Faye Thomsit | Dr Tijana Blanuša | Dr Emmanuel Essah | Professor Paul Hadley
Regulating ivy aerial root attachment
Introduction
• Climbing plants such as Hedera helix and H.
hibernica (common ivy and Irish ivy), can be used
for façade greening around buildings (Figure 1).
Façade greening can insulate the building
exterior against weather extremes thus reducing
the need for winter heating and summer cooling.
Their use around houses however, is anecdotally
associated with potential damage to house walls
and difficulty controlling ivy's aerial roots, which
deters many homeowners from using ivy.
• The project aims to overcome some of the
reticence to structural greening by manipulating
the substrate conditions and thus ivy attachment.
Project Aims
• The main aim for the first year of the project is to
understand the management requirements for ivy
which would decrease its attachment on unwanted
surfaces thus increasing its use as a form of exterior
cladding.
• There will be two areas of investigation:
• 1. Biological properties of ivy will be measured;
understanding the distances ivy can climb without
adhesion and the height it grows to before converting to
its mature form are important for implementing design
and building material specifications. The impacts of root
manipulation, when planting, on plant growth will also
be studied.
• 2. Differences between building materials in resistance
to ivy adhesion will be established. Ivy is unable to adhere
to several materials such as glass, ceramics and steel
(Melzer et al. 2009). These materials could be used
around sensitive areas such as guttering if the costs were
not prohibitive. Whether the ivy would adhere
underneath panels of these materials however, would
need consideration.
References
1. Melzer et al. (2009). “Mechanics and Structure of the Attachment System of English Ivy (Hedera helix L .)” 6th Plant Biomechanics Conference Cayenne.
2. Melzer et al. (2010) "The Attachment Strategy of English Ivy: A Complex
Mechanism Acting on Several Hierarchical Levels." Journal of the Royal
Society Interface 7: 1383-1389.
Acknowledgements
This project is funded by ESPRC, RHS (Royal Horticultural Society) and Sutton Griffin Architects
Contact information
Department of Agriculture, Policy and Development, University of Reading, Whiteknights, RG6 6AR.
Email: [email protected]
www.reading.ac.uk/ tsbe/Current-research-projects/EngDProfiles/Faye-thomsit.aspx
Figure 2. Spirally curled flattened root hair, SEM image. Fresh root hair
growing into a cavity in the substrate, schematic drawing. Drying root
hair anchored to protrusions inside the cavity, pulling the attachment
root towards the substrate, schematic drawing (Melzer et al. 2010).
Figure 3. Schematic of the modelling arena (ongoing experiments, 2013).
Biomechanical Attachment of Ivy
• Ivy has special roots, called aerial or adventitious roots, to allow
it to attach to structures, these roots have microscopic root
hairs that excrete a glue-like substance to aid in attachment.
The aerial roots grow into cracks and the texture of the wall and
as they dry, they deform, bracing against the structure of the
wall (Figure 2 from Melzer et al. 2010).
Figure 4. Whole plant experiment using H. hibernica
(ongoing experiments, 2013)
Figure 5. Test tube cuttings experiment using H. hibernica (ongoing experiments, 2013).
Figure 1. Ivy growing unsupported on a building (Photograph by
Faye Thomsit)
• The Modelling Arena
• The project aims are currently being tested in an ideal
model system (Figures 3 & 4) from which barriers to aerial root
attachment can be tested. The experiment is also being repeated
with cuttings (Figure 5) to provide a faster turnover of results
which can be referenced against the whole plants.
• Once the system has been modelled successfully, methods of
preventing attachment can be trialled. Current plans include the
use of anti-graffiti paints, different textured surfaces and
phytotoxic compounds. The role of plant hormones such as
auxins will also be investigated.