Chemical composition and leaching characteristics of granules made of wood ash and dolomite     

S. L. Holmberg  B. B. Lind  T. Claesson 《Environmental Geology》2000,40(1-2):1-10

 In 1995, the central heating plant Draken in Kalmar, Sweden, started manufacturing a granular ash product for nutrient recycling to forest soil, instead of dumping the ash in landfills. Chemical composition, leaching and dissolution characteristics were determined for the Draken wood ash, the dolomite used in granule manufacturing and the final granule product. The heavy metal concentrations in fly ash were within the limit values recommended by the Swedish National Board of Forestry for ash recycling, except for Cd and As levels which occasionally exceeded the limit values. The Ca, Mn and P levels were too low for nutrient recycling at the time. Adding dolomite insures that the levels of the important nutrients Ca and Mg are sufficient in the granules. After 7 months in the field, about 60 % of Na and K was leached out from granules. Between 20 and 60% of trace elements Mo, Sc, V, Y and Zr were leached out after 7 months. The release of Ca and Mg was low, 1–5% during 7 months. Received: 12 July 1999 · Accepted: 31 August 1999  相似文献   

A New Species of Tsuga (Pinaceae) based on Lignified Wood from the Late Miocene of Central Yunnan, China, and Its Paleoenvironmental Implications     

WANG Haobo  Olesia V. BONDARENKO  Frédéric M. B. JACQUES  WANG Yuehu  ZHOU Zhekun 《《地质学报》英文版》2015,89(5):1429-1439

A new species, Tsuga nanfengensis sp. nov. (Pinaceae), is described on the basis of lignified fossil wood from the late Miocene of the Xianfeng Basin, central Yunnan, southwestern China. Detailed observation of the fossil wood specimens show the following characteristics: distinct growth rings, absence of resin canals, uniseriate bordered pits in the radial wall of tracheids, ray tracheids and piceoid and cupressoid cross-field pits. These features indicate similarities to the wood of extant Tsuga canadensis, T. chinensis, and T. dumosa. According to the fossil record, Tsuga was present in Xundian County during the Miocene. Today Tsuga is drought intolerant, preferring wet conditions with no extant species growing naturally in Xundian County. The presence of Tsuga in the Miocene of Xundian County indicates a humid climate consistent with previous palaeoclimatic reconstructions showing a wetter and probably shorter dry season in the Miocene, relative to the present day. Therefore, the change in the local climate such as increasing aridity through the Miocene might explain the local extinction of Tsuga from central Yunnan.  相似文献   

Logs and Snags in a Shola Forest of Kerala, India     

U.M. Chandrashekara  V. Sibichan 《山地科学学报》2006,3(2):131-138

Introduction Dead wood is an important structural and functional component of a forest ecosystem(Fridman and Welheim 2000). Recent studies also indicate that dead wood is important for maintaining both plant and animal diversity in different forest ecosystems (Grove 2001) as it serve as an energy source (Bray and Gorham 1964) and habitat for an array of organisms. Dead wood can also help reduce erosion, increase soil organic matters (McFee and Stone 1966), and suitable conditions for seedli…  相似文献   

采用SilviScan-3TM研究木材性质的方法及其在气候变化研究中的应用          下载免费PDF全文

徐金梅  吕建雄  鲍甫成  肖军  Robert Evans  黄荣凤  徐明 《气候变化研究进展》2012,8(2):124-130

系统介绍了利用SilviScan-3TM测量细胞结构、木材密度、微纤丝角和划分年轮界线的方法,并以祁连山青海云杉为例,分析青海云杉6个木材性质参数(年轮细胞直径、年轮细胞壁厚、年轮宽度、年轮密度、年轮微纤丝角、年轮弹性模量)与气候因子的关系,以期为利用多个树轮参数研究气候提供参考。结果表明:6个木材性质参数与月平均气温和月降水量都有显著相关的月份,但显著相关的时间段不同,并且微纤丝角和细胞结构参数中包含的气候信息强于常用的年轮宽度和年轮密度。SilviScan-3TM测量木材性质参数的优越性体现在:测量精度高、速度快,能在同一个试样上测量多个参数并能精确定年。  相似文献   

Reflections on the history of research on large wood in rivers     

Frederick J. Swanson  Stanley V. Gregory  Andres Iroumé  Virginia Ruiz-Villanueva  Ellen Wohl 《地球表面变化过程与地形》2021,46(1):55-66

Dynamics and functions of large wood have become integral considerations in the science and management of river systems. Study of large wood in rivers took place as monitoring of fish response to wooden structures placed in rivers in the central United States in the early 20th century, but did not begin in earnest until the 1970s. Research has increased in intensity and thematic scope ever since. A wide range of factors has prompted these research efforts, including basic understanding of stream systems, protection and restoration of aquatic ecosystems, and environmental hazards in mountain environments. Research and management have adopted perspectives from ecology, geomorphology, and engineering, using observational, experimental, and modelling approaches. Important advances have been made where practical information needs converge with institutional and science leadership capacities to undertake multi-pronged research programmes. Case studies include ecosystem research to inform regulations for forest management; storage and transport of large wood as a component in global carbon dynamics; and the role of wood transport in environmental hazards in mountain regions, including areas affected by severe landscape disturbances, such as volcanic eruptions. As the field of research has advanced, influences of large wood on river structures and processes have been merged with understanding of streamflow and sediment regimes, so river form and function are now viewed as involving the tripartite system of water, sediment, and wood. A growing community of researchers and river managers is extending understanding of large wood in rivers to climatic, forest, landform, and social contexts not previously investigated. © 2020 John Wiley & Sons, Ltd.  相似文献   

Structural complexity influences the ecosystem engineering effects of in-stream large wood     

Matthew J. Cashman  Gemma L. Harvey  Geraldene Wharton 《地球表面变化过程与地形》2021,46(10):2079-2091

Large wood (LW) is an ecosystem engineer and keystone structure in river ecosystems, influencing a range of hydromorphological and ecological processes and contributing to habitat heterogeneity and ecosystem condition. LW is increasingly being used in catchment restoration, but restored LW jams have been observed to differ in physical structure to naturally occurring jams, with potential implications for restoration outcomes. This article examines the structural complexity and ecosystem engineering effects of LW jams at four sites with varying management intensity incorporating natural and restored wood. Our results reveal: (i) structural complexity and volume of jams was highest in the site with natural jams and low intensity riparian management, and lowest in the suburban site with simple restored jams; and (ii) that structural complexity influences the ecosystem engineering role of LW, with more complex jams generating the greatest effects on flow hydraulics (flow concentration, into bed flows) and sediment characteristics (D₅₀, organic content, fine sediment retention) and the simplest flow deflector-style restored jams having the least pronounced effects. We present a conceptual model describing a continuum of increasing jam structural complexity and associated hydromorphological effects that can be used as a basis for positioning and evaluating other sites along the management intensity spectrum to help inform restoration design and best practice.  相似文献   

Ecological Footprint Evaluation of Three Types of Wood Flooring in China based on Their Production Data from 2000 to 2018     

LI Jianquan  YUAN Yue  LUO Shuzheng 《资源与生态学报(英文版)》2021,12(3):430-436

To encourage the environmental responsibility of consumers and manufacturers for forest management, it is necessary to evaluate the environmental influences of forest products. Ecological footprint (EF) is an internationally recognized indicator for estimating the natural capital consumption and environmental influences of various forest products. In this study, we developed an accounting model for the EF evaluation of wood flooring, which is a tertiary forest product, by the method of transformation. Next, we used that model to evaluate the EF of three types of wood flooring in China according to their production data from 2000 to 2018. We collected the necessary data by visiting typical enterprises in China and referring to the relevant literature. According to our results, the average EFs of solid wood flooring, engineered solid wood flooring and laminate flooring between 2000 to 2018 were 3.13×10 ⁶, 1.05×10 ⁷ and 5.07×10 ⁶gha, respectively. The total EFs of solid wood flooring, engineered solid wood flooring and laminate flooring from 2000 to 2018 were 5.95×10 ⁷, 1.99×10 ⁸and 9.64×10 ⁷gha, respectively. The coefficients of variation (CV) of the EFs for these three types of wood flooring were 0.45, 0.87 and 0.76, respectively. The average and total EFs of the engineered solid wood flooring were the largest among the three types of wood flooring. The per capita EF and unit EF for the engineered solid wood flooring were also the highest among the three types of wood flooring. The EFs showed an upward trend with irregular fluctuations from 2000 to 2018 for all three types of wood flooring. It is necessary to reduce the EF of the engineered solid wood flooring and use more environmentally friendly products, such as solid wood flooring, for environmental protection.  相似文献   

用X射线荧光光谱法测定Cl、S等31个元素     

杨剑  万飞  王佳丽  杨婷 《吉林地质》2009,28(2):116-119

采用硼酸镶边垫底的粉末样品压片制样,用ARL ADVANT′XP＋型X射线荧光光谱仪对土壤和水系沉积物样品中Na、Mg、Al、Si、P、S、Cl等31个组分进行测定。重点研究了Cl和S等元素的测定条件、痕量元素的背景选择和谱线重叠校正问题。使用经验系数法和康普敦散射作内标校正基体效应。经标准物质校验,结果与标准值吻合。方法的检出限、精密度和准确度能满足多目标地球化学调查样品的分析要求。  相似文献   

粉末压片-X射线荧光光谱法分析富硒土壤样品中的硒及主次量元素   总被引：1，自引：0，他引：1  

李迎春  张磊  尚文郁 《岩矿测试》2022,(1):145-152

目前土壤中Se主要采用原子荧光光谱法测定,存在用酸量大、前处理相对复杂等缺点,对于高含量Se的测定则需要高倍稀释,无疑会扩大分析误差.本文采用粉末压片波谱-能谱复合X射线荧光光谱法测定湖北富硒土壤样品中的Se等17个主次量元素,波谱分析10个元素的同时,能谱分析As、Cu、Rb、Sr、Zr、Ba、Ni等7个元素,大幅节...  相似文献   

轻型定向秸秆板-榫卯连接木骨架剪力墙抗震性能试验研究   总被引：1，自引：0，他引：1  

谢启芳  吕西林  熊海贝 《地震工程与工程振动》2012,32(4):159-165

为了促进适合我国国情的轻型木结构发展,介绍了一种自主开发的轻型定向秸秆板-榫卯连接木骨架剪力墙,该剪力墙由墙体模块、顶梁板、底梁板三部分组成,墙体模块的木骨架间采用榫卯连接,面板采用定向秸秆板.通过12片分别由3个剪力墙模块组成的剪力墙的水平单向加载和低周反复加载试验研究,得到了剪力墙的破坏特征、抗剪强度、滞回性能、延性及耗能等性能指标,分析了洞口大小、洞口位置及竖向荷载对剪力墙抗震性能的影响以及剪力墙与单个墙体模块抗震性能的区别.结果表明:剪力墙的破坏主要是面板破坏及面板与钉的连接破坏,剪力墙的抗剪强度比墙体模块的要低约10％,滞回曲线呈明显的反S型并有明显滑移,等效粘滞阻尼系数约为0.13.  相似文献