The IPCC guidelines for greenhouse gas inventories divide the planet's forest ecosystems into
Estimation of carbon sequestration rates in forests depends on the quantification of carbon stock in different part of the ecosystem which are given here:
Forests are highly dynamic systems with strong short and long term cycles of change, thus all of these forest ecosystem components will vary in time and in space across as part of the natural cycles of energy flux.
Carbon is stored in many different forest types such as boreal forests, tropical rainforests, mangroves, urban forests and plantations. Those forests differ in their capability to store carbon and in their biomass production, but all of them play an important role in climate protection and provide many ecosystem services.
The studies below provide information on the carbon sequestration of all forest types. Generally it can be said that tropical forests store more carbon than those in temperate zones as their biomass production is higher.
Viele eindringende einheimische Pflanzen sind, wenn sie richtig gehandhabt werden, ausgezeichnete Begleitpflanzen für die Pflanzenarten, zusätzlich zu der Tatsache, dass sie gut an die bestehenden edaphischen Bedingungen angepasst sind. mehr
Diese Studie beschäftigt sich mit dem Ertrag von Winterweizen im Vergleich zu dem aus monokulturellen Anbau. mehr
Dr. Jaconette Mirck von der BTU Cottbus-Senftenberg kommt bereits 2016 zu dem Ergebnis, dass der Ertrag von Winterweizen aus Agroforstsystemen um 10% höher liegt im Vergleich zu monokulturellen Anbau. Hinzu kommt noch der Gewinn aus der Energieholznutzung.
Diese Studie beschäftigt sich mit dem Beitrag von Agroforstsystemen zur Ernährungssicherung. mehr
Prof. Plieninger von der Universität Kassel kommt bei seiner Untersuchung (2017) über den Beitrag von Agroforstsystemen zur Ernährungssicherung zu einem überraschenden Ergebnis: Wird auf einem Weizenfeld 20% der Fläche mit einem einfachen Agroforstsystem bepflanzt und dazwischen wie bisher Weizen auf den verbleibenden 80% ausgesät, so liegt der Ertrag aus Holz und Weizenernte pro Hektar um etwa 17% höher im Vergleich zum klassischen Anbau von Weizen in Monokultur. Selbst bei einem Vergleich von Weizenanbau auf 100% der Fläche in Monokultur mit Weizenanbau auf 80% der Fläche in Agroforstsystemen, so liegt auch hier der Netto-Weizenertrag mit einem Agroforstsystem um 2,6 % höher. Diese Untersuchungen zeigen das große Potenzial von Agroforstsystemen für die Landwirtschaft.
Diese Studie befasst sich damit, wie Agroforstsysteme dabei helfen können, die Nitrateinträge der Landwirtschaft in das Grundwasser deutlich zu senken. mehr
Auf intensiv genutzten landwirtschaftlichen Flächen kommt es häufig zu einem Überschuss an Stickstoff (N), der ins Grundwasser gelangt und dort den Anteil von Nitrat (NO3-) erhöht. In vielen Regionen lagen in letzter Zeit die Nitratwerte im Grundwasser deutlich über den zugelassenen Werten. Bäume auf dem Acker können hier helfen. Ihr tiefgreifendes Wurzelsystem, das sich auch unterhalb der landwirtschaftlichen Ackerkulturen ausbreitet, funktioniert wie ein Sicherheitsnetz. Zum einen nehmen die Baumwurzeln überschüssiges Nitrat auf, zum anderen reduziert ihr feines Wurzelnetzwerk die Auswaschung von Stoffen ins Grundwasser insgesamt.
This study is about the carbon sequestration of trees and how this can influence the greenhouse effect. mehr
Trees remove carbon dioxide from the atmosphere through the natural process of photosynthesis and store the carbon (C) in their leaves, branches, stems, bark and roots. Approximately half the dry weight of a tree’s biomass is carbon. One tonne of C = 3.67 tonnes of ‘carbon dioxide equivalent’ (CO2-e).
Trees in forests (including plantations), if well-stocked, typically sequester carbon at a maximum rate between about age 10 and age 20–30. As an indication, at age 30 years about 200 to 520 tonnes CO2-e are sequestered per ha in forests with productivity ranging from low to high. Reforesting cleared areas will create carbon sinks to counteract greenhouse gas emissions, and will assist in other aspects of environmental improvement such as salinity control and creation of wildlife habitat.
Based on long-term studies this report tries to estimate the global carbon sink of forests. mehr
The terrestrial carbon sink has been large in recent decades, but its size and location remain uncertain. Using forest inventory data and long-term ecosystem carbon studies, a total forest sink of 2.4 T 0.4 petagrams of carbon per year (Pg C year–1 ) globally for 1990 to 2007 was estimated.
A source of 1.3 T 0.7 Pg C year–1 from tropical land-use change was also estimated, consisting of a gross tropical deforestation emission of 2.9 T 0.5 Pg C year–1 partially compensated by a carbon sink in tropical forest regrowth of 1.6 T 0.5 Pg C year–1 . Together, the fluxes comprise a net global forest sink of 1.1 T 0.8 Pg C year–1 , with tropical estimates having the largest uncertainties.
The total forest sink estimate is equivalent in magnitude to the terrestrial sink deduced from fossil fuel emissions and land-use change sources minus ocean and atmospheric sinks.
This study highlights the importance of "leakage" in projects dealing with carbon sequestration. This means, that the benefit of these projects is diminished due to the release of carbon at other places. mehr
eakage from forest carbon sequestration—the amount of a program’s direct carbon benefits undermined by carbon releases elsewhere—depends critically on demanders’ ability to substitute non-reserved timber for timber targeted by the program. Analytic, econometric, and sector-level optimization models are combined to estimate leakage from different forest carbon sequestration activities.
Empirical estimates for the U.S. show leakage ranges from minimal (<10 percent) to enormous (>90 percent), depending on the activity and region. These results suggest that leakage effects should not be ignored in accounting for the net level of greenhouse gas offsets from land use change and forestry mitigation activities.
This study provides an overview of the carbon cycle in the forest, of the measuring and influencing of the carbon level and of government programs that influence the forestry sector in the US. mehr
A report prepared for US congress on issues concerning the role of forests in carbon sequestration. The effects of changes in land use are covered, as well as the effects of forestry practises such as timber harvesting in relation to old forest growth to promote new forest growth.
The problem of “leakage” is also considered. Leakage occrus when “wood supply might shift to other sites, including other countries, exacerbating global climate change and causing other environmental problems, or that wood products might be replaced by other products that use more energy to manufacture, thus releasing more CO2.” Possible technical and financial provisions for promoting measures to mitigate carbon sequestration are covered.
A scientific study that provides a data base about above-ground biomass and its carbon carrying capacity in global forests. mehr
This study is based on the creation of a database of site above-ground biomass (AGB) of global mature forests to obtain AGB carbon carrying capacity (CCC) of global forests by interpolating global mature forest site data.
The results show a strong latitudinal decline in AGB in mature forests from tropical forests to boreal forests, and that maximum AGB occurs in middle latitude regions. Results also showed that temperature and precipitation are the principal AGB drivers in mature forests. The above-ground biomass CCC of global forests was estimated at approximately 586.2±49.3 Pg C.
The ecology of forest carbon is well understood, but measurement and projection of carbon sequestration at small scales can be costly. Some forest management activities qualify as offsets in various carbon markets. mehr
Carbon (C) is stored in forest ecosystems in the form of living tree biomass and dead organic matter. In most forests, the largest C pools are aboveground live biomass and mineral soil organic matter, with lesser amounts in roots and surface detritus. The rate at which C accumulates in the ecosystem – net ecosystem production (NEP) – represents the sum of changes in each of these pools. Biologically, NEP is the difference between net primary production (NPP, the annual net carbon fixation by plant photosynthesis) and heterotrophic respiration (CO2emission by non-photosynethetic organisms).
Both NEP and the size of these C pools are highly sensitive to forest management activities. The most rapidly changing pool is usually aboveground live biomass, which can be estimated accurately through allometric approaches (Jenkins et al. 2003; Kloeppel et al. 2007). Quantifying changes in the other C pools is more difficult. Root biomass is hard to measure directly, but it is usually closely correlated with aboveground biomass (average root:shoot biomass ratio = 0.26; Cairns et al. 1997), permitting reasonably accurate, indirect estimates.
Soil organic matter comprises the largest C pool in many forests, but changes in soil C pool size are difficult to detect because of high spatial variability. Soil C pools exhibit complex responses to changes in land use, such as deforestation and afforestation (Paul et al. 2002), with the magnitude and direction of response depending upon vegetation, soil properties, and climate (Guo and Gifford 2002). Thick litter layers develop on the surface of some forest soils, storing smaller amounts of C than do mineral soils, but with larger and more predictable temporal fluctuations (eg after fires or forest harvest).
Finally, in many forests, large quantities of C accumulate in the form of coarse woody debris. Unfortunately, the size of this pool is not closely related to aboveground biomass or forest age (Keeton et al. 2007; Woodall et al. 2008).
This study re-evaluates the biomass carbon densities of the world's major forest biomes based on a global synthesis of site data of biomass measurements in forest plots. mehr
From analysis of published global site biomass data (n = 136) from primary forests, we discovered (i) the world's highest known total biomass carbon density (living plus dead) of 1,867 tonnes carbon per ha (average value from 13 sites) occurs in Australian temperate moist Eucalyptus regnans forests, and (ii) average values of the global site biomass data were higher for sampled temperate moist forests (n = 44) than for sampled tropical (n = 36) and boreal (n = 52) forests (n is number of sites per forest biome).
Spatially averaged Intergovernmental Panel on Climate Change biome default values are lower than our average site values for temperate moist forests, because the temperate biome contains a diversity of forest ecosystem types that support a range of mature carbon stocks or have a long land-use history with reduced carbon stocks. We describe a framework for identifying forests important for carbon storage based on the factors that account for high biomass carbon densities, including (i) relatively cool temperatures and moderately high precipitation producing rates of fast growth but slow decomposition, and (ii) older forests that are often multiaged and multilayered and have experienced minimal human disturbance.
Our results are relevant to negotiations under the United Nations Framework Convention on Climate Change regarding forest conservation, management, and restoration. Conserving forests with large stocks of biomass from deforestation and degradation avoids significant carbon emissions to the atmosphere, irrespective of the source country, and should be among allowable mitigation activities. Similarly, management that allows restoration of a forest's carbon sequestration potential also should be recognized.
Forests have an important role in preventing the effects created by climate change mehr
Forests are an essential link in the global carbon cycle, through their ability to absorbance by CO2 from the atmosphere by photosynthesis and store it in their biomass, soil and litter, thus representing the largest reservoir of carbon in the terrestrial biosphere.
The carbon storage in soil and biomass of different ecosystems in the Andes is investigated in this study. mehr
Carbon storage and changes of forest cover due to anthropogenic impacts were sensitive and vulnerable to global change, since forest biomass and plant growth depended on local climate conditions. Based on this hypothesis, the comparative analysis of carbon storage of disturbed and non-disturbed forest areas in tropical Andean ecosystems showed a relationship between carbon storage content and the degree of physical disturbance, with a consistent depletion in approximately 10 to 20 % of carbon sequestration in soils, forest biomass and land-water interaction of wetland zones in each studied ecosystems.
The net carbon storage (COS) in non-disturbed forests of Chingaza (PNN) was calculated in about 1102,4 t ha-1, and was significantly higher than the mean values observed in forest areas of Los Nevados (PNN), estimated in 762,8 t ha-1. The carbon sink dynamics in each of the compartments of the studied ecosystems is also related to three predominant climatic variables: humidity, temperature and soil moisture availability.
Those variables are dependent of global warming changes at both, regional and global climatic scales. Thus, forest areas with drier climatic conditions common in LosNevados (PNN) paramo, registered lower mean values of carbon storage. The dominant plant species on each forestry plots indicated that woody vegetation type favors carbon accumulation in system soils. Therefore, the progressive deforestation and the increased anthropogenic activities in those high mountain ecosystems suggest a strong effect on the carbon fluxes.
The carbon sequestration in tropical mangrove forest is quantified in this study. Additionally the annual increase of the carbon level is determined. mehr
In this study it is shown that carbon stock is lower in the tropical mangrove forest than in the terrestrial tropical forest and their annual increase exhibits faster turn over than the tropical forest. Variable for above ground biomass are in decreasing order of importance, breast height diameter (d), height (H) and wood density (ρ). The above ground biomass (AGB) and live below ground biomass (LBGB) held different biomass (39.93 ± 14.05 t C ha−1 versus 9.61 ± 3.37 t C ha−1). Carbon accrual to live biomass (4.71–6.54 Mg C ha−1 a−1) is more than offset by losses from litter fall (4.85 Mg C ha−1 a−1), and carbon sequestration differs significantly between live biomass (1.69 Mg C ha−1 a−1) and sediment (0.012 Mg C ha−1 a−1).
Growth specific analyses of taxon density suggest that changes in resource availability and environmental constraints could be the cause of the annual increase in carbon stocks in the Sundarbans mangrove forest in contrast to the disturbance – recovery hypotheses.
In this study the potential carbon sequestration on aboveground biomass in different forest ecosystems in Thailand were assessed. mehr
This study assessed the potential of carbon sequestration on aboveground biomass in the different forest ecosystems in Thong Pha Phum National Forest, Thailand. The assessment was based on a total inventory for woody stems at ≥ 4.5 cm diameter at breast height (DBH). Aboveground biomass was estimated using the allometric equation and aboveground carbon stock was calculated by multiplying the biomass with a 0.5 conversion factor. From the results, carbon sequestration among varied different types of forests.
Tropical rain forest (Ton Mai Yak station) had higher carbon stock than dry evergreen forest (KP 27 station) and mixed deciduous forest (Pong Phu Ron station) with 137.73 ± 48.07, 70.29 ± 7.38 and 48.14 ± 16.72 tonne C/ha, respectively. In the study area, all forest types had a similar pattern of tree size class, with a dominant size class at ≥ 4.5 - 20 cm. The ≥ 4.5 - 20 cm trees potentially provided a greater carbon sequestration in tropical rain forest and dry evergreen forest while the size of > 20 - 40 cm gave potentially high carbon sequestration in mixed deciduous forest.
In conclusion, the greatest carbon sequestration potential is in mixed deciduous forest followed by tropical rain forest and dry evergreen forest in Thong Pha Phum National Forest.
This study is about the accumulation of biomass and the carbon sequestration of restored forest over time and shows the significance of those forests for the climate protection. mehr
In the present study the aboveground biomass (AGB) of 10 tree species (fast-growing and slow-growing tree species) that are representative of the Brazilian Atlantic forest was evaluated to test if biomass accumulation varies with tree age and ecological group (fast and slow-growing).
Differences suggest that the fast-growing tree species contribute more to the carbon stock during the early years (approximately 37 years) of the restoration and that the slow-growing species contribute more signiﬁcantly during the later stages of succession. We estimated that second-growth forests (41–60 years old) accumulate more than two-fold carbon than immature forest (21–40 years old) and much more than ten-fold carbon than young forests (7–20 years old).
These differences in carbon sequestration magnitudes suggest that services provided by restoration areas, can increase exponentially in the ﬁrst 60 years, and this is particularly important for future conservation and management of areas undergoing restoration.
This study compares the carbon sequestration of natural restored mangrove forests and different mangrove plantations. Furthermore other ecosystem services of mangrove forests are mentioned. mehr
Above and below ground biomass was studied in six years old mangrove plantations and a naturally regenerated stand under regeneration. Results are promising concerning the feasibility of mangrove plantations and natural regeneration as a carbon sequestration tool. The induced natural regeneration method showed high feasibility as a low cost management to enhance the rapid restoration of the mangrove ecosystem.
In addition to the determination of carbon level and flux, the drivers of carbon density and flux in the forests of the Pacific Northwest are identified. mehr
The National Forest System (NFS) of the United States plays an important role in the carbon cycle because these lands make up a large proportion of the forested land in the country and commonly store more wood per unit area than other forest ownerships. In addition to sustaining natural resources, these lands are managed for multiple objectives that do not always align with maximizing carbon (C) sequestration.
The objectives of this study were to determine C stocks and flux in measured pools on Pacific Northwest Region NFS lands and the major ecological drivers of C flux. Tree, dead wood, and understory vegetation data from 11,435 systematically-placed inventory plots were compiled and growth, mortality,decay, removals, and disturbance events based on two full measurements spanning 1993–2007 were estimated.
Mangrove forests belong to most important ecosystems in the world when it comes to carbon sequestration. This study highlights particularly the importance of the soils of these forests. mehr
This study was carried out in the mangrove forests of Sofala Bay, Central Mozambique, with the aim of quantifying carbon stocks of live and dead plant and soil components. The methods followed the procedures developed by the Center for International Forestry Research (CIFOR) for mangrove forests.
The average total carbon storage of Sofala Bay mangrove was 218.5 Mg·ha−1, of which around 73% are stored in the soil. Mangrove conservation has the potential for REDD+ programs, especially in regions like Mozambique, which contains extensive mangrove areas with high deforestation and degradation rates.
A report with data on planting practices and methods to calculate ecosystem carbon and timber carbon yields as well as carbon sequestration rates for rural tree planting and management programmes. mehr
A report that examines the potential contribution of rural tree planting programmes to redcing CO2 emissions in the USA. Croplands, pasture and forest lands are included in the study. Planting and management data is based on US Department of Agriculture recommendations.
In this study the carbon storage of the decidous forest in theNorth America are investigated in field measurements. mehr
Field measures of tree and shrub dimensions were used with established biomass equations in a stratified, two-stage cluster sampling design to estimate above-ground ovendry woody biomass and carbon storage of the eastern deciduous forest of North America. Biomass averaged 8.1 + 1.4 (95% C.I.) kg/m2 and totaled 18.1 ? 3.1 (95% C.I.) gigatons. Carbon storage averaged 3.6 + 0.6 (95% C.I.) kg/m2 and totaled 8.1 ? 1.4 (95% C.I.) gigatons.
These values are lower than previous estimates commonly used in the analysis of the global carbon budget which range from 17.1 to 23.1 kg/m2 for biomass and 7.7 to 10.4 kg/m2 for carbon storage.
The shift from dense forests to open lichen woodlands leads to a higher albedo and it is questionable if reforestation of these forests is reasonable in terms of the climate. mehr
Forest fires in closed-canopy black spruce forests cause shifts towards open lichen–spruce woodlands in parts of the boreal forest of eastern North America. The shift from dark black spruce canopies to pale lichen ground cover offers a dramatic contrast in reflectance that may compensate for the CO2 emissions from forest fires in terms of radiative forcing.
This study on climate change feedback that would result from the generation of lichen woodlands through changes in albedo and in stored carbon showed that the generation of open lichen woodlands provides a possible negative feedback to climate change and that carbon sequestration through the afforestation of boreal lichen woodlands may not provide desired climate change mitigation benefits.
An assessment of the potential impact of conifer encroachment on soil organic carbon dynamics and storage in montane aspen-conifer forest systems. mehr
A compiled database of site above-ground biomass (AGB) of global mature forests to obtain AGB carbon carrying capacity (CCC) of global forests by interpolating global mature forest site data. The results show a strong latitudinal decline in AGB in mature forests from tropical forests to boreal forests, and that maximum AGB occurs in middle latitude regions.
Results also showed that temperature and precipitation are the principal AGB drivers in mature forests. The above-ground biomass CCC of global forests was estimated at approximately 586.2±49.3 Pg C.
In this study the carbon storage of different types of forest in the US are investigated to highlight the relevance of forests for the reduction of atmospheric carbon dioxide. mehr
A technical report that provides information in the form of tables on carbon storage in the forest systems of the USA. Data is given on different forest types and production cycles. Information is broken down into the principal components used to estimate carbon storage, namely Trees: all above and below-ground portions of all live and dead trees, Soil: all organic carbon in mineral horizons to a depth of I meter, excluding coarse tree roots; Forest floor: all dead organic matter above the mineral soil horizons and Understory: all live vegetation except that vegetation defined as live trees.
This report provides an overview of the carbon cycle and sequestration and of the status quo of research on forests and carbon storage in the US. mehr
Using forests to mitigate climate change has gained much interest in science and policy discussions. The evidence for carbon benefits, environmental and monetary costs, risks and trade-offs are examined for a variety of activities in three general strategies: (1) land use change to increase forest area (afforestation) and avoid deforestation; (2) carbon management in existing forests; and (3) the use of wood as biomass energy, in place of other building materials, or in wood products for carbon storage.
Many strategies can increase forest sector carbon mitigation above the current 162–256 Tg C/yr, and that many strategies have co-benefits such as biodiversity, water, and economic opportunities. Each strategy also has trade-offs, risks, and uncertainties including possible leakage, permanence, disturbances, and climate change effects.
An article which provides scientific and political information about forest and fire management for the forest in Ontario. mehr
Boreal forests and peatlands in northern circumpolar areas, including Ontario, store globally significant amounts of carbon but are subject to forest fires and other natural disturbances that cycle carbon between terrestrial ecosystems and the atmosphere. Climate change projections for the 21st century suggest that wildland fire regimes will become more severe, with more fires, more extreme weather events, and the likelihood of increased area burned. Even if fire suppression resources are increased to cope with the changing fire conditions, suppression efforts will be challenged.
This literature review and policy discussion is intended to provide Ontario's forest and fire managers with current scientific and policy information to inform future decision-making.
In this study models are used to investigate the impact of changes in the atmosphere on carbon accumulation in trees and soils in Europe. mehr
Changes in the Earth’s atmosphere are expected to influence the growth, and therefore, carbon accumulation of European forests. The authors identified three major changes: (1) a rise in carbon dioxide concentration, (2) climate change, resulting in higher temperatures and changes in precipitation and (3) a decrease in nitrogen deposition.
The authors used a hydrological model (Watbal), a soil model (SMART2) and a vegetation model (SUMO2) to asses the effect of expected changes in the period 1990 up to 2070 on the carbon accumulation in trees and soils of 166 European forest plots. Predicted effects of changes in climate, CO2 concentration and nitrogen deposition on carbon sequestration by trees depended largely on tree species and location (latitude).
This study contains information on carbon storage of trees, litter, organic soil content and wooden products in plantations. mehr
A carbon-flow model for managed forest plantations was used to estimate carbon storage in UK plantations differing in Yield Class (growth rate), thinning regime and species characteristics. Time-averaged, total carbon storage (at equilibrium) was generally in the range 40-80 Mg C ha(-1) in trees, 15-25 Mg C ha(-1) in above- and belowground litter, 70-90 Mg C ha(-1) in soil organic matter and 20-40 Mg C ha(-1) in wood products (assuming product lifetime equalled rotation length)...
If we divide the forest areas by latitudes, we observe an uneven distribution of forest types across the four classified geo-climatic regions in Europe mehr
With respect to the sensitivity of tree species to temperature changes, this has been studied in terms of specific forest types located in different geo-climatic regions in Europe. In Mediterranean Europe, most forests consist of sclerophyllous and some deciduous species that are adapted to summer soil water deficits. Temperature changes may allow the expansion of some thermophilous tree species (e.g. quercus pyrenaica) when water availability is sufficient (IPCC, 2001).
Similarly, Garcia-Gonzalo et al. (2007) find that in Scandinavian Europe, where growth of boreal forests is currently limited by a short growing season, low summer temperature and short supply of nitrogen, climate change can be associated with an increase in forest productivity in terms of carbon stock. This is because an increase in temperature can prolong the growing season, enhance the decomposition of soil organic matter and thus increase the supply of nitrogen.
In turn, these changes may have positive impacts on forest growth, timber yield and the accumulation of carbon in the boreal forests (Melillo et al. 1993; Lloyd and Taylor 1994; Giardian and Ryan 2000; Jarvis and Linder 2000; Luo et al. 2001).
The carbon sequestration and emissions were estimated for the woodlands in the Exmoor National Park. mehr
The Forestry Commission National Woodland Inventory (1999) shows the area of woodland over 2 hectares in Exmoor National Park (ENP) as 8,331 hectares. A recent but incomplete inventory suggests that the area of woodland over 0.5 hectares is currently 9,300 hectares. From the 1999 inventory, 34% of the woodland is conifer and 66 % is broadleaved. Using the 1999 inventory data the following estimates of carbon storage, sequestration and emissions have been developed.
The CARBiFOR project provides data about carbon stocks and sequestration of the main forest type in Ireland and determines the potential carbon storage of these forest. mehr
Carbon sequestration work carried out as part of the CARBiFOR project to update estimates of carbon uptake in Sitka spruce forest stands. Ecosystem level uptakes and fluxes of greenhouse gases were also assessed to contribute to a better understanding on how forest ecosystems interact with the global climate.
The ability of forests to store and sequester atmospheric carbon is well known and established. Indeed, forests represent the largest global terrestrial store of carbon, containing approximately 39% of global soil carbon and 77% of global vegetation carbon. mehr
Forests play an important role in the global carbon cycle and the maintenance of forests is a vital component of any efforts to mitigate climate change. At national level, forests have the potential to play a significant role not only through the maintenance of existing forests and the creation of new ones, but also in the utilisation of wood products for energy and in the displacement of energy intensive products.
Although recent years have seen considerable advances in our understanding of the C balance in Irish forests many information gaps remain before a robust C accounting system can be created for Irish forests. Principal among these is a plot-based forest inventory repeated every five to ten years. Current research efforts will provide valuable information and understanding which, combined with forest inventory data, will lay the foundations of a C accounting system which will meet the standards of best international practice.
In this study the CO2 exchange over a beech forest was measured during 12 years. mehr
The CO2 exchange over a beech forest near Sorø, Denmark, was measured continuously during 12 years (1996-2008). Simultaneously climate variables were measured which makes it possible to relate the CO2 exchange to recent climate changes. The CO2 exchange was measured by the eddy covariance method which gives a direct measure of the net ecosystem exchange (NEE) at a half hourly basis. Ecosystem respiration (RE) was estimated from nighttime values and gross ecosystem exchange (GEE) was calculated as the sum of RE and NEE.
Over the 12 years the beech forest acted as a sink of an average of 115 g C/m2/y. Only during one of the years the forest acted as a small source. During the 12 years there was ageneral increase in annual NEE. RE increased during the time span, but GEE increased even more resulting in the forest acting as an increasing sink. The increase in RE can be explained by increasing temperature; the increase in GEE by a longer growing season; in this case especially a longer lifetime of the beech leaves thus increasing the annual assimilation capacity of the forest. The increase in the CO2during the time-span may be an additional factor for the increase in GEE.
Climate change has significant effects on forests in Romania. mehr
In order to lower emission levels, humans need to make permanent changes to their lifestyles and methods of doing business. In the short term, however, many scientists have researched the carbon cycle to devise possible plans to capture CO2 from the atmosphere. A technique being explored and tested is by means of forest sequestration. It is a stable fact that forests around the world store large amounts of carbon within their tree trunks, roots, leaves, stems and other biomass associated with them, such as surrounding soils.
10 cities in the US were investigated for this study to acquire data on the carbon sequestration in urban forests and their potential contribution to the reduction of CO2. mehr
Based on field data from 10 USA cities and national urban tree cover data, it is estimated that urban trees in the coterminous USA currently store 700 million tonnes of carbon ($14,300 million value) with a gross carbon sequestration rate of 22.8 million tC/yr ($460 million/year). Carbon storage within cities ranges from 1.2 million tC in New York, NY, to 19,300 tC in Jersey City, NJ.
Regions with the greatest proportion of urban land are the Northeast (8.5%) and the southeast (7.1%). Urban forests in the north central, northeast, south central and southeast regions of the USA store and sequester the most carbon, with average carbon storage per hectare greatest in southeast, north central, northeast and Pacific northwest regions, respectively. The national average urban forest carbon storage density is 25.1 tC/ha, compared with 53.5 tC/ha in forest stands.
These data can be used to help assess the actual and potential role of urban forests in reducing atmospheric carbon dioxide, a dominant greenhouse gas.
Cities should try to reduce emissions and plant big, healthy trees to store as much carbon as possible and to develop urban forests, which also generate a social benefit. mehr
Climate change is a world-wide issue, and it may seem as if only actions by national governments can work effectively against it. In fact, individuals and small communities, too, can make wise choices and impacts. Communities can mitigate climate change through reducing fossil fuel consumption and good management of its urban forest. Urban trees can reduce concentrations of atmospheric carbon dioxide by storing carbon in their roots, stems, and branches. Urban forests can also help reduce carbon dioxide emissions from fossil-fuel-based power plants because their shade and wind protection reduces energy consumption for heating and cooling buildings.
By estimating the amount of carbon removed by trees, the role of urban forests in mitigating climate change can be determined and an economic value to the amount of carbon sequestered by an urban forest can be assigned.
This study analysed the carbon sequestration in higher altitudes as these regions have been deforested and are a possible carbon offset. mehr
High altitude tropical regions have been heavily deforested and offer large areas for carbon offsets by secondary forest regeneration. However, a general assumption exists that productivity, and thus, carbon sequestration of high altitude forests is low, but the scarcity of data from high altitude tropical forests does not allow for a sound confirmation of this assumption. To determine the carbon sequestration potential of natural forest regeneration and reforestation efforts at high altitudes, aboveground biomass was quantified of several successional stages of two monospecific secondary forests in the high Ecuadorian Andes.
The studied forests were, at 3200 m, an Alnus acuminata forest with 8-, 20-, 30- and 45-year-old stands and, at 3600 m, a Polylepis incana forest with 6-, 15- and 30-year-old stands and old growth forest without known age. Both trees are pioneer species. Additionally, a soil survey was conducted and leaf N/P ratios and N and P retranslocation rates were determined. Total aboveground biomass (TAGB) estimates of the oldest stages of the two forests were 241 Mg ha1 for the Alnus and 366 Mg ha1 for the Polylepis forest. Productivity, expressed as annual aboveground biomass accumulation (ABA) was in both forests highest in the establishment phase (14.2 and 15.0 Mg ha1 per year at 8 and 6 years, respectively) due to high sapling numbers, and then slowed down significantly (5.9 and 6.9 Mg ha1 per year, respectively at age 30).
TAGB and ABA figures of the investigated forests are comparable to those of lowland tropical forests and do not indicate a significant decrease of these parameters at higher altitudes in the tropics. Analysis of site conditions, ecological requirements and ecophysiological properties of the tree species indicated that in both cases an optimal combination of these factors strongly favoured forest growth. The results do show, however, that high carbon offsets at high altitudes are possible.
This study shows that secondary forests accumulate a significant amount of carbon and additionally support biodiversity. mehr
Climate change and biodiversity loss can be addressed simultaneously by well-planned conservation policies, but this requires information on the alignment of co-benefits under different management actions. One option is to allow forests to naturally regenerate on marginal agricultural land: a key question is whether this approach will deliver environmental co-benefits in an economically viable manner. A survey of carbon stocks, biodiversity and economic values is reported from one of the world’s most endemic-rich and threatened ecosystems: the western Andes of Colombia.
It is shown that naturally regenerating secondary forests accumulate significant carbon stocks within 30 years, and support biodiverse communities including many species at risk of extinction. Cattle farming, the principal land use in the region, provides minimal economic returns to local communities, making forest regeneration a viable option despite weak global carbon markets. Efforts to promote natural forest regeneration in the tropical Andes could therefore provide globally significant carbon and biodiversity co-benefits at minimal cost.
Increasing both forest stocks and timber harvest will buy time while we learn more about how trees absorb carbon. mehr
Trees absorb carbon dioxide from the atmosphere, and wood can be a substitute for fossil fuels and carbon-intensive materials such as concrete and steel. The best way to manage forests to store carbon and to mitigate climate change is hotly debated. Trees absorb carbon dioxide from the atmosphere, and wood can be a substitute for fossil fuels and carbon-intensive materials such as concrete and steel. In the past few decades, the world's forests have absorbed as much as 30% (2 petagrams of carbon per year; Pg C year−1) of annual global anthropogenic CO2 emissions1 — about the same amount as the oceans. Two-thirds of forests are managed.
Much has been learned about the carbon cycle in forests, but there are still too many gaps in our knowledge. New observations have called long-accepted theories into question: the finding that unharvested forests, for example, are absorbing more carbon than they release, accounting for half the sink, is contrary to the tenet of ecology, known as Odum's framework, that carbon flows in natural forests should be in equilibrium. This carbon-sink behaviour of mature forests is attributed to large-scale environmental changes that violate the assumption of the steady conditions underlying Odum's framework: higher atmospheric CO2 concentrations are accelerating tree growth worldwide and nitrogen emitted by industry, agriculture and fossil-fuel burning is increasingly fertilizing managed forest soils in Europe, China and the eastern United States.
To make good decisions about how to cultivate forests for climate-change mitigation, such as whether it is better to harvest or conserve trees, we must better understand the cause and future behaviour of this in situ carbon sink. Until more is known, we propose that forestry management should prioritize 'win–win' strategies — those that increase both forest stocks and timber harvest, through measures such as protecting trees from animals, or replacing dying or low-productivity forests.
In this study, the Scientific Advisory Council for the German Federal Government (WBGU) evaluate the Kyoto Protocol concerning the accounting of biological carbon sinks. mehr
In this study, the German Advisory Council on Global Change (WBGU) assesses the Kyoto Protocol with regard to the accounting of biological sources and sinks.The idea of combining climate and sink protection is generally endorsed by the Advisory Board.
At the time (1998), however, the way in which "land use change and forestry" activities are regulated in the Kyoto Protocol was assessed as inadequate and in need of improvement in order to meet the objectives of "climate protection" and "biodiversity" to serve together.
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