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Available from: Marcelo Trindade Nascimento, Oct 06, 2015
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    ABSTRACT: Tropical rain forest dominated by Peltogyne gracilipes (Fabaceae) occurs on Maracá Island, Roraima, Brazil, on a range of soil types. Three forest types were stratified for sampling, according to the occurrence of Peltogyne trees: (1) Peltogyne-rich forest (PRF), (2) Peltogyne-poor forest (PPF), and (3) forest without Peltogyne (FWP). Biomass increment and change in total stand biomass were calculated from mortality, recruitment, and growth data for trees in the three forest types. Data were derived from permanent plots established in 1991, where all trees (≥10cm diameter at breast height), including palms and vines (lianas), were tagged and measured in three plots, each of 0.25ha, in each of the three forest types. Field surveys were carried out in October 1991 and March 2003. Over a period of 11years, the above-ground biomass in all forest types declined slightly (<5%), associated with the death of large trees, especially in the monodominant forests (PRF and PPF). Within the study period, the forest on Maracá experienced two heavy droughts, related to El Niño events (1997–1998 and 2002–2003) and most mortality and loss of biomass probably occurred during these events. Therefore, as the Maracá forests appear not be increasing in above-ground biomass overall, they may not be acting as a sink for atmospheric CO2. The trees of the five most abundant species (Ecclinusa, Lecythis, Licania, Peltogyne, and Pradosia) accounted for about 55% of the total biomass in both FWP and PPF and for 74% in PRF. Peltogyne gracilipes had a stable, regenerating population in PRF, and is clearly a persistent dominant in a monodominant forest.
    Plant Ecology 10/2007; 192(2):181-191. DOI:10.1007/s11258-007-9303-z · 1.46 Impact Factor
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    ABSTRACT: Background: Previous work has shown that Amazonian tropical forests have experienced two widespread changes in dynamics over recent decades, increases in both tree stem turnover and above-ground biomass. However, data from an Amazonian monodominant forest dominated by Peltogyne gracilipes have shown that the above-ground biomass of this forest type has declined slightly (<5%) over an 11-year period. Aims: To determine whether the tree communities in three types of forest, with or without Peltogyne gracilipes (Peltogyne-rich forest (PRF), Peltogyne-poor (PPF) and forest without Peltogyne (FWP)) on Maracá Island, Roraima, have experienced a change in structure and floristic composition over a 20-year period. Methods:We have quantified the variation in the occurrence and abundance of tree species, the above-ground biomass (AGB) and change in total stand biomass from mortality, recruitment and growth for trees, palms and large lianas, ≥10 cm diameter at breast height, in three plots of 0.25 ha in each of the three forest types. Results: Floristic composition showed little change, with no shift in the rank abundance amongst the 10 most important tree species, although in FWP there was a reduction in species richness from 51 to 43. Recruitment is shown to offset the losses caused by mortality in PRF and FWP. The annual mean mortality rates were low, at around 1%. In 2011 AGB in the three forest types varied from 434 Mg ha−1 (PPF) to 363 Mg ha−1 (FWP). PRF experienced an AGB decline of 4.1%, associated with the death of large trees, while FWP showed a slight increase in biomass (2.6%). Conclusions: Over the last 20 years Maracá forest stands appear to have been stable in terms of their floristic composition and structure, some showing a persistent monodominance by Peltogyne gracilipes. Keywords: biomass change; forest dynamics; Peltogyne forest; tree growth; turnover rate
    Plant Ecology & Diversity 01/2013; DOI:10.1080/17550874.2013.772673 · 1.77 Impact Factor