Biomass estimates trees

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%. 

A comparison of these data with those of an Amazonian forest shows that the aerial biomass of the trees of a cerrado sensu stricto in central Brazil may be only 8 to 22% of that of an Amazonian forest, and the basal area only 10 to 26% (Table 5.3). This difference in biomass reflects directly on the nutrient pools in the biomass. A comparison of the data reported by Klinge et al. (1995) for the aboveground biomass and nutrient stock in two inundation forests in the Ilha de Marchantaria with the data for a cerrado sensu stricto from central Brazil (Silva 1990) illustrates how nutritionally poor the cerrado is in quantitative terms. The proportions of stock of essential nutrients in the tree biomass of cerrado are 7 to 16% for P, 1.7 to 4.6% for K, 0.83 to 3.09% for Ca, and 3.5 to 7.4% for Mg. Thus Ca, K, and Mg seem to be much more deficient in the cerrados than P. We have no corresponding data for the stock of nutrients in the root biomass of trees for comparison among the two ecosystems. This comparison is only illustrative of two specific sites. Estimates of aboveground biomass for the Amazonian forests may vary... 

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. 

Uranium Content and Biomass of Tree Components and Humus in the Pine Stand Growing on U-Mining Dump H382 and Estimation of the Total U Amount and Its Relative Distribution between Tree Components and at Stand Level... 

Biosynthesis in plants and trees using sun radiation, atmospheric carbon dioxide, water, and soil nutrients produces huge amounts of biomass estimated up to 200 Gt/y, a figure to be compared to 7 Gt/y of extracted fossil fuels. Increasing use of biomass for energy, chemicals and material supply is one of the key issues of sustainable development because bio-based resources are renewable and CO2 neutral unlike fossil fuels. Presently, only 7% of the annual biomass is harvested for food, feed and non-food sq)plications. Food and feed will remain priority number one, but improved agricultural techniques and genetic modification of crops will increase yields substantially. Renewables dedicated to non-food applications could come from specialized crops or... 

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. 

Intrinsic forest factors such as the percent of bark and hollow trees should be studied better, as well as the estimates for carbon content of each forest type. The nonforest biomass also needs better refinement, as it contributes on the order of 2.6% of the total stock of carbon contained in vegetation biomass of the Legal Amazon (Gra a, 1997). 

Estimates through indirect methods should improve the regression equations to estimate the biomass of larger trees, which represent... 

Figure 13 Distribution of bomb testing between the atmosphere, ocean, and terrestrial biosphere as reconstructed by Broecker and Peng (1994). The ocean contribution is obtained by a model constrained by the inventory based on the GEOSECS survey. The contribution of the terrestrial biosphere is based on estimates of the biomass and turnover times for trees and active soil humus.

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