Modelling the discrimination of 13CO2 above and within a temperate broad-leaved forest canopy on hourly to seasonal time scales

  title={Modelling the discrimination of 13CO2 above and within a temperate broad-leaved forest canopy on hourly to seasonal time scales},
  author={Dennis D. Baldocchi and David R. Bowling},
  journal={Plant Cell and Environment},
Fluxes and concentrations of carbon dioxide and 13CO2 provide information about ecosystem physiological processes and their response to environmental variation. The biophysical model, CANOAK, was adapted to compute concentration profiles and fluxes of 13CO2 within and above a temperate deciduous forest (Walker Branch Watershed, Tennessee, USA). Modifications to the model are described and the ability of the new model (CANISOTOPE) to simulate concentration profiles of 13CO2, its flux density… 

Coupled carbon-water exchange of the Amazon rain forest, I. Model description, parameterization and sensitivity analysis

Abstract. Detailed one-dimensional multilayer biosphere-atmosphere models, also referred to as CANVEG models, are used for more than a decade to describe coupled water-carbon exchange between the

Modeling dynamics of stable carbon isotopic exchange between a boreal forest ecosystem and the atmosphere

Stable isotopes of CO2 contain unique information on the biological and physical processes that exchange CO2 between terrestrial ecosystems and the atmosphere. In this study, we developed an

Biogeosciences Coupled carbon-water exchange of the Amazon rain forest , I . Model description , parameterization and sensitivity analysis

Detailed one-dimensional multilayer biosphereatmosphere models, also referred to as CANVEG models, are used for more than a decade to describe coupled watercarbon exchange between the terrestrial

Short-term variations in δ13C of ecosystem respiration reveals link between assimilation and respiration in a deciduous forest

It is shown that during daytime low vertical mixing inside the canopy can lead to decoupling of the air in the lower and upper canopy layer resulting in large spatial variation of δ13C in CO2 of canopy air, highlighting the importance of short-term physiological processes within ecosystems for the isotopic composition of CO2 in the atmosphere, not reflected by bulk plant and soil organic samples.

Spatial and temporal scaling of intercellular CO2 concentration in a temperate rain forest dominated by Dacrydium cupressinum in New Zealand.

Seven methods, including measurements of photosynthesis and stomatal conductance, carbon isotope discrimination, ecosystem CO2 and water vapour exchange using eddy covariance, were employed to derive estimates of intercellular CO2 concentration (Ci) across a range of spatial and temporal scales in a low productivity rain forest ecosystem dominated by the conifer Dacrydium cupressinum Lamb.

Partitioning the net CO2 flux of a deciduous forest into respiration and assimilation using stable carbon isotopes

Partitioning net ecosystem CO2 fluxes measured by the eddy covariance technique into their components assimilation and respiration is crucial for predicting future responses and feedbacks of

Modelling environmental controls on ecosystem photosynthesis and the carbon isotope composition of ecosystem-respired CO2 in a coastal Douglas-fir forest.

The results indicated that deltaR is a good proxy for canopy-level C(c)/C(a) and 13C discrimination during photosynthetic gas exchange, and therefore has several applications in ecosystem physiology.



Spatial distribution of leaf water‐use efficiency and carbon isotope discrimination within an isolated tree crown

The spatial variations in the stable carbon isotope composition ( δ 13 C) of air and leaves (total matter and soluble sugars) were quantified within the crown of a well-watered, 20year-old walnut

Measuring and modelling carbon dioxide and water vapour exchange over a temperate broad‐leaved forest during the 1995 summer drought

Forests in the south-eastern United States experienced a prolonged dry spell and above-normal temperatures during the 1995 growing season. During this episode, nearly continuous, eddy covariance

13C discrimination during CO2 assimilation by the terrestrial biosphere

From this model, it is estimated that, on a global basis, 21% of GPP is by C4 plants and for the terrestrial biosphere as a whole, an average isotope discrimination during photosynthesis of 14.8‰ is calculated, which is slightly less than would be calculated from C4 plant dry matter carbon isotopic composition.

13C content of ecosystem respiration is linked to precipitation and vapor pressure deficit

There was a strong link between δ13CR and the vapor saturation deficit of air 5–10 days earlier, both across and within sites, and this relationship is consistent with stomatal regulation of gas exchange and associated changes in photosynthetic carbon isotope discrimination.

Dynamics of isotopic exchange of carbon dioxide in a Tennessee deciduous forest

The combination of isotopic measurements and micrometeorological flux measurements is a powerful new approach that will likely lead to new insight into the dynamics of CO2 exchange between

Carbon 13 exchanges between the atmosphere and biosphere

We present a detailed investigation of the gross 12C and 13C exchanges between the atmosphere and biosphere and their influence on the δ13C variations in the atmosphere. The photosynthetic

Spatial and seasonal variability of photosynthetic parameters and their relationship to leaf nitrogen in a deciduous forest.

There was extensive variability in photosynthetic capacity as a result of vertical canopy position, species type, leaf age and drought, and temporal changes in V(cmax) were often poorly correlated with leaf nitrogen, especially in spring and summer and during drought.

Scaling carbon dioxide and water vapour exchange from leaf to canopy in a deciduous forest. II. Model testing and application

The scaling of CO 2 and water vapour transfer from leaf to canopy dimensions was achieved by integrating mechanistic models for physiological (photosynthesis, stomatal conductance and soil/root and

Carbon isotope discrimination during photosynthesis and the isotope ratio of respired CO2 in boreal forest ecosystems

Our objective was to measure the carbon isotope ratio of CO 2 released by respiration (δ r ) within forest canopies at different times during the growing season and to use this information to