Forest residues

Hoogwijk et al. (2005) assume the biomass energy potential in Western Europe from energy crops, agricultural residues, forest residues and industrial biogenic residues to be of the order of 10000 PJ/year and 16000 PJ/year by 2050. The analysis is based on the IMAGE 2.2 model using the four scenarios from the Special Report on Emissions Scenarios (SRES), (Nakicenovic, 2000) as main assumptions for the included food demand and supply. 

Most wood and wood-derived materials (spent pulping liquors) that are used for energy are consumed by the forest products industry itself. The source of this fuel is almost entirely in the wood-processing and manufacturing operations, termed manufacturing residuals or mill residues. Forest residues from logging operations and the noncommercial trees in the forest also are utilized for fuels. 

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... 

Pressures on forest resources and competing uses of fresh wood have resulted in greater recovery of sawlogs from trees that are formerly considered a fiber resource. On the west coast of North America, the larger trees are primarily used for lumber and plywood, leaving only the residues for pulp chips. In order to minimize butt damage, many operations use sawheads rather than shears on the feUer-bunchers. 

The forest products industry encompasses a broad spectrum of operations which range from the raismg of trees, through cutting and removing the timber, to complete utilization of the wood residue (17). 

The maximum temperature and duration of heating during fires are important variables that influence the soil nutrient status, as well as the survival of residual vegetation following fire (Table III). Deforestation results in the presence of large quantities of wood debris in close proximity to the soil surface. Fires in this scenario result in soil temperatures and magnitudes of heat flux far in excess of those which occur in fires in uncut forests (Shea, R. W. Oregon State University, unpublished data). 

Dimond JB, Owen RB (1996) Long-term residue of DDT compounds in forest soils in Maine. 

In 1932, nine out of ten kilos of textiles the Germans used had been imported. This ratio applied to most other household things. Farben went into the forests. Soon every other citizen arose to the tinkle of a Farben plastic clock, rolled back a new synthetic-fabric spread. Every other man shaved with Farben soap that had been made from the residue of the paraffin that had been made from the coal. At least twice a week, the German ate a new Farben food cooked in synthetic fat. Six out of ten dinner tables were spread with Farben cloths. After the worker went to his job, his wife cleaned the linen, the curtains, the casements, and dusted the furniture goods — all made from beechwood. 

Gasification coupled with water-gas shift is the most widely practiced process route for biomass to hydrogen. Thermal, steam, and partial oxidation gasification technologies are under development. Feedstocks include both dedicated crops and agricultural and forest product residues of hardwood, softwood, and herbaceous species. 

Figure 3. The general nitrogen model for illustrating the bio geochemical cycling in Forest ecosystems. Explanations for the fluxes 1, ammonia volatilization 2, forest fertilization 3, N2-fixation 4, denitrification 5, nitrate respiration 6, nitrification 7, immobilization 8, mineralization 9, assimilatory and dissimilatory nitrate reduction to ammonium 10, leaching 11, plant uptake 12, deposition N input 13, residue composition, exudation 14, soil erosion 15, ammonium fixation and release by clay minerals 16, biomass combustion 17, forest harvesting 18, litterfall (Bashkin, 2002).

However, the microbial activity is depressed during long and severe wintertime, and this leads to an accumulation of semi-mineralizable plant residues on the soil surface. With the increasing duration of cold season from south to north, the mass of these half-destroyed remains enlarges from 15 ton/ha of dry organic matter in Broad-Leaved Sub-Boreal Forest ecosystems to 80-85 ton/ha in Northern Taiga Forest ecosystems. 

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