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The aim of this research was to assess how aboveground biomass (AGB) changes along an altitudinal gradient in evergreen Andean–Amazonian forests [Evergreen Lower Montane Forest, northeastern Cordillera of the Andes; Evergreen Piedmont Forest (EPF), northeastern Cordillera of the Andes; and Evergreen Lowland Forest (ELF), Napo–Curaray] from 373 to 1,826 m above sea level (m.a.s.l.). All trees measured in nine permanent 0.36-ha plots (60 × 60 m) were ≥ 10-cm (diameter at breast height) in the aforementioned ecosystems. We assessed tree density, basal area, species richness, and AGB. In the tree inventory, we measured 2,132 trees (Lower Montane Forest 687, Piedmont Forest 773, and Lowland Forest 672). AGB (Mg ha–1) increases with decreasing elevations: 310.26 ± 81.59 (SD) for the Evergreen Lower Montane Forest, 347.73 ± 90.38 (SD) for the EPF, and 377.39 ± 42.73 (SD) for the ELF. Otoba glycycarpa and Alchornea latifolia were the species with the highest biomass importance value (BIV) in the Evergreen Lower Montane Forest (1,421–1,826 m.a.s.l.), Spirotheca rosea and Pouteria glomerata in the EPF (892–1,195 m.a.s.l.), and Otoba glycycarpa and Iriartea deltoidea in ELF (373–394 m.a.s.l.). Biomass contribution along the altitudinal gradient in the evergreen Andean–Amazonian forests is concentrated in few species. This has implications in forest management and reforestation programs where the main focus is on carbon sequestration.

Resumo-Os sistemas de transmissão em blocos, permitem a transmissão de N símbolos de forma simultânea, seja em modulação de portadoraúnica ou multiportadora. A recepçãó otima, no sentido de máxima verossimilhança em canais com multipercursos apresenta um custo computacional elevado de A N , onde Aé a ordem da constelação (A = 2 para BPSK). Para evitar este alto custo computacionalé usual fazer a detecção símbolo a símbolo após a equalização. Neste trabalhoé proposto um receptor com detecção por grupos que apresenta um bom compromisso entre complexidade computacional e desempenho em termos de taxa de erro médio de bit. Palavras-Chave-OFDM, sistemas de portadoraúnica, detecção por grupos, detecção MLAbstract-Block transmission system, allows transmissions of N symbols simultaneously, with single carrier or multi-carrier modulation. Maximum likelihood optimal reception in multipath channels have a high computational cost of A N , where A is the constellation order (A = 2 for BPSK). To avoid this cost is usual to make symbol by symbol detection after equalization. In this work we propose a receiver with group detection having a good trade of between computation complexity and bit error rate performance.

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