Reconciling carbon-cycle processes from ecosystem to global scales

Area of Science:

• Ecology
• Earth Science
• Environmental Science

Background:

• Global carbon (C) dynamics understanding is a significant scientific challenge.
• Expansion of carbon dioxide (CO2) observatories enables C-cycle process estimation but reveals data discrepancies.
• Ecosystem-specific C retention varies widely, with grasslands retaining 2% and needleleaf forests 30% of fixed C.

Purpose of the Study:

• To reconcile spatial mismatches in C-cycle process estimates across scales.
• To identify potential carbon loss pathways using novel data integration.
• To advance C-cycle science across the land-water interface.

Main Methods:

• Utilizing newly available satellite and atmospheric data.
• Combining independent datasets from terrestrial and aquatic environments.
• Comparing ecosystem measurements with continental-scale estimates.

Main Results:

• Continental US scale net ecosystem exchange (NEE) accounts for only 5% of photosynthetically fixed C.
• Significant spatial mismatches exist, with the Southeast showing high gross primary productivity and the Midwest high NEE.
• Ecosystem measurements reveal substantial variations in C retention across different biomes.

Conclusions:

• Innovative integration of diverse datasets is crucial for accurate C-cycle assessments.
• Addressing spatial mismatches is key to improving global carbon budget estimations.
• Integrating land and water C-cycle science provides a more holistic understanding of global C dynamics.