Natural Capital Team, James Hutton Institute

1. How can research contribute to future
resilient landscapes? Case studies from
woodland habitats
Alison Hester, Ruth Mitchell, Alice Broome

2. Talk structure
• Primary research – what,
where, when, why, how…?
• Synthesis – bringing together
different research findings to
draw common conclusions and
identify gaps
• Advice/recommendations –
what can we recommend and
with what degree of
confidence?

3. 1. Primary research – contribution
to future resilient landscapes
• Direct impacts of pathogen on ‘host’ tree(s); presence of
resistant genotypes; cures (e.g. garlic & sudden oak
death)
• Wider impacts – dependent species; other ecosystem
functions (e.g. nutrient cycling); ‘alternative’ tree
species?
• Factors affecting infection and spread – global transport
of seedlings (etc); spatial distribution/condition of trees;
habitat configuration within the wider landscape…
* Red colour = examples I will show today

4. 1a. Primary research – dependent
species / ecosystem function
Both require intensive, field and lab
based measurements…
 e.g. the species databases we
examined (for tree species use)
have >1.2 million UK field records
for lichens (BLS) and >1 million for
fungi (FRDBI)
 e.g. for ecosystem functions of ash,
we found 420 published field/lab
studies on this topic

5. 1b. Primary research – habitat
configuration within the landscape
• Requires spatial data
collection – air
photos/satellite, field
survey then spatial
modelling
• e.g. how connected are
our forests at present?
(Gimona et al, JHI)
• Implications for species
spread (good and bad)
Landscape permeability to forest species
Present-day connectivity potential 90th
percentile
75th
percentile
Potential Current
Broadleaved
Woodland

6. 2. Synthesis – contribution to
future resilient landscapes
• Data collation – hugely important for providing best
available information and levels of confidence – examples:
Collation of individual studies into a searchable database
– e.g. JHI ash database – example outputs: species most
at risk if host tree declines; ‘alternative’ host tree species
Meta-analysis of published studies – e.g. tree resilience
to different pathogens; ecosystem functions of different
tree species...
• Future projections – speed of spread; likelihood of
resistance developing; impacts of climate change …

7. 2a. Synthesis: AshEcol Database (MS Access)
Can create such a database for any tree species …
– critically important to assess potential impacts of other
pathogens on UK native tree species, e.g.:
• Oaks: oak processionary moth (Thaumetopoea processionea ),
Phytopthora (Phytophthora quercina)
• Oak, beech: Phytopthora (P. ramorum & P Kernoviae)
• Elm: Dutch elm disease (Ophiostoma novo-ulmi)
• Scots pine: needle blight (Dothistroma septosporum), pine pitch canker
(Fusarium circinatum), pine processionary moth (Thaumetopoea
pityocampa), pine wood nematode (Bursaphelenchus xylophilus )
• Ash: emerald ash borer (Agrilus planipennis).

8. -> AshEcol: numbers of ash-associated species
Group
Level of association with F. excelsior
High Partial Cosmopolitan Uses
Bird 7 5
Bryophyte 6 30 10 12
Fungi 30 38
Invertebrate 53 36 19 131
Lichen 17 231 294 6
Mammal 1 2 25
Total 106 343 330 174
* Plus 78 vascular plants & other birds/mammals that use habitat not tree

9. -> AshEcol - species most at risk from loss of ash
Species group
Impact of Ash dieback
Red Amber Yellow Green
Bird 0 3 4 5
Bryophyte 6 3 39 10
Fungi 30 1 37 0
Invertebrate 53 73 94 19
Lichens 17 45 190 294
Mammals 0 7 19 2
 Takes conservation status into account
 Can also be assessed by location/ species distribution/ presence of
alternative ‘host’ tree species

10. 2b. Synthesis - alternative tree species, both as
‘hosts’ and to ‘replace’ ecosystem function?
Alternative species if
ash is lost?
Decompos-ition
Litter
quality
Nutrient
cycling
No. of a-a
species
Acer campestre
Acer pseudoplatanus
Alnus glutinosa
Betula pubescens/pendula
Fagus sylvatica
Juglans regia
Populus tremula
Prunus avium
Quercus robur/petraea
Sorbus aucuparia
Tilia cordata
Most suitable alternative
Intermediate alternative
Least suitable alternative
NB these conclusions are dependent on available
data – in some cases there are few or no data and
this must be explicit, to indicate confidence level…

11. 2c. Synthesis – impacts of
climate change – tree health
• Site conditions (now and into the future) are critical for tree
health – trees under stress are more vulnerable to pests and
pathogens
• Data synthesis examples (Broadmeadow & Ray 2005 - FR):

12. -> wider landscape issues and climate change
– habitat networks for species movement?
Potential loss due to agric. Landscape permeability to forest species intensification
Potential loss due to agric. intensification
Gimona et al (2012)
Landscape permeability to forest species
Present-day connectivity potential 2050s projection – Climate & Land Use
Change
90th
percentile
75th
percentile
Current
Broadleaved
Woodland
90th
percentile
75th
percentile
Potential
Loss of
connectivity
Present-day connectivity potential 2050s projection – Climate & Land Use
Change
90th
percentile
75th
percentile
Current
Broadleaved
Woodland
90th
percentile
75th
percentile
Potential
Loss of
connectivity
Source: Gimona et al - JHI

13. 3. Advice & recommendations
- future resilient landscapes
• Simplified searchable databases for woodland managers –
best available information for each pathogen/tree species
• Woodland management guidance for areas vulnerable to
loss of trees due to pathogen attack e.g.:
Which tree species are best alternative hosts?
Are tree species mixtures better than single species?
Protocols for assessing different management methods to
reduce damage/aid recovery at different sites
• Wider landscape context - spatial modelling and analysis

14. 3a. Alternative tree species as hosts?
– examples for ash-associated species
• Some tree alternatives only ‘good hosts’ for certain
groups of ash-associated species
• Conifers generally not “good” for ash-associated species
• Oak ‘good host’ for many ash-associated species

15. 3b. Advice - are mixtures of species
better than single species?
19 tree species = 91.6%
Corylus avellana = 86%
Fraxinus ornus = 83.6%
Ulmus procera/glabra = 78.6%
Quercus robur/petraea = 68.5%
• YES – mixtures will
support the greatest
number of species
• YES – other research
(Ray et al – FR) has also
shown reduced
pathogen attack in
mixed forests
• BUT: site conditions
need to be suitable for
species selected
• AND ecosystem function
also needs to be
considered…

16. 3b. Five step process to assess different
site management options
1. Assess biodiversity of site (desk study –
site records, NBN database…)
2. Short list priority species for conservation
(AshEcol database)
3. Identify alternative tree and shrub
species that could support the ash-associated
species if ash is lost (AshEcol)
4. Assess site conditions on the ground –
trees present, etc
5. Assess management options
15 case
study
sites

17. -> Case study summary: vulnerable
species; alternative trees and shrubs
Number of sites
7
6
5
4
3
2
1
0
<10 10 - 49 50 - 99 100 - 149
Number of vulnerable species
a. Species vulnerable to loss of ash:
Half the case study sites had
50+ species vulnerable to
loss of ash
b. Status of alternative trees and shrub species:
Most case study sites had
alternative ‘host’ trees and
shrubs present, but often at
low abundance

18. -> Case study summary: management
options to aid persistence of ash-associated
biodiversity if ash is lost
Site ID
Current
management New management
Encourage
natural
regeneration
Introduce
species by
planting
1 min intervention no change X
2 min intervention no change X
5 min intervention no change X
13 min intervention no change X
8 coppicing no change X
7 coppicing no change X
14 thinning no change X
12 limited coppicing thinning/small patch felling X
15 min intervention thinning / group felling X
4 limited coppicing small patch felling X
6 min intervention thinning / group felling X
11 limited coppicing increase extent of coppicing X
9 min intervention group felling X
3 min intervention group felling X
10 min intervention group felling X
Increasing change in site management
photo R Harmer
photo M Mackinnon

19. Summary
• Research synthesis to provide ‘best
available information’, level of
confidence and gaps should
underpin management decisions
on tree health and future resilient
landscapes
• We have powerful analysis tools
and can readily do this for different
pathogens and different tree
species….NOW
• Pathogens can have rapid and
devastating impacts on our species
and landscapes – if we wait until
there is an ‘impact’, it is often ‘too
late’ to have much effect….
Pathogens
are not
always
predictable!

20. Thank you
alison.hester@hutton.ac.uk
Ash project team:
• The James Hutton Institute
• Forest Research
• Royal Botanic Garden Edinburgh
• University of Aberdeen
• RSPB
• Independent Bryologist
Funders:
• Defra
• DoE Northern Ireland
• Forestry Commission
• JNCC
• Natural England
• Natural Resources Wales
• Scottish Natural Heritage