Using Direct Phloem Transport Manipulation to Advance Understanding of Carbon Dynamics in Forest Trees

Research output: Contribution to journalArticle


Carbon dynamics within trees are intrinsically important for physiological functioning, in
particular growth and survival, as well as ecological interactions on multiple timescales.
Thus, these internal dynamics play a key role in the global carbon cycle by determining
the residence time of carbon in forests via allocation to different tissues and pools, such
as leaves, wood, storage, and exudates. Despite the importance of tree internal carbon
dynamics, our understanding of how carbon is used in trees, once assimilated, has major
gaps. The primary tissue that transports carbon from sources to sinks within a tree is the
phloem. Therefore, direct phloemtransportmanipulation techniques have the potential to
improve understanding of numerous aspects of internal carbon dynamics. These include
relationships between carbon assimilation, nonstructural carbon availability, respiration
for growth and tissue maintenance, allocation to, and remobilization from, storage
reserves, and long-term sequestration in lignified structural tissues. This review aims
to: (1) introduce the topic of direct phloem transport manipulations, (2) describe the
three most common methods of direct phloem transport manipulation and review their
mechanisms, namely (i) girdling, (ii) compression and (iii) chilling; (3) summarize the known
impacts of these manipulations on carbon dynamics and use in forest trees; (4) discuss
potential collateral effects and compare the methods; and finally (5) highlight outstanding
key questions that relate to tree carbon dynamics and use, and propose ways to address
them using direct phloem transport manipulation.


External organisations
  • University of Cambridge
  • Harvard University
  • Northern Arizona University
  • Swiss Federal Institute for Forest, Snow and Landscape Research
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Forest Science
  • Other Earth and Related Environmental Sciences


  • Carbon dynamics, Tree growth, phloem, girdling, compression, chilling, carbon sink, source, allocation
Original languageEnglish
Number of pages17
JournalFrontiers in Forests and Global Change
Publication statusPublished - 2019 May 2
Publication categoryResearch
Externally publishedYes