Quantifying, Understanding and Managing the Carbon Cycle in the Next Decades

Climatic Change (Impact Factor: 3.43). 12/2004; 67(2):147-160. DOI: 10.1007/s10584-004-3765-y
Source: OAI


The human perturbation of the carbon cycle via the release of fossil CO2 and land use change is now well documented and agreed to be the principal cause of climate change. We address three fundamental research areas that require major development if we were to provide policy relevant knowledge for managing the carbon-climate system over the next few decades. The three research areas are: (i) carbon observations and multiple constraint data assimilation; (ii) vulnerability of the carbon-climate system; and (iii) carbon sequestration and sustainable development.

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    • "The growing stock volume (GSV) of a forest, defined as the total volume of the stems of all living trees per unit area (m /ha), is often used for forest resource management and planning (FAO, 2004) and as a predictor of carbon-related variables such as above-ground biomass (AGB) and carbon stocks (Somogyi et al., 2008). Quantification of forest GSV and AGB is necessary to understand the spatial distribution of carbon in forests (Brown, 2002; Canadell, Ciais, Cox, & Heimann, 2004) and to derive prognostics for monitoring trends of carbon stocks (Kauppi, Mielikainen, & Kuusela, 1992; Fang, Oikawa, Kato, Mo, & Wang, 2005; Pan et al., 2011; Dolman et al., 2012; Nabuurs et al., 2013). Traditional approaches to estimate forest GSV rely upon field surveys by establishing plots that can then be combined to extrapolate estimates at stand, provincial or national levels (Tomppo, Gschwantner, Lawrence, & McRoberts, 2010). "
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    ABSTRACT: This paper presents and assesses spatially explicit estimates of forest growing stock volume (GSV) of the northern hemisphere (north of 10°N) from hyper-temporal observations of Envisat Advanced Synthetic Aperture Radar (ASAR) backscattered intensity using the BIOMASAR algorithm. Approximately 70,000 ASAR images at a pixel size of 0.01° were used to estimate GSV representative for the year 2010. The spatial distribution of the GSV across four ecological zones (polar, boreal, temperate, subtropical) was well captured by the ASAR-based estimates. The uncertainty of the retrieved GSV was smallest in boreal and temperate forest (< 30% for approximately 80% of the forest area) and largest in subtropical forest. ASAR-derived GSV averages at the level of administrative units were mostly in agreement with inventory-derived estimates. Underestimation occurred in regions of very high GSV (> 300 m3/ha) and fragmented forest landscapes. For the major forested countries within the study region, the relative RMSE between ASAR-derived GSV averages at provincial level and corresponding values from National Forest Inventory was between 12% and 45% (average: 29%)
    Remote Sensing of Environment 08/2015; 168:316-334. DOI:10.1016/j.rse.2015.07.005 · 6.39 Impact Factor
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    • "The vulnerability of the ecosystems to climate change brings important consequences for the climate system, as ecosystem changes may release carbon into the atmosphere, hence amplifying global warming (Canadell et al., 2004), which is considered a negative vegetation–climate feedback. Land use changes, with increased rate of logging and mining in the forest areas could increase the vulnerability of the forest. "
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    ABSTRACT: In Cameroon and elsewhere in the Congo Basin, the majority of rural households and a large proportion of urban households depend on plant and animal products from the forests to meet their nutritional, energy, cultural and medicinal needs. This paper explores the likely impacts of climate-induced changes on the provisioning of forest ecosystem goods and services and its effect on the economic and social well-being of the society, including the national economy and the livelihoods of forest-dependent people. The analysis focuses on four identified vulnerable sectors — food (NTFPs), energy (fuelwood), health (medicinal plants) and water (freshwater) through a multi-stakeholder dialog at national and regional levels. We use a vulnerability assessment framework by combining the elements of exposure, sensitivity and adaptive capacity to conceptualize vulnerability in these sectors. The identified sectors in relation to the forest ecosystem are discussed in view of providing an understanding of the sector's potential adaptive capacities for policy intervention. Our analysis presents the possible implications of the vulnerability of these sectors for planning local and national adaptation strategies. Local and national adaptive capacities to respond to climate impacts in the orest sectors includes: reducing poverty, enhancing food security, water availability, combating land degradation and reducing loss of biological diversity.
    Forest Policy and Economics 10/2012; 23:1-9. DOI:10.1016/j.forpol.2012.06.009 · 1.86 Impact Factor
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    • "The terrestrial biosphere offers significant possibilities for future sink enhancement through changes in vegetation and soil management. However this sink is also vulnerable under climate change and variability and it may become saturated (Scholes and Noble, 2001; Canadell et al., 2004). Uncertainty in net ecosystem exchange of carbon (F NEE ) is highest for the Land Use Change and Forestry Sector of the Kyoto Protocol; hence improved methods for estimating F NEE are needed to reduce uncertainty in carbon budgets across the spectrum of spatial and temporal scales. "
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    ABSTRACT: Net ecosystem exchange of carbon (FNEE) was estimated for a temperate broadleaf, evergreen eucalypt forest ecosystem at Tumbarumba in south-eastern Australia to investigate the processes controlling forest carbon sinks and their response to climate. Measurements at a range of temporal and spatial scales were used to make three different estimates of FNEE based on: (1) the difference between fluxes of carbon input by photosynthesis and output by autotrophic plus heterotrophic respiration, (2) changes over time in the carbon pools in the above- and below-ground biomass, soil and litter, and (3) micrometeorological flux measurements that provide a continuous estimate of the net exchange. A rigorous comparison of aggregated component fluxes and the net eddy fluxes within a flux tower source area was achieved based on an inventory of the site and a detailed sampling strategy. Measurements replicated in space and time provided mean values, confidence limits and patterns of variation of carbon pools and fluxes that allowed comparisons within known limits of uncertainty. As a result of comparisons between nighttime eddy flux and chamber measurements of respiration, a revised micrometeorological method was developed for estimating nighttime carbon flux using flux tower measurements. Uncertainty in the final estimate of FNEE was reduced through mutual constraints of each of these measurement approaches. FNEE for the period October 2001–September 2002, with average rainfall, was an uptake of 6.7 (5.1–8.3) tC ha−1 yr−1 estimated from component fluxes, and 5.4 (3.0–7.5) tC ha−1 yr−1 estimated from the revised eddy flux method. Biomass increment was 4.5 (3.7–5.4) tC ha−1 yr−1 and the remaining 0.9–2.2 tC ha−1 yr−1 could represent a carbon sink in the soil and litter pools or lie within the confidence limits of the measured fluxes. FNEE was reduced to −0.1 to 2.4 tC ha−1 yr−1 during a period of drought and insect disturbance in October 2002–September 2003, with biomass increment being the main component reduced. The forest is a large carbon sink compared with other forest ecosystems, but this is subject to high-annual variability in response to climate variability and disturbance.
    Agricultural and Forest Meteorology 03/2009; 149(3-4-149):535-558. DOI:10.1016/j.agrformet.2008.10.002 · 3.76 Impact Factor
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