TY - JOUR
T1 - The future of tundra carbon storage in Greenland – Sensitivity to climate and plant trait changes
AU - López-blanco, Efrén
AU - Langen, Peter L.
AU - Williams, Mathew
AU - Christensen, Jens Hesselbjerg
AU - Boberg, Fredrik
AU - Langley, Kirsty
AU - Christensen, Torben Røjle
N1 - Funding Information:
This work was supported by the Greenland Ecosystem Monitoring programme ( g-e-m.dk ) funded by the Danish Environmental Protection Agency and the Danish Energy Agency . The authors wish to thank the Nuuk and Zackenberg Ecological Research Operations. We thank more specifically the GeoBasis and ClimateBasis sub-programmes that manage the eddy covariance systems as well as the in-situ climate stations. We want to also thank the Danish Meteorological Institute for sharing the high-resolution downscaled climate data used in this study. ELB was supported by the Greenland Research Council (GRC) grant number 80.35 , financed by the “Danish Program for Arctic Research”. Additionally, ELB gratefully acknowledges the support from NVIDIA Academic Hardware Grant Program donating a high capacity Quadro RTX 8000 GPU to the modelling effort emerging from the above mentioned GRC grant. We thank Luke Smallman for support in developing the SPA model. ELB would like to also thank Ida B. D. Jacobsen for active discussions on nutrient availability controls in plants. PLL gratefully acknowledges the contributions of Aarhus University Interdisciplinary Centre for Climate Change (iClimate, Aarhus University). We finally thank Anne M. Poulsen from the Department of Ecoscience in Aarhus University for the professional language editing assistance.
Funding Information:
This work was supported by the Greenland Ecosystem Monitoring programme (g-e-m.dk) funded by the Danish Environmental Protection Agency and the Danish Energy Agency. The authors wish to thank the Nuuk and Zackenberg Ecological Research Operations. We thank more specifically the GeoBasis and ClimateBasis sub-programmes that manage the eddy covariance systems as well as the in-situ climate stations. We want to also thank the Danish Meteorological Institute for sharing the high-resolution downscaled climate data used in this study. ELB was supported by the Greenland Research Council (GRC) grant number 80.35, financed by the “Danish Program for Arctic Research”. Additionally, ELB gratefully acknowledges the support from NVIDIA Academic Hardware Grant Program donating a high capacity Quadro RTX 8000 GPU to the modelling effort emerging from the above mentioned GRC grant. We thank Luke Smallman for support in developing the SPA model. ELB would like to also thank Ida B. D. Jacobsen for active discussions on nutrient availability controls in plants. PLL gratefully acknowledges the contributions of Aarhus University Interdisciplinary Centre for Climate Change (iClimate, Aarhus University). We finally thank Anne M. Poulsen from the Department of Ecoscience in Aarhus University for the professional language editing assistance. In-situ data are archived and freely available in the GEM database (data.g-e-m.dk) while HIRHAM5 climate data can be found in http://prudence.dmi.dk/data/temp/FBO/GCB/.
Publisher Copyright:
© 2022 The Authors
PY - 2022/11/10
Y1 - 2022/11/10
N2 - The continuous change in observed key indicators such as increasing nitrogen deposition, temperatures and precipitation will have marked but uncertain consequences for the ecosystem carbon (C) sink-source functioning of the Arctic. Here, we use multiple in-situ data streams measured by the Greenland Ecosystem Monitoring programme in tight connection with the Soil-Plant-Atmosphere model and climate projections from the high-resolution HIRHAM5 regional model. We apply this modelling framework with focus on two climatically different tundra sites in Greenland (Zackenberg and Kobbefjord) to assess how sensitive the net C uptake will expectedly be under warmer and wetter conditions across the 21st century and pin down the relative contribution to the overall C sink strength from climate versus plant trait variability.Our results suggest that temperatures (5–7.7 °C), total precipitation (19–110 %) and vapour pressure deficit will increase (32–36 %), while shortwave radiation will decline (6–9 %) at both sites by 2100 under the RCP8.5 scenario. Such a combined effect will, on average, intensify the net C uptake by 9–10 g C m−2 year−1 at both sites towards the end of 2100, but Zackenberg is expected to have more than twice the C sink strength capacity of Kobbefjord. Our sensitivity analysis not only reveals that plant traits are the most sensitive parameters controlling the net C exchange in both sites at the beginning and end of the century, but also that the projected increase in the net C uptake will likely be similarly influenced by future changes in climate and existing local nutrient conditions. A series of experiments forcing realistic changes in plant nitrogen status at both sites corroborates this hypothesis.This work proves the unique synergy between monitoring data and numerical models to assist robust model calibration/validation and narrow uncertainty ranges and ultimately produce more reliable C cycle projections in understudied regions such as Greenland.
AB - The continuous change in observed key indicators such as increasing nitrogen deposition, temperatures and precipitation will have marked but uncertain consequences for the ecosystem carbon (C) sink-source functioning of the Arctic. Here, we use multiple in-situ data streams measured by the Greenland Ecosystem Monitoring programme in tight connection with the Soil-Plant-Atmosphere model and climate projections from the high-resolution HIRHAM5 regional model. We apply this modelling framework with focus on two climatically different tundra sites in Greenland (Zackenberg and Kobbefjord) to assess how sensitive the net C uptake will expectedly be under warmer and wetter conditions across the 21st century and pin down the relative contribution to the overall C sink strength from climate versus plant trait variability.Our results suggest that temperatures (5–7.7 °C), total precipitation (19–110 %) and vapour pressure deficit will increase (32–36 %), while shortwave radiation will decline (6–9 %) at both sites by 2100 under the RCP8.5 scenario. Such a combined effect will, on average, intensify the net C uptake by 9–10 g C m−2 year−1 at both sites towards the end of 2100, but Zackenberg is expected to have more than twice the C sink strength capacity of Kobbefjord. Our sensitivity analysis not only reveals that plant traits are the most sensitive parameters controlling the net C exchange in both sites at the beginning and end of the century, but also that the projected increase in the net C uptake will likely be similarly influenced by future changes in climate and existing local nutrient conditions. A series of experiments forcing realistic changes in plant nitrogen status at both sites corroborates this hypothesis.This work proves the unique synergy between monitoring data and numerical models to assist robust model calibration/validation and narrow uncertainty ranges and ultimately produce more reliable C cycle projections in understudied regions such as Greenland.
U2 - 10.1016/j.scitotenv.2022.157385
DO - 10.1016/j.scitotenv.2022.157385
M3 - Article
VL - 846
JO - Science of the Total Environment
JF - Science of the Total Environment
SN - 0048-9697
M1 - 157385
ER -