20 documents found, page 1 of 2
Integration of C1 and C2 metabolism in trees
Jardine, Kolby J.; Souza, Vinícius Fernandes de; Oikawa, Patricia Yoshino; Higuchi, Niro; Bill, Markus; Porras, Rachel C.; Niinemets, ÜloC1 metabolism in plants is known to be involved in photorespiration, nitrogen and amino acid metabolism, as well as methylation and biosynthesis of metabolites and biopolymers. Although the flux of carbon through the C1 pathway is thought to be large, its intermediates are difficult to measure and relatively little is known about this potentially ubiquitous pathway. In this study, we evaluated the C1 pathway an...
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 ...
Dry and hot: The hydraulic consequences of a climate change–type drought for Am...
Fontes, Clarissa Gouveia; Dawson, Todd E.; Jardine, Kolby J.; McDowell, Nathan G.; Gimenez, Bruno Oliva; Anderegg, Leander D.L.How plants respond physiologically to leaf warming and low water availability may determine how they will perform under future climate change. In 2015 – 2016, an unprecedented drought occurred across Amazonia with record-breaking high temperatures and low soil moisture, offering a unique opportunity to evaluate the performances of Amazonian trees to a severe climatic event. We quantified the responses of leaf w...
The Amazon forest and the rain
Higuchi, Niro; Santos, Joaquim dos; Lima, Adriano José Nogueira; Higuchi, Francisco Gasparetto; Chambers, Jeffrey QuintinThe article "The Amazon Forest and the rain" shows that the average annual rainfall is the main weather variable for the forestry sector in the Amazon. The average annual temperature has little variation in the Amazon; only 8%. The average annual rainfall has a greater variation, almost 100%. The growth and increment of Amazonian trees show significant correlations with precipitation. The interannual precipitat...
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, ...
Highly reactive light-dependent monoterpenes in the Amazon
Jardine, Angela B.; Jardine, Kolby J.; Fuentes, José D.; Martin, Scot T.; Martins, Giordane Augusto; Durgante, Flávia MachadoDespite orders of magnitude difference in atmospheric reactivity and great diversity in biological functioning, little is known about monoterpene speciation in tropical forests. Here we report vertically resolved ambient air mixing ratios for 12 monoterpenes in a central Amazon rainforest including observations of the highly reactive cis-β-ocimene (160 ppt), trans-β-ocimene (79 ppt), and terpinolene (32 ppt) wh...
Methanol and isoprene emissions from the fast growing tropical pioneer species ...
Jardine, Kolby J.; Jardine, Angela B.; Souza, Vinicius F.; Carneiro, Vilany Matilla Colares; Ceron, João Vitor Barbosa; Gimenez, Bruno OlivaIsoprene (Is) emissions by plants represent a loss of carbon and energy resources leading to the initial hypothesis that fast growing pioneer species in secondary tropical forests allocate carbon primarily to growth at the expense of isoprenoid defenses. In this study, we quantified leaf isoprene and methanol emissions from the abundant pantropical pioneer tree species Vismia guianensis and ambient isoprene con...
Green leaf volatile emissions during high temperature and drought stress in a c...
Jardine, Kolby J.; Chambers, Jeffrey Quintin; Holm, Jennifer A.; Jardine, Angela B.; Fontes, Clarissa Gouveia; Zorzanelli, Raquel F.Prolonged drought stress combined with high leaf temperatures can induce programmed leaf senescence involving lipid peroxidation, and the loss of net carbon assimilation during early stages of tree mortality. Periodic droughts are known to induce widespread tree mortality in the Amazon rainforest, but little is known about the role of lipid peroxidation during drought-induced leaf senescence. In this study, we ...
Dynamic balancing of isoprene carbon sources reflects photosynthetic and photor...
Jardine, Kolby J.; Chambers, Jeffrey Quintin; Alves, Eliane Gomes; Teixeira, Andrea; Garcia, Sabrina; Holm, Jennifer A.; Higuchi, NiroThe volatile gas isoprene is emitted in teragrams per annum quantities from the terrestrial biosphere and exerts a large effect on atmospheric chemistry. Isoprene is made primarily from recently fixed photosynthate; however, alternate carbon sources play an important role, particularly when photosynthate is limiting. We examined the relative contribution of these alternate carbon sources under changes in light ...