6 documents found, page 1 of 1
Age-dependent leaf physiology and consequences for crown-scale carbon uptake du...
Albert, Loren P.; Wu, Jin; Prohaska, Neill; Camargo, Plínio Barbosa de; Huxman, Travis E.; Tribuzy, Edgard Siza; Ivanov, Valeriy Yu; Oliveira, Rafael S.Satellite and tower-based metrics of forest-scale photosynthesis generally increase with dry season progression across central Amazônia, but the underlying mechanisms lack consensus. We conducted demographic surveys of leaf age composition, and measured the age dependence of leaf physiology in broadleaf canopy trees of abundant species at a central eastern Amazon site. Using a novel leaf-to-branch scaling appro...
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 ...
Embolism resistance drives the distribution of Amazonian rainforest tree specie...
Oliveira, Rafael S.; Costa, Flávia Regina Capellotto; van Baalen, Emma Jan A.; Jonge, Arjen de; Bittencourt, Paulo R.L.; Almanza, YaninaSpecies distribution is strongly driven by local and global gradients in water availability but the underlying mechanisms are not clear. Vulnerability to xylem embolism (P 50 ) is a key trait that indicates how species cope with drought and might explain plant distribution patterns across environmental gradients. Here we address its role on species sorting along a hydro-topographical gradient in a central Amazo...
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 ...
Reassimilation of leaf internal CO2 contributes to isoprene emission in the neo...
Garcia, Sabrina; Jardine, Kolby J.; Souza, Vinícius Fernandes de; Souza, Rodrigo Augusto Ferreira de; Duvoisin Júnior, SérgioIsoprene (C5H8) is a hydrocarbon gas emitted by many tree species and has been shown to protect photosynthesis under abiotic stress. Under optimal conditions for photosynthesis, ~70%-90% of carbon used for isoprene biosynthesis is produced fromrecently assimilated atmospheric CO2. While the contribution of alternative carbon sources that increase with leaf temperature and other stresses have been demonstrated, ...