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1.
Standing biomass and carbon storage of above-ground structures in dominant mangrove trees in the Sundarbans 总被引：1，自引：0，他引：1
We evaluated carbon stocks in the above-ground biomass (AGB) of three dominant mangrove species (Sonneratia apetala, Avicennia alba and Excoecaria agallocha) in the Indian Sundarbans. We examined whether these carbon stocks vary with spatial locations (western region vs. central region) and with seasons (pre-monsoon, monsoon and post-monsoon). Among the three studied species, S. apetala showed the maximum above-ground carbon storage (t ha−1) followed by A. alba (t ha−1) and E. agallocha (t ha−1). The above-ground biomass (AGB) varied significantly with spatial locations (p < 0.05) but not with seasons (p < 0.05). The variation may be attributed to different environmental conditions to which these areas are exposed to such as higher siltation and salinity in central region compared to western region. The relatively higher salinity in central region caused subsequent lowering of biomass and stored carbon of the selected species. 相似文献
2.
中国森林系统对全球碳平衡的作用与地位 总被引：2，自引：0，他引：2
结合林业系统的远景规划,提出了“20 a 20 a”的林业建设模式。根据该模式,从2004年开始,经过20 a的造林工作,我国森林覆盖率将达到25%,再经过20 a将达到30%。剔除每年2×108m3的木材采伐量,在第1个20a期间,平均年消耗大气C折合CO22.24×108t,占1996年我国CO2排放量的27.8%;以森林覆盖率25%计算,在第2个20 a期间,平均年消耗大气C折合CO26.31×108t,占1996年我国CO2排放量的78.3%。将每年2×108m3的木材采伐量计算在内,则消耗的CO2分别为8.32×108t和12.36×108t,约占1996年CO2排放量的103%和153%。在“20 a 20 a”模式下,我国森林系统将成为巨大的碳汇。这一方面可使我国的生态环境得到优化,实现国民经济的可持续发展,另一方面可减轻我国在碳排放问题上所受到的国际压力,有利于拓宽我国的经济发展空间。 相似文献
3.
作为陆地生态系统的主体,森林生态系统的碳循环与碳蓄积对研究陆地生态系统碳循环起着重要作用.生物量、生产力、土壤有机质以及凋落物量及其分解等相互关系决定了森林生态系统的碳库量和碳交换量.本文简单地介绍了在碳蓄积研究中森林生物量和生产力的几种研究方法,并对研究过程中的问题(大尺度生物量的精确估算,地下生物量的研究,森林生态系统土壤碳库估算)进行了探讨. 相似文献
4.
毛竹林的碳密度和碳贮量及其空间分布 总被引：47，自引：8，他引：47
利用标准样方法研究毛竹林碳密度和碳贮量以及空间分布。结果表明 :毛竹不同器官碳密度波动在0 4 6 83～ 0 5 2 10g·g- 1 ,按碳密度高低排列依次为竹根 >竹秆 >竹蔸 >竹枝 >竹鞭 >竹叶 ;碳贮量在毛竹不同器官中的分配以竹秆占比例最大 ,为 5 0 97% ,其次为竹根 ,占 19 79% ,占比例最小的是竹叶 ,仅占 4 87% ;毛竹林生态系统中碳总贮量为 10 6 36 2t·hm- 2 ,其中植被层 34 2 31t·hm- 2 ,占了 32 18% ,枯落物和土壤层 (0～ 6 0cm) 72 131t·hm- 2 ,占了 6 7 82 % ;毛竹林乔木层碳素年固定量为 5 0 97t·hm- 2 a- 1 ,与粗放经营竹林相比 ,毛竹集约经营 10年后 ,竹林生态系统中碳贮量减少了 8 133t·hm- 2 ,但乔木层年净固定碳量增加了 0 5 89t·hm- 2 a- 1 。 相似文献
5.
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. 相似文献
6.
长白山高山冻原生态系统碳储量和碳动态研究 总被引：1，自引：0，他引：1
本研究分析了长白山高山冻原植被-凋落物-土壤生态系统的碳储量和碳动态.冻原植被中年净储存有机碳约17251 t;凋落物中有机碳储量为15043.1 t,凋落物中有机碳储量空间分布格局：TA＞LA＞MA＞SA＞FA;冻原土壤（0～20 cm）中年均储存有机碳为1054 t·a^-1,土壤中有机碳储量为3.16×10^5 t;每年约有1.4×104 t·a^-1土壤有机碳通过土壤呼吸释放到大气圈.植被-凋落物-土壤系统共储存碳452624 t.长白山高山冻原年均固碳为3146 t·a^-1. 相似文献
7.
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。 相似文献
8.
采用材积源-生物量法（Volume-Biomass Method）对江门市行道树的碳储量进行研究。计算了芒果Mangifera indica、高山榕Ficus altissima、美丽异木棉Chorisia speciosa、蒲葵Livistona chinensis、海南红豆Ormosia pinnata、尾叶桉Eucalyptus urophylla、乌墨Syzygium cumini和火焰树Spathodea campanulata等8种行道树的立木碳储量,进而估算江门市城区行道树的碳储量。结果表明：江门市主要行道树平均树高8.92±0.19 m,平均胸径23.18±0.49 cm,平均蓄积量0.22±0.01 m3,生物量为5166.69 t,碳储量为2546.75 t,单株碳储量乌墨最高。可见行道树具有重要的碳汇功能,对改善江门市的城市生态环境有积极的作用。 相似文献
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10.
油松人工林碳汇功能的研究 总被引：2，自引：0，他引：2
对木兰林管局油松人工林19块标准地分林木层、灌木层、草本植物层、枯落物层和土壤层进行了生物现存量的实测与碳储量的研究,结果表明林木层和土壤层的碳储量构成了林分碳储量的主体.分配次序为土壤层＞林木层＞地表枯落物层＞草本层＞根桩＞灌木层,林木层碳储量分配次序为干＞枝＞根＞叶.建立了林木蓄积与生物量、碳储量的回归模型,认为幂函数形式有较好的适用性.以林龄(A)和3株优势木平均高(H)建立了土壤有机碳密度(Soc)拟合方程,可用于具体小班土壤碳密度的估测.木兰林管局油松人工林林分碳密度为76.586 2～284.417 8t/hm2,平均值为143.1 t/hm2,其中林木平均碳密度为30.454 5t/hm2,土壤平均碳密度为110.773 5t/hm2;现有油松人工林碳储量估测结果为983 314.0 t,其中林木碳储量为208 923.0 t,占总碳储量的21.25%,土壤碳储量为760 881.0 t,占总碳储量的77.38%. 相似文献
11.
Comparison of uncertainties in carbon sequestration estimates for a tropical and a temperate forest 总被引：1，自引：1，他引：0
G.J. Nabuurs B. van Putten T.S. Knippers G.M.J. Mohren 《Forest Ecology and Management》2008,256(3):237
We compare uncertainty through sensitivity and uncertainty analyses of the modelling framework CO2FIX V.2. We apply the analyses to a Central European managed Norway spruce stand and a secondary tropical forest in Central America. Based on literature and experience we use three standard groups to express uncertainty in the input parameters: 5%, 10% and 20%. Sensitivity analyses show that parameters exhibiting highest influence on carbon sequestration are carbon content, wood density and current annual increment of stems. Three main conclusions arise from this investigation: (1) parameters that largely determine model output are stem parameters, (2) depending on initial state of the model, perturbation can lead to multiple equilibrium, and (3) the standard deviation of total carbon stock is double in the tropical secondary forest for the wood density, and current annual increment. The standard deviation caused by uncertainty in mortality rate is more than 10-fold in the tropical forest case than in the temperate managed forest. Even in a case with good access to data, the uncertainty remains very high, much higher than what can reasonably be achieved in carbon sequestration through changes in forest management. 相似文献
12.
采用材积源生物量法和四川省2007年森林资源监测数据,计测了四川森林总碳量和碳密度.研究结果表明:2007年四川森林总碳量629.76 Tg,平均碳密度50.67 Mg·hm-2,主要得益于成熟林的贡献.四川森林的碳贮量具有极大的空间差异性,在地貌上表现为:用西高山峡谷区(261.58 Tg C)>川西南山地区(114.32 TgC)>盆地西缘山地区(74.08 Tg C)>盆地丘陵区(59.33 Tg C)>川西北高原区(45.15 Tg C)>盆地南缘山地区(41.45 TgC)>盆地北缘山地区(33.85 Tg C);在流域上表现为:岷江流域(228.57 Tg C)>雅砻江流域(160.25 TgC)>嘉陵江流域(128.25 Tg C)>金沙江流域(84.89 Tg C)>长江干流(16.55 Tg C)>沱江(11.25 Tg C).森林碳密度有由东南向西北遂渐增加的趋势,即盆地北缘山地区(28.83 Mg·hm-2)<盆地丘陵区(31.71 Mg·hm-2)<川西南山地区(42.80 Mg·hm-2)<盆地南缘山地区(48.54 Mg·hm-2)<盆地西缘山地区(56.75 Mg·hm-2)<川西高山峡谷区(66.96 Mg·hm-2)<川西北高原区(69.76 Mg·hm-2),或长江干流域(30.09 M8·hm-2)<沱江流域(36.41 Mg·hm-2)<嘉陵江流域(3s.72 Mg·hm-2)<雅砻江流域(52.94 Mg·hm-2)<金沙江流域(54.48 Mg·hm-2)<岷江流域(62.24 Mg·hm-2).文中还讨论了森林碳贮量与碳密度的空间差异性在森林经营与区划中意义,分区规划和分类经营管理是提高四川森林碳吸存能力的有效措施. 相似文献
13.
This study was conducted to determine carbon (C) dynamics following forest tending works (FTW) which are one of the most important forest management activities conducted by Korean forest police and managers. We measured organic C storage (above- and below-ground biomass C, forest floor C, and soil C at 50 cm depth), soil environmental factors (soil CO2 efflux, soil temperature, soil water content, soil pH, and soil organic C concentration), and organic C input and output (litterfall and litter decomposition rates) for one year in FTW and non-FTW (control) stands of approximately 40-year-old red pine (Pinus densiflora S. et Z.) forests in the Hwangmaesan Soopkakkugi model forest in Sancheonggun, Gyeongsangnam-do, Korea. This forest was thinned in 2005 as a representative FTW practice. The total C stored in tree biomass was significantly lower (P < 0.05) in the FTW stand (40.17 Mg C ha−1) than in the control stand (64.52 Mg C ha−1). However, C storage of forest floor and soil layers measured at four different depths was not changed by FTW, except for that at the surface soil depth (0–10 cm). The organic C input due to litterfall and output due to needle litter decomposition were both significantly lower in the FTW stand than in the control stand (2.02 Mg C ha−1 year−1 vs. 2.80 Mg C ha−1 year−1 and 308 g C kg−1 year−1 vs. 364 g C kg−1 year−1, respectively, both P < 0.05). Soil environmental factors were significantly affected (P < 0.05) by FTW, except for soil CO2 efflux rates and organic C concentration at soil depth of 0–20 cm. The mean annual soil CO2 efflux rates were the same in the FTW (0.24 g CO2 m−2 h−1) and control (0.24 g CO2 m−2 h−1) stands despite monthly variations of soil CO2 efflux over the one-year study period. The mean soil organic C concentration at a soil depth of 0–20 cm was lower in the FTW stand (81.3 g kg−1) than in the control stand (86.4 g kg−1) but the difference was not significant (P > 0.05). In contrast, the mean soil temperature was significantly higher, the mean soil water content was significantly lower, and the soil pH was significantly higher in the FTW stand than in the control stand (10.34 °C vs. 8.98 °C, 48.2% vs. 56.4%, and pH 4.83 vs. pH 4.60, respectively, all P < 0.05). These results indicated that FTW can influence tree biomass C dynamics, organic C input and output, and soil environmental factors such as soil temperature, soil water content and soil pH, while soil C dynamics such as soil CO2 efflux rates and soil organic C concentration were little affected by FTW in a red pine stand. 相似文献
14.
A substantial portion of the carbon (C) fixed by the trees is allocated belowground to ectomycorrhizal (EM) symbionts, but this fraction usually declines after fertilization. The aim of the present study was to estimate the effect of optimal fertilization (including all the necessary nutrients) on the growth of EM fungi in young Norway spruce forests over a three year period. In addition, the amount of carbon sequestered by EM mycelia was estimated using a method based on the difference in δ13C between C3 and C4 plants. Sand-filled ingrowth mesh bags were used to estimate EM growth, and similar bags amended with compost made from maize leaves (a C4 plant) were used to estimate C sequestration. Fertilizers had been applied either every year or every second year since 2002 and the estimates of EM growth started in 2007. The application of fertilizer reduced EM growth to between 0% and 40% of the growth in the control plots at one site (Ebbegärde), while no significant effect was found at the other three sites studied. The effect of the fertilizer was similar in sand-filled and maize-compost-amended mesh bags, but the total production of EM fungi was 3-4 times higher in maize-compost-amended mesh bags. The fertilizer tended to reduce EM growth more when applied every year than when applied every second year. The amount of C sequestered in maize-compost-amended mesh bags collected from unfertilized treatments was estimated to be between 0.2 and 0.7 mg C g sand−1 at Ebbegärde and between 0.2 and 0.5 mg C g sand−1 at Grängshammar. This corresponds to between 300 and 1100 kg C per ha, assuming a similar production in the soil as in the mesh bags. Fertilization at the Ebbegärde site reduced carbon sequestration, which confirmed the results based on estimates of fungal growth (ergosterol levels). A correlation was found between fungal biomass and δ13C in mesh bags amended with maize compost. Based on this, it was estimated that a fungal production of 1 μg ergosterol corresponded to 0.33 mg of sequestered carbon. In conclusion, the effect of the fertilizer on EM growth seemed to be dependent on the effect of the fertilizer on tree growth. Thus, at Ebbegärde, were tree growth was less stimulated by the fertilizer, EM growth was reduced upon fertilization. At other sites, where tree growth was more stimulated, the fertilizer did not influence EM growth. The large amounts of carbon sequestered during the experiment may be a result of fungal residues remaining in the soil after the death of the hyphae. 相似文献
15.
The net gain of carbon in European Union (EU) forest vegetation during 1990–2005 was estimated at 360–400 Tg CO2 year−1 by analysing international data. This amount is at low end of the range of recent corresponding estimates, but greater than earlier estimates published for the period 1971–1990. The sequestration took place almost exclusively in areas which were already forested in 1990. In 2005, new plantations, established after 1990, contributed only about 8% to the estimated net gain. The sequestration was estimated to be the greatest in Germany, France, Italy, Finland and Poland regardless of data source and method of estimation. On a per capita basis, the sequestration was estimated to be the greatest in Finland and Latvia. Carbon sequestration in forests is an important component of the long-term carbon balance of the EU. Carbon sequestration in forests is partly driven by a recovery of the ecosystems from human-induced degradation in the 19th century and the first half of the 20th century. Forest management has affected carbon sequestration and merits attention in climate policy presuming that new policies and measures are reconciled with those already in place for the promotion of the diverse goals of land management in Europe. 相似文献
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We examined the carbon stock and rate of carbon sequestration in a tropical deciduous forest dominated by Dipterocarpus tuberculatus in Manipur,North East India.Estimation of aboveground biomass was determined by harvest method and multiplied with density of tree species.The aboveground biomass was between18.27–21.922 t ha-1and the carbon stock ranged from9.13 to 10.96 t C ha-1across forest stands.Aboveground biomass and carbon stock increased with the increase in tree girth.The rate of carbon sequestration varied from1.4722 to 4.64136 t ha-1year-1among the dominant tree species in forest stands in tropical deciduous forest area.The rate of carbon sequestration depends on species composition,the density of large trees in different girth classes,and anthropogenic disturbances in the present forest ecosystem.Further work is required to identify tree species having the highest potential to sequester CO2 from the atmosphere,which could lead to recommendations for tree plantations in a degraded ecosystem. 相似文献
18.
Dynamics and potentials of carbon sequestration in managed stands and wood products in Finland under changing climatic conditions 总被引：1，自引：0，他引：1
Timo Karjalainen 《Forest Ecology and Management》1996,80(1-3):113-132
Carbon (C) sequestration was studied in managed boreal forest stands and in wood products under current and changing climate in Finland. The C flows were simulated with a gap-type forest model interfaced with a wood product model. Sites in the simulations represented medium fertile southern and northern Finland sites, and stands were pure Scots pine and Norway spruce stands or mixtures of silver and pubescent birch.
Changing climate increased C sequestration clearly in northern Finland, but in southern Finland sequestration even decreased. Temperature is currently the major factor limiting tree growth in northern Finland. In southern Finland, the total average C balance over the 150 year period increased slightly in Scots pine stands and wood products, from 0.78 Mg C ha−1 per year to 0.84 Mg C ha−1 per year, while in birch stands and wood products the increase was larger, from 0.64 Mg C ha−1 per year to 0.92 Mg C ha−1 per year. In Norway spruce stands and wood products, the total average balance decreased substantially, from 0.96 Mg C ha−1 per year to 0.32 Mg C ha−1 per year. In northern Finland, the total average C balance of the 150 year period increased under changing climate, regardless of tree species: in Scots pine stands and wood products from 1.10 Mg C ha−1 per year to 1.42 Mg C ha−1 per year, in Norway spruce stands and wood products from 0.69 Mg C ha−1 per year to 0.99 Mg C ha−1 per year, and in birch stands and wood products from 0.43 Mg C ha−1 per year to 0.60 Mg C ha−1 per year.
C sequestration in unmanaged stands was larger than in managed systems, regardless of climate. However, wood products should be included in C sequestration assessments since 12–55% of the total 45–214 Mg C ha−1 after 150 years' simulation was in products, depending on tree species, climate and location. The largest C flow from managed system back into the atmosphere was from litter, 36–47% of the total flow, from vegetation 22–32%, from soil organic matter 25–30%. Emissions from the production process and burning of discarded products were 1–6% of the total flow, and emissions from landfills less than 1%. 相似文献
19.
土壤碳排放量测定技术 总被引：1，自引：0，他引：1
土壤呼吸作为碳的主要输出途径和CO2的重要源(汇),对于它进行精确、系统的测定已成为全球变化研究中的关键问题。本文探讨的LI-8100自动土壤CO2流量系统测定土壤碳排放量技术,对于研究森林土壤、农田土壤和草地土壤碳循环问题,提出参考。 相似文献
20.
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. 相似文献