Can Carbon Sinks be Operational? An RFF Workshop Summary

An RFF Workshop brought together experts from around the world to assess the feasibility of using biological sinks to sequester carbon as part of a global atmospheric mitigation effort. The chapters of this proceeding are a result of that effort. Although the intent of the workshop was not to generate a consensus, a number of studies suggest that sinks could be a relatively inexpensive and effective carbon management tool. The chapters cover a variety of aspects and topics related to the monitoring and measurement of carbon in biological systems. They tend to support the view the carbon sequestration using biological systems is technically feasible with relatively good precision and at relatively low cost. Thus carbon sinks can be operational.carbon, sinks, global warming, sequestration, forests

Amount and distribution of coarse woody debris in pine ecosystems of north-western Spain, Russia and the United States

The quantity and characteristics of coarse woody debris (CWD) were examined in four distinct pine ecosystems of north-western (NW) Spain, NW Russia and the NW USA. The average CWD volume and biomass ranged from 3.76 m³ ha⁻¹, 1.55 Mg ha⁻¹ in pine plantations in NW Spain to 24.86 m3 ha⁻¹, 6.69 Mg ha⁻¹ in Scots pine forest in NW Russia to 55.35 m³ ha⁻¹, 20.38 Mg ha⁻¹ and 77.04 m³ ha⁻¹, 28.84 Mg ha⁻¹ in ponderosa and lodgepole pine forests in the NW USA. Despite differences in species, ecological conditions and management histories, in all four ecosystems the mean snag volume was less than that of logs, most of the CWD mass was in an intermediate degree of decay, and mature stands had the greatest amount of CWD mass, followed by middle-age and then young stands. The CWD ratio (ratio of dead to live wood volume) ranged from 2.8% to 126.6%, depending on pine ecosystem and stand age, and was influenced by the type of natural and human disturbance. The difference in CWD amount and distribution among the regions studied reflected differences in disturbance history and management practices. Only in NW USA was the sample size large enough to examine the effect of disturbance type on CWD amount and distribution. There, fire and insect damage were found to considerably influence the amount of CWD in both lodgepole and ponderosa pine forests. Comparison of how different factors affect the amount and distribution of CWD in different ecosystems could be useful in developing ecologically sustainable forest management guidelines.Keywords: Ponderosa Pine, Dead Wood, Lodgepole Pine, Disturbance, Scots PineKeywords: Ponderosa Pine, Dead Wood, Lodgepole Pine, Disturbance, Scots Pin

Assessment of carbon stores in tree biomass for two management scenarios in Russia

Accurate quantification of terrestrial carbon storage and its change is of key importance to improved understanding of global carbon dynamics. Forest management influences carbon sequestration and release patterns, and gap models are well suited for evaluating carbon storage. An individual-based gap model of forest dynamics, FAREAST, is applied across Russia to estimate aboveground carbon storage under management scenarios. Current biomass from inventoried forests across Russia is compared to model-based estimates and potential levels of biomass are estimated for a set of simplified forestry practices. Current carbon storage in eastern Russia was lower than for the northwest and south, and lower than model estimates likely due to high rates of disturbance. Model-derived carbon storage in all regions was not significantly different between the simulated ‘current’ and hypothetical ‘even-aged’ management strategies using rotations of 150 and 210 years. Simulations allowing natural maturation and harvest after 150 years show a significant increase in aboveground carbon in all regions. However, it is unlikely that forests would be left unharvested to 150 years of age to attain this condition. These applications indicate the value of stand simulators, applied over broad regions such as Russia, as tools to evaluate the effect of management regimes on aboveground carbon storage.Keywords: boreal forest, modelling, validation, biomass, carbo

The Northern Eurasia Earth Science Partnership: An Example of Science Applied to Societal Needs

Northern Eurasia, the largest landmass in the northern extratropics, accounts for ~20% of the global land area. However, little is known about how the biogeochemical cycles, energy and water cycles, and human activities specific to this carbon-rich, cold region interact with global climate. A major concern is that changes in the distribution of land-based life, as well as its interactions with the environment, may lead to a self-reinforcing cycle of accelerated regional and global warming. With this as its motivation, the Northern Eurasian Earth Science Partnership Initiative (NEESPI) was formed in 2004 to better understand and quantify feedbacks between northern Eurasian and global climates. The first group of NEESPI projects has mostly focused on assembling regional databases, organizing improved environmental monitoring of the region, and studying individual environmental processes. That was a starting point to addressing emerging challenges in the region related to rapidly and simultaneously changing climate, environmental, and societal systems. More recently, the NEESPI research focus has been moving toward integrative studies, including the development of modeling capabilities to project the future state of climate, environment, and societies in the NEESPI domain. This effort will require a high level of integration of observation programs, process studies, and modeling across disciplines

Carbon balance on federal forest lands of Western Oregon and Washington: The impact of the Northwest Forest Plan

The management of federal forest lands in the Pacific Northwest (PNW) region changed in early 1990s when the Northwest Forest Plan (NWFP) was adopted with the primary goal to protect old-growth forest and associated species. A major decline in timber harvest followed, extending an earlier downward trend. The historic and projected future change in carbon (C) stores and balance on federally managed forest lands in Western Oregon (OR) and Western Washington (WA) was examined using the LANDCARB 3.0 simulation model. The projections include C stores on-site, in harvested wood products and disposal and reflect a set of contrasting visions of future forest management in the region formulated as 5 alternative management scenarios that extend to year 2100. A significant and long-lasting net increase in total C stores on federal forest lands relative to early 1990s level was projected for both OR and WA under all examined management scenarios except the Industry Scenario which envisioned a return to historic high levels of timber harvest. In comparison with the Industry Scenario, the low levels of timber harvest under the NWFP between 1993 and 2010 were estimated to increase total C stores by 86.0 TgC (5.1 TgC yr⁻¹ or 2.16 MgC ha⁻¹ yr⁻¹) in OR; in WA the respective values were 45.2 TgC (2.66 TgC yr⁻¹ or 1.33 MgCha⁻¹ yr⁻¹). The projected annual rate of C accumulation, reached a maximum between 2005 and 2020 approaching 4 TgC yr⁻¹ in OR and 2.3 TgC yr⁻¹ in WA, then gradually declined towards the end of projection period in 2100. Although not the original intent, the NWFP has led to a considerable increase in C stores on federal forest lands within the first decade of plan implementation and this trend can be expected to continue for several decades into the future if the limits on timber harvest set under the NWFP are maintained. The primary goal of the NWFP to protect and restore old-growth forest may take several decades to achieve in WA whereas in OR the area protected from clearcut harvest may be insufficient to meet this goal before the end of projection period in 2100.Keywords: Landscape carbon stores, Pacific Northwest, Timber harvest, Old-growth conservation, Forest managemen

Mapping Russian Forest Biomass With Data From Satellites and Forest Inventories

The forests of Russia cover a larger area and hold more carbon than the forests of any other nation and thus have the potential for a major role in global warming. Despite a systematic inventory of these forests, however, estimates of total carbon stocks vary, and spatial variations in the stocks within large aggregated units of land are unknown, thus hampering measurement of sources and sinks of carbon. We mapped the distribution of living forest biomass for the year 2000 by developing a relationship between ground measurements of wood volume at 12 sites throughout the Russian Federation and data from the MODIS satellite bidirectional reflectance distribution function (BRDF) product (MOD43B4). Based on the results of regression-tree analyses, we used the MOD43B4 product to assign biomass values to individual 500 m × 500 m cells in areas identified as forest by two satellite-based maps of land cover. According to the analysis, the total living biomass varied between 46 and 67 Pg, largely because of different estimates of forest area. Although optical data are limited in distinguishing differences in biomass in closed canopy forests, the estimates of total living biomass obtained here varied more in response to different definitions of forest than to saturation of the optical sensing of biomass

Accounting for density reduction and structural loss in standing dead trees: Implications for forest biomass and carbon stock estimates in the United States

<p>Abstract</p> <p>Background</p> <p>Standing dead trees are one component of forest ecosystem dead wood carbon (C) pools, whose national stock is estimated by the U.S. as required by the United Nations Framework Convention on Climate Change. Historically, standing dead tree C has been estimated as a function of live tree growing stock volume in the U.S.'s National Greenhouse Gas Inventory. Initiated in 1998, the USDA Forest Service's Forest Inventory and Analysis program (responsible for compiling the Nation's forest C estimates) began consistent nationwide sampling of standing dead trees, which may now supplant previous purely model-based approaches to standing dead biomass and C stock estimation. A substantial hurdle to estimating standing dead tree biomass and C attributes is that traditional estimation procedures are based on merchantability paradigms that may not reflect density reductions or structural loss due to decomposition common in standing dead trees. The goal of this study was to incorporate standing dead tree adjustments into the current estimation procedures and assess how biomass and C stocks change at multiple spatial scales.</p> <p>Results</p> <p>Accounting for decay and structural loss in standing dead trees significantly decreased tree- and plot-level C stock estimates (and subsequent C stocks) by decay class and tree component. At a regional scale, incorporating adjustment factors decreased standing dead quaking aspen biomass estimates by almost 50 percent in the Lake States and Douglas-fir estimates by more than 36 percent in the Pacific Northwest.</p> <p>Conclusions</p> <p>Substantial overestimates of standing dead tree biomass and C stocks occur when one does not account for density reductions or structural loss. Forest inventory estimation procedures that are descended from merchantability standards may need to be revised toward a more holistic approach to determining standing dead tree biomass and C attributes (i.e., attributes of tree biomass outside of sawlog portions). Incorporating density reductions and structural loss adjustments reduces uncertainty associated with standing dead tree biomass and C while improving consistency with field methods and documentation.</p

Comparison and assessment of coarse resolution land cover maps for Northern Eurasia

Information on land cover at global and continental scales is critical for addressing a range of ecological, socioeconomic and policy questions. Global land cover maps have evolved rapidly in the last decade, but efforts to evaluate map uncertainties have been limited, especially in remote areas like Northern Eurasia. Northern Eurasia comprises a particularly diverse region covering a wide range of climate zones and ecosystems: from arctic deserts, tundra, boreal forest, and wetlands, to semi-arid steppes and the deserts of Central Asia. In this study, we assessed four of the most recent global land cover datasets: GLC-2000, GLOBCOVER, and the MODIS Collection 4 and Collection 5 Land Cover Product using cross-comparison analyses and Landsat-based reference maps distributed throughout the region. A consistent comparison of these maps was challenging because of disparities in class definitions, thematic detail, and spatial resolution. We found that the choice of sampling unit significantly influenced accuracy estimates, which indicates that comparisons of reported global map accuracies might be misleading. To minimize classification ambiguities, we devised a generalized legend based on dominant life form types (LFT) (tree, shrub, and herbaceous vegetation, barren land and water). LFT served as a necessary common denominator in the analyzed map legends, but significantly decreased the thematic detail. We found significant differences in the spatial representation of LFT's between global maps with high spatial agreement (above 0.8) concentrated in the forest belt of Northern Eurasia and low agreement (below 0.5) concentrated in the northern taiga-tundra zone, and the southern dry lands. Total pixel-level agreement between global maps and six test sites was moderate to fair (overall agreement: 0.67-0.74, Kappa: 0.41-0.52) and increased by 0.09-0.45 when only homogenous land cover types were analyzed. Low map accuracies at our tundra test site confirmed regional disagreements and difficulties of current global maps in accurately mapping shrub and herbaceous vegetation types at the biome borders of Northern Eurasia. In comparison, tree dominated vegetation classes in the forest belt of the region were accurately mapped, but were slightly overestimated (10%-20%), in all maps. Low agreement of global maps in the northern and southern vegetation transition zones of Northern Eurasia is likely to have important implications for global change research, as those areas are vulnerable to both climate and socio-economic changes. (C) 2011 Elsevier Inc. All rights reserved.Keywords: Land cover, MODIS, Eurasia, Global, Validation, GLC-2000, LCCS, GLOBCOVERKeywords: Land cover, MODIS, Eurasia, Global, Validation, GLC-2000, LCCS, GLOBCOVE

Quantifying the effectiveness of climate change mitigation through forest plantations and carbon sequestration with an integrated land-use model

<p>Abstract</p> <p>Background</p> <p>Carbon plantations are introduced in climate change policy as an option to slow the build-up of atmospheric carbon dioxide (CO₂) concentrations. Here we present a methodology to evaluate the potential effectiveness of carbon plantations. The methodology explicitly considers future long-term land-use change around the world and all relevant carbon (C) fluxes, including all natural fluxes. Both issues have generally been ignored in earlier studies.</p> <p>Results</p> <p>Two different baseline scenarios up to 2100 indicate that uncertainties in future land-use change lead to a near 100% difference in estimates of carbon sequestration potentials. Moreover, social, economic and institutional barriers preventing carbon plantations in natural vegetation areas decrease the physical potential by 75–80% or more.</p> <p>Nevertheless, carbon plantations can still considerably contribute to slowing the increase in the atmospheric CO₂concentration but only in the long term. The most conservative set of assumptions lowers the increase of the atmospheric CO₂concentration in 2100 by a 27 ppm and compensates for 5–7% of the total energy-related CO₂emissions. The net sequestration up to 2020 is limited, given the short-term increased need for agricultural land in most regions and the long period needed to compensate for emissions through the establishment of the plantations. The potential is highest in the tropics, despite projections that most of the agricultural expansion will be in these regions. Plantations in high latitudes as Northern Europe and Northern Russia should only be established if the objective to sequester carbon is combined with other activities.</p> <p>Conclusion</p> <p>Carbon sequestration in plantations can play an important role in mitigating the build-up of atmospheric CO₂. The actual magnitude depends on natural and management factors, social barriers, and the time frame considered. In addition, there are a number of ancillary benefits for local communities and the environment. Carbon plantations are, however, particularly effective in the long term. Furthermore, plantations do not offer the ultimate solution towards stabilizing CO₂concentrations but should be part of a broader package of options with clear energy emission reduction measures.</p