Wood Characteristics of Amazon Forest Types

Abstract

The Tambopata region of the southern Peruvian Amazon supports a high diversity of both woody plants and forest types. Woods collected from low riverside vegetation, floodplain forest, clay-soil forest on an upper terrace, sandy-soil forest, and swamp forest provide an opportunity to test for significant differences in quantitative anatomical characters among forest types. Vessel-element length in floodplain-forest trees is significantly greater than in the other forest types. Specific gravity is lower in the two early-successional associations (low riverine forest and mature floodplain forest). Vessel diameter and density do not show significant differences among forest types and may be responding to overall climate controls. These two characters, however, show a pattern of variation within a transect extending back from the river along a gradient of increasing substrate and forest age; in addition, sites characterized by frequent flooding or presence of standing water lack vessels in the wider-diameter classes. The six characters analyzed show distributions that are, with the exception of wood specific gravity, significantly nonnormally distributed, a consideration that may be important in representing characteristics of assemblages of taxa. The degree of variability seen in some of the quantitative characters shows the importance of either basing analysis on adequate sample sizes or identifying robust indicators that can be used with small samples.

Functional and ecological xylem anatomy

“…On a global scale, vessel diameters tend to increase with decreasing latitude, that is, in warmer regions (Baas 1986). Woodcock et al (2000) found very large vessel diameters (>200 µm) and only a few narrow vessels in trees from the Amazon forest where temperatures do not fall below 0°C. However, even in tropical regions there is an upper limit for a useful vessel diameter.…”

Branch xylem density variations across Amazonia

“…There have already been several reports of variations with site/growth conditions of order 10% for plantation tropical tree species (Roque, 2004;Erskine et al, 2005). Similarly, site specific differences have been noted when comparing the same species growing in different forests or site conditions (Gonzalez and Fisher, 1998;Woodcock et al, 2000;Muller-Landau, 2004;Parolin and Ferreira, 2004;Roque, 2004;Nogueira et al, 2005;Nogueira et al, 2007). Lower D w is often associated with early and secondary succession vegetation (Saldarriaga 1989;Woodcock et al, 2000) and higher growth rates (Wiemann and Williamson, 1989;Erskine et al, 2005;Nogueira et al, 2005;King et al, 2005King et al, , 2006.…”

Tendências ecológicas na anatomia da madeira de espécies da comunidade arbórea da Reserva Biológica de Poço das Antas, Rio de Janeiro, Brasil

“…Tais características são consideradas importantes para o desempenho das funções do xilema em condições ambientais diversas e expressam as tendências ecológicas em gradientes latitudinais e altitudinais em diferentes macro e mesoclimas (p. ex. Baas et al 1983;Dickison 1989;Woodcock et al 2000). Wheeler & Baas (1991) utilizando o modelo proposto por Dickison (1989) e a literatura disponível, relacionaram as tendências ecológicas gerais para hábitats xéricos, montanos e tropicais.…”