柽柳对滨海盐渍土的改良作用及其应用

以山东省威海市高区环海路上的柽柳为研究对象,在其根系附近采集实验组土样并在其周围的空白地面上采集对照组土样,测定几组能够说明其土质的数据,如土壤中生物的分类与计数、有机质的含量、土壤的pH值、土壤中空气的体积以及土壤颗粒的贮水能力.通过将实验组与对照组的比较,分析得出在滨海盐渍土上栽植柽柳不但可增加土壤中微生物的含量,而且可增加土壤中的空气和有机质的含量,提高土壤颗粒的贮水能力,还可降低土壤的pH值,增加观赏性.因此,根据所测的各项指标得出柽柳对滨海盐渍土具有改良作用的结论,为推动与利用柽柳在滨海盐渍土上的种植提供理论依据.     

沙枣对滨海盐渍土的改良作用探究

实验以野生沙枣为研究对象，在根系附近采集实验组土样，在周围裸露土地上采集对照组土样。通过实验组与对照组的各项指标对照表明，在盐渍土上种植沙枣，不但可增加土壤中的含水量，而且可增加土壤中的空气体积和有机质含量，提高土壤中的K含量，降低土壤中pH值。沙枣对滨海盐渍土有着很好的改良效果和一定的经济效益。     

盐生植物单叶蔓荆对盐碱地的修复效应研究

以盐生植物单叶蔓荆为研究对象，在威海高区海水浴场的沙滩边缘提取实验组与对照组土样，然后分别测定几组能够描述土壤质量的数据，如土壤颗粒中空气的体积、贮水能力、有机质含量以及pH值等，最后通过比较实验组和对照组中土壤颗粒的空气体积、贮水能力、有机质含量以及pH值的不同，从所得实验结果中分析得出盐生植物单叶蔓荆对盐碱土具有修复效应的结论，并结合威海的实际情况讨论了在海边盐碱地上种植单叶蔓荆的意义。     

盐生小藜对碱性土壤的修复作用研究

以碱性植物小藜为研究对象,在威海市高区玛珈山上提取实验组与对照组的土壤,分别测定能够描述土壤性质数据,通过比较实验组、对照组以及培养组中土壤颗粒关于空气体积、贮水能力、有机质含量、pH值之间的不同,分析得出盐生植物小藜对盐碱土具有修复作用.结合实际情况讨论在海边盐碱地上种植小藜的意义,为其他盐生植物的研究提供依据.     

pH值对土壤吸附二氯喹啉酸的影响研究

采用间歇平衡震荡法研究pH值对二氯喹啉酸在红土、黑土、潮土三种供试土壤中吸附特征。结果表明:二氯喹啉酸在不同土壤中的吸附特征存在差异,土壤的pH值影响二氯喹啉酸的吸附特征,当pH值趋近于二氯喹啉酸的pKa(4.35)时,容易被土壤吸附;pH值在较高情况下(pH=7.4),二氯喹啉酸大多呈离子状态,不易被土壤吸附;有机质含量降低将导致土壤对二氯喹啉酸的吸附能力下降。     

川西北高寒草地沙化土壤特征及治理模式探讨——以阿坝州红原县为例

通过对川西北高寒草地不同类型的沙化样地0—10cm,10～20cm和20～30cm土壤有机质、pH和含水量进行分析。结果表明：（1）随着沙化程度加重,土壤有机质含量和土壤含水量明显降低;（2）随着土层深度增加,土壤有机质含量降低;未沙化、轻度沙化样地的土壤含水量随土层深度增加而降低,重度沙化样地则相反;（3）中度和重度沙化样地土壤pH约7．0,未沙化和轻度沙化pH值在6．5左右;沙地土壤有机质与pH值呈显著负相关关系,沙化土壤有机碳与水分损失是一个正反馈。鉴于川西高寒草地特殊环境,探讨了选用适宜的多年生高原药用植物或者其他高价值资源植物作为固沙材料,将治沙与经济发展相结合,建立高寒沙化草地治理模式。     

深度脱水污泥掺混土壤改性及资源化技术研究

为实现深度脱水污泥的改性和资源化利用,以上海某城市污水处理厂的两种不同含水率的深度脱水污泥A和B为例,通过向污泥中掺混土壤,研究土壤对污泥含水率、有机质、抗压强度、恶臭和植物毒性等的影响,探索其用作填埋场封场覆盖绿化用土的可行性.结果表明,掺混土壤可明显降低污泥含水率、有机质和臭气强度,并显著提高其抗压强度和种子发芽率,且相关性分析表明,土壤对污泥的有机质、臭气强度和浸出液种子发芽率的改善效果较强;当土壤添加量分别为60％和30％时,污泥A和B的抗压强度可分别由32.99kPa和196.67kPa的初始值增加至117.6kPa和227.5kPa,臭气强度可由4.5级和4级下降至2级和1.5级,浸出液白菜种子发芽率可由50％和56.7％增加至90％和80％.改性后的污泥A和B均能满足填埋场封场覆盖绿化用土的要求,实现其资源化利用.     

四川某地区土壤中Cd、Se微量元素含量水平及有效性特征初步研究

为合理布局种植规划，保障土壤环境质量及农产品安全，采集区内表层土壤(0～20 cm),分析检测Cd、Se、有效镉、有效硒含量及pH值，通过数理统计的方法，对区内土壤中Cd、Se元素含量水平进行评价，探讨其有效性特征。区内土壤中Cd元素含量范围为0.21～1.22 mg/kg,均未超过“管控值”,92.19%的样品超过“筛选值”,可能存在生态环境风险，土壤pH≤6.5条件下Cd元素平均含量(0.44 mg/kg)低于其在pH>6.5条件下平均含量(0.72 mg/kg),Cd元素有效度与土壤pH值均呈负相关，表现为Cd元素有效性随土壤pH值升高呈明显下降趋势；Se元素平均含量(0.63 mg/kg)达到富硒土壤要求(大于0.40 mg/kg),其含量、有效度与土壤pH值关系较弱，含量基本稳定。区内分布大片高镉富硒土地属自然背景继承，酸性土壤环境下Cd元素活性程度较大，随pH值升高Cd元素活性程度下降趋势明显，表明农作物吸收土壤中Cd元素水平呈下降趋势亦明显，同时Se元素活性程度受土壤pH值影响较弱。可通过控制土壤pH值，合理布局种植规划，为规避或降低土壤中高镉可能带来的生态环境风险...     

基于模糊数学方法的土壤肥力综合评价及应用

模糊数学是一种研究和处理模糊现象的定量化分析方法,在各个领域具有广泛的应用价值.以GIS技术为基础,阐述了该方法在土壤肥力综合评价中的应用.以安庆市土壤样点数据为例,建立包括土壤的pH值、有机质、全氮等8项指标土壤肥力多指标评价模型,对安庆市范围的土壤肥力状况进行评价,分析土壤肥力空间分布.结果表明,模糊数学方法在土壤肥力综合指标评价中具有简便可行性.     

仁寿县龙泉山南端土壤Mn、B的分布特征及影响因素研究

采用ArcGIS 9.3和GPS技术对仁寿县龙泉山南端202个土壤样点耕层(0—20cm)的Mn、B含量空间分布特征及影响因素进行了研究。结果表明:龙泉山脉南端土壤中Mn含量由西向东呈先增加后降低趋势,平均含量为(169.70+62.99)mg/kg;B含量由西向东呈逐渐减少趋势,平均含量为(0.51±0.39)mg/kg;在pH各分级之间的Mn、B含量差异性分别达到极显著水平,且Mn含量与pH呈极显著正相关关系;在有机质含量各分级之间的Mn、B含量差异性分别达到极显著水平,且B含量与有机质含量呈极显著正相关关系。     

Boater preferences for beach characteristics downstream from Glen Canyon Dam, Arizona

Release flow decisions are increasingly being influenced by an array of social values, including those related to river-based recreation. A substantial portion of past recreation research on downstream impacts of dams has focused on variability of instream flows. This study complements past research by assessing user preferences for beach characteristics affected by long-term impacts of flow regimes. Based upon a study of three recreational user groups (private trip leaders, commercial passengers, and river guides) of the Colorado River in Grand Canyon, preferences for beach size, presence of shade on beach, and presence of vegetation on beach are examined. Results indicate that large size beaches with shade from trees are setting characteristics with highly reliable and strong user preferences. The multinomial regression models developed for each user group indicate that 80% of all respondents would choose beach campsites 800 m(2); results were the same regardless of respondents' past boating experience, boat type (i.e. oar or motorized), or group size. In addition, size of beach was consistently reported to be a trip feature of moderate importance to respondents' river trip. Implications of this research are related to future prospects for controlled floods (i.e. spike flows) released from Glen Canyon Dam.     

威海典型海滩沉积地貌及质量评价

选择威海双岛湾附近海滩、国际海水浴场海滩、金海滩、青叽岛以西海滩、青叽岛以东海滩、天鹅湖海滩、桑沟湾海滩、楮岛海滩、南海新区海滩和乳山银滩十处代表性岸滩进行了海滩地貌和底质调查,结合沙滩表层样品分析测试数据,对研究区海滩地貌、沉积物粒度分布特征及海滩质量进行了综合评价。结果表明:威海海滩沉积物主要包括砾砂、粗砂、中砂、细砂四种类型,其中中砂分布最广,约占所有点位的35.6%,细砂、粗砂、砾砂分别占34.4%,26.7% 和3.3%。岸滩坡度一般较缓,宽度中等以上,岸滩质量整体较好,部分岸滩受沉积物粒度影响,质量稍差。     

Do Embedded Roadway Lights Protect Sea Turtles?

Street lighting on coastal roadways is often visible at sea turtle nesting beaches, and disrupts the nocturnal orientation of hatchlings as they crawl toward the sea. Our objective was to determine whether an alternative lighting system (light-emitting diodes, embedded in the roadway pavement) prevented orientation disruption. Hatchlings at the beach oriented normally when only the embedded lights were on, or when all lighting was switched off. However, turtles showed poor orientation when street lighting was on. Measurements confirmed that street lighting was scattered to the beach, whereas embedded lighting was not. We conclude that embedded lighting keeps the beach dark and thus protects sea turtles. However, on two overcast evenings, lighting (“skyglow”) from nearby development, reflected by cloud cover to the beach, weakened hatchling orientation. Thus, both indirect (reflected) and direct sources of lighting negatively impact the turtles.     

红厚壳野生资源的开发型保护途径分析

从红厚壳的生物学特性和具有的油用、药用、材用、观赏、生态保护等多种用途角度出发,针对砍伐严重的状况,提出通过驯化栽培、开发油脂应用范围和加强海岸防护林的设置来保护红厚壳;同时建议政府和科研部门重视并探索红厚壳在中药和油脂加工方面的价值。     

Evaluation of beach quality as perceived by users

Recreational beaches are strategic ecosystems for tourism and should be used in a sustainable manner. We studied three beaches in the municipality of Guaymas (NW Mexico), in order to assess their beach quality and identify key management issues. The evaluation was based on the perceptions of users concerning: (1) the user profile; (2) the recreational habits of users; and (3) the biophysical characteristics, infrastructure, services, and cleanliness of each beach. The results showed that the beaches were of different quality. The key management issues identified were the need to design and apply specific management programs for each beach, specifically in regards to improving infrastructure and services, and obtaining certification as a sustainable beach. The evaluation of the beaches as perceived by users suggests that it would be useful to assess beach quality in order to support management goals and be applicable to other beaches, both nationally and internationally.     

Impacts of Off-Road Vehicles (ORVs) on Macrobenthic Assemblages on Sandy Beaches

Sandy beaches are the prime sites for human recreation and underpin many coastal economies and developments. In many coastal areas worldwide, beach recreation relies on the use of off-road vehicles (ORVs) driven on the shore. Yet, the use of ORVs is not universally embraced due to social conflicts with other beach user groups and putative environmental consequences of vehicle traffic on sandy shores. Such ecological impacts of ORVs are, however, poorly understood for endobenthic invertebrates of the intertidal zone seawards of the dunes. Consequently, this study quantified the degree to which assemblages of intertidal beach invertebrates are affected by traffic. The study design comprised a series of temporally replicated spatial contrasts between two reference sites (no ORVs) and two beaches with heavy ORV traffic (in excess of 250,000 vehicles per year) located in South-East Queensland, Australia. Macrobenthic assemblages on ORV-impacted beaches had significantly fewer species at substantially reduced densities, resulting in marked shifts in community composition and structure. These shifts were particularly strong on the middle and upper shore where vehicle traffic was concentrated. Strong effects of ORVs were detectable in all seasons, but increased towards the summer months as a result of heavier traffic volumes. This study provides clear evidence that ORVs can have substantial impacts on sandy beach invertebrates that are manifested throughout the whole community. Demonstrating such an ecological impact caused by a single type of human use poses a formidable challenge to management, which needs to develop multi-faceted approaches to balance environmental, social, cultural, and economic arguments in the use of sandy shores, including management of “beach traffic.”     

Impact of Off-road Vehicles (ORVs) on Ghost Crabs of Sandy Beaches with Traffic Restrictions: A Case Study of Sodwana Bay,South Africa

Off-road vehicles (ORVs) are popular in coastal recreation, although they have negative impacts on sandy shores. In South Africa, ORVs are banned from most coastal areas, while some areas are designated for restricted ORV use, providing an opportunity to assess whether ORV traffic restrictions translate into biological returns. In Sodwana Bay, the impact of ORVs on ghost crab populations was investigated. During Easter 2012, ghost crab burrows were counted on beach sections open and closed to traffic. Burrow density in the Impact section was less than a third that of the Reference section, and by the end of the study burrow size in the Impact section was half that of the Reference section. ORV traffic caused a shift in burrow distribution to the Lower beach. However, differences in burrow densities between sections were 14 times smaller than differences obtained at a time when ORV use in Sodwana Bay was not controlled. While confirming the well-established detrimental effects of ORV use on sandy beach ecosystems, results demonstrated that traffic restrictions on beaches measurably minimize impacts to the fauna, thus translating into clear-cut biological returns.     

Environmental impacts of shore-parallel breakwaters along Nagahama and Ohgata, District of Joetsu, Japan

A combination of sedimentological analysis of beach sands, field surveys and the assessment of the empirical methods for the breakwater design is used to investigate the impacts of offshore breakwaters on beach morphology along Nagahama and Ohgata. The results indicate that the nearshore sedimentation has been substantially disrupted due to the features formed behind the breakwaters stopping littoral transport, which led to sediment accretion on the updrift side of the breakwaters, and erosion on their downdrift side. Sedimentological analysis of beach sands made it possible to recognize the dominant process at the sections considered. In fact, the occurrence of strong offshore-going currents, the removal of finer mean grain size and the predominance of high-density heavy minerals led us to deduce that the two sections undergo a natural sedimentary imbalance.