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Biased-corrected richness estimates for the Amazonian tree flora
ter Steege, H.; Prado, Paulo I.; Lima, Renato A.Fde; Pos, Edwin T.; Coelho, Luiz Souza de; Lima Filho, Diógenes de Andrade; Salomão, Rafael PaivaAmazonian forests are extraordinarily diverse, but the estimated species richness is very much debated. Here, we apply an ensemble of parametric estimators and a novel technique that includes conspecific spatial aggregation to an extended database of forest plots with up-to-date taxonomy. We show that the species abundance distribution of Amazonia is best approximated by a logseries with aggregated individuals,...
Evolutionary heritage influences amazon tree ecology
Souza, Fernanda Coelho de; Dexter, Kyle Graham; Phillips, Oliver L.; Brienen, Roel J.W.; Chave, Jérôme; Galbraith, David R.; Lopez-Gonzalez, GabrielaLineages tend to retain ecological characteristics of their ancestors through time. However, for some traits, selection during evolutionary history may have also played a role in determining trait values. To address the relative importance of these processes requires large-scale quantification of traits and evolutionary relationships among species. The Amazonian tree flora comprises a high diversity of angiospe...
Basin-wide variations in Amazon forest structure and function are mediated by b...
Quesada, Carlos Alberto; Phillips, Oliver L.; Schwarz, Michael; Czimczik, Claudia I.; Baker, Timothy R.; Patiño, Sandra; Fyllas, Nikolaos M.Forest structure and dynamics vary across the Amazon Basin in an east-west gradient coincident with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates. Soil samples were collected in a total of 59 different forest plots across the Amazon Basin and analys...
Individual-based modeling of amazon forests suggests that climate controls prod...
Fauset, Sophie; Gloor, Manuel U.; Fyllas, Nikolaos M.; Phillips, Oliver L.; Asner, Gregory P.; Baker, Timothy R.; Patrick Bentley, LisaClimate, species composition, and soils are thought to control carbon cycling and forest structure in Amazonian forests. Here, we add a demographics scheme (tree recruitment, growth, and mortality) to a recently developed non-demographic model—the Trait-based Forest Simulator (TFS)—to explore the roles of climate and plant traits in controlling forest productivity and structure. We compared two sites with diffe...
Drought-mortality relationships for tropical forests
Phillips, Oliver L.; Van Der Heijden, Geertje M.F.; Lewis, Simon L.; Lopez-Gonzalez, Gabriela; Aragao, L. E.O.C.; Lloyd, Jon; Malhi, Yadvinder SinghThe rich ecology of tropical forests is intimately tied to their moisture status. Multi-site syntheses can provide a macro-scale view of these linkages and their susceptibility to changing climates. Here, we report pan-tropical and regional-scale analyses of tree vulnerability to drought. We assembled available data on tropical forest tree stem mortality before, during, and after recent drought events, from 119...
Tree height integrated into pantropical forest biomass estimates
Feldpausch, Ted R.; Lloyd, Jon; Lewis, Simon L.; Brienen, Roel J.W.; Gloor, Manuel E.; Monteagudo-Mendoza, Abel; Lopez-Gonzalez, GabrielaAboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer the following questions: ; 1. What is the best H-model form and geographic unit to include in biomass models to mi...
Estimating the global conservation status of more than 15,000 Amazonian tree sp...
Steege, Hans Ter; Pitman, Nigel C.A.; Killeen, Timothy J.; Laurance, William F.; Peres, Carlos A.; Guevara, Juan Ernesto; Salomão, Rafael PaivaEstimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red ...
Species Distribution Modelling: Contrasting presence-only models with plot abun...
Gomes, Vitor H.F.; IJff, Stéphanie D.; Raes, Niels; Amaral, Iêda Leão do; Salomão, Rafael Paiva; Coelho, Luiz Souza deSpecies distribution models (SDMs) are widely used in ecology and conservation. Presence-only SDMs such as MaxEnt frequently use natural history collections (NHCs) as occurrence data, given their huge numbers and accessibility. NHCs are often spatially biased which may generate inaccuracies in SDMs. Here, we test how the distribution of NHCs and MaxEnt predictions relates to a spatial abundance model, based on ...
Rarity of monodominance in hyperdiverse Amazonian forests
ter Steege, H.; Henkel, Terry W.; Helal, Nora; Marimon, Beatriz Schwantes; Marimon Júnior, Ben Hur; Huth, Andreas; Groeneveld, Jürgen J.Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such “monodominant” forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric ...
Variation in stem mortality rates determines patterns of above-ground biomass i...
Johnson, Michelle O.; Galbraith, David R.; Gloor, Manuel E.; Deurwaerder, Hannes de; Guimberteau, Matthieu; Rammig, Anja; Thonicke, KirstenUnderstanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we...