森林碳汇助力碳中和的几点认识

森林碳汇不是“杯水车薪”,而是国之重器,森林碳汇功能及其对碳中和的贡献已成为全球共识,森林碳汇的形成、提升、监测、计量、核证、交易等已成为科学研究和社会发展的重要领域。本研究探讨人类文明进程中的人碳关系变化特点,梳理森林碳汇全链条中的一些基本问题,包括森林定义对碳汇计量的影响,森林碳的源-汇关系,碳汇计量边界,碳汇的监测、报告和核算,以及碳汇项目开发、碳汇交易的基本要求等,分析我国森林碳汇提升面临的挑战、潜力和路径。研究认为,要进一步加强森林碳汇科技创新体系建设,深入认识生态修复、森林经营、森林利用过程中的碳汇机制;要进一步优化与森林生态系统碳循环相关的社会制度和规则、技术和文化体系的设计和应用,支撑国家碳达峰碳中和战略实施和生态文明发展。     

“碳中和”背景下木质林产品碳汇能力提升路径研究

在努力实现"3060"碳中和目标的过程中,森林生态系统的作用至关重要。森林是陆地生态系统重要的贮碳库,木质林产品作为这一碳库的主要组成部分,对提升林业碳汇能力发挥了重要作用。介绍了我国碳排放现状和碳中和目标,分析了森林碳汇功能和木质林产品固碳作用,探讨了提升木质林产品碳汇能力的有效路径。     

遥感估算法在森林碳汇估算中的应用进展

作为陆地生态系统主体,森林具有碳源和碳汇的双重作用。目前,国内外众多学者对区域尺度森林碳汇的估算提出的方法较多,但还没有统一的估算方法。遥感估算法是估算森林碳汇的重要方法之一。通过总结该方法的优缺点及应用范围,为碳储量估算精度和碳评估提供合理的参考。     

山西省森林生态系统碳汇特征及提升措施

森林生态系统碳汇功能的强弱与碳达峰、碳中和的量直接相关。分析了山西省森林生态系统碳汇特征,提出了提升总量与质量、优化结构、减少干扰4项措施,提升山西森林生态系统碳汇能力。     

钟祥市盘石岭林场近自然森林经营模式研究

指出了在我国加快推进碳达峰、碳中和的新形势下,努力增加森林碳汇是一项十分紧迫的战略任务。国有林场作为重要的森林资源基地和碳储存库,在实现碳达峰和碳中和目标过程中肩负着重大的责任和使命。提出了近自然森林经营是提升森林碳汇功能和碳封存能力的重要路径,探讨了钟祥市盘石岭林场现有马尾松林、湿地松林和松栎混交林3种林分的近自然经营模式,以期为我国的森林可持续经营提供参考和借鉴,为按期实现碳达峰、碳中和作出林业部门应有的贡献。     

双碳目标下森林碳汇发展路径研究

当前，碳中和碳达峰背景下，通过提升森林固碳功能是抵消与吸纳碳排放的重要途径之一。我国碳汇造林已取得了瞩目成绩，但在森林碳汇方面仍有广阔提升空间。该文在对森林碳汇研究现状基础上，分析了当前林业碳汇面临的主要问题，并据此提出应加强相关标准建设、试点非碳效应评估、完善配套政策体系等对策建议。     

“双碳”背景下基于碳汇交易的河北省森林生态效益补偿机制研究

森林碳汇在“碳中和”中起着重要作用，建立基于碳汇交易的森林生态效益补偿机制，是促进“绿水青山向金山银山”转化目标尽快实现的重要保障。目前，我国基于森林碳汇交易的生态效益补偿机制处于探索阶段，急需将森林碳汇价值完整纳入森林生态效益补偿体系，建立有效、稳定的森林生态效益补偿机制。以森林碳汇交易与生态效益补偿为主线，论述了森林碳汇作为生态效益补偿依据的可行性，分析了河北省森林碳汇交易现状及面临的问题，提出了基于碳汇交易的河北省森林生态效益补偿机制的思路与对策，以期为河北省建立市场化、多元化的森林生态效益补偿制度提供参考依据，为河北省实现“双碳”目标提供支撑。     

安徽省青阳县栎类阔叶林乔木层固碳效益研究

森林是重要的陆地生态系统,在应对全球气候变化中扮演着重要的角色。森林碳汇指森林等吸收并储存CO：的多少,或者吸收并储存CO2的能力。森林碳汇对降低大气中温室气体浓度、减缓全球气候变暖具有十分重要的作用。目前国内有关森林碳汇的计量方法主要有蓄积量法、生物量法和基于蓄积量法、生物量法的生物清单法。对于生物量一碳储量转换因子...     

国外森林地上部分碳汇遥感监测方法综述

森林的碳汇功能对缓解气候变化具有重要作用, 森林碳汇的计量和监测方法备受关注, 其中应用遥感方法对森林地上部分碳汇进行监测计量已经成为目前林业遥感的热点。文中基于光学遥感、微波雷达和激光雷达3种常用的遥感数据源综述了国外森林地上部分碳汇遥感监测的主要方法, 并讨论了这些监测方法的精度和不确定性。得出:1)基于光学遥感数据的多元回归分析法在森林地上部分碳汇估算中应用最为广泛, 人工神经网络法具有更高的估算精度; 2)微波雷达系统能够穿透云层, 可用于多云地区森林地上部分碳汇的估算; 3)基于激光雷达数据的估算结果是三者中精度最高的, 可用于高生物量地区森林地上部分碳汇的监测。     

碳中和目标下中国森林碳储量、碳汇变化预估与潜力提升途径

增强森林固碳增汇功能是减缓大气二氧化碳浓度上升和全球气候变暖的重要手段,也是实现碳中和国家战略目标的有效途径。本研究基于文献分析法和模型模拟,系统阐述中国森林碳储量和碳汇现状、动态变化与潜力提升途径。根据国家森林资源连续清查数据测算的森林植被碳储量近5年平均年增长0.152 Pg(以C计),2000s—2010s中国陆地生态系统碳汇量约229.7 Tg·a^-1(以C计),其中森林植被(指乔木林)碳储量约增加150.6 Tg·a^-1(以C计),约占整个陆地生态系统植被碳汇量的65.6%。过去70年,中国森林已从碳源转变为逐渐增强的碳汇。在森林面积保持不变的情景下,相比2000s—2010s时段,2030年后现有乔木林的生物量碳汇将有所下降;如果森林面积未来持续增加,2030—2050年中国新增乔木林的碳汇量仍将呈增加趋势。在全球变化背景下,气候变化及其引发的风险(极端干旱与热浪事件、森林火灾、病虫害等)可能会削弱森林碳汇功能。为维持并提升森林碳储量和碳汇潜力,需要采取森林碳储与碳汇双增以及森林碳汇与木质林产品碳库协同提升的策略,从保碳、增碳、扩...     

林火干扰对广东省2种典型针叶林森林生物碳密度的影响

[目的]定量研究不同林火干扰对森林生物碳库的变化规律,揭示林火干扰对森林生物碳密度的影响机制,为林火干扰后森林生态系统碳汇管理提供参考依据。[方法]以广东省亚热带2种典型针叶林为研究对象,采用相邻样地比较法,以野外调查采样与室内试验分析为主要手段,定量测定不同林火干扰强度对森林生物碳库(植被碳库和凋落物碳库)碳密度与碳分配格局的影响。[结果]林火干扰对亚热带2种典型针叶林的植被和凋落物碳密度有影响,均表现为对照>轻度林火干扰>中度林火干扰>重度林火干扰。轻度林火干扰对植被碳密度的影响差异不显著(P<0.05),而中度和重度林火干扰则显著降低了植被碳密度(P<0.05).相同林火干扰强度下,植被各组分碳密度的变化均表现为乔木最大。乔木碳密度在不同林火干扰强度下均呈现为对照>轻度林火干扰>中度林火干扰>重度林火干扰,而草本碳密度则呈现与乔木碳密度相反的变化趋势。林火干扰显著影响乔木和草本碳密度,亦对灌木碳密度产生了影响。不同林火干扰强度对凋落物碳密度的影响有所差异,但不同林火干扰强度均显著减少了凋落物碳密度(P<0.05),并随林火干扰强度的增加其减少幅度增大。[结论]林火干扰减少了植被和凋落物碳密度,进而对森林生态系统的碳密度产生重要影响。     

碳达峰、碳中和目标下全球气候治理新格局与林草发展机遇

自2020年9月以来，习近平总书记在多个国际重要场合发表重要讲话，向国际社会郑重宣布中国二氧化碳排放力争于2030年前达到峰值，努力争取2060年前实现碳中和，2030年森林蓄积量将比2005年增加60亿m3。目前，全球已有54个国家实现了碳达峰，且越来越多的国家正在将碳中和转化为国家发展战略。文中梳理了碳达峰、碳中和的概念、要求和进展；分析了面向碳达峰、碳中和，国际谈判重点议题的变化、美国立场的不确定性等全球气候治理新格局，及其对中国的影响；提出在新格局下，森林湿地草原等生态系统碳汇作用将更加凸显，以及我国林草业应对气候变化的关键点，以期充分发挥我国林草业在助推碳中和目标实现中的潜力，并在保障国家外交战略和促进绿色发展中作出贡献。     

火干扰对森林碳库影响的量化研究进展

火干扰是森林生态系统的主要干扰因子之一, 会对森林碳储量和碳动态产生重要影响。准确量化火干扰对森林中各碳库的影响程度, 对国家及全球碳预算具有重要意义。文中对国内外火干扰下森林碳储量的研究现状、研究方法和研究内容进行了综述。大量研究表明, 燃烧效率、火烧烈度等关键因子的准确量化是精确估算火干扰对森林碳储量影响的基础, 火烧样地调查与遥感反演法和模型模拟法的综合运用有利于精确量化火干扰下的森林碳库, 各种火烧数据源的同化处理是准确揭示火干扰对森林碳库影响的重要保证。在此基础上, 提出一些更加准确量化火干扰对森林碳储量影响的研究途径, 并对未来的研究方向进行了展望。     

基于碳中和愿景的竹林生态系统管理思考

竹子具有良好的固碳增汇能力,为实现中国在2060年前达到碳中和目标,竹林生态系统的经营与管理至关重要。文章从竹林生态系统合理布局、结构优化及综合管理等方面,探讨了碳中和愿景下竹林生态系统经营模式及管理方式,旨在为充分发挥和巩固竹林碳中和贡献提供依据,同时展望了后碳中和时代,竹林经营与管理发展方向。     

国内外混交林研究进展

在应对气候变化与实现碳中和目标以及社会发展对森林生态系统要求更加多样化的时代背景下,混交林的重要性在世界各国已达成共识。通常认为,相对于纯林,混交林能够增加生物多样性、提高生产力、增加碳储量,具有更高的生态韧性（抵抗力与恢复力）。但混交林是否必然优于纯林,且混交林与生物多样性、生产力、碳汇、生态韧性以及混交效应的关系一直是国内外学者探讨与研究的问题。混交林绝不是简单的树种组合与排列,其结构与生态过程相对复杂。文中通过文献梳理,总结分析混交林与生物多样性、生产力、碳储量、生态韧性以及混交林经营管理5个方面的国内外研究成果,发现关于混交林与生态功能和生产力的关系研究结果多样,总的结论是,若要得到混交林的积极效应,不能单纯增加树种多样性,更重要的是要考虑树种特性、生态互补、林分结构以及立地和环境的影响。我国混交林研究主要是通过造林实验对比分析生长效果,选择较优混交造林技术。文中最后提出我国混交林研究发展建议,旨在促进对混交林的科学和全面认识。     

Disturbance ecology benchmarks for Schima–Castanopsis forests in the central Himalayas

Roughly 2.8 billion people burn wood for basic energy needs, and traditional wood-fuel represents ~55% of global wood harvest. With increasing anthropogenic disturbance of natural forests, the “stability/fragility” paradigm of forest ecology is gradually being replaced by a “disturbance/recovery” paradigm. In order to understand effects of human-induced disturbances on natural forest ecosystems, and to plan for recovery of disturbed forests, appropriate metrics become necessary. Such metrics will aid in assessment and management of forests for carbon sequestration, biodiversity conservation, ecosystem health, and sustainability of natural resources. Such metrics are especially needed in “wood-fuel hotspots” of the world where over 275 million people live and harvest wood-fuel unsustainably. In this article, I provide metrics of human-induced disturbance in Nepal’s Schima–Castanopsis dominated forests and show relationships of disturbance intensity with forest structure and composition, site productivity potential, natural regeneration, and tree species diversity. Benchmark data were collected from survey of two protected reference forests and compared against three other forests representing a disturbance gradient. The Schima–Castanopsis association is a common dominant forest type in the warm temperate zone of the central Himalayas, and the findings from this study should have wider application.     

Biomass and carbon pools of disturbed riparian forests

Quantification of carbon pools as affected by forest age/development can facilitate riparian restoration and increase awareness of the potential for forests to sequester global carbon. Riparian forest biomass and carbon pools were quantified for four riparian forests representing different seral stages in the South Carolina Upper Coastal Plain. Three of the riparian forests were recovering from disturbance (thermal pollution), whereas the fourth represents a mature, relatively undisturbed riparian forest. Above and belowground carbon pools were determined from linear transects established perpendicular to the main stream channels and spanning the width of the riparian area. The objective of this study was to quantify the biomass and carbon pools in severely disturbed, early successional bottomland hardwood riparian forests and to compare these values to those of a less disturbed, mature riparian forest.

Aboveground biomass in all four riparian forests increased during the 2.5-year investigation period. The total carbon pool in these South Carolina Coastal Plain riparian forests increased with forest age/development due to greater tree and soil carbon pools. The mature riparian forest stored approximately four times more carbon than the younger stands. The importance of the herbaceous biomass layer and carbon pool declined relative to total aboveground biomass with increasing forest age. As stands grew older fine root biomass increased, but an inverse relationship existed between percentages of fine root biomass to total biomass. The root carbon pool increased with forest age/development due to a combination of greater fine root biomass and higher root percent carbon.

Aboveground net primary production (NPP) in young riparian forests rapidly approached and exceeded NPP of the more mature riparian forest. As a woody overstory became established (after 8–10 years) annual litterfall rate as a function of NPP was independent of forest age and litterfall amount in the young riparian forests was comparable to mature riparian forests. Biomass in the riparian forest floor and carbon pool declined with increasing riparian forest development. Woody debris in these riparian forests comprised a relatively small carbon pool. An understanding of bottomland hardwood riparian forest carbon pools at different stages of succession allows us to assess how time since disturbance influences these pools, leading to a better understanding of the recovery processes.     

林火碳排放模型研究进展

林火作为干扰因子, 影响着森林演替、森林生物量和生产力以及生物地球化学循环。森林燃烧所释放的含碳温室气体对全球气候变化具有重要影响。对森林火灾释放的含碳气体进行有效估算, 可以弄清林火产生的含碳气体对全球碳循环的影响。文中介绍了2种林火碳排放模型, 即基于有效可燃物模型和火干扰下碳循环模型。通过对这2种估算方法的比较, 指出未来林火碳排放估算方法的发展趋势。     

The impact of windthrow on carbon sequestration in Switzerland: a model-based assessment

Carbon sequestered in biomass is not necessarily stored infinitely, but is exposed to human or natural disturbances. Storm is the most important natural disturbance agent in Swiss forests. Therefore, if forests are taken into account in the national carbon budget, the impact of windthrow on carbon pools and fluxes should be included. In this article the forest scenario model MASSIMO and the soil carbon model YASSO were applied to assess the effect of forest management and an increased storm activity on the carbon sequestration in Swiss forests. First, the soil model was adapted to Swiss conditions and validated. Second, carbon fluxes were assessed applying the two models under various forest management scenarios and storm frequencies. In particular, the influence of clearing after a storm event on the carbon budget was analyzed. The evaluation of the model results showed that the soil model reliably reproduces the amount of soil carbon at the test sites. The simulation results indicated that, within the simulated time period of 40 years, forest management has a strong influence on the carbon budget. However, forest soils only react slightly to changes in the above-ground biomass. The results also showed that a storm frequency increase of 30% has a small impact on the national carbon budget of forests. To develop effective mitigation strategies for forest management, however, longer time periods must be regarded.     

Assessing rates of forest change and fragmentation in Alabama,USA, using the vegetation change tracker model

Forest change is of great concern for land use decision makers and conservation communities. Quantitative and spatial forest change information is critical for addressing many pressing issues, including global climate change, carbon budgets, and sustainability. In this study, our analysis focuses on the differences in geospatial patterns and their changes between federal forests and nonfederal forests in Alabama over the time period 1987–2005, by interpreting 163 Landsat Thematic Mapper (TM) scenes using a vegetation change tracker (VCT) model. Our analysis revealed that for the most part of 1990 s and between 2000 and 2005, Alabama lost about 2% of its forest on an annual basis due to disturbances, but much of the losses were balanced by forest regeneration from previous disturbances. The disturbance maps revealed that federal forests were reasonably well protected, with the fragmentation remaining relatively stable over time. In contrast, nonfederal forests, which are predominant in area share (about 95%), were heavily disturbed, clearly demonstrating decreasing levels of fragmentation during the time period 1987–1993 giving way to a subsequent accelerating fragmentation during the time period 1994–2005. Additionally, the identification of the statistical relationships between forest fragmentation status and forest loss rate and forest net change rate in relation to land ownership implied the distinct differences in forest cutting rate and cutting patterns between federal forests and nonfederal forests. The forest spatial change information derived from the model has provided valuable insights regarding regional forest management practices and disturbance regimes, which are closely associated with regional economics and environmental concerns.