Abstract
Societal Impact Statement: Forest ecosystems absorb and store about 25% of global carbon dioxide emissions annually and are increasingly shaped by human land use and management. Climate change interacts with land use and forest dynamics to influence observed carbon stocks and the strength of the land carbon sink. We show that climate change effects on modeled forest land carbon stocks are strongest in tropical wildlands that have limited human influence. Global forest carbon stocks and carbon sink strength may decline as climate change and anthropogenic influences intensify, with wildland tropical forests, especially in Amazonia, likely being especially vulnerable. Summary: Human effects on ecosystems date back thousands of years, and anthropogenic biomes—anthromes—broadly incorporate the effects of human population density and land use on ecosystems. Forests are integral to the global carbon cycle, containing large biomass carbon stocks, yet their responses to land use and climate change are uncertain but critical to informing climate change mitigation strategies, ecosystem management, and Earth system modeling. Using an anthromes perspective and the site locations from the Global Forest Carbon (ForC) Database, we compare intensively used, cultured, and wildland forest lands in tropical and extratropical regions. We summarize recent past (1900-present) patterns of land use intensification, and we use a feedback analysis of Earth system models from the Coupled Model Intercomparison Project Phase 6 to estimate the sensitivity of forest carbon stocks to CO2 and temperature change for different anthromes among regions. Modeled global forest carbon stock responses are positive for CO2 increase but neutral to negative for temperature increase. Across anthromes (intensively used, cultured, and wildland forest areas), modeled forest carbon stock responses of temperate and boreal forests are less variable than those of tropical forests. Tropical wildland forest areas appear especially sensitive to CO2 and temperature change, with the negative temperature response highlighting the potential vulnerability of the globally significant carbon stock in tropical forests. The net effect of anthropogenic activities—including land-use intensification and environmental change and their interactions with natural forest dynamics—will shape future forest carbon stock changes. These interactive effects will likely be strongest in tropical wildlands.
| Original language | English |
|---|---|
| Pages (from-to) | 1027-1042 |
| Number of pages | 16 |
| Journal | Plants People Planet |
| Volume | 7 |
| Issue number | 4 |
| DOIs | |
| State | Published - Jul 2025 |
Funding
This work is the product of the New Phytologist symposium “Anthromes, CO2, and Terrestrial Carbon: From the deep past to net-zero” held in Potomac, MD in March 2023. We acknowledge all attendees who stimulated our thinking on this topic. We thank the New Phytologist Foundation and the US Department of Energy (DOE) Oak Ridge National Laboratory (ORNL). ORNL is managed by UT-Battelle, LLC, for the DOE under contract DE-AC05-00OR22725. We acknowledge the World Climate Research Programme, which, through its Working Group on Coupled Modelling, coordinated and promoted CMIP6. We thank the climate modeling groups for producing and making available their model output, the Earth System Grid Federation (ESGF) for archiving the data and providing access, and the multiple funding agencies that support CMIP6 and ESGF. This work was partially funded by a USDA Forest Service grant: 21-JV-11242305-097. VH was supported by RECCAP2 project, which is part of the ESA Climate Change Initiative (contract no. 22 4000123002/18/I-NB) during the workshop and further supported by the CGIAR MITIGATE+ project, the WRI Land and Carbon Lab, and the Open Earth Monitor Project funded by the European Union (grant agreement no.101059548). This research was supported in part by an appointment to the United States Forest Service (USFS) Research Participation Program administered by the Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between DOE and the U.S. Department of Agriculture (USDA). ORISE is managed by ORAU under DOE contract number DE-SC0014664. All opinions expressed in this paper are the author's and do not necessarily reflect the policies and views of USDA, DOE, or ORAU/ORISE. This research was supported in part by an appointment to the United States Forest Service (USFS) Research Participation Program administered by the Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between DOE and the U.S. Department of Agriculture (USDA). ORISE is managed by ORAU under DOE contract number DE‐SC0014664. All opinions expressed in this paper are the author's and do not necessarily reflect the policies and views of USDA, DOE, or ORAU/ORISE. This work is the product of the symposium “Anthromes, CO, and Terrestrial Carbon: From the deep past to net‐zero” held in Potomac, MD in March 2023. We acknowledge all attendees who stimulated our thinking on this topic. We thank the New Phytologist Foundation and the US Department of Energy (DOE) Oak Ridge National Laboratory (ORNL). ORNL is managed by UT‐Battelle, LLC, for the DOE under contract DE‐AC05‐00OR22725. We acknowledge the World Climate Research Programme, which, through its Working Group on Coupled Modelling, coordinated and promoted CMIP6. We thank the climate modeling groups for producing and making available their model output, the Earth System Grid Federation (ESGF) for archiving the data and providing access, and the multiple funding agencies that support CMIP6 and ESGF. This work was partially funded by a USDA Forest Service grant: 21‐JV‐11242305‐097. VH was supported by RECCAP2 project, which is part of the ESA Climate Change Initiative (contract no. 22 4000123002/18/I‐NB) during the workshop and further supported by the CGIAR MITIGATE+ project, the WRI Land and Carbon Lab, and the Open Earth Monitor Project funded by the European Union (grant agreement no.101059548). New Phytologist 2
Keywords
- Coupled Model Intercomparison Project Phase 6
- Global Forest Carbon Database (ForC)
- carbon cycle feedbacks
- human-influenced forests
- tropical vs. temperate and boreal