碳中和目标下轻型木结构建筑碳排放计算及降碳策略研究北大核心

为提供一种适合轻型木结构建筑碳排放计算方式及降碳路径,采用全生命周期分析方法,将轻型木结构建筑生命周期分为木材固碳、建筑建材的生产与运输、建筑施工、运行使用、拆除处理五个阶段,通过研究各个阶段的碳排放计算,得出符合轻型木结构建筑特点的全生命周期碳排放计算方法,并提出合理选择建筑木材、延长木材储碳周期、优化能源消耗结构、科学管理工程施工等降碳策略,以期为轻型木结构建筑全生命周期碳排放计算提供方法指导,为轻型木结构建筑选材、建设、运行及拆除处理等阶段相关方案优化提供参考依据。     

木结构材料与其他建筑结构材料的碳排放对比

以生命周期理论为基础,建立木结构与其他建筑结构材料的碳排放算法模型,量化分析不同建材的碳排放量。结果表明:木结构材料的碳排放明显少于钢结构和混凝土结构材料;四个树种的木结构材料中,东北落叶松的碳排放最小,为68 tCO_2:北美冷杉的碳排放最大,为1 175 t CO_2。合理选择木材树种及产地,将进一步降低木结构建筑的碳排放。     

竹木结构建筑物化阶段碳排放量和碳汇评估北大核心

目前关于竹木结构的碳排放量和固碳量对比研究较少,现行计算方法较少考虑其中金属连接件贡献,低估了其碳排放量。通过研究轻型木结构和竹结构建筑物化阶段的碳循环,提出了考虑金属连接件贡献的竹木结构碳排放量计算方法,探究其在整个建筑物化阶段的贡献度,进而对竹木结构、混凝土结构和钢结构的建筑碳排放量结果进行对比。结果表明:轻型木结构是具有较高固碳能力的低碳建筑,其固碳量可抵消82.80%碳排放量;竹结构单位建筑面积固碳量为碳排放量的1.27倍,是负碳建筑;金属连接件在轻型木结构和竹结构中碳排放量的占比分别为13.76%和35.32%,竹木结构碳排放量计算中需考虑金属连接件的贡献。     

论木结构建筑设计中儒家思想的传承与发展

儒家思想是渗透到中国古代社会生活各个领域的正统哲学和伦理观念,它对中国木结构建筑有着深远影响。因此,中国木结构建筑的研究不应该只从"历史"和技术发展入手,还要将文化和建筑的发展结合起来。介绍并分析了儒家文化对中国古代木结构建筑发展的影响,概述儒家思想影响下的中国古代木结构建筑哲学,分析了木结构建筑设计中儒家思想传承与发展的不足,并提出了相应对策,以期为中国木结构建筑的创新和发展提供借鉴。     

现代木结构建筑在森林公园中的应用研究

概述了木结构建筑在国内的应用范围,介绍了现代木结构建筑优点,分析了现代木结构建筑在森林公园中,尤其是在国家级森林公园中的应用优势,为森林公园规划设计中采用木结构建筑提供参考。     

当代木结构建筑艺术表现与视觉审美元素探究

木材作为一种低碳环保的建筑材料,其艺术表现力和研究价值,已经引起建筑学术界的重视。木材的艺术表现力在木结构建筑设计中起着重要作用。为探寻木材在木结构建筑设计表达中优秀的艺术表现力以及审美元素,通过探讨木结构建筑的广泛应用,发掘木结构建筑艺术的表现倾向,为我国木结构建筑设计的创新发展提供新思路。     

国内外木结构建筑耐火性能的研究进展

为推动现代木结构建筑在国内的发展,分析了木结构建筑耐火的关键性,重点介绍了近二十年来国内外在木结构建筑耐火模拟测试、建筑及其结构耐火极限试验、防火材料应用和软木制品的保温隔热检测与耐火应用等方面的研究进展及成果。在学习和借鉴的基础上,通过总结国外研究成果和经验,提出目前国内在木结构建筑耐火研究方面尚存在的一些问题,与国外相比研究工作的薄弱环节。建议在国内外已有的木结构建筑相关标准规范基础上,加强国内在木结构建筑防火研究的理论基础工作,尤其是模拟试验研究,为木结构建筑的耐火性能评估奠定基础。同时,强调软木材料自身特性,提出在木结构建筑构件及其连接节点处使用软木材料覆面,在保证实用性的基础上,还起到绝缘、隔热、装饰的作用,进一步提高木构件的防火性能,从而提高建筑整体的耐火性。通过上述分析,以期为我国现代木结构建筑防火优化设计提供有益参考。     

初探BIM与木结构:使用Revit创建木制框架墙

BIM(建筑信息模型)是一种新的工程建设流程和技术,在当前工程建设领域已有成功应用的项目案例,将其应用于木结构建筑工程,可在工程设计、施工组织以及项目维护等方面带来有益帮助。Revit是支持BIM技术应用的一款主流软件,在其强大的功能中,也为木结构的设计应用提供了一些专门功能,支持和协助木结构建筑设计师实现高质量、高能效的工程设计。笔者以加拿大木业协会一幅资料图片为例,简要介绍使用Revit软件创建一组木制框架墙的方法,以期为木结构设计起到抛砖引玉的作用。     

我国木结构建筑的发展思考

在全球生态危机的背景下,我国建筑业面临着巨大的环境压力.如何减少建筑能耗以及温室气体排放,推进我国绿色建筑的发展迫在眉睫.木结构建筑作为最名副其实的绿色建筑,其发展符合我国推行绿色节能建筑的方针.总结了我国木结构建筑发展中存在的主要问题,然后通过当今国内外木结构建筑先进的技术解决这些问题,最后为加快发展我国木结构建筑提出几点建议.     

大型木结构体育建筑核心空间设计研究

为凸显"地标性建筑"优势,很多建筑从建筑材料入手进行优选。木结构建筑以其强重比高、绿色节能等特点,被较多应用在大型体育建筑设计方案中。介绍了大型木结构建筑特点,简要分析了大型木结构体育建筑设计要点;分别以日本树海体育馆和美国木结构体育场综合体为例,探讨了大型木结构体育建筑核心空间设计方案,在此基础上提出了大型木结构体育建筑发展方向。     

森林采运作业过程碳排放分析

合理的森林采伐能开发利用森林资源,促进林木生长,但盲目采伐会导致生态环境的破坏。以生命周期评价法的B2B（business-to-business）模式为基础,采用过程分析法,核算森林采运过程各阶段的温室气体排放量。结果表明：采运过程中产生的碳排放约为7.530 6~11.659 8 kg/m3,约占其固碳能力的2.2%~5.7%;燃油消耗是最主要的碳排放源,CO2是其排放的最主要温室气体,碳排放量与集运材距离呈正相关;采伐段碳排放最少,仅0.573 6 kg/m3,索道集材、拖拉机集材排放分别是采伐段的1.04、1.72倍,运材段产生的排放量最多,当运材距离为40 km时,汽车运材和农用车运材排放量分别是采伐段的11.1和17.6倍;油锯采伐＋索道集材＋汽车运材为最优作业模式。研究结果可为森工作业的减排提供理论参考。     

试论广东碳汇林业建设

低碳发展是新时代的趋势,而林业作为生态建设的主体和生态文明建设的主要承担者,是推动经济社会可持续发展、促进低碳时代进步的关键。碳汇林业在积极应对气候变化、助推结构减排和广东开展国家低碳省建设中发挥着重要的作用。广东省碳汇林业具有区别于一般林业的内涵和特征,其主要内容是通过多种营造林工程措施,增加森林面积、改善森林结构,提高森林的碳密度、碳储量,减少森林碳排放、碳损失,增加碳汇、提升森林服务功能。把森林碳汇纳入国家低碳减排政策、把碳汇交易纳入区域发展、完善碳汇林业建设体系等是碳汇林业未来发展的方向。     

Potential impacts of carbon taxes on carbon flux in western Oregon private forests

This study considers a carbon tax system as a policy tool for encouraging carbon sequestration through modification of management in existing forests and examines its welfare impacts and costs of the carbon sequestered. The simulated carbon tax leads to reduced harvest and increased carbon stock in the standing trees and understory biomass. Changes in the level of silvicultural investments vary by owner, depending on the nature of their initial inventory. In general investment under the tax is concentrated in regimes that establish faster growing plantations. Average rotation age increases, varying in extent across ownerships and site qualities. The carbon tax reduces both consumer and producer surpluses in regional timber markets. Producers are compensated by the carbon subsidies, except at low carbon tax levels. Not all rates of carbon tax will attract interest from private owners if participation is voluntary. Estimates of the marginal cost of sequestering carbon in western Oregon private forests are shown to be within the range of costs for projects considering afforestation alone in some eastern regions of the United States.     

废旧木材的回收利用与碳素储存

根据不同木材的材质与特性,对废旧家具材料进行分类回收再利用,符合现代木材工业在循环经济中的发展理念,提高了木材利用的科技含量;将废旧家具回收与木材碳素储存相结合,研究在延长木材生命周期中碳素储量的变化,对比分析综合整理家具回收前后经济效益和碳素储量的关系,为科学合理利用木材、继续深入研究低碳经济与循环经济奠定前期研究基础。     

Will either cap and trade or a carbon emissions tax be effective in monetizing carbon as an ecosystem service

Economists argue that if the cost of carbon emissions was bid into markets, consumers would effectively make purchases that would reduce emissions. Life-cycle inventory and assessment studies have identified how to make many environmental improvements such as reducing carbon emissions at every stage of processing. Most importantly, almost every change in building design, product selection alternative or forest management alternative results in changed levels of carbon emissions across many different stages of processing. These studies raise questions about the effectiveness of carbon registries, cap and trade systems or taxes to effectively monetize the reduction of carbon emissions. A three-tier credit system that accounts for carbon sequestration and storage in the forest sector including users of forest products can mimic many of the expected effects of an economy-wide carbon tax. Insight is provided on policies that are more likely to reflect the value of carbon emissions in purchasing and production systems and to avoid counterproductive results. The relationship between carbon emissions and other forest ecosystem services such as habitat is also examined.     

城市绿地建设中碳减排和碳增汇的实施路径

城市绿地建设具有工程建设“碳排放”和植物光合“固碳”双重特征,是实现“碳减排、碳增汇”的主要途径。传统绿地的建设注重景观而忽略生态,植物配置不合理,追求快速成景,改造频繁且未妥当处理园林绿化废弃物,不但降低了植物光合固碳,而且增加了建设碳排放。在“碳达峰、碳中和”背景下,绿地建设应综合考虑碳减排、碳增汇,减少硬景工程、增加绿量,优化植物配置,优选本地低碳材料和适龄苗木,利用自然塑造地形,精细施工,避免频繁改造,并推进园林绿化废弃物资源化利用,以满足生态文明建设和应对气候变化的新需求。     

Forest management and carbon sequestration in wood products

Wood products are considered to contribute to the mitigation of carbon dioxide emissions. A critical gap in the life cycle of wood products is to transfer the raw timber from the forest to the processing wood industry and, thus, the primary wood products. Therefore, often rough estimates are used for this step to obtain total forestry carbon balances. The objectives of this study were (1) to examine the fate of timber harvested in Thuringian state forests (central Germany), representing a large, intensively managed forested region, and (2) to quantify carbon stocks and the lifetime of primary wood products made from this timber. The analyses were based on the amount and assortments of actually sold timber, and production parameters of the companies that bought and processed this timber. In addition, for coniferous stands of a selected Thuringian forest district, we calculated potential effects of management, as expressed by different thinning regimes on wood products and their lifetimes. Total annual timber sale of soft- and hardwoods from Thuringian state forests (195,000 ha) increased from about 136,893 t C (~0.7 t C ha⁻¹ year⁻¹) in 1996 to 280,194 t C (~1.4 t C ha⁻¹ year⁻¹) in 2005. About 47% of annual total timber harvest went into short-lived wood products with a mean residence time (MRT) < 25 years. Thirty-one per cent of the total harvest went into wood products with an MRT of 25–43 years, and only 22% was used as construction wood and glued wood, products with the longest MRT (50 years). The average MRT of carbon in harvested wood products was 20 years. Thinning from above throughout the rotation of spruce forests would lead to an average MRT in harvested wood products of about 23 years, thinning from below of about 18 years. A comparison of our calculations with estimates that resulted from the products module of the CO2FIX model (Nabuurs et al. 2001) demonstrates the influence of regional differences in forest management and wood processing industry on the lifetime of harvested wood products. To our knowledge, the present study provides for the first time real carbon inputs of a defined forest management unit to the wood product sector by linking data on raw timber production, timber sales and wood processing. With this new approach and using this data, it should be possible to substantially improve the net-carbon balance of the entire forestry sector.     

竹材碳足迹内涵及其对产业发展的调控作用

植物是陆地上唯一能够从大气中固碳的自然生态系统，其减缓气候变化、改善人类生活质量的能力远未被认识和充分发挥。竹子是世界上生长最快的植物之一，固碳潜力巨大，一次种植可永续利用。竹子从光合作用、生长发育、采伐收获、产品制造、友好利用直至分解释放的全生命周期过程，是碳汇或碳封存的全过程，即竹材碳足迹。通常研究的竹林碳汇只涉及竹林生长阶段，忽略产品使用阶段，以及相互之间的联系。开展竹材碳足迹的全过程系统监测和研究，完善竹林碳汇的内涵，正确认识碳循环规律，是当前全球气候变暖背景下碳汇研究的必由之路；特别是在竹材碳足迹的理论指导和政策实施之下，促进竹林定期采伐、全量收获、健康生长，促进竹产品量产利用，增加产品碳封存时间、提高产品寿命，促进资源高效利用、脱贫增收致富、延缓碳排放，调控全生命周期各个环节合理有序、协同发展，意义更加重大。竹材碳足迹理念的实施对系统认识竹林碳汇、指导竹林健康生长、提高产品产量和质量、推进竹业全产业链发展、减少二氧化碳排放，具有重要学术价值和实用价值。     

基于生命周期(LCA)的园林碳排放评价初探

国内对低碳园林的研究多数还处于定性评价研究阶段,对园林碳排放量的定量分析研究还较少。文中运用生命周期法(LCA),对园林建造、使用及拆除处置等不同阶段的碳排放量进行初步的量化分析,明确低碳园林的内涵,提出了低碳园林生命周期碳排放评价的框架与方法。       

SECTION 4:INTEGRATED ASSESSMENTS

Abstract

Reforestation of degraded lands is occurring on a limited basis in portions of the Panama Canal Watershed (PCW). In theory, markets for ecosystem services could encourage more extensive reforestation and ensure that reforestation efforts provide more than just timber. The most relevant ecosystem markets for the PCW are carbon sequestration, watershed services, and four biodiversity markets-bioprospecting, certification of biodiversity friendly products, ecotourism, and existence value. This paper examines the possibility for a land owner or land manager to participate in two or more of these markets. Two land use scenarios-native forest plantation and small-holder agroforestry-emerge as likely candidates for participation in multiple ecosystem service markets. These scenarios are examined to determine whether the strength of incentives to provide a bundle of timber and ecosystem services is sufficient to encourage expansion of these land uses with the Panama Canal Watershed.