6 research outputs found
Skid trail use influences soil carbon flux and nutrient pools in a temperate hardwood forest
Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO2
Atmospheric carbon dioxide concentration ([CO2]) is increasing, which increases leafâscale photosynthesis and intrinsic waterâuse efficiency. These direct responses have the potential to increase plant growth, vegetation biomass, and soil organic matter; transferring carbon from the atmosphere into terrestrial ecosystems (a carbon sink). A substantial global terrestrial carbon sink would slow the rate of [CO2] increase and thus climate change. However, ecosystem CO2âresponses are complex or confounded by concurrent changes in multiple agents of global change and evidence for a [CO2]âdriven terrestrial carbon sink can appear contradictory. Here we synthesise theory and broad, multiâdisciplinary evidence for the effects of increasing [CO2] (iCO2) on the global terrestrial carbon sink. Evidence suggests a substantial increase in global photosynthesis since preâindustry. Established theory, supported by experiments, indicates that iCO2 is likely responsible for about half of the increase. Global carbon budgeting, atmospheric data, and forest inventories indicate a historical carbon sink, and these apparent iCO2âresponses are high in comparison with experiments and theory. Plant mortality and soil carbon iCO2âresponses are highly uncertain. In conclusion, a range of evidence supports a positive terrestrial carbon sink in response to iCO2, albeit with uncertain magnitude and strong suggestion of a role for additional agents of global change