Investigations on tree species suitable for the recultivation of degraded land areas in Central Amazonia.

In this project the influence of site conditions of degraded land areas on growth and wood formation of eight selected native tree species (Swietenia macrophylla King, Carapa guianensis, Cedrela odorata L., Dipteryx odorata Willd., Hymenaea courbaril L., Ceiba pentandra Gaertn., Virola surinamensis Warb., Tabebuia heptaphylla were investiated. In order to study the influence of the management of degraded areas on growth and wood formation of tree especies, the investigationson the relationship of enviromental input and tree growth were carried out in three different plantation systems (monoculture system, mixed culturesystem, enrichment of a 25-year-old secondary forrest established in 1992/19993 at the Embrapa Amazonia Ocidental, Manaus-AM (Brasil). Due to the specific site conditions of degraded lands areas, the investigations were carried out with special reference to water and mineral element supply of the trees and their impact on the growth dynamics and wood production throughout the year. Preliminary results of the structure and function of the fine roots Swietenia and Carapa during the wet and the dry season suggest that carapa might be better adapted to drought than Swietenia. In addition to the eight selected tree species for high-quality wood production, also six species from the secondary forest system of the family of Melastomataceae were studied in relation to water and nutrient supply in order to get some insight in possible relations of competition within the entichment system in the secondary forest. In turned out that special strategies put the species to a more competitive position within the system. From these investigations, some practical help for the selection of tree species for high-quality timber production in mixed culture plantation systems on degraded land areas with special regard to ecological and economic aspects can be derived.bitstream/item/153067/1/Investigations-on-tree-species-suitable-Luadir.pd