Precipitation thresholds regulate net carbon exchange at the continental scale

Liu, Zhi Hua; Ballantyne, Ashley P.; Poulter, Benjamin; Anderegg, William R. L.; Li, Wei; Bastos, Ana; Ciais, Philippe

doi:10.1038/s41467-018-05948-1

Cited by 44 publications

(45 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar positive association between Rs and intermediate levels of soil moisture is well established (Davidson & Janssens, ), and interannual variability in precipitation and water storage is known to be strong temporal driver of global carbon cycling (Humphrey et al, ; Jung et al, ). However, the relationships between soil moisture, precipitation, and their effects on annual Rs across spatial scales are complex and multifaceted (Liu et al, ) and warrant further investigation for improving our ability to interpret machine learning based global Rs models. This is partially shown by the very different partial dependence plot of MWP (Figure d), which had an increasingly positive effect on predicted annual Rs across the low and intermediate values (0–250 mm).…”

Section: Discussionmentioning

confidence: 99%

Spatial Predictions and Associated Uncertainty of Annual Soil Respiration at the Global Scale

Warner

Bond‐Lamberty

Jian

et al. 2019

Global Biogeochemical Cycles

108

View full text Add to dashboard Cite

Soil respiration (Rs), the soil‐to‐atmosphere CO2 flux produced by microbes and plant roots, is a critical but uncertain component of the global carbon cycle. Our current understanding of the variability and dynamics is limited by the coarse spatial resolution of existing estimates. We predicted annual Rs and associated uncertainty across the world at 1‐km resolution using a quantile regression forest algorithm trained with observations from the global Soil Respiration Database spanning from 1961 to 2011. This model yielded a global annual Rs estimate of 87.9 Pg C/year with an associated global uncertainty of 18.6 (mean absolute error) and 40.4 (root mean square error) Pg C/year. The estimated annual heterotrophic respiration (Rh), derived from empirical relationships with Rs, was 49.7 Pg C/year over the same period. Predicted Rs rates and associated uncertainty varied widely across vegetation types, with the greatest predicted rates of Rs in evergreen broadleaf forests (accounting for 20.9% of global Rs). The greatest prediction uncertainties were in northern latitudes and arid to semiarid ecosystems, suggesting that these areas should be targeted in future measurement campaigns. This study provides predictions of Rs (and associated prediction uncertainty) at unprecedentedly high spatial resolution across the globe that could help constrain local‐to‐global process‐based models. Furthermore, it provides insights into the large variability of Rs and Rh across vegetation classes and identifies regions and vegetation types with poor model performance that should be prioritized for future data collection.

show abstract

Section: Discussionmentioning

confidence: 99%

Spatial Predictions and Associated Uncertainty of Annual Soil Respiration at the Global Scale

Warner

Bond‐Lamberty

Jian

et al. 2019

Global Biogeochemical Cycles

108

View full text Add to dashboard Cite

show abstract

“…MsTMIP models might underestimate the contribution of agricultural activities to the MCU, because most models do not explicitly represent crops and agricultural management (Huang et al, ; Thomas et al, ). In addition, most models underestimate the magnitude of heterotrophic respiration (Liu et al, ). It is difficult to capture the complexity of heterotrophic respiration (e.g., microbial responses; Mäkiranta et al, ), which impacts ecosystem respiration and thus on MCU and CUP.…”

Section: Discussionmentioning

confidence: 99%

Maximum carbon uptake rate dominates the interannual variability of global net ecosystem exchange

Stoy

Poulter

et al. 2019

Global Change Biology

Self Cite

View full text Add to dashboard Cite

Terrestrial ecosystems contribute most of the interannual variability (IAV) in atmospheric carbon dioxide (CO 2 ) concentrations, but processes driving the IAV of net ecosystem CO 2 exchange (NEE) remain elusive. For a predictive understanding of the global C cycle, it is imperative to identify indicators associated with ecological processes that determine the IAV of NEE. Here, we decompose the annual NEE of global terrestrial ecosystems into their phenological and physiological components, namely maximum carbon uptake (MCU) and release (MCR), the carbon uptake period (CUP), and two parameters, α and β, that describe the ratio between actual versus hypothetical maximum C sink and source, respectively. Using long-term observed NEE from 66 eddy covariance sites and global products derived from FLUXNET observations, we found that the IAV of NEE is determined predominately by MCU at the global scale, which explains 48% of the IAV of NEE on average while α, CUP, β, and MCR explain 14%, 25%, 2%, and 8%, respectively. These patterns differ in water-limited ecosystems versus temperature-and radiation-limited ecosystems; 31% of the IAV of NEE is determined by the IAV of CUP in water-limited ecosystems, and 60% of the IAV of NEE is determined by the IAV of MCU in temperature-and radiation-limited ecosystems. The Lund-Potsdam-Jena (LPJ) model and the Multi-scale Synthesis and Terrestrial Model Inter-comparison Project (MsTMIP) models underestimate the contribution of MCU to the IAV of NEE by about 18% on average, and overestimate the contribution of CUP by about 25%. This study provides a new perspective on the proximate causes of the IAV of NEE, which suggest that capturing the variability of MCU is critical for modeling the IAV of NEE across most of the global land surface. K E Y W O R D S carbon uptake period, interannual variability, maximum carbon uptake rate, net ecosystem exchange, phenology, physiology S U PP O RTI N G I N FO R M ATI O N Additional supporting information may be found online in the Supporting Information section at the end of the article. How to cite this article: Fu Z, Stoy PC, Poulter B, et al. Maximum carbon uptake rate dominates the interannual variability of global net ecosystem exchange. Glob Change Biol. 2019;25:3381-3394. https ://doi.

show abstract

“…In over 72% of the FLUXNET sites (Table S1) with more than 5 years of observations, GPP IAV has a larger contribution than TER IAV to the IAV of net land carbon flux (Figure d; e.g., Baldocchi, Chu, & Reichstein, ; Jensen, Herbst, & Friborg, ; Marcolla et al, ; Wu et al, ), since GPP is more sensitive to climatic variations interannually (e.g., Kim, Kug, Yoon, & Jeong, ; Schwalm et al, ; Shi et al, ). Large uncertainties remain on the spatial patterns of the relative contribution of photosynthesis and respiration fluxes to IAV of net land carbon flux (Figure b–d; e.g., Ahlström et al, ; Ciais, Piao, Cadule, Friedlingstein, & Chédin, ; Jung et al, ; Liu, Ballantyne, et al, ; Piao et al, ).…”

Section: Photosynthesis Carbon Uptake Contributes More To Iav Than Ecmentioning

confidence: 99%

Interannual variation of terrestrial carbon cycle: Issues and perspectives

Piao

Wang

et al. 2019

Global Change Biology

Self Cite

298

206

View full text Add to dashboard Cite

With accumulation of carbon cycle observations and model developments over the past decades, exploring interannual variation (IAV) of terrestrial carbon cycle offers the opportunity to better understand climate–carbon cycle relationships. However, despite growing research interest, uncertainties remain on some fundamental issues, such as the contributions of different regions, constituent fluxes and climatic factors to carbon cycle IAV. Here we overviewed the literature on carbon cycle IAV about current understanding of these issues. Observations and models of the carbon cycle unanimously show the dominance of tropical land ecosystems to the signal of global carbon cycle IAV, where tropical semiarid ecosystems contribute as much as the combination of all other tropical ecosystems. Vegetation photosynthesis contributes more than ecosystem respiration to IAV of the global net land carbon flux, but large uncertainties remain on the contribution of fires and other disturbance fluxes. Climatic variations are the major drivers to the IAV of net land carbon flux. Although debate remains on whether the dominant driver is temperature or moisture variability, their interaction,that is, the dependence of carbon cycle sensitivity to temperature on moisture conditions, is emerging as key regulators of the carbon cycle IAV. On timescales from the interannual to the centennial, global carbon cycle variability will be increasingly contributed by northern land ecosystems and oceans. Therefore, both improving Earth system models (ESMs) with the progressive understanding on the fast processes manifested at interannual timescale and expanding carbon cycle observations at broader spatial and longer temporal scales are critical to better prediction on evolution of the carbon–climate system.

show abstract

Precipitation thresholds regulate net carbon exchange at the continental scale

Cited by 44 publications

References 71 publications

Spatial Predictions and Associated Uncertainty of Annual Soil Respiration at the Global Scale

Spatial Predictions and Associated Uncertainty of Annual Soil Respiration at the Global Scale

Maximum carbon uptake rate dominates the interannual variability of global net ecosystem exchange

Interannual variation of terrestrial carbon cycle: Issues and perspectives

Contact Info

Product

Resources

About