Effect of Peat-based Container Media on Establishment of Scots Pine,Norway Spruce and Silver Birch Seedlings after Transplanting in Contrasting Water Conditions

Abstract

Urban woodlands are the subject of complex decision-making that requires a strategic overview of the resource. This article contributes a national study of municipal woodland in Denmark. Data were collected among all Danish municipalities through a postal survey (with a response rate of 52%). As much as 83% of the woodland units were located within urban settlements or at their fringe, emphasising that municipalities are important urban woodland providers. Municipal woodland resources were typically divided into many separate units of varying size. On average, the responding municipalities owned 12.6 woodland units with an allocated area of 265 ha, resulting in a mean size of 21.5 ha. A general lack of management plans, and a significant drop in recreational facilities provided with decreasing woodland size indicate that the recreational use potential of small woodland units was largely overlooked. Municipal woodland units frequently bordered other woodland or nature areas of different ownership. Thus even small municipal woodlands can play a key role in the development of multifunctional green infrastructures in the urban landscape. Only municipalities with extensive woodland property had issued a woodland policy, and/or certified woodland management. This indicates a need for development of governance and strategic management instruments attractive to municipalities with limited woodland property.     

昆明都市农业的地位和作用研究——基于滇中城市经济圈一体化发展的视角

随着《云南省滇中城市经济圈区域协调发展规划》的出台，昆明市作为经济圈的核心，其农业发展为加快经济圈的一体化进程、保持圈内经济社会的和谐发展，将产生重要作用。分析了在经济圈一体化发展格局下，昆明都市农业的地位和功能，以及都市农业发展的内涵拓延，并提出了相关政策建议。     

城乡一体化视角中贵州农村劳动力素质研究

推进城乡一体化,建设社会主义新农村,需要具有高素质的新型农民。目前贵州省农民整体素质相对较低,与全面建设小康社会不相适应。因而在城乡一体化过程中,要发挥农民在新农村建设中的主体作用,就应把提高农民素质、培育新型农民作为一项战略任务,加大农村教育培训的力度,采用多种形式,实施培训工程,培养有文化、懂技术、会经营的新型农民。     

北京市顺义区畜牧业发展问题的思考

对北京顺义区畜牧业现状进行了调研,总结顺义区畜牧业发展的经验,分析其面临的新挑战和新机遇,对如何建设都市型现代畜牧业提出对策和建议。     

Does returning sites of historic peri‐urban waste disposal to vegetable production pose a risk to human health? – A case study near Manchester,UK

Urban waste disposal occurred on fenland to the west of Manchester, England, between 1900 and 1964. The reclaimed fenland, Chat Moss, is now used for mixed arable farming. A total of 1.92 Mt of waste including privy midden, street sweepings, clinkers and slaughterhouse refuse was incorporated into the moss resulting in a modified topsoil with raised pH and reduced organic matter content compared with the subsoil. Elevated levels of potentially toxic elements (PTEs) are observed in the topsoil beyond the typical depth of atmospheric contamination; Cd and As concentrations exceed soil guideline values (SGVs) at 1.8 and 43 mg/kg, respectively. Sequential extraction indicates that waste‐derived Pb, Zn and Ni remain predominantly in the residual fraction, whereas Cu was mainly organically bound. Arsenic was predominately found in oxide and organic matter fractions with Cd in carbonate, oxide, organic matter and residual fractions. Pot trials indicated limited uptake of PTEs by vegetables grown on the waste‐amended soil, with the exception of Cd uptake by lettuce (0.22 mg/kg FW) and Pb uptake by radish (0.16 mg/kg FW), which exceeded current EU limits of 0.2 and 0.1 mg/kg FW, respectively. Hazard quotients (HQs) identified no risks to adults from consumption of vegetables grown in these soils with the exception of lettuce consumption with a HQ of 1.4. Risks to children were slightly greater with HQs >1 for Cd in lettuce, spinach, carrots and onion, As in lettuce, parsley and onion and for Zn in spinach.     

Anthropogenic effects on the physical and chemical properties of subtropical coastal urban soils

We investigated the effects of various anthropogenic factors on urban soil properties in subtropical, coastal Tampa, FL, USA. Specifically, we explored the influence of (i) urbanization as measured by land use, land cover, population density and years since urban development and (ii) socioeconomic conditions as reflected in household income and property values on bulk density (BD) and several key soil chemical properties. Results indicate that Tampa’s urban soils were affected to varying degrees by these factors with chemical properties being more variable than BD. Across land uses significant differences were found for Mehlich‐1 (M1) extractable P, Ca and Na. A similar trend was observed for land‐cover classes, although significant differences were also found for pH and M1‐Cu. Soil properties had no statistically significant relationship with population density. However, time since urbanization did with M1‐P and Na varying significantly across age categories. For our socioeconomic analyses, M1‐K and Mg levels differed significantly by household income while pH, P, Ca and Na values differed significantly by property value. Overall, our findings indicate that despite their inherent heterogeneity, there are identifiable patterns among subtropical coastal urban soil properties. We suggest that a more thorough understanding of these patterns and their drivers is an essential first step towards developing soil management strategies aimed at maintaining environmental quality and ecosystem services in subtropical cities.     

辽阳县城市道路绿化建设与发展对策

本文介绍了辽阳县城市道路绿化的现状和主要做法,分析了城市道路绿化存在的问题,从绿地规划、树立节约型绿化理念、科学植绿、依法治绿方面提出了城市道路绿化的发展对策。     

绿视率在城市道路绿地设计中的应用

分析城市道路绿地的界定及城市道路绿地在城市中发挥的作用；结合绿视率及其相关理论，论述绿视率的基本特征，结合沈阳市城市道路绿地设计，从城市道路绿地设计的角度阐述绿视率在实际工作中的应用。     

旅游英语教学和实习中的秦皇岛本土文化推介

全国著名旅游城市秦皇岛有着悠久的历史和深厚丰富的本土文化底蕴,地处秦皇岛的高职院校大都开设旅游英语专业。但是在教师的教学中以及指导学生实习和实训过程中发现：学生在向中外游客宣传和推介秦皇岛的本土文化时困难重重,秦皇岛本土文化没能得到有效推介。分析了这种情况产生的原因,并提出了教学和实习改革对策。旨在使学生在涉外旅游中更好地输出秦皇岛本土文化,使高职教育更好地服务地区旅游经济发展。     

基于神经网络模型的青岛市城区土壤重金属污染源定位

建立基于遗传算法的BP神经网络系统,该模型可以有效描绘区域中重金属元素的分布情况,并由此通过各元素浓度极大值点求出污染源近似坐标,实现对污染源的定位.将该模型运用于青岛市,根据青岛市不同功能区的土壤重金属含量调查结果,实现了对可能重金属元素污染源位置的预测.