[en] Short communication

[en] General conclusions regarding the implementation of biotic policy options in the US suggest that it is important for policymakers to differentiate between the theoretically possible and practically feasible global warming mitigation benefit associated with each biotic policy option. In the case of almost every option, the practical potential is considerably smaller than the theoretical potential. Biotic options within the US could in principle offset or displace almost all current fossil fuel CO₂ emissions, the equivalent of more than 1.5 billion tons of carbon per year. In practice, however, storing or displacing just 150 to 400 million tons of carbon per year, or 9 to 25% of current US fossil fuel emissions, would require an aggressive and successful multipronged policy effort

[en] The development of photo-biological energy conversion systems has long-term implication from the energy, wood fibre and chemical points etc. Power generation through biomass combustion and gasification has proved to be very successful venture. The energy needs of the people in the remote, rural and even urban areas of the country can be met economically by the energy from the renewable source such as biomass. The biomass energy is full of opportunities, and future trends are emerging towards renewable energy

[en] The results of the UNIDO symposium are presented. The symposium covered a variety of subjects, beginning with a comparison of biomass energy production and potential uses in different regions, specific country case studies about the present situation and trends in biomass energy utilisation. Technological aspects discussed included the production of biomass resources, their conversion into energy carriers and technology transfer to developing countries. An analysis of financial resources available and mechanisms for funding biomass projects were given. Environmental effects and some relatively successful biomass projects under development were described. (K.A.)

[en] This paper examines environmental concerns regarding intensive forest harvesting, and outlines current knowledge. Site productivity and nutrient removal, site productivity and soil disturbance, and site preparation impacts are discussed. Biodiversity, off-site impacts, positive environmental impacts of intensive biomass harvesting, acid rain, climate change, estimating the carbon stored by a forest, site productivity research needs and application of models are discussed. (UK)

[en] This paper is a preliminary attempt to provide information on the probable environmental effects of energy crop production relative to other potential uses of the land. While dedicated energy crop production is anticipated to occur primarily on land currently in agricultural production, some pastureland and forestland with a high potential for conversion to agricultural production may be utilized. Experimental results suggest that chemical use on energy crops will be lower than on most row crops and that land producing energy crops should experience less erosion than land producing row crops. Long-term site productivity should not be a major issue if macro-and micro-fertilizers are added as needed and nutrient-conserving production techniques are used. (Author)

[en] An update is presented of a study carried out to: determine the factors affecting the cost of energy conversion feedstocks in short rotation intensive culture plantations of trees; determine the factors influencing biomass yield; identify interrelationships between the previous two objectives; present estimates of potential biomass yields and associated economics; and to identify gaps in the knowledge of the economics and yields of biomass production and their interrelationships. Developments in economics and yields in short rotation intensive silviculture for the production of biomass energy since 1991 are documented. The most substantial changes have been: the introduction of new clones in Sweden with a 20% increase in yield; illustrating the potential genetic gains achievable through selection and breeding; and halving of harvesting costs with new machinery. Harvesting costs with chipping incorporated have fallen to $51.21/dry tonne. The twin row ESM and Frobbester harvesters have lower estimated costs of $36.62 and $ 33.69 respectively. Agricultural based machines have further reduced costs to $19.42 and $26.12/dry tonne. Using these new data, three new scenarios were developed for cost of production analysis, using contract labour, farm labour or farm labour plus a subsidy. A contracted operation is now viable with an annual equivalent net value (AENV) of $35/ha. With the use of farm labour for most operations and omitting land rent, profitability increased to $127/ha. With a subsidy of $75/ha, the AENV increases to $205/ha. 25 refs., 1 fig., 3 tabs

[en] Polarimetric Synthetic Aperture Radar Interferometry (Pol-InSAR) is an active radar remote sensing technique based on the coherent combination of both polarimetric and interferometric observables. The Pol-InSAR technique provided a step forward in quantitative forest parameter estimation. In the last decade, airborne SAR experiments evaluated the potential of Pol-InSAR techniques to estimate forest parameters (e.g., the forest height and biomass) with high accuracy over various local forest test sites. This dissertation addresses the actual status, potentials and limitations of Pol-InSAR inversion techniques for 3-D forest parameter estimations on a global scale using lower frequencies such as L- and P-band. The multi-baseline Pol-InSAR inversion technique is applied to optimize the performance with respect to the actual level of the vertical wave number and to mitigate the impact of temporal decorrelation on the Pol-InSAR forest parameter inversion. Temporal decorrelation is a critical issue for successful Pol-InSAR inversion in the case of repeat-pass Pol-InSAR data, as provided by conventional satellites or airborne SAR systems. Despite the limiting impact of temporal decorrelation in Pol-InSAR inversion, it remains a poorly understood factor in forest height inversion. Therefore, the main goal of this dissertation is to provide a quantitative estimation of the temporal decorrelation effects by using multi-baseline Pol-InSAR data. A new approach to quantify the different temporal decorrelation components is proposed and discussed. Temporal decorrelation coefficients are estimated for temporal baselines ranging from 10 minutes to 54 days and are converted to height inversion errors. In addition, the potential of Pol-InSAR forest parameter estimation techniques is addressed and projected onto future spaceborne system configurations and mission scenarios (Tandem-L and BIOMASS satellite missions at L- and P-band). The impact of the system parameters (e.g., bandwidth, NESZ, ambiguities) and the operation scenario (e.g., temporal decorrelation due to a repeat-pass orbit) is evaluated and discussed with respect to the retrieval of the forest parameters. The study is supported and validated by using repeat-pass Pol-InSAR data at L- and P-band acquired by DLR's E-SAR system over Remningstorp (BioSAR 2007, hemi-boreal forest), Krycklan (BioSAR 2008, boreal forest) and Traunstein (TempoSAR 2008 and 2009, temperate forest) test sites. The simulated spaceborne data sets generated during the BioSAR 2007 campaign are used to carry out the performance analysis.

[en] Biomass can play a dual role in greenhouse gas mitigation related to the objectives of the UNFCCC, i.e. as an energy source to substitute fossil fuels and as a carbon store. However, compared to the maintenance and enhancement of carbon sinks and reservoirs, it appears that the use of bioenergy has so far received less attenuation as a means of mitigating climate change. Modern bioenergy options offer significant, cost-effective and perpetual opportunities toward meeting emission reduction targets while providing additional ancillary benefits. Moreover, via the sustainable use of the accumulated carbon, bioenergy has the potential for resolving some of the critical issues surrounding long-term maintenance of biotic carbon stocks. < finally, wood products can act as substitutes for more energy-intensive products, can constitute carbon sinks, and can be used as biofuels at the end of their lifetime. (author)

[en] The authors propose a mathematical model for numerical estimation of the influence exerted by substitution of biofuel for imported fuels derived from oil. Forecast is given both for the consumption of oil products in transport and for the changes in their minimum reserves in Latvia at the expected growth in the output and use of biofuel. In the model, different biofuel substitutes are considered. (Authors)