非表示:
キーワード:
Central Amazonian floodplains; várzea; use of timber and forest products; logging
要旨:
Central Amazonian whitewater floodplains (várzea) are periodically inundated by sediment rich rivers and therefore have rich soils and a high primary production. 250 tree species have been described as typical, many of which have low wood densities. Although total wood production is not higher than in temperate forests, várzea forests have been exploited since the end of the last century. The easy accessibility and the high number of individuals of a species per area are advantageous. Natural ressources like the production of oil, soap, resines, textile fibres, tannins, colours and medicines, aromas, latex, and fruits are of local and commercial importance. Timber is a very important good since the beginning of the century, where it was used for energy production in steamboats, and for civil and naval
construction. On a large scale the extraction of timber started in the 1920s. Logging is done by hand, and the wood is transported by raft to Manaus where sawmills and timber industry are concentrated. 80 % of the processed wood remain in the State of Amazonas. The rest is exported mainly to Southern Brazil, while international trade is neglectable.
The floodplains are of exceptional economic importance also for the cultivation of crops and cattle raising, which leads to the destruction of the forested areas. Many commercially used tree species are threatened, especially in the vicinity of big cities.
