9 documents found, page 1 of 1
Living on borrowed time – Amazonian trees use decade-old storage carbon to surv...
Muhr, Jan; Trumbore, Susan Elizabeth; Higuchi, Niro; Kunert, NorbertNonstructural carbon (NSC) reserves act as buffers to sustain tree activity during periods when carbon (C) assimilation does not meet C demand, but little is known about their age and accessibility; we designed a controlled girdling experiment in the Amazon to study tree survival on NSC reserves. We used bomb-radiocarbon (14C) to monitor the time elapsed between C fixation and release (‘age’ of substrates). We ...
Slow growth rates of Amazonian trees: Consequences for carbon cycling
Vieira, Simone Aparecida; Trumbore, Susan Elizabeth; Camargo, Plínio Barbosa de; Selhorst, Diogo; Chambers, Jeffrey Quintin; Higuchi, NiroQuantifying age structure and tree growth rate of Amazonian forests is essential for understanding their role in the carbon cycle. Here, we use radiocarbon dating and direct measurement of diameter increment to document unexpectedly slow growth rates for trees from three locations spanning the Brazilian Amazon basin. Central Amazon trees, averaging only ≈1 mm/year diameter increment, grow half as fast as those ...
The Amazon Tall Tower Observatory (ATTO): Overview of pilot measurements on eco...
Andreae, Meinrat O.; Acevedo, Otávio C.; Araüjo, Alessandro Carioca de; Artaxo, Paulo; Barbosa, Cybelli G.G.; Barbosa, H. M. J.; Brito, Joel F.The Amazon Basin plays key roles in the carbon and water cycles, climate change, atmospheric chemistry, and biodiversity. It has already been changed significantly by human activities, and more pervasive change is expected to occur in the coming decades. It is therefore essential to establish long-term measurement sites that provide a baseline record of present-day climatic, biogeochemical, and atmospheric cond...
Windthrows control biomass patterns and functional composition of Amazon forests
Marra, Daniel Magnabosco; Trumbore, Susan Elizabeth; Higuchi, Niro; Ribeiro, Gabriel Henrique Pires de Mello; Negrón-Juárez, Robinson I.Amazon forests account for ~25% of global land biomass and tropical tree species. In these forests, windthrows (i.e., snapped and uprooted trees) are a major natural disturbance, but the rates and mechanisms of recovery are not known. To provide a predictive framework for understanding the effects of windthrows on forest structure and functional composition (DBH ≥10 cm), we quantified biomass recovery as a func...
The steady-state mosaic of disturbance and succession across an old-growth cent...
Chambers, Jeffrey Quintin; Negrón-Juárez, Robinson I.; Marra, Daniel Magnabosco; Di Vittorio, Alan V.; Tews, Jörg; Roberts, Dar A.Old-growth forest ecosystems comprise a mosaic of patches in different successional stages, with the fraction of the landscape in any particular state relatively constant over large temporal and spatial scales. The size distribution and return frequency of disturbance events, and subsequent recovery processes, determine to a large extent the spatial scale over which this old-growth steady state develops. Here, ...
Large-scale wind disturbances promote tree diversity in a Central Amazon forest
Marra, Daniel Magnabosco; Chambers, Jeffrey Quintin; Higuchi, Niro; Trumbore, Susan Elizabeth; Ribeiro, Gabriel Henrique Pires de MelloCanopy gaps created by wind-throw events, or blowdowns, create a complex mosaic of forest patches varying in disturbance intensity and recovery in the Central Amazon. Using field and remote sensing data, we investigated the short-term (four-year) effects of large (>2000 m2) blowdown gaps created during a single storm event in January 2005 near Manaus, Brazil, to study (i) how forest structure and composition...
Tropical Trees as Time Capsules of Anthropogenic Activity
Caetano Andrade, Victor L.; Clement, Charles Roland; Weigel, Detlef; Trumbore, Susan Elizabeth; Boivin, Nicole L.; Schöngart, Jochen; Roberts, PatrickAfter the ice caps, tropical forests are globally the most threatened terrestrial environments. Modern trees are not just witnesses to growing contemporary threats but also legacies of past human activity. Here, we review the use of dendrochronology, radiocarbon analysis, stable isotope analysis, and DNA analysis to examine ancient tree management. These methods exploit the fact that living trees record informa...
Windthrows increase soil carbon stocks in a central Amazon forest
dos Santos, Leandro T.; Marra, Daniel Magnabosco; Trumbore, Susan Elizabeth; Camargo, Plínio Barbosa de; Negrón-Juárez, Robinson I.Windthrows change forest structure and species composition in central Amazon forests. However, the effects of widespread tree mortality associated with wind disturbances on soil properties have not yet been described in this vast region. We investigated short-term effects (7 years after disturbance) of widespread tree mortality caused by a squall line event from mid-January of 2005 on soil carbon stocks and con...
Estimation of biomass and carbon stocks: The case of the Atlantic Forest
Vieira, Simone Aparecida; Alves, Luciana Ferreira; Aidar, Marcos Pereira Marinho; Araújo, Luciana Spinelli; Baker, Timothy R.The main objective of this paper is to present and discuss the best methods to estimate live above ground biomass in the Atlantic Forest. The methods presented and conclusions are the products of a workshop entitled "Estimation of Biomass and Carbon Stocks: the Case of Atlantic Rain Forest". Aboveground biomass (AGB) in tropical forests is mainly contained in trees. Tree biomass is a function of wood volume, ob...