Tree species diversity in a seasonally-dry forest: the case of the Pinkaití site, in the Kayapó Indigenous Area, Southeastern limits of the Amazon

Abstract

This study investigates patterns of forest structure and tree species diversity in an anthropogenic palm grove and undisturbed areas at the seasonally-dry Pinkaití research station, in the Kayapó Indigenous Area. This site, managed by the Conservation International do Brasil, is the most southeastern site floristically surveyed in the Amazon until now. The secondary and a nearby undisturbed forest were sampled in a group of 52 floristic plots of 0.0625-ha (25x25-m) where all trees with DBH $ 10 cm were measured and identified. The analyses were complemented with other two floristic plots of 1-ha (10x1000-m). The present study has shown that the Pinkaití, like other seasonally-dry forests, have great heterogeneity in forest structure and composition, associated with biotic characteristics of the most important tree species, natural disturbance and history of land-use. The palm grove, moderately dominated by the arborescent palm Attalea maripa (Aubl.) Mart., presented high tree species diversity and was floristically similar to undisturbed forests at the study site. It is discussed the importance of large arborescent palms for the seasonally-dry Amazon forests regeneration. KEY WORDSAmazon, anthropogenic forest, arborescent palms, floristics, tropical forests. PALAVRAS-CHAVEAmazônia, florística, floresta antropogênica, floresta tropical, palmeiras arborescentes.

Physiographic and floristic gradients across topography in transitional seasonally dry evergreen forests of southeast Pará, Brazil

“…Species diversity recorded at Marajoara (103 ± 2.2 ha -1 >10 cm diameter) was nearly identical to values reported by Baider (2000) and Salm (2004) from slightly wetter forests 185 km west of the study area. While the two sites shared many of the same species, patterns of dominance were quite different.…”

“…Patches of vine forest may coalesce into extensive tangled stands. Baider (2000) and Salm (2004) provide floristic descriptions from sites ca. 200 km west of Marajoara.…”

A model for the importance of large arborescent palms in the dynamics of seasonally-dry amazonian forests

“…The results of these studies show that the large arborescent palm A. maripa are generally rare at undisturbed areas of the Pinkaití (2 palms ha -1 ), but abundant in naturally disturbed (12 palms ha -1 ) (Salm 2005) and dominant at a patch of secondary forests within the study site (53 palms ha -1 ) (Salm 2004a). These findings support the proposed notion of large arborescent palms as light demanding successional species that depend on large events of disturbance to become ecologically dominant -a view that, although disputed (Svenning 1999), is largely accepted (Kahn 1986, de Granville 1992, Kahn & de Granville 1992, and essential to our model.…”

“…Additionally, the studied patch of secondary forest seems to be in an advanced stage of regeneration, having senescent palm populations (Salm 2004b) and floristically resembling the pristine areas of the Pinkaití Research Station (Salm 2004a). The successional nature of the palm grove is in fact evident on the structure of this forest patch.…”

“…In a 16 ha grid system, established at the limit between these areas, adult palms were exhaustively searched and 569 A. maripa palms were mapped. Within this grid, and at a surrounding undisturbed forest, studies were conducted on tree species diversity (Salm 2004a), palm growth (Salm 2004b) and the importance of forest disturbance for the recruitment of large arborescent palms (Salm 2005).…”