Growth strategies of the arborescent palmIriartea deltoideain a western Amazonian forest

Abstract

Stem development in palms usually involves the building up of a trunk of maximum diameter before emerging from the ground. Unlike most arboreal palms, the oligarchic palm Iriartea deltoidea has been shown to grow in both height and diameter. Nevertheless, the drivers of this unusual growth strategy are poorly known. We examined the growth rates of 554 stems found in 10 ha of the 50-ha Yasun ı Forest Dynamics Plot. We explored whether palm growth responds to: (1) the size of individual palms; (2) light availability; or (3) the number of conspecifics and heterospecifics in the surrounding neighbourhood. Individual growth rates were positively related to palm height in the three life stages considered here (seedlings, saplings and adults). The mean annual diameter increment was higher (3.2 AE 4.6 mm year À1 ) in individuals with a diameter at breast height (DBH) of < 20 cm, and mean vertical elongation of juveniles (0.2 AE 0.2 m year À1 ) was initiated early in development until they became pre-adults. Growth in I. deltoidea was minimally affected by the presence of neighbours (basal area of conspecifics and heterospecifics), suggesting that this species can succeed at high densities with low levels of interspecific competition. Under the forest canopy, growth rates were not significantly different in palms with greater light exposure. Our findings contribute to an understanding of the factors that make I. deltoidea a dominant species in western Amazonia.

Influence of Reproduction and Basal Area on the Increment of Euterpe edulis

“…These results are also corroborated by Granville (1991), who classified erect and single-stemmed palms as adapted to canopy openings and frequent in disturbed areas, which has been confirmed for the E. precatoria congener (Avalos, 2016). The availability of light has been reported as a limiting factor to the neotropical palms' growth and reproduction (Ninazunta et al, 2016;Svenning, 2002), and its influence has been observed on the survival and development of E. edulis seedlings (Guimarães et al, 2018;Ribeiro et al al., 2011).…”

“…The reduced vegetative growth (height, diameter, and leaf emission) during the reproductive period and the costs of reproduction have been shown in dioecious palms, where female plants tend to show less development than male plants (Cepeda-Cornejo & Dirzo, 2010;Edwards et al, 2015). In the monoic palms -such as E. edulis -the cost of reproductive activity has been poorly reported, although it has already been recorded for other genera (Ninazunta et al, 2016;Souza et al, 2003) and trees (Thomas, 2011).…”

An accurate pattern classification for empty fruit bunch based on the age profile of oil palm tree using neural network

“…Detail for each class is shown in Table 1. The age is being identified by measuring the length of EFB spikelet [6,7]. This is done manually by MPOB employees.…”

Palms - emblems of tropical forests

“…The stilt‐root palm Iriartea deltoidea, which is one of the most abundant and common palms in the Amazon basin, differs from many other palms in having combined longitudinal growth and diameter increment. It grows well in shaded conditions, but it also benefits from the higher levels of light when it approaches the canopy and its final height of close to 30 m, which it may reach after 120 years (Ninazunta et al ., ). Oenocarpus bataua Mart.…”