Contrasting controls on tree ring isotope variation for Amazon floodplain and terra firme trees.

ABSTRACT: Isotopes in tropical trees rings can improve our understanding of tree responses to climate. We assessed how climate and growing conditions affect tree-ring oxygen and carbon isotopes (δ18OTR and δ13CTR) in four Amazon trees. We analysed within-ring isotope variation for two terra firme (non-flooded) and two floodplain trees growing at sites with varying seasonality. We find distinct intra-annual patterns of δ18OTR and δ13CTR driven mostly by seasonal variation in weather and source water δ18O. Seasonal variation in isotopes was lowest for the tree growing under the wettest conditions. Tree ring cellulose isotope models based on existing theory reproduced well observed within-ring variation with possible contributions of both stomatal and mesophyll conductance to variation in δ13CTR. Clima

SUBMITTER: Barcante Ladvocat Cintra B 

PROVIDER: S-EPMC6594573 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature