Biomass forests

Sepa.ra.tlon, It maybe desirable to separate the feedstock into two or more components for different appHcations. Examples include separation of agricultural biomass into foodstuffs and residues that may serve as fuel or as a raw material for synfuel manufacture, separation of forest biomass into the darker bark-containing fractions and the pulpable components, separation of marine biomass to isolate various chemicals, and separation of urban... 

Another biofuel of importance is wood. The Forest Service, which is part of USDA, administers national forest lands for the sale of wood for wood fuel. Besides determining the quantity of wood fuel to bring to market by collecting and analyzing statistics on woody biomass supply and use, the Forest Sendee sponsors forest biomass energy-related research in conjunction tvitli federal and state agencies, as well as universities. 

Most vegetation maps are derived from a variety of sources using different methods and made at different times. This can lead to an overlap between adjacent areas of interest, the exclusion of some areas, and the improper extrapolation of carbon densities, thus resulting in inaccurate estimates of reservoir size. We found that the biomass density of the southern North American boreal forest was over 2.5 times larger than the biomass density of the northern part of the boreal forest (55). Past estimates of boreal forest biomass density extrapolated southern biomass density values to the entire boreal forest, which in part accounts for the large overestimation (7). It is important that a consistent method be developed to map vegetation globally. 

Soil-related data (HM and BC content in soil parent materials) were included in calculations to account the values of HM weathering. Also we considered the influence of soil types on forest biomass productivity. Runoff data (at scale 0.5 x 0.50 were directly used to get input data on drainage water fluxes, Qie. Forest-type-related data (wood biomass growth and HM content in wood biomass) inserted into our database were subdivided depending on either coniferous, deciduous or mixed forests. 

Forest residues typically refer to those parts of trees such as treetops, branches, small-diameter wood, stumps and dead wood as well as undergrowth and low-value species. The conversion of wood to biofuels and biochemicals has long been a goal of the forest products industry. Forest residues alone count for some 50% of the total forest biomass and are currently left in the forest to rot (Demirbas, 2001). 

Zones of Surplus Forest Biomass and Estimated Wood Procurement Costs Adapted from Reference (6)... 

InterGroup Consulting Economists Ltd. (Winnipeg), Economic Prefeasibility Study Large-Scale Methanol Fuel Production from Surplus Canadian Forest Biomass, Part 1, Summary Report, Fisheries and Environment Canada, Environmental Management Service, Ottawa (1976). 

Methanol. If one takes as an illustration the many propo-sals (16,1y) to use forest biomass to produce methanol as a motor fuel the R D priorities and the barriers can be identified. The production route is ... 

Love, Peter, Overend, Ralph, "Tree Power An Assessment of the Energy Potential of Forest Biomass in Canada, Report ER 78-1, Renewable Energy Resources Branch, Department of Energy, Mines and Resources, Ottawa, Canada, 1978. 

Reinhardt, T., and D. E. Ward, Factors Affecting Methyl Chloride Emissions from Forest Biomass Combustion, Enriron. Sci. Techno , 29, 825-832 (1995). 

Fang J. Chen A. Peng C. Zhao S. and Ci L. (2001). Changes in forest biomass carbon storage in China between 1949 and 1998. Science, 292, 2320-2322. 

Vegetative emission source factors also depend on biomass factors to convert surface area estimates to biomass estimates. The leaf biomass factors used in this inventory (Table II) are those suggested by Zimmerman (31). A comparison of leaf biomass factors reported in the literature provides a simple illustration of the variability associated with the conversion factors used in this inventory. Monk et al. (321 reported a biomass factor of 8400 kg - ha 1 for trees with 14 cm diameter trunks in an oak hickory forest. Biomass factors of 5700 kg ha 1 (301 and 5800 kg - ha 1 (331 have been estimated for mixed deciduous forests. Amts et al. Q4) reported a range of biomass factors between 4400 kg ha 1 and 6340 kg ha 1 for a loblolly pine forest. The variability in these biomass estimates is less than 25%. 

Fearnside, P. M. 1992. Forest biomass in Brazilian Amazonia comments on the estimate by Brown and Lugo. Interciencia 17 0an-Feb) 19-27. 

Mature forest biomass was estimated by Nepstad (1989). Nutrient contents are estimated using average concentrations from other mature Amazonian forests. 

Secondary forest biomass was estimated by allometry using DBHs from ten permanent plots. Equations used are from Uhl et al., 1988 and Markewitz and Davidson unpublished data, 1996. Nutrient concentrations were estimated on site (Markewitz and Davidson, unpublished data, 1997). 

Prior to determining the carbon in phytomass it is necessary to determine the total biomass. Forest biomass is a basic factor in studies related to nutrient cycling and carbon release from terrestrial systems following deforestation. This is now one of the more important global research themes due to concerns about possible human-driven climatic changes. Biomass estimates have an enormous influence in modeling based on emissions of carbon from deforestation. The use of inaccurate values for this parameter will drastically affect the reliability of the results of the models. 

The Brazilian Legal Amazon is about 5 X 10 km and represents 60% of Brazil s territory, with an area originally occupied by forests of approximately 4 x 10 km (Fearnside 1997a). This immense forest area possesses high potential to affect the carbon flows among the terrestrial and atmospheric systems. For forest areas of large extension, as is the Amazon case, estimating the forest biomass should be a priority. 

---