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Updated: May 21, 2026
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Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling
Published on: January 16, 2014
Pulse-labelling trees to study carbon allocation dynamics: a review of methods, current knowledge and future
Daniel Epron1, Michael Bahn, Delphine Derrien
1Université de Lorraine, UMR 1137, Ecologie et Ecophysiologie Forestières, Faculté des Sciences, F-54500 Vandoeuvre-les-Nancy, France. daniel.epron@univ-lorraine.fr
Tree Physiology
|June 16, 2012
Summary
Pulse-labelling trees with carbon isotopes tracks carbon movement within forests. This method quantifies carbon partitioning, crucial for understanding tree growth, resource use, and carbon sequestration, despite experimental challenges.
Area of Science:
- Forest Ecology
- Plant Physiology
- Biogeochemistry
Background:
- Pulse-labelling with carbon (C) isotopes traces CO2 fate in trees and soil.
- It quantifies forest carbon partitioning, impacting tree growth, resource acquisition, and carbon sequestration.
- Challenges exist in tracer choice, tracing methods, and quantitative analysis of C dynamics.
Purpose of the Study:
- To review and synthesize findings from pulse-labelling studies on carbon allocation in trees.
- To identify best practices for experimental design and analysis.
- To propose future research directions in tree carbon dynamics.
Main Methods:
- Analysis of data from 47 published studies on tree pulse-labelling experiments.
- Measurement of (13)C in respiratory efflux for estimating mean residence times.
- Development of a conceptual model for temperate and boreal trees.
Main Results:
- Carbon transfer rates vary between broadleaved and coniferous species, decreasing with lower temperatures and soil water.
- Belowground carbon transfer is rapid but slowed by drought.
- Half-lives of carbon differ across tree compartments: short in phloem sap and mature leaves, longer in sink organs.
- Sink strength variations are key drivers of carbon fluxes.
Conclusions:
- Pulse-labelling is a powerful tool for studying tree carbon allocation and forest C dynamics.
- Understanding environmental and physiological controls on carbon allocation requires in situ whole-tree labelling experiments on mature trees.
- Future research should focus on whole-tree C source-sink relations, allocation to secondary metabolism, environmental responses, seasonality, and C-N interactions.
