How much additional biomass
carbon does Ivy (Hedera Helix)
contribute to woodlands?
A preliminary study
Ian Grange
Royal Agricultural University, Cirencester
[email protected]
Andrew Wilson
Eden Tree Care & Fencing, Coalville
Ivy (Hedera helix)
• Common &
widespread
• Fertile, neutral,
heavier
textured soils
• Secondary
woodland (Ash)
• Hedgerows/
lines of trees
Ivy as a carbon sink/
source of additional
biomass?
• We know quite a bit about biomass and carbon contents of
woodland and forest trees and how to estimate these from
simple surrogate measurements made in the field (height, dbh).
• Other potential carbon pools, are often overlooked, including
ivy. But, more variable and difficult to measure.
• The objective of this work was to quantify the ivy growing in an
ash woodland and develop a predictive formula that could be
easily used in the field to estimate ivy biomass carbon contents.
Methods
The experimental
woodland site (Kemble,
Glos) was dominated by
ash, with 93% of the
trees supporting Ivy.
25m x 25m plot*
Trees were measured
and five trees felled and
cut into 1m sections. The
biomass of both the tree
and ivy was weighed in
the field.
*McKenzie et al. (2000) Sampling, measurement and analytical protocols for carbon estimation in soil, litter and coarse woody
debris National Carbon Accounting System Technical Report No. 14. Australian Greenhouse Office, Commonwealth of
Australia, Canberra.
Ivy growth structure compared to the host
tree. Mean values of 5 samples presented.
20
18
Ivy mass
16
tree mass
14
Height (m)
12
10
8
6
4
2
0
0
1
2
3
4
5
Mass (kg)
6
7
8
9
10
Results
Results cont.
Ivy height vs Ivy mass
Ivy height (m)
24
22
20
18
16
14
12
10
8
6
4
2
0
y = 2.1748x0.4613
R² = 0.9452
0
24
22
20
18
16
14
12
10
8
6
4
2
0
y = 2.2925x0.4251
R² = 0.9559
0
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
Ivy mass (kg)
Tree mass (kg)
Ash tree mass vs Ivy mass
160
140
Tree mass (kg)
Tree height (m)
Ash tree height vs tree mass
120
100
80
60
y = 0.4956x1.1346
R² = 0.9377
40
20
0
0
20
40
60
80
100
Ivy mass (kg)
120
140
160
Discussion & Conclusions
• Ivy biomass (carbon) was shown to be easily estimated from a simple
surrogate measurement of ivy height: Care with variability.
• Good initial relationships, but more woodland tree/ Ivy samples needed
to bolster relationships reported in this work – planned for Autumn.
• Ivy makes an important contribution to biomass C in woodland – What
about Ivy in hedgerows?
• The assumption of 50% C in Ivy needs to be tested. Ivy growth ring
analyses work also being conducted.
• Extrapolation/ modelling work:
– Additional surveys of Ivy in woodland/ hedges to better characterize the
significance of this work.
– Ivy growth/ biomass production in relation to tree species/ planting
density/ girth/ management etc.
Questions?
Ian Grange
[email protected]