Search

Hoping to support sustainability, countries have established policies to foster the bioeconomy (BE), based on the use of biomass and knowledge on biological principles. However, appropriate monitoring is still lacking. We estimate global key environmental footprints (FPs) of the German BE in a historic analysis from 2000–2015 and in projection until 2030. Overall, the agricultural biomass FP is dominated by animal-based food consumption, which is slightly decreasing. The forestry biomass FP of consumption could potentially shift from net import to total supply from domestic territory. Agricultural land use for consumption is triple that of domestic agricultural land (which covers half of Germany) and induced substantial land use change in other regions from 2000–2015. The FP of irrigation water withdrawals has decreased over 2000–2015 and might continue to decline in absolute terms by 2030, but the share of supply regions with water stress might increase. The climate FP of BE contributes 18–20% to the total climate FP of domestic consumption, while employment makes up 10% and value added only 8% of the total German economy. These findings imply that sufficient monitoring of the BE needs to consider both production and consumption perspectives, as well as global FPs of national economies. An analysis of the German bioeconomy between 2000 and 2015 finds that its environmental footprints are dominated by animal-based food consumption, and agricultural land use for consumption abroad is double the domestic one.

Hoping to support sustainability, many countries established policies to foster bioeconomy (BE). While shifting towards more biomass use bears chances and risks, appropriate monitoring is still lacking. Here we show for the first time global key environmental footprints (FPs) of the German BE. From 2000 to 2030, the agricultural biomass FP is dominated by animal-based food consumption, which is slightly declining. Forest biomass FP of consumption could be potentially supplied from domestic territory. Agricultural land use for consumption is triple of domestic agricultural land (which covers half of Germany), having induced significant land use change in other regions from 2000 to 2015. Water FP for irrigation has decreased and might decline in absolute terms, but the share of supply regions with water stress might increase until 2030. The climate FP of BE contributes 20 to 18 % to the total climate FP of domestic consumption, while employment makes up 10 % and value added only 8 % of total.

Changes in soil organic carbon stocks depend on the management regime and a variety of environmental actors including climatic conditions and soil properties. So far, the dynamics of soil organic carbon have not been explicitly represented in global economic land use optimization models. Here, we apply an approach to represent soil organic carbon dynamics explicitly in a global bottom-up recursive dynamic partial equilibrium model using carbon response functions simulated with a biophysical process-based model. We project soil organic carbon emissions from European cropland to decrease by 40% from 64 MtCO2 in 2010 to about 39 MtCO2 in 2050 mainly due to saturation effect when soils converge toward their equilibrium after management, crop rotation, or land use change. Moreover, we estimate a soil organic carbon mitigation potential for European cropland between 9 and 38 MtCO2 per year until 2050 for carbon prices between 10 and 100 USD/tCO2. The total European mitigaion potential including co-benefits from the crop and livestock sector due to the carbon price is even higher with 60 MtCO2 equivalents (eq) per year. Thus carbon sequestration in soils could compensate 7% of total emissions from agriculture within the EU, 10% when including co-benefits from the crop and livestock sector. However, as production is realocated outside Europe with increasing carbon prices, emissions decrease in Europe but increase in the rest of the world (20 MtCO2 eq). Preventing GHG emission leakage to the rest of the world would decrease the European soil organic carbon mitigation potential by around 9% and the total European mitigation potential including co-benefits by 16%. Nevertheless, the net global mitigation potential would still increase. We conclude that no significant contributions to emission reduction targets should be expected from the European cropland carbon sequestration options considered in this study.

Increasing bioenergy production from forest harvest residues decreases litter input to the soil and can thus reduce the carbon stock and sink of forests. This effect may negate greenhouse gas savings obtained by using bioenergy. We used a spatially explicit modelling framework to assess the reduction in the forest litter and soil carbon stocks across Europe, assuming that a sustainable potential of bioenergy from forest harvest residues is taken into use. The forest harvest residue removal reduced the carbon stocks of litter and soil on average by 3% over the period from 2016 to 2100. The reduction was small compared to the size of the carbon stocks but significant in comparison to the amount of energy produced from the residues. As a result of these land-use-related missions, bioenergy production from forest harvest residues would need to be continued for 60-80 years to achieve a 60% carbon dioxide (CO2) emission reduction in heat and power generation compared to the fossil fuels it replaces in most European countries. The emission reductions achieved and their timings varied among countries because of differences in the litter and soil carbon loss. Our results show that extending the current sustainability requirements for bioliquids and biofuels to solid bioenergy does not guarantee efficient reductions in greenhouse gas emissions in the short-term. In the longer-term, bioenergy from forest harvest residues may pave the way to low-emission energy systems.

Industrialized countries agreed on a reduction of greenhouse gas emissions under the Kyoto Protocol. Many countries elected forest management activities and the resulting net balance of carbon emissions and removals of non-CO 2 greenhouse gases by forest management in their climate change mitigation measures. In this paper a generic dynamic forestry model (FORMICA) is presented. It has an empirical basis. Several modules trace C pools relevant for the Kyoto Protocol and beyond: biomass, litter, deadwood and soil, and harvested wood products. The model also accounts for the substitution of fossil fuels by wood products and bioenergy. FORMICA was used to first study the model sensitivity and uncertainty based on data from Thuringia, a federal state of Germany, to determine the major sources of uncertainty in carbon accounting at different levels of carbon pool aggregation (biomass, ecosystem, forestry sector and enhanced forestry sector including the accumulated substitution effect). Rotation length and maximum increment contributed most to uncertainty in biomass. The influence of the latter did not diminish with higher level of pool aggregation. Uncertainty in the enhanced forestry sector was to a smaller degree controlled by product and substitution related parameters. Relative uncertainty decreased with the level of aggregation and comprehensiveness of the carbon budget. In a second step the model estimated the sink potential of the Thuringian forestry sector. The projected average biomass sink for the period of 2003–2043 of 0.6 t C ha −1 year −1 could be increased by 50% by broadening the perspective to the entire forestry sector, including substitution effects. A simulation of forest conservation on 20% of the forest area increased C fixation. However, even in the biomass C pool the expected C stock changes did not exceed the estimated uncertainty of 40%. A higher level of aggregation (i.e. the inclusion of soil and litter, product pool and substitution effects) decreases relative uncertainty but also diminishes differences between different management options. The analysis demonstrates that the choice of management mitigation options under an accounting scheme should include the impacts on forest products and of substitution effects.

Temperate forest ecosystems have recently been identified as an important net sink in the global carbon budget. The factors responsible for the strength of the sinks and their permanence, however, are less evident. In this paper, we quantify the present carbon sequestration in Thuringian managed coniferous forests. We quantify the effects of indirect human-induced environmental changes (increasing temperature, increasing atmospheric CO2 concentration and nitrogen fertilization), during the last century using BIOME-BGC, as well as the legacy effect of the current age-class distribution (forest inventories and BIOME-BGC). We focused on coniferous forests because these forests represent a large area of central European forests and detailed forest inventories were available. The model indicates that environmental changes induced an increase in biomass C accumulation for all age classes during the last 20 years (1982‐2001). Young and old stands had the highest changes in the biomass C accumulation during this period. During the last century mature stands (older than 80 years) turned from being almost carbon neutral to carbon sinks. In high elevations nitrogen deposition explained most of the increase of net ecosystem production (NEP) of forests. CO2 fertilization was the main factor increasing NEP of forests in the middle and low elevations. According to the model, at present, total biomass C accumulation in coniferous forests of Thuringia was estimated at 1.51tCha � 1 yr � 1 with an averaged annual NEP of 1.42tCha � 1 yr � 1 and total net biome production of 1.03tCha � 1 yr � 1 (accounting for harvest). The annual averaged biomass carbon balance (BCB: biomass accumulation rateharvest) was 1.12tCha � 1 yr � 1 (not including soil respiration), and was close to BCB from forest inventories (1.15tCha � 1 yr � 1 ). Indirect human impact resulted in 33% increase in modeled biomass carbon accumulation in coniferous forests in Thuringia during the last century. From the forest inventory data we estimated the legacy effect of the age-class distribution to account for 17% of the inventory-based sink. Isolating the environmental change effects showed that these effects can be large in a long-term, managed conifer forest.

The release behavior of delayed neutron (DN) precursors from the breached fuel was analyzed, based on the diffusional release model. In this analysis, spherical co-ordinate simple approach as well as two-dimensional finite element method were used for the predomiant DN precursor 137I. It was shown that the fuel sodium reaction product (FSRP) layer at the pellet outer surface provided a predominant role for the accelerated release of DN precursors. The macroscopic diffusion coefficient for DN precursors in the FSRP layer was estimated to be 10−9 to 10−10 m2/s, which is greater than that in unreacted fuel by more than about 106. It was demonstrated that the DN signal response correlated to the growth of the FSRP layer, and did not depend on temperature change of interior fuel itself.

Starting from the experimental determination of the characteristic curve, the modulation transfer function and the Wiener spectrum of a considerable number of commercial colour and black-and-white films, several objective criteria of image quality (signal-to-noise ratio, information capacity, detective quantum efficiency, objective resolving power) COliid be determined under comparable corlditions for the first time. At a logarithmic representation the criteria give good linear correlation with the logarithm of sensitivity; tile slopes of the straight lines, however, slightly deviate from the theoretical values.

A 2030 climate and energy policy framework was endorsed by the European Council in 2014. The main elements are a binding 40 % greenhouse gas (GHG) reduction target compared to 1990, a renewable energy share of 27 %, and an energy savings target of at least 27 % by 2030. In this paper, we assess the impact of these targets on the European land use, land use change, and forestry (LULUCF) sector using a Europe focused global land use model linked with a detailed forest management model. We show that implementing a 40 % GHG emission reduction target by 2030 may only have a small negative impact on the domestic LULUCF sink if the additional biomass demand for energy is mostly met through ligno-cellulosic energy crops rather than forest removals. However, if the increased biomass demand were met through higher rates of forest harvest removals, a more negative impact on the LULUCF sink could be expected.

After approval of the construction of the new separated function electron synchrotron, DESY II, in May 1983, the design and fabrication of all components was completed and the new machine fully installed during a four month winter shutdown from Nov. 84 until Feb. 85. The new machine will be tested in parallel with normal operation of the old 7 GeV synchrotron, DESY I, by using 200 MeV electrons injected from the upgraded Linac I. Provisional power supplies run the magnets up to 1 GeV. During a second shutdown in winter 85/86 it is planned to install full magnetand rf-power and to connect all beam transfer lines to PETRA and DORIS. DESY I will then be turned off and most of the components will be used to form a new proton synchrotron (DESY III) for the HERA e--p project. An updated parameter list and first results from the initial tests of DESY II will be presented.

Methods to assess pulse-to-pulse timing jitter in periodically gain-switched semiconductor lasers are investigated. The power spectrum of the optical pulse train for mutually incoherent fluctuations of the turn-on delay time and the pulse amplitude is calculated. The result shows that a measurement of the power spectrum alone is not sufficient for the characterization of the inherent timing jitter. Additional knowledge of the optical waveform and the transfer characteristics of the detection system is necessary.