基于四元联系数原理的北京市郊安达木河生态评价

以北京市郊安达木河为研究对象,通过调查河流的生态特征、水文特征、地貌特征以及景观娱乐功能,在综合指数分析法的基础上,将集对分析的确定与不确定系统引入综合评价中,从相同、偏同差异、偏反差异、相异4个方面进行了分析,同时采用时间尺度和空间尺度相结合并着重从时间尺度上对评价结果进行分析。结果表明,近年来,安达木河局部河段生态环境遭到破坏,加强河流生态环境的治理,寻找农村垃圾合理有效的处理方式,减少不必要的人类活动对河流生态的影响,以及在发展旅游业和河流生态整治方面寻找平衡点,将成为下一步河流生态整治的重点内容。     

生态河流构建原理与技术

传统的河流整治技术，如裁弯取直、疏开挖河道、浆砌石或混凝土加固河岸、高筑河堤等，忽略了河流的生态特性，结果导致河流水文发生改变，生态系统受到严重创伤。分析了河流治理技术的发展现状及遇到的问题，提出生态河流的概念，并探讨了生态河流的基本特征和构建原理，然后分别从河道景观设计、河道平面形态设计、河道断面设计和岸堤设计几个方面论述了生态河流构建的技术体系。最后，以镇江古运河生态岸堤构建为例，介绍了生态岸堤构建的实施办法，旨在探讨河流的生态治理的方法，实现人与自然和谐发展。     

河流生态修复研究进展

在河流生态系统普遍遭受严重破坏的今天,河流生态修复成为研究的热点。该文在广泛查阅国内外河流生态修复资料的基础上,分析认为河流生态系统的影响因素主要为水文条件、流域气候、河流地貌、河流的水力特性和水质,以及人类活动在传统水利工程、污染物排放、过量引水及农渔业活动方面对河流生态系统的胁迫作用。在明确河流生态修复概念与任务的基础上,对河流生态修复理论研究中的河流健康、河流生态需水、河流生态修复尺度与机理,以及河流生态修复模型进行了分析与综述。对河流生态修复原则及生态修复中的几个重要技术问题进行了分析与评价。最后提出了我国河流生态修复研究和建设中应特别关注的几个问题及发展建议。     

中国西北部生态脆弱区典型区域土地综合整治分区——以甘肃省兰州市为例

[目的]探讨土地整治规划的重要内容——土地整治分区,为确定土地整治重点区域和土地整治规划提供参考依据。[方法]以西北部生态脆弱区典型区域甘肃省兰州市为研究区域,基于生态保护视角,在充分考虑区域自然地理特征、土地利用特点及区域主要生态问题的基础上,从地形地貌、降雨、土壤类型、植被类型、水土流失、土地利用等5方面选取指标因子初步构建分区指标体系,并从水资源供给、水系分布及行政区划等方面进一步完善。同时运用ArcGIS空间叠加分析功能,使用综合分析法进行土地综合整治分区。[结果]形成了"方位+地貌+土地利用类型"命名的土地整治两级分区体系,二级分区较为详细。兰州市划分为7个一级区和15个二级区。[结论]中国西北部生态脆弱区域在土地综合整理过程中应该通过选择合理的指标体系分区进行整治。各分区应该针对其土地资源、水资源、生态环境状况等具体特征,基于生态保护视角采取有效措施进行土地综合整治。     

基于模糊矩阵法的河流健康评价体系

基于河流健康评估,针对威胁河流生态健康及河流治理的问题,提供关于河流健康及其问题河段的科学解释与依据。在综合国内外河流健康状况评价方法及各项表征指标的基础上,建立了基于模糊矩阵法的河流健康评价体系。应用模糊关系合成原理,从多个因素对河流隶属等级状况进行综合评判。具体评价时分为目标层、准则层和指标层,结合模糊矩阵采用层层推进的计算方法,最后将计算结果分为自然、近自然、退化、人工4大类。结果表明:怀沙河总体得分为2.6分,其中自然状态占整条河段的41%,近自然状态占整条河段的32%,退化自然状态占整条河段的27%。分段评价结果表明:三岔、渤海、口头河段状态较好,四渡河、南冶、辛营需要采用合理措施来改善河流生态系统。该评价方法可以针对性地提出改进措施和建议,为城市郊区河流的健康和生态环境建设的可持续性提供思路。     

石嘴山:搞好北武当河生态修复 创建水生态文明城市

<正>为贯彻习近平生态文明思想,落实宁夏生态立区战略部署,石嘴山市于2016年开展了北武当河生态修复综合整治工程建设,是石嘴山市水生态文明试点城市建设十大示范项目之一。项目包括河流两岸绿色走廊和生态防护林工程,水景观提升工程,园路、栈道、亲水平台、岸边护栏、公共设施及景观小品等工程,总投资4.43亿元。北武当河自四向东进入星海湖流域,全长7.2 km,贯穿全市,是连接贺兰山东麓生态屏障与星海湖湿地的生态廊道,是新城与老城沟通的纽带及城市生态系统的重要组成部分。北武当河生态修复综合整治工程创新性地把防洪工程与生态工程、全域旅游相结合,成为连接"两     

城市内小流域综合整治及效益分析--以重庆市清水溪流域为例

城市内小流域是城市生态系统的重要组成部分。城市小流域的合理规划和综合整治,是城市水土保持和城市可持续的重要途径。清水溪是流经重庆市主城区的一条河流,流域污染严重,环境恶化,已严重影响城市形象,制约城市发展。本文在界定城市内小流域概念的基础上,对清水溪小流域综合整治的措施及环境效益进行了分析。认为城市内小流域的综合整治应以通过恢复小流域生态系统为目标;城市内小流域综合整治的效益分析,应从生态、经济和社会等几方面进行评价。     

浅淡城市河流整治与生态环境保护

城市河流是城市生态系统的组成要素之一 ,其供水、环保、绿化、游乐等生态功能 ,已逐渐被应用到生态城市建设中。传统的用混凝土等硬化覆盖河岸的城市河流整治方法 ,已逐步被各国普遍否定 ,而建设生态河堤成为国际大趋势。城市河流整治应以保护、修复生态环境为前提 ,以建立良好的滨水环境为目的。     

西苕溪流域健康状况的模糊诊断

西苕溪是太湖上游的重要支流,由于人类活动的干扰,河流健康状况受损,功能下降。基于河流健康的内涵,选取河流形态结构、河流社会经济功能和河流生态功能3类诊断河流健康状况的1级指标。针对西苕溪流域健康现状和可获取的资料,构建了诊断西苕溪健康状况的18个2级指标。选用多目标多层次模糊模型诊断西苕溪健康状况,建立了各指标标准特征值,确定了各指标权重。计算和分析结果表明,西苕溪综合健康状况大部分处于中等和良好状态,河流形态结构的改变和较差的水质是影响其健康的主要原因。西苕溪流域的生态修复措施主要包括创建多样性生物栖息地,有效控制面源污染,建立水库适应性管理程序等。     

生态修复背景下的国土综合整治分析

生态环境保护的主要工作就是国土综合整治。国土综合整治在生态文明建设中发挥着重要作用。生态修复背景下强化国土综合整治工作具有现实意义。以生态修复背景为着手点,分析国土综合整治工作措施,促进国土综合整治质量的提升。     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Enhanced establishment and growth of giant cardon cactus in an eroded field in the Sonoran Desert using native legume trees as nurse plants aided by plant growth-promoting microorganisms and compost

To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.     

Karyotypic and genome size variation in Cajanus cajan (L.) Millsp. (pigeonpea) and some wild relatives

Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.     

Effect of some fungicide seed treatments on the survival of Bradyrhizobium japonicum and on the nodulation and yield of soybean [Glycine max. (L) Merr.]

Several commercial fungicide seed treatments were evaluated for their possible effect on the survival of Bradyrhizobium japonicum on seeds and on the nodulation and yield of soybeans in a greenhouse and a field experiment. quinolate Pro (carbendazim and oxine copper), Vitavax 200FF (carboxin and thiram), and Monceren (pencycuron) had a small effect or no effect on the survival of B. japonicum and on the nodulation and yield of soybeans. They can thus be considered compatible with soybean seed inoculation. Germipro UFB (carbendazim and iprodione), Apron 35J (metalaxyl), and Tachigaren (hymexazol) decreased B. japonicum survival and the nodulation and yield of soybeans and thus cannot be considered compatible with soybean seed inoculation.     

Einfluss der düngungsmethoden auf die entwicklung von zuckerrübenkrankheiten

Während neunjähriger (1994-2002) Untersuchungen in der Versuchsanstalt Ba?cyny (Fahlerde, Fall-Gleyboden, ausgebildet aus leichtem Lehmboden) wurde der Befall mit Krankheiten an der Zuckerrübe in Abhängigkeit von der Düngungsmethode bewertet. Folgende Methoden wurden angewendet: A - Mineraldünger, B - Stalldung und Mineraldünger, C - Stroh-, Gründung und Mineraldünger, D - Kompostdünger und Biopräparate (ökologische Düngung). Auf den Objekten A, B, C wurden bei konstanter Phosphor-Kalium-Düngung die Stickstoffgaben von 0 bis 180 kg.ha^?1 differenziert. Auf dem ökologischen Objekt D ohne Mineraldünger wurden statt Stickstoff die Biopräparate P₅₀₀ und P₅₀₁ verabreicht. Der geringste Befall von Krankheiten wurde an der Zuckerrübe auf jenem Objekt festgestellt, das mit Kompost und den Biopräparaten gedüngt worden war. Im Rahmen der konventionellen Düngungsmethoden wurde allgemein die höchste Intensität der Krankheiten an der mit Stroh, Gründung und Mineraldünger gedüngten Zuckerrübe beobachtet. Ausnahmen von dieser Regel bildete das Vorkommen von echtem Mehltau und Keimlingsfäule. Auf den Objekten A, B, C nahm die Intensität der Krankheiten mit der Steigerung der Stickstoffgabe zu. Auch die auf Objekt D verabreichten Biopräparate stimulierten die Entwicklung der Krankheiten. The effect of various fertilization methods on the diseases of sugar beet was estimated on the basis of nine-year studies (1994-2002) conducted in the Experimental Production Farm in Ba?cyny on loess-based, sedimentary-gley, light-clay soil. The following fertilization methods were applied: A - mineral fertilization, B - mineral and manure fertilization, C - straw, green manure and mineral fertilization, D - ecological compost and biodynamic preparations fertilization. In the objects A, B and C fertilized with phosphorus and potassium, various doses of nitrogen ranging from 0 to 180 kg/ha^?1 were used. In the ecological object D, where mineral fertilization was not used, biodynamic preparations P₅₀₀ and P₅₀₁ were applied instead of nitrogen. The lowest ratio of the diseases of sugar beet was observed in the object fertilized with the compost and biodynamic preparations. In view of the conventional fertilization methods, generally the highest incidence of diseases was noted in the sugar beet fertilized with straw, green manure and mineral fertilizers. The exception was the occurrence of powdery mildew and the black leg. In objects A, B and C the incidence of the diseases increased with the increase in nitrogen doses. The applied biodynamical preparations in the object D stimulated the development of diseases too.     

Prospects for control of Pythium damping-off of lettuce with Trichoderma,Gliocladium and Enterobacter spp.

Summary Damping-off of lettuce (Lactuca sativa) caused by Pythium ultimum was studied in pots containing a non-sterile potting mix in the glasshouse. Fifty P. ultimum sporangia g^-1 compost reduced the plant stand to 15% and shoot dry weight to 18%, but this reduction was totally prevented by applying Trichoderma harzianum at 2×10⁵ viable propagules g^-1 potting mix. Gliocladium virens and Enterobacter cloacae also alleviated the damping-off. E. cloacae did not adversely affect the action of the fungal antagonists. The co-existence of the bacterial and fungal antagonists was revealed on the root surface and inner surface of the testa by scanning electron microscopy, indicating the compatibility of the biocontrol agents.     

细菌、真菌及植物氮营养信号研究进展

氮素吸收代谢是所有生物生命活动的核心部分,因此,各种生物对氮的吸收与同化过程都有精细的调节。这种调节依赖于生物对体内氮素状况信号及体外（生长介质中）氮素信号的感受。过去几十年中,在细菌、真菌中已经对氮素营养信号有了较好的研究,而植物中则相对缓慢,但也有了一定的认识。本文重点比较细菌、真菌及植物中氮信号系统的组成,以期为进一步认识植物中的氮信号接受与转导系统提供启示。     

Aircraft operations near concentrations of birds in Antarctica: The development of practical guidelines

Aircraft operations have the potential to disturb and to impact negatively on bird life. A gradient of increasing behavioural response is evident in birds when exposed to increasing aircraft stimulus. The most major disturbance is likely to lead to impacts on the health, breeding performance and survival of individual birds, and perhaps bird colonies. A process of revision to policies on aircraft operations contained in management plans for a number of specially protected areas in Antarctica by the United Kingdom, accompanied by consultations made within the scientific community through the Scientific Committee on Antarctic Research (SCAR) and with operational interests through the Council of Managers of National Antarctic Programmes (COMNAP) resulted in new guidelines being adopted by the Antarctic Treaty Consultative Parties in June 2004. The principal recommendations of the guidelines are that bird colonies should not be overflown below 2000 ft (∼610 m) above ground level and landings within 1/2 nautical mile (∼930 m) of bird colonies should be avoided wherever possible. These guidelines are less stringent and less specific than those that were recommended by the SCAR specialist group on birds, and represent a compromise to accommodate operational needs. While the adoption of clear and consistent guidelines for the operation of aircraft in Antarctica is welcome in that this provides practical advice that is likely to reduce incidences of close aircraft/bird encounters, there remains insufficient knowledge of the interactions between aircraft and birds in Antarctica, and the consequent impacts on individual birds and on bird populations. It is important, therefore, that the guidelines adopted are considered interim, and should be kept under scrutiny with revisions made as new and improved research results appear.     

The abundance of heterocystous blue-green algae in rice soils and inocula used for application in rice fields

Summary Algal populations were quantified (as colony-forming units [CFU] per square centimetre) in 102 samples of rice soils from the Philippines, India, Malaysia and Portugal, and in 22 samples of soil-based inocula from four countries. Heterocystous blue-green algae (BGA) were present in all samples. Nostoc was the dominant genus in most samples, followed by Anabaena and Calothrix. In soils, heterocystous BGA occurred at densities ranging from 1.0 × 10² to 8.0 × 10⁶ CFU/cm² (median 6.4 × 10⁴) and comprised, on average, 9% of the total CFU of algae. Their abundance was positively correlated with the pH and the available P content of the soils. In soil-based inocula, heterocystous BGA occurred at densities ranging from 4.6 × 10⁴ to 2.8 × 10⁷ CFU/g dw (dry weight), comprising only a moderate fraction (average 13%) of the total algae. In most soils, the density of indigenous N₂-fixing BGA was usually higher than that attained by applying recommended rates of soil-based inoculum. Whereas research on the practical utilization of BGA has been mostly directed towards inoculation with foreign strains, our results suggest that attention should also be given to agricultural practices that enhance the growth of indigenous strains already adapted to local environmental conditions.Maître de Recherches ORSTOM (France), Visiting Scientist at IRRI