Trees forest biomass

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). 

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. 

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%. 

Forest biomass in the Amazon has been estimated through direct and indirect methods. Independent of the method used, one should take into consideration that all components of forest biomass must be quantified. Besides the trees that are the main component of the forest, other components to be included are vines Gianas), understory plants, litter, roots, palms, etc. 

Indirect methods, based on allometric inference, from measurements of the diameter at breast height (DBH) and the height of the trees to obtain wood volumes, is the main method adopted to estimate biomass in the Amazon. Forest biomass estimates are made through regression analysis, where several fitting curves are tested to obtain an ideal model that can be applied to the trees. These models are calibrated by direct weighing of the biomass from a subsample of trees (see for example, Jordan and Uhl 1978, Higuchi et al. 1994, Brown et al. 1995), and could also include other compartments besides trees, such as vines or understory. Indirect methods are broadly adopted in the forestry industry to evaluate the volume of commercial wood. 

There have been numerous estimates made on the total biomass and biomass potential of our forests 3,1Q). The inventory procedure used is based on estimates and averages, and is fully described by Wahlgren and Ellis (U). Forest surveys based on biomass measurement techniques are needed to accurately determine the quantities and location of our wood resource. Many studies on measuring the weight of individual trees, and to a lesser extent forest stands, have been made. This work has been summarized by Keays (12). and Hitchcock and McDonnell (12)- As work in forest biomass measurement is refined, regional weight tables can be developed and accurate biomass inventories compiled. 

The moisture content of various forest biomass varies widely with species, geographic locations, genetic differences, tree components used, and tree age. Published data indicate that moisture content of mature wood may range from about 30 percent to more than 200 percent ( ). Also, moisture content of the stem sapwood portion is usually higher than that of the associated heartwood. For young hardwood sprouts (6 to 15 years old), an average... 

Chemical engineering in general and chemical reaction engineering in particular are in key position to carry out this transformation. One of the most important sources of biomass is forests, not only the rain forests and eucalyptus trees growing in the tropical areas of the earth but also the forests in the Northern hemisphere, for instance in Canada, USA, Russia, and in the Fenno-Scandic region. The big... 

Table 2. Parameters of wood biomass growth for main tree types in the forests of European Russia results of simulating based on EFIMOD (Chertov, Komarov, 1997).

We can see from Table 4 that most of the Spruce Forest ecosystem biomass is accumulated in trees, with trunk mass predominating. The values of annual Net Primary Production (NPP) and litterfall production are more connected with needles. In living matter, the mass of moss and bush species makes up to 2-3% of the tree biomass, whereas in dead matter (litterfall), it is up to 10%. 

We can see that the tree vegetation absorbs annually from soil tens of grams per hectare of Zn and Ba, units of grams of Ni, V, and Co. The absorption of trace metals by low bush species is smaller by an order of magnitude. Simultaneously, a similar amount of metals is released from the living biomass of the Spruce Forest ecosystems. 

Using our definition for alkalinity or ANC whereby any decrease (increase) in concentrations of base cations (e.g., K+, Ca2+, Fe2+, etc.) or any increase (decrease) in concentrations of "acid anions" (e.g., NO3, HPO2, SOf, etc.) is accompanied by a decrease (increase) in alkalinity. Thus, as illustrated in Fig. 5.17 net synthesis of terrestrial biomass (e.g., on the forest and forest floor, where more cations than anions are taken up by the plants (trees), is accompanied by a release of H+ to the environment. 

The rate of growth of the trees slows as the forest reaches maturity and canopy closure occurs. In addition, the forest eventually establishes equilibrium with the environment, where the rate of carbon sequestration is exactly balanced by the loss of carbon dioxide to the atmosphere due to decay of dead trees and other biomass. 

The process of tree growth utilizes atmospheric carbon in the production of wood biomass. Furthermore, this sequestered carbon can continue to be held in products that are manufactured from wood. Although much research has been done in investigating forests as actual or potential carbon sinks, there has been rather less work looking at the implications of the use of wood products as a medium-term carbon store. 

Wood biomass involves trees with cotranercial stracture and forest residues not being used in the traditional forest products industries. Available forest residues may appear to be an attractive fuel source. Collection and handling and transport costs are critical factors in the use of forest residues. Although the heat produced from wood wastes is less than that from oil or gas, its cost compared to fossil fuels makes it an attractive somce of readily available heat or heat and power. The most... 

In a conifer forest, litter production and decomposition release about 80% of the total minerals in the biomass of the stand the remainder is retained in the living parts of the tree. Standing dead material is not considered litter. 

These other forest resources - unutilized trees from intensive forest management and the residue today left in the forest - could, if pressed to their maximum availability, contribute around 1 EJ to the energy supply. To do this will, however, require extensive end use product markets since the end use requirement of heat production in the forest industry will already be essentially satisfied by the industries own residue. The conversion problem is therefore the transformation of biomass to energy intermediates such as electricity for transmission elsewhere, automobile fuels such as the much discussed methanol option, or into energy intensive tonnage chemicals such as ammonia and ethylene. 

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