浅析2010年至2012年山西省森林碳变化

林业在应对全球气候变化时所起的作用是不容忽视的。在山西省森林资源清查数据的基础上,笔者依据《省级温室气体清单编制》方法估算森林和其它木质生物量碳储量、森林转化生物量碳、枯死木碳库的年度变化,通过主要参数、数据源、森林碳变化量等指标的分析得出,山西省林业碳汇量2012年比2010年有明显增加,呈正增长趋势。     

丽水市森林碳储量和碳汇经济价值研究

为精确计量丽水市森林碳储量和碳汇量，核算森林碳汇经济价值，运用系统抽样方法，在丽水市全域系统布设固定样地716个，根据固定样地数据，结合单株生物量模型法和单位面积生物量模型，测算丽水市2016—2021年各年的森林碳储量和2017—2021年各年的森林碳汇量；在此基础上，利用碳税率法、造林成本法、碳市场CEA价格法，分别测算森林碳汇经济价值。结果表明，丽水市年平均森林碳储量为6 654.97万t，年平均森林碳汇量为290.32万t；森林植被碳储量组成主体是乔木林，占82.90%，其次为竹林，占7.98%，灌木林占2.67%；其他林地（包括疏林、散生木、四旁木等）占6.45%；在乔木林、竹林、灌木林3种森林类型中，乔木林的碳密度（单位面积的碳储量）最高，竹林居中，灌木林最低，同时，森林平均碳密度和乔木林碳密度呈逐年递增趋势；根据抽样估计理论与计算方法，在P<0.05的可靠性保证下，丽水市森林植被碳储量各年的估计精度都大于93%，估计结果有较好的精度保证；按碳税率法、造林成本法、碳市场CEA价格法，2017—2021年年平均森林碳汇价值为分别为34.84亿元、7.93亿元和1.68亿...     

库布齐沙漠地区碳汇造林项目碳汇计量监测实践——以伊泰集团杭锦旗碳汇造林项目为例

伊泰集团杭锦旗碳汇造林项目地位于内蒙古库布齐沙漠地区,项目区土地荒漠化、土壤盐碱化严重。本项目活动采用耐干旱、耐沙埋、耐盐碱的乡土灌木以及乔木树种实施造林,造林模式因地制宜,监测结果显示,项目碳储量为325891.07 tCO_(2)-e。其中,乔木林生物质碳储量占项目碳储量的19.65%;灌木生物质碳储量占项目碳储量的75.30%;木产品碳储量占5.05%;各碳库中,地上生物量碳库碳储量为119759.40 tCO_(2)-e,占项目碳储量的36.75%;地下生物量碳库碳储量206131.67 t CO_(2)-e,占63.25%。项目减排量为325891.07 tCO_(2)-e,年均减排量为54315.18 tCO_(2)-e。本造林项目在提高项目地区植被覆盖率、增加碳汇量方面具有明显作用。     

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...     

将乐县针阔混交林生态系统碳储量格局

依据全国碳汇专项调查的理论和调查方法,对福建省将乐县不同龄组针阔混交林生态系统的碳储量进行调查分析。结果表明:针阔混交林生态系统碳储量随着林分年龄的增加而增加,幼龄林、中龄林、成熟林生态系统总碳储量分别为121.13、176.00、253.33 t·hm-2;在幼龄林、中龄林和成熟林中,乔木层碳储量所占比重分别为33.16%、46.94%、28.27%,土壤层有机碳储量所占比重分别为60.10%、50.45%、68.21%,土壤层和乔木层碳储量占生态系统总碳储量的90%以上;除成熟林中,30~100 cm土层有机碳储量略高于10~30 cm土层外,土壤层有机碳储量在各龄组针阔混交林中均表现为随土壤深度的增加而减少,随着林分年龄的增加而增加;各龄组针阔混交林其他层次不同组分碳储量差异各不相同,估算针阔混交林生态系统碳储量应充分考虑这种差异性,以提高估算精度。     

山东省主要森林碳库分量参数的初步测定

山东森林是以平原地区用材林为主的农区森林,低山丘陵区森林立地条件差,生产力偏低,不具备温带森林的代表性。结合全国林业碳汇计量监测专项调查数据,建立符合山东省森林特点的森林碳储量不同碳库分量参数体系,对于提高区域森林碳储量估算精度具有重要意义。     

霞浦县阔叶混交林生态系统碳、氮储量格局

依据全国碳汇专项调查的理论和方法,对福建省霞浦县不同林龄阔叶混交林生态系统各组分的碳、氮含量及碳、氮储量格局进行调查分析,结果表明:灌木层各器官碳含量从大到小依次为枝干根叶,氮含量为叶干根枝;草本层碳、氮含量从大到小均为地上部分地下部分;土壤碳、氮含量均随土层深度增加而降低,随林龄的增大而上升;系统各组分C/N从大到小依次为枝根干枯落物叶土壤;12年生、19年生和28年生阔叶混交林生态系统的碳储量分别为164.066、231.751和290.985t!hm-2,氮储量分别为15.011、23.503和31.236t!hm-2,其中,土壤层碳储量所占比重分别为60.27%、46.50%和39.50%,氮储量所占比重分别为45.94%、33.09%和28.67%;乔木层、灌木层、枯落物层和土壤层碳、氮储量均随林龄的增大而增加。     

贵州不同林龄华山松人工林生态系统碳储量

本研究调查分析了不同林龄华山松人工林生态系统土壤碳含量和碳储量,测定了林地凋落物层和林下植被层及根系碳储量,并用生物量方程法估测了乔木层碳储量。结果表明:华山松人工林生态系统碳储量随着林龄的增加而增加,在8、30和40年生华山松人工林生态系统内,总碳储量分别为104.9 t·hm-2、136.67t·hm-2和176.89 t·hm-2,乔木层碳储量所占比重分别为5.9%、14.97%和28.48%,土壤层碳储量所占比重为90.73%、72.98%和68.01%。乔木层和土壤层碳储量的正向积累是导致不同林龄华山松人工林生态系统碳储量逐年增加的主要因素。     

基于森林资源二类调查的县域森林碳汇及其价值估算研究——以湖北省当阳市为例

基于当阳市第四次(2009年)和第五次(2019年)森林资源二类调查成果，运用生物量转换因子法，对森林生物量进行了估算；运用生物量-碳储量转换系数法，估算了森林碳储量；按照IPCC(2006年)提供的库-差别方法，对当阳市2009～2019年10 a期间森林碳汇量进行了估算，采用均值法(市场价值法和造林成本法平均值),评价了当阳市森林碳汇价值。结果表明：2009年和2019年当阳市森林碳储量分别为98.20×10⁴tC和147.42×10⁴tC;平均碳密度分别为14.27 tC·hm^-2和22.23 tC·hm^-2(含地上部分和地下部分，不包括枯死木、枯落物和土壤有机碳);2009～2019年10 a期间当阳市森林碳汇量为180.47×10⁴ tCO₂(49.22×10⁴ tC),单位面积年碳汇量为2.93 tCO₂·hm^-2·a^-1(0.8tC·hm^-2     

不同经营措施对毛竹林生态系统净碳汇能力的影响

【目的】探讨不同经营措施对毛竹林生态系统净碳汇能力的影响,为毛竹林固碳经营提供依据。【方法】利用两因素随机区组设计,排除地形因子等影响,选取施肥量和采伐方式2个因素,每个因素分别设置3个水平,共9个试验组合:大量施肥强度采伐、大量施肥中度采伐、大量施肥弱度采伐、中等施肥强度采伐、中等施肥中度采伐、中等施肥弱度采伐、不施肥强度采伐、不施肥中度采伐和不施肥弱度采伐,研究2010—2013年不同经营措施对毛竹林生态系统净碳汇能力的影响。【结果】2010和2013年两期0~50 cm土层土壤有机碳储量差异显著(P0.05),而0~10 cm土层土壤有机碳贮量差异不显著(P0.05);两期植被总碳储量和毛竹碳储量差异均极显著(P0.01),而两期林下植被总碳储量差异不显著(P0.05);样地外运输总泄漏量仅占样地内施肥总排放量的7.32%;中等施肥弱度采伐处理与大量施肥强度采伐处理净碳汇量差异显著(P0.05),中等施肥弱度采伐处理林分的净碳汇量最多,达到64.721 tC·hm~(-2),而大量施肥强度采伐处理林分的净碳汇量最少,为-14.237tC·hm~(-2),说明过度集约经营可能造成毛竹林生态系统的碳排放,而合理经营方式有利于毛竹林生态系统的碳积累;土壤碳库变化量占所有碳库变化量总和的70.99%±12.30%,毛竹碳库变化量占所有碳库变化量总和的23.37%±11.24%,林下植被碳库变化量占所有碳库变化量总和的0.63%±0.37%,运输泄漏量占所有碳库变化量总和的0.40%±0.16%,施肥排放量占所有碳库变化量总和的4.60%±4.85%,其中土壤碳库和毛竹碳库的变化量之和占所有碳库变化量总和的94.36%。【结论】在碳汇项目计量监测时,为了节约成本,可以忽略林下植被碳库和运输泄漏以及施肥引起的温室气体排放。大量施肥强度采伐的毛竹林常规经营方式不仅植被总碳储量增加较少,而且还引起了明显的土壤碳排放,不利于毛竹林生态系统净碳汇量的积累。采用中等施肥弱度采伐的生态经营方式,不仅使植被总碳储量增加最多,同时土壤碳储量也增加最多,是一种最有利于毛竹林增汇减排的经营方式。     

永平县森林生物量的碳储量初步估算

以云南省永平县的森林资源数据为基础,采用公式:碳储量(C)=林木蓄积湿重×比值×(1-含水率)×含碳率,分别计算林木、林下灌木、林下草本植物、林下凋落物生物量的碳储量,并以2005年为基准年,采用复利公式Cnt=A(1+B)n对永平县2005~2015年森林生物量的碳储量进行了预估.     

山东省森林碳汇动态的研究

本研究以山东省各森林类型为统计单元,得出山东省现有森林碳储量为105.5Tg,占全国的3%,是全国单位面积碳储量平均水平的1.92倍(按土地面积计),各森林类型碳密度差异较大,介于9.23~46.59Mg.hm-2之间,密度大小与人为干扰程度有直接关系。并根据历年森林碳储量与碳密度变化情况,对未来18年山东省碳储量及碳密度变化情况进行了预测,至2020年,全省森林碳储量可达155.04Tg,比现在增长47%,至2030年达到199.08Tg,比2012年增长89%。     

Carbon dynamics of North American boreal forest after stand replacing wildfire and clearcut logging

Boreal forest carbon (C) storage and sequestration is a critical element for global C management and is largely disturbance driven. The disturbance regime can be natural or anthropogenic with varying intensity and frequency that differ temporally and spatially the boreal forest. The objective of this review was to synthesize the literature on C dynamics of North American boreal forests after most common disturbances, stand replacing wildfire and clearcut logging. Forest ecosystem C is stored in four major pools: live biomass, dead biomass, organic soil horizons, and mineral soil. Carbon cycling among these pools is inter-related and largely determined by disturbance type and time since disturbance. Following a stand replacing disturbance, (1) live biomass increases rapidly leading to the maximal biomass stage, then stabilizes or slightly declines at old-growth or gap dynamics stage at which late-successional tree species dominate the stand; (2) dead woody material carbon generally follows a U-shaped pattern during succession; (3) forest floor carbon increases throughout stand development; and (4) mineral soil carbon appears to be more or less stable throughout stand development. Wildfire and harvesting differ in many ways, fire being more of a chemical and harvesting a mechanical disturbance. Fire consumes forest floor and small live vegetation and foliage, whereas logging removes large stems. Overall, the effects of the two disturbances on C dynamics in boreal forest are poorly understood. There is also a scarcity of literature dealing with C dynamics of plant coarse and fine roots, understory vegetation, small-sized and buried dead material, forest floor, and mineral soil.     

片段化生境中木本植物种子大小对幼苗存活的影响

以千岛湖29个样岛木本植物的种子与幼苗为研究对象,分析了种子大小与种子数量的相关性,以及岛屿参数、地形因素和土壤养分含量如何影响种子大小并作用于幼苗早期存活.结果显示:(1)物种间种子大小与种子数量存在权衡关系;(2)种子大小对幼苗半年存活率无显著正效应,但坡向朝东、土壤碳含量低增加了种子大小对幼苗存活率的正效应,而夏...     

Country-level carbon balance of forest soils: a country-specific model based on case studies in Hungary

International agreements require countries to annually report on greenhouse gas emissions and removals. For the land-use sector, this includes estimating stock changes in various carbon pools. For carbon pools like mineral forest soil where a country-level statistical inventory based on measurements is very difficult, models are usually applied together with data from case studies. In this paper, we present a country-specific model together with case studies that aim at capturing major soil processes due to forestry activity. These processes include “hot moments”, e.g., disturbances that occur rarely but might result in relatively high emissions. The model only aims at developing a conservative estimate, rather than a central one, of net country-level carbon stock change with emissions overestimated and removals underestimated. The model is partially parameterised using paired sampling of soil organic carbon in the uppermost 30-cm layer, applying standard methods including those suggested by IPCC, in afforestations on former croplands and in artificial regenerations. Results show that soils of afforested croplands act as a sink, and carbon stock after regeneration might decrease due to disturbance by forest operations, but might also increase due to transfer of carbon from dead roots to soil depending on disturbance levels. The estimation at the country level, which involves additional considerations and data from the literature, suggests that overall, forest soils are a net sink in Hungary, but also that artificially limiting soil organic carbon changes estimation to the uppermost 30-cm layer as applied in the IPCC methodology might lead to artefacts.     

Forest carbon storage in the northeastern United States: Net effects of harvesting frequency,post-harvest retention,and wood products

Temperate forests are an important carbon sink, yet there is debate regarding the net effect of forest management practices on carbon storage. Few studies have investigated the effects of different silvicultural systems on forest carbon stocks, and the relative strength of in situ forest carbon versus wood products pools remains in question. Our research describes (1) the impact of harvesting frequency and proportion of post-harvest structural retention on carbon storage in northern hardwood-conifer forests, and (2) tests the significance of including harvested wood products in carbon accounting at the stand scale. We stratified Forest Inventory and Analysis (FIA) plots to control for environmental, forest structural and compositional variables, resulting in 32 FIA plots distributed throughout the northeastern U.S. We used the USDA Forest Service's Forest Vegetation Simulator to project stand development over a 160 year period under nine different forest management scenarios. Simulated treatments represented a gradient of increasing structural retention and decreasing harvesting frequencies, including a “no harvest” scenario. The simulations incorporated carbon flux between aboveground forest biomass (dead and live pools) and harvested wood products. Mean carbon storage over the simulation period was calculated for each silvicultural scenario. We investigated tradeoffs among scenarios using a factorial treatment design and two-way ANOVA. Mean carbon sequestration was significantly (α = 0.05) greater for “no management” compared to any of the active management scenarios. Of the harvest treatments, those favoring high levels of structural retention and decreased harvesting frequency stored the greatest amounts of carbon. Classification and regression tree analysis showed that management scenario was the strongest predictor of total carbon storage, though site-specific variables were important secondary predictors. In order to isolate the effect of in situ forest carbon storage and harvested wood products, we did not include the emissions benefits associated with substituting wood fiber for other construction materials or energy sources. Modeling results from this study show that harvesting frequency and structural retention significantly affect mean carbon storage. Our results illustrate the importance of both post-harvest forest structure and harvesting frequency in carbon storage, and are valuable to land owners interested in managing forests for carbon sequestration.     

How much carbon can the Siberian boreal taiga store: a case study of partitioning among the above-ground and soil pools

In the context of global carbon cycle management, accurate knowledge of carbon content in forests is a relevant issue in contemporary forest ecology. We measured the above-ground and soil carbon pools in the darkconiferous boreal taiga. We compared measured carbon pools to those calculated from the forest inventory records containing volume stock and species composition data. The inventory data heavily underestimated the pools in the study area(Stolby State Nature Reserve, central Krasnoyarsk Territory, Russian Federation). The carbon pool estimated from the forest inventory data varied from 25(t ha-1)(low-density stands) to 73(t ha-1)(highly stocked stands). Our estimates ranged from 59(t ha-1)(lowdensity stands) to 147(t ha-1)(highly stocked stands). Our values included living trees, standing deadwood, living cover, brushwood and litter. We found that the proportion of biomass carbon(living trees): soil carbon varied from99:1 to 8:2 for fully stocked and low-density forest stands,respectively. This contradicts the common understanding that the biomass in the boreal forests represents only16–20 % of the total carbon pool, with the balance being the soil carbon pool.     

Short- and long-term responses of total soil organic carbon to harvesting in a northern hardwood forest

The long-term response of total soil organic carbon pools (‘total SOC’, i.e. soil and dead wood) to different harvesting scenarios in even-aged northern hardwood forest stands was evaluated using two soil carbon models, CENTURY and YASSO, that were calibrated with forest plot empirical data in the Green Mountains of Vermont. Overall, 13 different harvesting scenarios that included four levels of aboveground biomass removal (20%, 40%, 60% and 90%) and four different rotation lengths (60 year, 90 year, 120 year, and No Rotation (NR)) were simulated for a 360 year period. Simulations indicate that following an initial post-harvest increase, total SOC decreases for several decades until carbon inputs into the soil pool from the re-growth are greater than losses due to decomposition. At this point total SOC begins to gradually increase until the next harvest. One consequence of this recovery pattern is that between harvests, the size of the SOC pool in a stand may change from −7 to 18% of the pre-harvest pool, depending on the soil pool considered. Over 360 years, the average annual decrease in total SOC depends on the amount of biomass removed, the rotation length, and the soil pool considered. After 360 years a stand undergoing the 90yr-40% scenario will have 15% less total SOC than a non-harvested stand. Long-term declines in total SOC greater than 10% were observed in the 60yr-60%, 60yr-90%, and 90yr-90% scenarios. Long-term declines less than 5% were observed in scenarios with 120 year rotations that remove 60% or less of the aboveground biomass. The long-term decreases simulated here for common management scenarios in this region would require intensive sampling procedures to be detectable.     

甘肃祁连山国家级自然保护区天然林保护工程生态效益初步评价分析

根据天保工程效益监测数据、森林生态系统长期连续定位观测数据和森林资源二类调查数据,利用《森林生态系统服务功能评估规范》评估模型,对祁连山自然保护区天保工程区新增的28.29万hm2森林进行生态效益评价。结果显示:保护区天保工程区新增森林生态系统产生的生态效益总价值为174.85亿元/a;从森林生态系统各项服务功能所占比重看,从大到小依次为保育土壤、生物多样性保护、固碳释氧、涵养水源、净化环境、森林防护、积累营养物质、森林游憩。