Modeling the circulation of carbon in the world's terrestrial ecosystems

Emanuel, William R.; Killough, G.G.; Olson, Jerry S.

doi:10.2172/5927764

Cited by 15 publications

(47 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similarly, forcing the model of Emanuel et al . () with a time depending signal also confirms that incorrectly using the autonomous case formulas for the nonautonomous case results in large discrepancies between the two estimates of transit times (Fig. ).…”

Section: Carbon Cycle Models As Dynamical Systemssupporting

confidence: 65%

See 1 more Smart Citation

The muddle of ages, turnover, transit, and residence times in the carbon cycle

Sierra

Müller

Metzler

et al. 2016

Global Change Biology

134

150

View full text Add to dashboard Cite

Comparisons among ecosystem models or ecosystem dynamics along environmental gradients commonly rely on metrics that integrate different processes into a useful diagnostic. Terms such as age, turnover, residence, and transit times are often used for this purpose; however, these terms are variably defined in the literature and in many cases, calculations ignore assumptions implicit in their formulas. The aim of this opinion piece was i) to make evident these discrepancies and the incorrect use of formulas, ii) highlight recent results that simplify calculations and may help to avoid confusion, and iii) propose the adoption of simple and less ambiguous terms.

show abstract

Section: Carbon Cycle Models As Dynamical Systemssupporting

confidence: 65%

“…As an example, consider the five‐pool carbon cycle model of Emanuel et al . (). The model is expressed in matrix and vector form as

\frac{d bold-italicx}{d t} = \dot{x} = bold-italicI + A \cdot bold-italicx,

where x is a vector of carbon pools, I is a vector of photosynthetic inputs, and A is a matrix of cycling and transfer rates.…”

Section: Carbon Cycle Models As Dynamical Systemsmentioning

confidence: 97%

The muddle of ages, turnover, transit, and residence times in the carbon cycle

Sierra

Müller

Metzler

et al. 2016

Global Change Biology

134

150

View full text Add to dashboard Cite

show abstract

“…However, since the model biosphere does not predict any CO 2 concentrations in leaves, the respective proportions of F L and GPP to NPP were estimated by the following procedures. where φ is the proportion of CO 2 released by plant respiration relative to GPP. In a reflexive way, we obtain, In this study, the values of φ were set to be 0.8, 0.6 and 0.4 for low, middle and high latitudes (Box, 1978; Emanuel et al, 1981; Jarvis and Leverenz, 1983; Medina and Klinge, 1983). The ratio of F L / F IN is thought to be the same as that of β= C c / C a where C c and C a are CO 2 concentrations in chloroplast and ambient air, respectively.…”

Section: Model Descriptionmentioning

confidence: 99%

A multi-box model study of the role of the biospheric metabolism in the recent decline of delta18O in atmospheric CO2

Ishizawa¹,

Nakazawa²,

Higuchi³

2002

Tellus B

View full text Add to dashboard Cite

From around 1993 to 1997, the NOAA‐CU δ18O measurements at Pt. Barrow, Mauna Loa, Cape Kumukahi, Cape Grim and the South Pole show a decrease in atmospheric CO2δ18O of about 0.5‰. Recently, Gillon and Yakir (2001) have attributed this decrease to a conversion of C3 forests to C4 grasslands through anthropogenic land‐use change. However, their explanation can account for only about 0.02‰ yr−1 decrease rate. In this paper we offer a viable alternative explanation. We have used a multi‐box model of the global carbon cycle and its δ18O to show that an increase in biospheric respiration (CO2 flux from plant with lower‐than‐atmosphere δ18O), combined with a decrease in the amount of CO2 (with higher‐than‐atmosphere δ18O) diffusing back from plant leaves before being assimilated as part of the gross primary production (GPP), could produce the observed decline in the atmospheric CO2δ18O. This decrease in the CO2 back diffusion out of leaves could be interpreted as an overall increase in both biospheric activities of photosynthesis and respiration. Change in the metabolic activities of the biosphere as a possible cause for the observed decrease in δ18O is a reasonable hypothesis, since isotopic fractionations that occur during CO2 exchange processes (photosynthesis and respiration) between the atmosphere and the biosphere contribute significantly to the observed variations in atmospheric CO2δ18O, while contribution from the net air‐sea CO2 exchange is negligible.

show abstract

“…The matrix equation has long been used to examine carbon balance in and transfers among pools (Bolin & Eriksson, ; Emanuel et al ., ) and can be argued to represent internal processes that drive carbon cycle toward equilibrium for all types of terrestrial ecosystems on the Earth (Bolker et al ., ; Luo & Weng, ). It has been recently used to derive a semi‐analytic solution to accelerate the computationally expensive spin up of the land models (Xia et al ., ) and to establish a traceability framework to facilitate model intercomparisons, benchmark analyses, and data assimilation (Xia et al ., ).…”

Section: Mathematical Analysis Of Predictabilitymentioning

confidence: 99%

Predictability of the terrestrial carbon cycle

Luo

Keenan

Smith

2014

Global Change Biology

207

178

View full text Add to dashboard Cite

Terrestrial ecosystems sequester roughly 30% of anthropogenic carbon emission. However this estimate has not been directly deduced from studies of terrestrial ecosystems themselves, but inferred from atmospheric and oceanic data. This raises a question: to what extent is the terrestrial carbon cycle intrinsically predictable? In this paper, we investigated fundamental properties of the terrestrial carbon cycle, examined its intrinsic predictability, and proposed a suite of future research directions to improve empirical understanding and model predictive ability. Specifically, we isolated endogenous internal processes of the terrestrial carbon cycle from exogenous forcing variables. The internal processes share five fundamental properties (i.e., compartmentalization, carbon input through photosynthesis, partitioning among pools, donor pool-dominant transfers, and the first-order decay) among all types of ecosystems on the Earth. The five properties together result in an emergent constraint on predictability of various carbon cycle components in response to five classes of exogenous forcing. Future observational and experimental research should be focused on those less predictive components while modeling research needs to improve model predictive ability for those highly predictive components. We argue that an understanding of predictability should provide guidance on future observational, experimental and modeling research.

show abstract

Modeling the circulation of carbon in the world's terrestrial ecosystems

Cited by 15 publications

References 0 publications

The muddle of ages, turnover, transit, and residence times in the carbon cycle

The muddle of ages, turnover, transit, and residence times in the carbon cycle

A multi-box model study of the role of the biospheric metabolism in the recent decline of delta18O in atmospheric CO2

Predictability of the terrestrial carbon cycle

Contact Info

Product

Resources

About