Evaluating the carbon budget pattern of Chinese terrestrial ecosystem from 1960 to 2006 using Integrated Biosphere Simulator

2016 ◽  
Vol 36 (13) ◽  
Author(s):  
杨延征 YANG Yanzheng ◽  
马元丹 MA Yuandan ◽  
江洪 JIANG Hong ◽  
朱求安 ZHU Qiu'an ◽  
刘金勋 LIU Jinxun ◽  
...  
Keyword(s):  
Carbon Budget ◽  
Terrestrial Ecosystem ◽  
Integrated Biosphere Simulator

scholarly journals A global CO<sub>2</sub> flux dataset (2015–2019) inferred from OCO-2 retrievals using the Tan-Tracker inversion system

2021 ◽  
Author(s):  
Zhe Jin ◽  
Xiangjun Tian ◽  
Rui Han ◽  
Yu Fu ◽  
Xin Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Carbon Cycle ◽  
Carbon Flux ◽  
Carbon Budget ◽  
Terrestrial Ecosystem ◽  
Carbon Fluxes ◽  
Global Carbon Cycle ◽  
Ocean Carbon ◽  
Global Carbon ◽  
Regional Fluxes

Abstract. Accurate assessment of the various sources and sinks of carbon dioxide (CO2), especially terrestrial ecosystem and ocean fluxes with high uncertainties, is important for understanding of the global carbon cycle, supporting the formulation of climate policies, and projecting future climate change. Satellite retrievals of the column-averaged dry air mole fractions of CO2 (XCO2) are being widely used to improve carbon flux estimation due to their broad spatial coverage. However, there is no consensus on the robust estimates of regional fluxes. In this study, we present a global and regional resolved terrestrial ecosystem carbon flux (NEE) and ocean carbon flux dataset for 2015–2019. The dataset was generated using the Tan-Tracker inversion system by assimilating Observing Carbon Observatory 2 (OCO-2) column CO2 retrievals. The posterior NEE and ocean carbon fluxes were comprehensively validated by comparing posterior simulated CO2 concentrations with OCO-2 independent retrievals and Total Carbon Column Observing Network (TCCON) measurements. The validation showed that posterior carbon fluxes significantly improved the modelling of atmospheric CO2 concentrations, with global mean biases of 0.33 ppm against OCO-2 retrievals and 0.12 ppm against TCCON measurements. We described the characteristics of the dataset at global, regional, and Tibetan Plateau scales in terms of the carbon budget, annual and seasonal variations, and spatial distribution. The posterior 5-year annual mean global atmospheric CO2 growth rate was 5.35 PgC yr−1, which was within the uncertainty of the Global Carbon Budget 2020 estimate (5.49 PgC yr−1). The posterior annual mean NEE and ocean carbon fluxes were −4.07 and −3.33 PgC yr−1, respectively. Regional fluxes were analysed based on TransCom partitioning. All 11 land regions acted as carbon sinks, except for Tropical South America, which was almost neutral. The strongest carbon sinks were located in Boreal Asia, followed by Temperate Asia and North Africa. The entire Tibetan Plateau ecosystem was estimated as a carbon sink, taking up −49.52 TgC yr−1 on average, with the strongest sink occurring in eastern alpine meadows. These results indicate that our dataset captures surface carbon fluxes well and provides insight into the global carbon cycle. The dataset can be accessed at https://doi.org/10.11888/Meteoro.tpdc.271317 (Jin et al., 2021).

scholarly journals Disequilibrium of terrestrial ecosystem CO<sub>2</sub> budget caused by disturbance-induced emissions and non-CO<sub>2</sub> carbon export flows: a global model assessment

2018 ◽  
Author(s):  
Akihiko Ito
Keyword(s):  
Biomass Burning ◽  
Carbon Budget ◽  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
Carbon Stocks ◽  
Historical Period ◽  
Model Assessment ◽  
Terrestrial Carbon ◽  
Wood Harvest ◽  
Global Carbon

Abstract. The global carbon budget of terrestrial ecosystems is chiefly determined by major flows of carbon dioxide (CO2) such as photosynthesis and respiration, but various minor flows exert considerable influence by reducing carbon stocks and accelerating turnover. This study assessed the effects of eight minor carbon flows on the terrestrial carbon budget using a process-based model, the Vegetation Integrative SImulator for Trace gases (VISIT), which also included non-CO2 carbon flows, such as CH4 and biogenic volatile organic compound (BVOC) emissions and subsurface carbon exports and disturbances such as biomass burning, land-use changes, and harvest activities. In the historical period of 1901–2016, the VISIT simulation indicated that the minor flows substantially influenced terrestrial carbon stocks, flows, and budgets. The simulations without and with minor flows estimated mean net ecosystem production in the 2000s as 3.04 ± 1.0 Pg C yr−1 and 4.94 ± 0.9 Pg C yr−1, respectively. Including minor carbon flows yielded an estimated net biome production of 2.19 ± 1.0 Pg C yr−1. Biomass burning, wood harvest, export of organic carbon by erosion, and BVOC emissions had impacts on the global terrestrial carbon budget amounting to around 1 Pg C yr−1 with specific interannual variability. After including the minor flows, ecosystem carbon storage was suppressed by about 280 Pg C, and its mean residence time was shortened by about 1.5 yr. The minor flows occur heterogeneously over the land, such that isoprene emission, subsurface export, and wood harvest occur mainly in the tropics and biomass burning occurs extensively in boreal forests. These minor flows differ in their decadal trends, due to differences in their driving factors. Aggregating the simulation results by cropland fraction and annual precipitation yielded more insight into the contributions of these minor flows to the terrestrial carbon budget. This study estimated uncertainties in the estimation of these flows through parameter ensemble simulations and sensitivity simulations, and the results have implications for observation, modeling, and synthesis of the global carbon cycle.

scholarly journals Microbial dormancy and its impacts on northern temperate and boreal terrestrial ecosystem carbon budget

2020 ◽  
Vol 17 (18) ◽  
pp. 4591-4610
Author(s):  
Junrong Zha ◽  
Qianla Zhuang
Keyword(s):  
Greenhouse Gases ◽  
Soil Carbon ◽  
Carbon Budget ◽  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
Carbon Dynamics ◽  
Earth System ◽  
New Model ◽  
Ecosystem Carbon ◽  
Earth System Models

Abstract. A large amount of soil carbon in northern temperate and boreal regions could be emitted as greenhouse gases in a warming future. However, lacking detailed microbial processes such as microbial dormancy in current biogeochemistry models might have biased the quantification of the regional carbon dynamics. Here the effect of microbial dormancy was incorporated into a biogeochemistry model to improve the quantification for the last century and this century. Compared with the previous model without considering the microbial dormancy, the new model estimated the regional soils stored 75.9 Pg more C in the terrestrial ecosystems during the last century and will store 50.4 and 125.2 Pg more C under the RCP8.5 and RCP2.6 scenarios, respectively, in this century. This study highlights the importance of the representation of microbial dormancy in earth system models to adequately quantify the carbon dynamics in the northern temperate and boreal natural terrestrial ecosystems.

scholarly journals Microbial dormancy and its impacts on Arctic terrestrial ecosystem carbon budget

2019 ◽  
Author(s):  
Junrong Zha ◽  
Qianlai Zhuang
Keyword(s):  
Greenhouse Gases ◽  
Carbon Budget ◽  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
Carbon Dynamics ◽  
The Arctic ◽  
Earth System ◽  
Ecosystem Carbon ◽  
Rcp 8.5 ◽  
Earth System Models

Abstract. A large amount of soil carbon in the Arctic terrestrial ecosystems could be emitted as greenhouse gases in a warming future. However, lacking detailed microbial processes such as microbial dormancy in current biogeochemistry models might have biased the quantification of the regional carbon dynamics. Here the effect of microbial dormancy was incorporated into a biogeochemistry model to improve the quantification for the last and this century. Compared with the previous model without considering the microbial dormancy, the new model estimated the regional soils stored 75.9 Pg more C in the terrestrial ecosystems during the last century, and will store 50.4 Pg and 125.2 Pg more C under the RCP 8.5 and RCP 2.6 scenarios, respectively, in this century. This study highlights the importance of the representation of microbial dormancy in earth system models to adequately quantify the carbon dynamics in the Arctic.

scholarly journals Microbial decomposition processes and vulnerable Arctic soil organic carbon in the 21st century

2018 ◽  
Author(s):  
Junrong Zha ◽  
Qianlai Zhuang
Keyword(s):  
Soil Carbon ◽  
20Th Century ◽  
21St Century ◽  
Carbon Budget ◽  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
The Arctic ◽  
Microbial Decomposition ◽  
Terrestrial Ecosystem Model ◽  
Rcp 8.5

Abstract. Inadequate representation of biogeochemical processes in current biogeochemistry models results in a large uncertainty in carbon budget quantification. Here, detailed microbial mechanisms were incorporated into a process-based biogeochemistry model, the Terrestrial Ecosystem Model (TEM). Ensemble regional simulations with the model estimated the Arctic ecosystem carbon budget is 76.0 ± 114.8 Pg C during the 20th century, −3.1 ± 61.7 Pg C under the RCP 2.6 scenario and a sink of 94.7 ± 46 Pg C under the RCP 8.5 scenario during the 21st century. Compared to the estimates using a simpler soil decomposition algorithm in TEM, the new model estimated that the Arctic terrestrial ecosystems stored 12 Pg less carbon over the 20th century, 19 Pg C and 30 Pg C less under the RCP 8.5 and RCP 2.6 scenarios, respectively, during the 21st century. When soil carbon within depths 30 cm, 100 cm and 300 cm was considered as initial carbon in the 21st century simulations, the region was estimated to accumulate 65.4, 88.6, and 109.8 Pg C, respectively, under the RCP 8.5 scenario. In contrast, under the RCP 2.6 scenario, the region lost 0.7, 2.2, and 3 Pg C, respectively, to the atmosphere. We conclude that the future regional carbon budget evaluation largely depends on whether or not the adequate microbial activities are represented in earth system models and the sizes of soil carbon considered in model simulations.

scholarly journals Short-term cropland responses to temperature extreme events during late winter

2013 ◽  
Vol 10 (4) ◽  
pp. 6493-6515 ◽  
Author(s):  
G. De Simon ◽  
G. Alberti ◽  
G. Delle Vedove ◽  
A. Peressotti ◽  
A. Zaldei ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Extreme Events ◽  
Carbon Budget ◽  
Plant Density ◽  
Terrestrial Ecosystem ◽  
Automated System ◽  
Late Winter ◽  
Natural Ecosystems ◽  
The Impact ◽  
Final Harvest

Abstract. In recent years, several studies have focused on terrestrial ecosystem response to extreme events. Most of this research has been conducted in natural ecosystems, but few have considered agro-ecosystems. In this study, we investigated the impact of a manipulated warmer or cooler late winter-early spring on the carbon budget and final harvest of a soybean crop (Glycine max (L.) Merr.). Soil temperature was altered by manipulating soil albedo by covering the soil surface with a layer of inert silica gravel. We tested three treatments: cooling (Co), warming (W), mix (M) and control (C). An automated system continuously measured soil heterotrophic respiration (Rh), soil temperature profiles, and soil water content across the entire year in each plot. Phenological phases were periodically assessed and final harvest was measured in each plot. Results showed that treatments had only a transient effect on daily Rh rates which did not result in a total annual carbon budget significantly different from control, even though cooling showed a significant reduction in final harvest. We also observed anticipation in seed germination in both W and M treatments and a delay in germination for Co. Moreover, plant density and growth increased in W and M and decreased in Co.

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