Forest burned biomass

Fearnside, P. M., P. M. L. A. Gtaga, N. Leal Filho, F. J. A. Rodrigues, and J. M. Robinson. 1999. Tropical forest burning in Brazilian Amazonia measurement of biomass loading, burning efficiency and charcoal formation at Altamira, Para, Forest Ecology and Management 123(1) 65-79. 

Brown S. and Gaston G. (1996) Estimates of biomass density for tropical forests. In Biomass Burning and Global Change (ed. J. S. Levine). MIT Press, Cambridge, MA, vol. 1, pp. 133-139. 

Sao Paulo, Brazil Urban, forest and biomass burning areas [66]... 

Woody biomass could supply the nation with about 5 quads of its total gross energy supply by the year 2050 with the use of approximately 112 million hectare (an area larger than the state of Texas). A city of 100,000 people using the biomass from a sustainable forest (3 t/ha) for fuel would require approximately 220,000 ha of forest area, based on an average electrical demand of 1 billion kilowatthours (860 kcal = 1 kWh). More than 70% of the heat energy produced from burning biomass is lost in its conversion into electricity this is similar to losses experienced in coal-fired plants. The forest area required to... 

Deforestation, Biomass Burning and the Biogeochemical Balance of Forests... 

The burning of slash following deforestation, whether intentional or unintentional, results in far greater direct and indirect losses of nutrients than deforestation alone. This is particularly true in many tropical forests where only a small fraction (if any) of the aboveground biomass is removed prior to burning. Carbon losses from slash fires in the tropical dry forest were 4-5 fold greater than C losses from wood export (Table IV) (55). Slash fires in tropical dry forests resulted in N losses of 428-500 kg ha whereas fuel wood export of the relatively N-poor coarse woody debris amounted to approximately 41 kg N ha" Losses of P increase with increasing fire severity. P losses of 10-77 kg ha" as a result of severe fires is not uncommon (Table TV) (53, 58, 60). 

Much of the surface soil erosion and hence nutrient loss occurs when deforestation and biomass burning removes and/or consumes the organic materials that protect the soil surface. Significant losses may occur by dry ravel or overland water erosion associated with precipitation events. Under a shifting cultivation system in a tropical deciduous forest ecosystem in Mexico, Maass et al. 61) reported first year losses of N, P, K, and Ca were 187, 27, 31, and 378 kg ha" respectively. In contrast, losses in adjacent undisturbed forests were less than 0.1 kg ha for all nutrients except Ca (losses were 0.1-0.5 kg ha for Ca). 

Figure 7. Another temperate coniferous forest site of the Pacific Northwest, USA following clearcutting and slash burning. Severe levels of deforestation result in large quantities of nutrient losses through wood export, biomass burning and accelerated erosion and leaching losses. (Photograph is by courtesy of Dian L. Cummings. ...

Tropical forests and savannas are the primary source of C emissions that originate from biomass burning (73, 75). However, temperate forests are also sources of atmospheric carbon. Harmon et al. (77) reported that conversion of primary temperate forests to younger, second-growth forests lead to increases in atmospheric CO2 levels, due to losses in long-term carbon storage within these forests. They ascertained that timber exploitation of 5 million hectares of primaiy forests in the Pacific Northwest of North America during the past century has resulted in the addition of 1,500 Tg of C to the atmosphere. 

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