Relevance of green stem tissues to hydraulics of urban trees

Trees in cities provide manifold services, such as structuring urban
environments or regulating local climate. Though, they are also
exposed to intense stress, such as heat or salt stress, and tree
hydraulics (i.e. water transport from roots to crown) are known to be
crucial for tree vitality. Green, photosynthetic tissues in stems were
suggested to support transport functions and help avoid and repair
critical bubble formation, so-called embolism, blocking tree water
transport.
This project deals with the relevance of green stem tissues to tree
hydraulics of urban trees. Based on numerous methods, such as sap
flow and stem diameter measurements or acoustic emission
analyses, the functional importance of these tissues during drought
and frost will be tested on potted trees of several species.
Manipulation experiments (covering of green tissues, salt stress) will
enable additional insights. On adult sycamore trees in Ghent and
Innsbruck novel real-time tree monitors will be installed to compare
their hydraulic performance under natural drought and winter stress
in a temperate versus alpine climate. Furthermore, a Citizen Science
approach will enable citizens to participate in monitoring of tree
growth in the two cities.
The project is a cooperation of Ghent University (PI Steppe) and the
University of Innsbruck (PI Mayr). Based on the unique expertise of
both PIs, pioneering results with high impact potential for both basic
and applied research are expected.