A model based investigation of the relative importance of CO2-fertilization, climate warming, nitrogen deposition and land use change on the global terrestrial carbon uptake in the historical period

2015 ◽  
Vol 47 (1-2) ◽  
pp. 173-190 ◽  
Author(s):  
N. Devaraju ◽  
G. Bala ◽  
K. Caldeira ◽  
R. Nemani
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Nitrogen Deposition ◽  
Climate Warming ◽  
Historical Period ◽  
Carbon Uptake ◽  
Relative Importance ◽  
Terrestrial Carbon ◽  
Co2 Fertilization ◽  
Model Based

scholarly journals Nitrogen deposition: how important is it for global terrestrial carbon uptake?

2013 ◽  
Vol 10 (7) ◽  
pp. 11077-11109 ◽  
Author(s):  
G. Bala ◽  
N. Devaraju ◽  
R. K. Chaturvedi ◽  
K. Caldeira ◽  
R. Nemani
Keyword(s):  
Nitrogen Deposition ◽  
Carbon Storage ◽  
Climate Warming ◽  
N Deposition ◽  
Carbon Uptake ◽  
Terrestrial Carbon ◽  
Co2 Fertilization ◽  
Current Increase ◽  
Community Land Model ◽  
Global Mean

Abstract. Global carbon budget studies indicate that the terrestrial ecosystems have remained a~large sink for carbon despite widespread deforestation activities. CO2-fertilization, N deposition and re-growth of mid-latitude forests are believed to be key drivers for land carbon uptake. In this study, we assess the importance of N deposition by performing idealized near-equilibrium simulations using the Community Land Model 4.0 (CLM4). In our equilibrium simulations, only 12–17% of the deposited Nitrogen is assimilated into the ecosystem and the corresponding carbon uptake can be inferred from a C : N ratio of 20:1. We calculate the sensitivity of the terrestrial biosphere for CO2-fertilization, climate warming and N deposition as changes in total ecosystem carbon for unit changes in global mean atmospheric CO2 concentration, global mean temperature and Tera grams of Nitrogen deposition per year, respectively. Based on these sensitivities, it is estimated that about 242 PgC could have been taken up by land due to the CO2 fertilization effect and an additional 175 PgC taken up as a result of the increased N deposition since the pre-industrial period. Because of climate warming, terrestrial ecosystem could have lost about 152 PgC during the same period. Therefore, since preindustrial times terrestrial carbon losses due to warming may have been approximately compensated by effects of increased N deposition, whereas the effect of CO2-fertilization is approximately indicative of the current increase in terrestrial carbon stock. Our simulations also suggest that the sensitivity of carbon storage to increased N deposition decreases beyond current levels, indicating climate warming effects on carbon storage may overwhelm N deposition effects in the future.

scholarly journals Nitrogen deposition: how important is it for global terrestrial carbon uptake?

2013 ◽  
Vol 10 (11) ◽  
pp. 7147-7160 ◽  
Author(s):  
G. Bala ◽  
N. Devaraju ◽  
R. K. Chaturvedi ◽  
K. Caldeira ◽  
R. Nemani
Keyword(s):  
Nitrogen Deposition ◽  
Carbon Storage ◽  
Climate Warming ◽  
N Deposition ◽  
Carbon Uptake ◽  
Terrestrial Carbon ◽  
Co2 Fertilization ◽  
Current Increase ◽  
Community Land Model ◽  
Global Mean

Abstract. Global carbon budget studies indicate that the terrestrial ecosystems have remained a large sink for carbon despite widespread deforestation activities. CO2 fertilization, N deposition and re-growth of mid-latitude forests are believed to be key drivers for land carbon uptake. In this study, we assess the importance of N deposition by performing idealized near-equilibrium simulations using the Community Land Model 4.0 (CLM4). In our equilibrium simulations, only 12–17% of the deposited nitrogen is assimilated into the ecosystem and the corresponding carbon uptake can be inferred from a C : N ratio of 20 : 1. We calculate the sensitivity of the terrestrial biosphere for CO2 fertilization, climate warming and N deposition as changes in total ecosystem carbon for unit changes in global mean atmospheric CO2 concentration, global mean temperature and Tera grams of nitrogen deposition per year, respectively. Based on these sensitivities, it is estimated that about 242 PgC could have been taken up by land due to the CO2 fertilization effect and an additional 175 PgC taken up as a result of the increased N deposition since the pre-industrial period. Because of climate warming, the terrestrial ecosystem could have lost about 152 PgC during the same period. Therefore, since pre-industrial times terrestrial carbon losses due to warming may have been more or less compensated by effects of increased N deposition, whereas the effect of CO2 fertilization is approximately indicative of the current increase in terrestrial carbon stock. Our simulations also suggest that the sensitivity of carbon storage to increased N deposition decreases beyond current levels, indicating that climate warming effects on carbon storage may overwhelm N deposition effects in the future.

scholarly journals Contrasting effects of CO<sub>2</sub> fertilization, land-use change and warming on seasonal amplitude of Northern Hemisphere CO<sub>2</sub> exchange

2019 ◽  
Vol 19 (19) ◽  
pp. 12361-12375 ◽  
Author(s):  
Ana Bastos ◽  
Philippe Ciais ◽  
Frédéric Chevallier ◽  
Christian Rödenbeck ◽  
Ashley P. Ballantyne ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Land Surface ◽  
Microbial Respiration ◽  
State Of The Art ◽  
Co2 Flux ◽  
Relative Importance ◽  
Co2 Fertilization ◽  
Surface Models ◽  
Co2 Monitoring

Abstract. Continuous atmospheric CO2 monitoring data indicate an increase in the amplitude of seasonal CO2-cycle exchange (SCANBP) in northern high latitudes. The major drivers of enhanced SCANBP remain unclear and intensely debated, with land-use change, CO2 fertilization and warming being identified as likely contributors. We integrated CO2-flux data from two atmospheric inversions (consistent with atmospheric records) and from 11 state-of-the-art land-surface models (LSMs) to evaluate the relative importance of individual contributors to trends and drivers of the SCANBP of CO2 fluxes for 1980–2015. The LSMs generally reproduce the latitudinal increase in SCANBP trends within the inversions range. Inversions and LSMs attribute SCANBP increase to boreal Asia and Europe due to enhanced vegetation productivity (in LSMs) and point to contrasting effects of CO2 fertilization (positive) and warming (negative) on SCANBP. Our results do not support land-use change as a key contributor to the increase in SCANBP. The sensitivity of simulated microbial respiration to temperature in LSMs explained biases in SCANBP trends, which suggests that SCANBP could help to constrain model turnover times.

scholarly journals Contributions of secondary forest and nitrogen dynamics to terrestrial carbon uptake

2010 ◽  
Vol 7 (2) ◽  
pp. 2739-2765 ◽  
Author(s):  
X. Yang ◽  
T. K. Richardson ◽  
A. K. Jain
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Secondary Forest ◽  
Nitrogen Dynamics ◽  
Carbon Uptake ◽  
Secondary Forests ◽  
Terrestrial Carbon ◽  
Tropical Regions ◽  
Forest Regrowth ◽  
Limiting Nutrient

Abstract. We use a terrestrial carbon-nitrogen cycle component of the Integrated Science Assessment Model (ISAM) to investigate the impacts of nitrogen dynamics on regrowing secondary forests over the 20th century. We further examine what the impacts of nitrogen deposition and land use change history are on terrestrial carbon uptake since preindustrial time. Our results suggest that global total net land use emissions for the 1990s associated with changes in cropland, pastureland, and wood harvest are 1.22 GtC/yr. Without considering the secondary forest regrowth, the estimated net global total land use emissions are 1.58 GtC/yr or about 0.36 GtC/yr higher than if secondary forest regrowth is considered. Results also show that without considering the nitrogen dynamics and deposition, the estimated global total secondary forest sink for the 1990s is 0.90 GtC/yr or about 0.54 GtC/yr higher than estimates that include the impacts of nitrogen dynamics and deposition. Nitrogen deposition alone is responsible for about 0.13 GtC/yr of the total secondary forest sink. While nitrogen is not a limiting nutrient in the intact primary forests in tropical regions, our study suggests that nitrogen becomes a limiting nutrient for regrowing secondary forests of the tropical regions, in particular Latin America and Tropical Africa. This is because land use change activities, especially wood harvest, removes large amounts of nitrogen from the system when slash is burnt or wood is removed for harvest. However, our model results show that carbon uptake is enhanced in the tropical secondary forests of the Indian region. We argue that this may be due to enhanced nitrogen mineralization and increased nitrogen availability following land use change in the Indian tropical forest ecosystems. Results also demonstrate that there is a significant amount of carbon accumulating in the Northern Hemisphere where most land use changes and forest regrowth has occurred in recent decades. This study indicates the significance of secondary forests to terrestrial carbon sinks, the importance of nitrogen dynamics to the magnitude of secondary forests carbon uptake, and therefore the need to include both primary and secondary forests and nitrogen dynamics in terrestrial ecosystem models.

scholarly journals Contributions of secondary forest and nitrogen dynamics to terrestrial carbon uptake

2010 ◽  
Vol 7 (10) ◽  
pp. 3041-3050 ◽  
Author(s):  
X. Yang ◽  
T. K. Richardson ◽  
A. K. Jain
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Secondary Forest ◽  
Nitrogen Dynamics ◽  
Carbon Uptake ◽  
Secondary Forests ◽  
Terrestrial Carbon ◽  
Tropical Regions ◽  
Forest Regrowth ◽  
Limiting Nutrient

Abstract. We use a terrestrial carbon-nitrogen cycle component of the Integrated Science Assessment Model (ISAM) to investigate the impacts of nitrogen dynamics on regrowing secondary forests over the 20th century. We further examine what the impacts of nitrogen deposition and land use change history are on terrestrial carbon uptake since preindustrial time. Our results suggest that global total net land use emissions for the 1990s associated with changes in cropland, pastureland, and wood harvest are 1.22 GtC/yr. Without considering the secondary forest regrowth, the estimated net global total land use emissions are 1.58 GtC/yr or about 0.36 GtC/yr higher than if secondary forest regrowth is considered. Results also show that without considering the nitrogen dynamics and deposition, the estimated global total secondary forest sink for the 1990s is 0.90 GtC/yr or about 0.54 GtC/yr higher than estimates that include the impacts of nitrogen dynamics and deposition. Nitrogen deposition alone is responsible for about 0.13 GtC/yr of the total secondary forest sink. While nitrogen is not a limiting nutrient in the intact primary forests in tropical regions, our study suggests that nitrogen becomes a limiting nutrient for regrowing secondary forests of the tropical regions, in particular Latin America and Tropical Africa. This is because land use change activities, especially wood harvest, removes large amounts of nitrogen from the system when slash is burnt or wood is removed for harvest. However, our model results show that carbon uptake is enhanced in the tropical secondary forests of the Indian region. We argue that this may be due to enhanced nitrogen mineralization and increased nitrogen availability following land use change in the Indian tropical forest ecosystems. Results also demonstrate that there is a significant amount of carbon accumulating in the Northern Hemisphere where most land use changes and forest regrowth has occurred in recent decades. This study indicates the significance of secondary forests to terrestrial carbon sinks, the importance of nitrogen dynamics to the magnitude of secondary forests carbon uptake, and therefore the need to include both primary and secondary forests and nitrogen dynamics in terrestrial ecosystem models.

scholarly journals Influence of Climate and Land Use Change on the Groundwater System of the Veluwe, The Netherlands: A Historical and Future Perspective

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2866
Author(s):  
Marjolein H. J. Van Huijgevoort ◽  
Bernard R. Voortman ◽  
Sjoerd Rijpkema ◽  
Kelly H. S. Nijhuis ◽  
Jan-Philip M. Witte
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
The Netherlands ◽  
Groundwater Recharge ◽  
Winter Precipitation ◽  
Pine Forest ◽  
Future Perspective ◽  
Historical Period ◽  
Groundwater Levels ◽  
The Future

Changes in land use and climate have a large influence on groundwater recharge and levels. In The Netherlands, precipitation shifts from summer to winter are expected, combined with an increase in summer temperature leading to higher evaporation. These changes in climate could threaten the fresh water supply and increase the importance of large groundwater reservoirs. Sustainable management of these groundwater reservoirs, therefore, is crucial. Changes in land use could help mitigate the effects of climate change by decreasing the evaporation. In this study, we investigate the effect of changes in climate and land use on a large groundwater reservoir in The Netherlands, the Veluwe, for a historical period (1850–2016) and in the future (2036–2065). During the historical period, evaporation increased due to conversions from heather and drift sand to pine forest across the Veluwe. This change in land use had a larger effect on the groundwater recharge than change in climate over the historical period. In the future, an increase in winter precipitation will lead to higher groundwater levels in the elevated parts of the region. Surrounding areas are more vulnerable to an increase in dry periods in the summer. Groundwater reservoirs provide an opportunity to store water during wetter periods, which could alleviate drought impacts in surrounding regions during dry periods. Land use change, such as conversion from pine forest to other land use types, is a possible measure to increase water availability.

A model-based assessment of the environmental impact of land-use change across scales in Southern Amazonia

2017 ◽  
Vol 18 (1) ◽  
pp. 161-173 ◽  
Author(s):  
Rüdiger Schaldach ◽  
Katharina H. E. Meurer ◽  
Hermann F. Jungkunst ◽  
Claas Nendel ◽  
Tobia Lakes ◽  
...  
Keyword(s):  
Land Use ◽  
Environmental Impact ◽  
Land Use Change ◽  
Model Based ◽  
Southern Amazonia
Sign in / Sign up

Export Citation Format

Share Document