Demographic and life-history correlates for Amazonian trees

Abstract

Questions: Which demographic and life‐history differences are found among 95 sympatric tree species? Are there correlations among demographic parameters within this assemblage? Location: Central Amazonian rain forest. Methods: Using long‐term data from 24 1–ha permanent plots, eight characteristics were estimated for each species: wood density, annual mortality rate, annual recruitment rate, mean stem diameter, maximum stem diameter, mean stem‐growth rate, maximum stem‐growth rate, population density. Results: An ordination analysis revealed that tree characteristics varied along two major axes of variation, the major gradient expressing light requirements and successional status, and the second gradient related to tree size. Along these gradients, four relatively discrete tree guilds could be distinguished: fast‐growing pioneer species, shade‐tolerant sub‐canopy species, canopy trees, and emergent species. Pioneers were uncommon and most trees were canopy or emergent species, which frequently had low mortality and recruitment. Wood density was negatively associated with tree mortality, recruitment, and growth rates when all species were considered. Growth rates varied markedly among and within species, with pioneers exhibiting far faster and less variable growth rates than did the other species. Slow growth in subcanopy species relative to canopy and emergent trees was not a simple consequence of mean tree size, but apparently resulted from physiological constraints imposed by low‐light and other conditions in the forest understorey. Conclusions: Trees of Amazonian rain forests could be classified with some success into four relatively distinctive guilds. However, several demographic and life‐history traits, such as those that distinguish early and late successional species, probably vary along a continuum, rather than being naturally grouped into relatively discrete categories.

Patterns of tree growth in relation to environmental variability in the tropical dry deciduous forest at Mudumalai, southern India

“…However, a few small groups of species may represent strategies similar to those described in rainforests. For example, juveniles of the canopy species T. crenulata and A. latifolia may represent a strategy similar to that of slowgrowing shade-tolerant species in wetter forests (Lieberman etal 1985;Nascimento et al 2005), although the same strategy was not evident in the adults. At the other growth extreme, C. fistula, K. calycina and H. isora adults suggested an "understory species" growth strategy of high relative growth rates.…”

“…Although grouping species into separate guilds sometimes appears arbitrary (Turner 2001), growth-related continuums from the 'pioneer' strategy characterized by high growth and shade-intolerance, to the "mature canopy" or "understory shade-tolerant" strategy characterized by progressively lower growth rates (Lieberman et al 1985;Welden et al 1991;Condit et al 1996;Clark and Clark 1999;Nascimento et al 2005) have been described. These classifications in tropical moist forests generally have been associated with species' partitioning of the light gradient, either horizontally or vertically (Baker et al 2003b).…”

Influence of functional traits on the demographic rates of 47 arboreal species in a tropical forest in northeastern Brazil

“…It was expected that growth would be affected by changes in SLA as this traits directly influences biomass investments in light interception (Kitajima, 1994). In the same way, it was expected that BWD would significantly negatively influence BAG, as was reported by Nascimento et al (2005) in the Amazon region, or that SS and Hmax would contribute heavily to the model (negatively and positively, respectively), as was suggested by Cornelissen et al (2003) and Diaz et al (2004). It is possible to conclude that the results of the multiple regression analyses did not corroborate the theoretical expectations.…”

Regeneration Traits of Four Dominant Species in a Cool-Temperate Conifer-Hardwood Mixed Forest, Northern Japan

“…Thus, Abies sachalinensis can grow and survive under closed-canopy conditions, but sporadic major disturbances accelerate the recruitment in conifer-hardwood forests like this study site. Acer mono [34] [35]. On the contrary, the number of recruits was less in Tilia japonica than Acer mono (3 versus 24 recruits during 1994 to 2004).…”