خيارات البحث
النتائج 1 - 10 من 11
Silver fir decline in the Vosges mountains (France): role of climate and silviculture.
1989
Becker M. | Landmann G. | Levy G.
Inventory review and environmental evaluation of first- and second-generation sugars through life cycle assessment
2021
Bello, Sara | Salim, Iana | Feijoo, Gumersindo | Moreira, Maria Teresa
In recent years, there has been a great movement towards the generation of knowledge related to the biorefinery concept. First-generation biorefineries bear the stigma of using arable land and edible crops for fuel instead of as sources of food and feed. However, second-generation biorefineries have not reached the level of full technical feasibility. Bearing in mind the objective of sugar production from sugar, starch, or lignocellulosic raw materials, the purpose of this study is to assess the environmental impact of first- and second-generation biorefineries, considering as an example for the comparative evaluation, the production of sugar fractions from crops (starch and sugar crops), and lignocellulosic biomass (hardwood and softwood). The characterization results were obtained using the ReCiPe 1.1 model, implemented through the SimaPro 9.0 software. Both production systems are inherently different and have strengths and weaknesses that must be carefully analyzed. The resulting environmental profile shows that the silviculture of wood contributes less to the environmental impact than cropping activities in most impact categories. In general, this study suggests that first-generation systems are burdened environmentally by the use of fertilizers, which have a significant impact on categories such as marine and freshwater eutrophication and terrestrial acidification, while second-generation systems are limited by the intensive processing steps needed for delignification, typically involving the use of chemicals and/or energy. LCA in early stages of the production of bio-based building blocks, rather than on the manufacture of biofuels or bioplastics, allows the precise identification of the environmental burdens that may be influencing the overall environmental profile of a biorefinery.
اظهر المزيد [+] اقل [-]Possibilities for increased carbon sequestration through the implementation of rational forest management in Russia
1997
Shvidenko, Anatoly | Nilsson, Sten | Roshkov, Vjacheslav
Huge areas of the Russian forests suffer from insufficient forest management. A scenario has been developed for an improved management program that would be implemented over the next 40 years. Possible options have been aggregated into three interlinked groups: increase in forest productivity through improvement of the forest conditions and the structure of the Forest Fund, decrease of carbon release by mitigation of disturbance regimes, and improvement of landscape management. One prerequisite in developing this scenario was that the cost of sequestering one ton of carbon should not exceed US$3 (1992 dollar value). In this article a simple model is described to illustrate the following possibilities for increased carbon fixation by improved forest management: large-scale reforestation and afforestation, replacement of stands with low productivity and replacement of so called soft deciduous species and “climax” stands, and implementation of rational silviculture (thinning). The results indicate a potential for an increase in carbon fixation in Russian forest ecosystems of 24.4 Pg over 100 years, after the first year that the actions discussed are implemented. The net sink of carbon was determined to be 16.5 Pg in the “low” estimate and 42.5 Pg in the “high” estimate. There are, however, many uncertainties in the data and there are difficulties in adequately modeling the possibilities for implementation under current conditions in Russia. In spite of these uncertainties, we conclude that there is great potential for economically justified increased carbon fixation through improved forest management in Russia.
اظهر المزيد [+] اقل [-][Promotion and conservation of natural regeneration of European beech in view of the deposition of air pollutants]
1989
Bressem, U. (Hessische Forstliche Versuchsanstalt, Hann.Muenden (Germany, F.R.). Inst. fuer Forstproduktion und Waldschutz)
Nutrient cycling in adirondack conifer plantations: is acidic deposition an influencing factor?
1989
Nowak, C.A. (State Univ. of New York, Syracuse, NY (USA). Coll. of Environmental Science and Forestry) | Shepard, J.P. | Downard, R.B. | White, E.H. | Raynal, D.J. | Mitchell, M.J.
[Plant succession on clear cut areas and silvicultural consequences]
1990
Irrgang, S. (Technische Univ. Dresden, Tharandt (Germany). Sektion Forstwirtschaft)
[Analysis of troughfall in various silvicultural systems]
1999
Kulhavy, J. | Betusova, M. (Mendelova Zemedelska a Lesnicka Univ., Brno (Czech Republic). Lesnicka a Drevarska Fakulta)
Silvicultural practices
1991
Lord, Roger G. | Dreesen, Alan D.
Processes, procedures, and methods to control pollution resulting from silvicultural activities
1973