Disclosing biome sensitivity to atmospheric changes: Stable C isotope ecophysiological dependences during photosynthetic CO2 uptake in Maritime pine and Scots pine ecosystems from southwestern Europe
Abstract
Background: The late XX century showed a sharp atmospheric δ13CO2 decline mainly ascribed to increased emissions of greenhouse gases (GHG) resulting from fossil fuel combustion. Thus, in the current global-warming scenario, a deep knowledge of biosphere-atmosphere interactions became especially relevant to adopt appropriate guidelines for climate change management.
Objective: Although tree-rings can attest long-term atmospheric composition trends, C isotopic variability among individual trees often disturbs the accurate interpretation of 13C atmospheric changes from tree-rings at different timescales. Therefore, the aim of this research is to overcome this intertree variability by applying an isotopic approach that can practically absorb high-frequency climatic irregularities and genetic variabilities from dendrochronological series, hence allowing the accurate deconvolution of past atmospheric composition to improve current models. Methods: This research is based on original isotopic dendrochronological results obtained by performing tree-by-tree differential studies with intra-tree δ13 C shifts to allow interspecies data standardization. Results: The isotopic composition of dendrochronological series collected from northwestern Spanish coniferous ecosystems clearly reflected the corresponding atmospheric 13 C changes but the stringency of the match also depended on some silvicultural parameters, tree-ring isotopic composition being able to exhibit either a magnification or attenuation of atmospheric changes according to specific metabolic differences that modulate photosynthetic 13 C discrimination in each ecological context. Conclusion: Relative isotopic changes revealed from our 25-year-long dendrological research, which properly mirrored the contemporary atmospheric 13CO2 composition (1978-2002), also showed the biome sensitivity to atmospheric changes, pointing towards a notable aptitude to respond to even incipient mitigation strategies and a significant resilience capacity of the Earth system.- Publication:
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Environmental Technology and Innovation
- Pub Date:
- October 2015
- DOI:
- 10.1016/j.eti.2015.04.007
- Bibcode:
- 2015EnvTI...4...52C
- Keywords:
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- Air 1<SUP>3</SUP> C records;
- Earth's system resilience;
- Global change;
- Pine forests;
- Stable C isotopes;
- Tree-ring variability