Biotic carbon feedbacks in a materially closed soil–vegetation–atmosphere system

Alexandru Milcu, Martin Lukac, Jens-Arne Subke, Pete Manning, Andreas Heinemeyer, Dennis Wildmann, Robert Anderson, Phil Ineson

Research output: Contribution to journalArticlepeer-review


Themagnitude and direction of the coupled feedbacks between
2 the biotic and abiotic components of the terrestrial carbon cycle
3 is a major source of uncertainty in coupled climate–carbon4
cyclemodels1–3.Materially closed, energetically open biological
5 systems continuously and simultaneously allow the two-way
6 feedback loop between the biotic and abiotic components
7 to take place4–7, but so far have not been used to their
8 full potential in ecological research, owing to the challenge
9 of achieving sustainable model systems6,7. We show that
10 using materially closed soil–vegetation–atmosphere systems
11 with pro rata carbon amounts for the main terrestrial carbon
12 pools enables the establishment of conditions that balance
13 plant carbon assimilation, and autotrophic and heterotrophic
14 respiration fluxes for periods suitable to investigate short-term
15 biotic carbon feedbacks. Using this approach, we tested an
16 alternative way of assessing the impact of increased CO2
17 and temperature on biotic carbon feedbacks. The results
18 show that without nutrient and water limitations, the short19
term biotic responses could potentially buffer a temperature
20 increase of 2:3 C without significant positive feedbacks to
21 atmospheric CO2. We argue that such closed-system research
22 represents an important test-bed platformformodel validation
23 and parameterization of plant and soil biotic responses to
24 environmental changes.
Original languageEnglish
Pages (from-to)281-284
Number of pages4
JournalNature Climate Change
Issue number4
Publication statusPublished - Apr 2012

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