditions. Ordination of FFGs from a set of riffle samples collected in mid-late summer showed only weak relationships between FFG distribution and water quality changes, except where variables changed sequentially down the river (e.g. pH and temperature). Individual species responses to water quality gradients were examined for nine riffle-dwelling species representing diverse FFGs. Following correspondence analysis of a matrix of environmental variables and species frequencies, some species showed strong associations with defined ranges of some variables. In particular, Adenophlebia auriculata (Leptophlebiidae, Ephemeroptera) from the headwater sampling site, was associated with low pH and low temperature. Simulium damnosum occurred under conditions of high turbidity, while Afronurus harrisoni was found under high concentrations of potassium, ammonium and nitrite ions.We conclude that although there was a distinct headwaters fauna in the Buffalo River, and sequential downstream changes in species composition, most FFGs (apart from shredders) were represented down the whole length of the river. FFG classifications are therefore unlikely to provide useful indications of water quality conditions in the Buffalo River.Using a categorical approach to classifying water quality variables, and by applying correspondence analysis to the resulting matrix, we recognised nine species that could be used to define water quality. These indicator species can be used to define tolerance ranges of the fauna for water quality conditions in different parts of the Buffalo river.     

Key Elements in a Framework for Land Use Impact Assessment Within LCA (11 pp)

Background, Aim and Scope Land use by agriculture, forestry, mining, house-building or industry leads to substantial impacts, particularly on biodiversity and on soil quality as a supplier of life support functions. Unfortunately there is no widely accepted assessment method so far for land use impacts. This paper presents an attempt, within the UNEP-SETAC Life Cycle Initiative, to provide a framework for the Life Cycle Impact Assessment (LCIA) of land use. Materials and Methods: This framework builds from previous documents, particularly the SETAC book on LCIA (Lindeijer et al. 2002), developing essential issues such as the reference for occupation impacts; the impact pathways to be included in the analysis; the units of measure in the impact mechanism (land use interventions to impacts); the ways to deal with impacts in the future; and bio-geographical differentiation. Results: The paper describes the selected impact pathways, linking the land use elementary flows (occupation; transformation) and parameters (intensity) registered in the inventory (LCI) to the midpoint impact indicators and to the relevant damage categories (natural environment and natural resources). An impact occurs when the land properties are modified (transformation) and also when the current man-made properties are maintained (occupation). Discussion: The size of impact is the difference between the effect on land quality from the studied case of land use and a suitable reference land use on the same area (dynamic reference situation). The impact depends not only on the type of land use (including coverage and intensity) but is also heavily influenced by the bio-geographical conditions of the area. The time lag between the land use intervention and the impact may be large; thus land use impacts should be calculated over a reasonable time period after the actual land use finishes, at least until a new steady state in land quality is reached. Conclusions: Guidance is provided on the definition of the dynamic reference situation and on methods and time frame to assess the impacts occurring after the actual land use. Including the occupation impacts acknowledges that humans are not the sole users of land. Recommendations and Perspectives: The main damages affected by land use that should be considered by any method to assess land use impacts in LCIA are: biodiversity (existence value); biotic production potential (including soil fertility and use value of biodiversity); ecological soil quality (including life support functions of soil other than biotic production potential). Bio-geographical differentiation is required for land use impacts, because the same intervention may have different consequences depending on the sensitivity and inherent land quality of the environment where it occurs. For the moment, an indication of how such task could be done and likely bio-geographical parameters to be considered are suggested. The recommendation of indicators for the suggested impact categories is a matter of future research.     

改革微生物实验教学 强化技能训练

为了提高学生的微生物实验技能,通过实验教学研究,对高职微生物实验教学进行了改革探讨。采用逻辑连贯性实验设计、加强基础实验教学、开设综合性实验强化实验技能训练。创新实验教学方法,运用多媒体展示、讲练融合增强实践动手能力。推行徒手练习、加强实验指导与严格规范操作,建立较完善的综合考核机制以调动学生实验的积极性和主动性,促进学生实验技能的提升与实验教学质量的提高。     

半干旱区沙质退化草地造林对土壤质量的影响

采用野外调查与室内培养相结合的方法,研究了我国北方半干旱区科尔沁沙地退化草地营造樟子松人工林32年后0～10 cm表层土壤理化性状、土壤碳氮矿化量、土壤微生物量以及土壤酶活性等的变化. 结果表明32年生樟子松人工林土壤有机碳、全氮和全磷等养分含量分别下降了21%、42%和45%;5月和11月樟子松人工林土壤NH4 -N显著高于草地(P=0.001;P=0.019),而5、8和11月草地土壤NO3--N含量显著高于樟子松人工林(P＜0.001;P=0.048;P=0.031);5、8和11月樟子松人工林土壤有机碳日矿化释放的CO2-C量均大于草地,而二者土壤氮矿化率差异不显著(P＞0.05);5和8月樟子松人工林土壤微生物量碳含量与草地相比差异不显著,11月则显著高于草地;土壤养分和水分含量是影响土壤微生物量碳含量的重要因素;与草地相比,樟子松人工林土壤脲酶和蔗糖酶活性降低,而土壤过氧化氢酶活性升高. 上述结果说明半干旱区沙质退化草地营造樟子松人工林32年后土壤质量出现一定程度的下降;由于植被的改变,樟子松人工林土壤理化性状和生物学性状等表现出与草地不同的季节动态特征.造林作为我国北方半干旱区沙地退化生态系统的一种恢复手段具有一定的局限性.     

哈尔滨二龙山水库浮游植物及水体污染状况的研究

报道了2000 年1 月、5 月、8 月、10 月四次对哈尔滨市境内的二龙山水库的浮游植物的调查结果。共发现浮游植物46 属55 种, 其中种类最多的是绿藻和硅藻。水库四季的平均浮游藻类数量为438.46 万个/升, 绿藻占46.98%, 硅藻占44.74%, 隐藻占6.76%。优势种是平裂藻、小环藻、直链藻、针杆藻、纤维藻、空星藻、十字藻、蹄形藻、栅藻、隐藻等。对8 月份水库及上游河流的水质进行了监测和分析。根据上述结果对水质进行了评价, 并对二龙山库区的水土保持及可持续性发展进行了探讨。     

Effect of fast-, medium- and slow-growing strains on meat quality of chickens reared under the organic farming method

The characteristics of meat quality, chemical and fatty acid composition, from fast-growing (FG) and medium-growing (MG) meat-type and slow-growing (SG) egg-type chickens reared under organic conditions were compared. Three-hundred and sixty 1-day-old male chicks, equally divided into three experimental groups represented by strains (FG: Cobb 700, MG: Naked neck Kabir and SG: Brown Classic Lohman) were housed into three poultry houses with outdoor pasture availability of 10 m(2)/bird located in the same Research Centre of the University of Perugia. All the birds were fed ad libitum the same diets formulated according to the European Union (EU) Regulations by using organic raw materials. Birds from the FG and MG groups were raised until 81 days, whereas birds from the SG group were raised until 96 days in order to achieve an acceptable market live weight. SG birds showed significantly (P < 0.01) higher breast meat drip and cook losses, Allo-Kramer shear values and collagen content. In comparison with FG and SG, MG exhibited a higher breast meat pH (5.86% v. 5.79% and 5.78%, respectively; P < 0.01) and a lower lightness (54.88% v. 57.81% and 56.98%, respectively; P < 0.05). Genotype dramatically affected the lipid content as well as the fatty acid composition of both breast and thigh meat. SG exhibited the lowest content of lipid, both in breast and in thigh meat, the lowest proportions of monounsaturated fatty acids (MUFA) and the highest proportions of polyunsaturated fatty acids (PUFA). The total n-3 PUFA of SG breast meat was double that of FG meat and intermediate with respect to MG birds (8.07% v. 4.07% v. 5.14% total fatty acids; P < 0.01). The fatty acid composition of thigh meat is similar to that of breast meat, but the differences among genotypes are less pronounced. Total saturated fatty acids were not affected by the genotype. In conclusion, meat functional properties of FG and MG strains appeared much more attractive both for industry and consumer (lower drip and cook losses and higher tenderness), whereas from a nutritional point of view, meat from SG appeared healthier (less fat and higher content of n-3 PUFA) and thus might better fit with the consumer's expectations of organic products.     

宽恕与睡眠质量关系的研究进展

近年来,国内外对宽恕的研究逐渐增多,但宽恕与睡眠质量关系的研究较少,本文通过综述现有的一些研究资料,分析二者之间的关系。分析表明,人际侵犯事件是影响宽恕的外部因素,其严重程度直接影响受害者的宽恕水平及睡眠质量;宽恕能够降低受害者的生理唤醒、情绪唤醒、及认知唤醒,从而改善睡眠质量,但之间的相互作用及具体的内在影响机制并不明确。同时,影响宽恕水平的宜人性、外倾等人格特质也会影响睡眠质量。最后分析了目前研究中存在的缺陷,并对宽恕与睡眠质量关系的研究前景进行了展望。     

Changes in diatom-dominated biofilms during simulated improvements in water quality: implications for diatom-based monitoring in rivers

Although benthic diatoms are used to assess river water quality, there are few data on the rate at which diatom assemblages react to changes in water quality. The aim of this study was to assess the reaction time of diatoms and to discuss the changes occurring during water quality improvement on the basis of their autecological characteristics. In order to simulate this improvement, diatom-dominated biofilms grown on artificial sandstone substrata were transferred from several polluted rivers to an unpolluted river. They were sampled three times: before transfer and 1 and 2 months after transfer. The ecology and growth-forms of the taxa explained most of the changes in species composition observed during the experiment. Adnate diatoms gradually replaced motile and stalked taxa. Gomphonema parvulum, a stalked diatom positioned vertically in the biofilm, is adapted for light and space competition in high-density algal biofilms. When transferred to an unpolluted site, this growth-form is less competitive and does not tolerate the high grazing pressure. Fistulifera saprophila is a single celled motile diatom, living in organic matrices. When the artificial substrata were transferred to the unpolluted site, this particular ecological niche disappeared quickly. On the other hand, Achnanthidium minutissimum, which is considered to be cosmopolitan and an early colonizer, increased during the first month of transfer and then decreased. It was gradually replaced by A. biasolettianum, which was the taxon best suited to this pristine stream. The changes observed differed between treatments depending on the species composition and architecture of the biofilms. In particular, biofilms dominated by stalked and motile diatoms were more quickly modified than those dominated by small motile diatoms. The diatom index reflects these changes, and its values showed that about 60 days following a water quality improvement were necessary for transferred diatom assemblages to reach diatom index values similar as those at the unpolluted river.     

复合菌剂M5对红螯螯虾(Cherax quadricarinatus)高密度养殖系统水质及其肠道微生物群落影响的初步研究

应用自制复合菌剂M5于红螯螯虾(Cherax quadricarinatus)的高密度养殖系统中,通过分析肠道菌群并监测养殖水质,研究了复合菌剂作用的效果及潜在的机理。结果显示,复合菌剂M5的使用可显著降低养殖水环境的pH值,降低污染物NH⁺₄、NO^-₂和COD的浓度,抑制弧菌属（Vibrio）中某些条件致病菌的生长。基于PICRUSt与KEGG数据库的功能预测及肠道菌群的群落分析,复合菌剂既可作为额外的营养补充物,缓解肠道群落之间对营养源的竞争,又可提高虾的消化能力、免疫力。新型复合菌剂M5可显著改善养殖水质并影响肠道菌群的组成与功能,从而提高养殖存活率。     

新疆罗布麻生态类型及其纤维品质研究

新疆塔里木河及叶尔羌河流域是我国能够提供商品精干罗布麻的主要地区。由于野生罗布麻生长高矮不一,形态各异,与其纤维品质的相关性较大。通过40个株号的罗布麻植株形态和纤维长度等的的测定,分析各类型罗布麻的纤维长度和罗布麻植株各部分纤维长度情况。研究结果表明：罗布红麻高杆类型主茎纤维最长,罗布麻放牧类型纤维最短。罗布麻植株各部分纤维长度是主茎上的大于分枝,主茎中部的最长,基部和梢部最短。为野生罗布麻资源开发利用提科学依据。