Falling palm fronds structure Amazonian rainforest sapling communities

Abstract

The senescence and loss of photosynthetic and support structures is a nearly universal aspect of tree life history, and can be a major source of disturbance in forest understoreys, but the ability of falling canopy debris in determining the stature and composition of understorey communities seems not to have been documented. In this study, we show that senescent fronds of the palm Iriartea deltoidea cause substantial disturbance in tropical forest sapling communities. This disturbance influences the species composition of the canopy and subcanopy by acting as an ecological filter, favouring sapling species with characteristics conducive to recovery after physical damage. The scale of this dominance suggests that falling I. deltoidea debris may be influencing sapling community structure and species composition in Amazonian rainforests over very large spatial scales.

The exotic palm Roystonea oleracea (Jacq.) O. F. Cook (Arecaceae) on an island within the Atlantic Forest Biome: naturalization and influence on seedling recruitment

“…Because the abundance, richness and diversity of seedling species were significantly lower beneath palm crowns, the spread of this palm could imply in a reduction of plant diversity in the areas it comes to dominate. The lower seedling abundance and diversity beneath palm crowns could have resulted from the fact that Roystonea oleracea individuals drop large leaves and reproductive parts (Peters et al 2004). The accumulation of leaves on the ground can inhibit the establishment of some species by altering light intensity and humidity (Farris-Lopez et al 2004;Aguiar & Tabarelli 2010).…”

“…This palm has been reported to be invasive, especially in the swamps of Guiana (Henderson et al 1995), in Panama (Svenning 2002), and in the Atlantic Forest of Brazil (Nascimento et al 2013). Arboreal palms can have negative effects on the seedling recruitment of other plant species due to the fact that their vegetative structures drop to the ground (Peters et al 2004). Palm leaves and reproductive structures typically decompose slowly, forming a deep litter layer.…”

Comparison of seedling recruitment under arborescent palms in two Neotropical forests

“…Their umbrella-like crown architecture may prevent seed arrival or cast particularly deep shade (Denslow et al 1991). Their large leaves can cause heavy damage to seedlings when they fall (Clark and Clark 1989;Clark and Clark 1991;Peters et al 2004). Their thick leaves may be slow to decay and accumulate as deep leaf litter that may hinder seed germination, seedling emergence, and root penetration.…”

Local extinction of an important seed disperser does not modify the spatial distribution of the endemic palm Astrocaryum aculeatissimum (Schott) Burret (Arecaceae)

“…The physical damage caused by the falling of vegetative structures is one factor that may explain the repulsion found among seedlings and infants very close to adults (<2 m); it has been considered a major cause of seedling mortality in the vicinity of arboreal palms (e.g., Peters et al 2004). This was demonstrated by Silva and Tabarelli (2001) in a study performed on the palm Bactris acanthocarpa in a remnant of Atlantic Forest in northeast Brazil.…”