professor alison hester, head of safe guarding
DESCRIPTION
Natural Capital Team, James Hutton InstituteTRANSCRIPT
How can research contribute to future resilient landscapes? Case studies from woodland habitats
Alison Hester, Ruth Mitchell, Alice Broome
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?
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
1a. Primary research – dependent species / ecosystem function
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
Both require intensive, field and lab based measurements…
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)
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
percentile75th
percentilePotential Loss of connectivity
Potential loss due to agric. intensification
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 …
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).
-> AshEcol: numbers of ash-associated species
* Plus 78 vascular plants & other birds/mammals that use habitat not tree
Group
High Partial Cosmopolitan UsesBird 7 5Bryophyte 6 30 10 12Fungi 30 38Invertebrate 53 36 19 131Lichen 17 231 294 6Mammal 1 2 25
Total 106 343 330 174
Level of association with F. excelsior
-> AshEcol - species most at risk from loss of ashSpecies group
Red Amber Yellow GreenBird 0 3 4 5Bryophyte 6 3 39 10Fungi 30 1 37 0Invertebrate 53 73 94 19Lichens 17 45 190 294Mammals 0 7 19 2
Impact of Ash dieback
Takes conservation status into account Can also be assessed by location/ species distribution/ presence of
alternative ‘host’ tree species
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
2b. Synthesis - alternative tree species, both as ‘hosts’ and to ‘replace’ ecosystem function?
Most suitable alternativeIntermediate alternativeLeast suitable alternative
Potential conflict
?
Ecosystem fu
nction v specie
s supporte
d
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…
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):
-> wider landscape issues and climate change – habitat networks for species movement?
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
percentile75th
percentilePotential Loss of connectivity
Potential loss due to agric. intensificationLandscape permeability to forest species
Present-day connectivity potential 2050s projection – Climate & Land Use Change
90th percentile
75th percentile
Current Broadleaved Woodland
90th
percentile75th
percentilePotential Loss of connectivity
Potential loss due to agric. intensification
Source: Gimona et al - JHI
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
• 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
3a. Alternative tree species as hosts? – examples for ash-associated species
3b. Advice - are mixtures of species better than single species?
Quercus robur/petraea = 68.5%
19 tree species = 91.6%Corylus avellana = 86%Fraxinus ornus = 83.6%Ulmus procera/glabra = 78.6%
• 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…
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
Num
ber o
f site
s
0
1
2
3
4
5
6
7
<10 10 - 49 50 - 99 100 - 149
Number of vulnerable species
Half the case study sites had 50+ species vulnerable to loss of ash
a. Species vulnerable to loss of ash:
-> Case study summary: vulnerable species; alternative trees and shrubs
Most case study sites had alternative ‘host’ trees and shrubs present, but often at low abundance
b. Status of alternative trees and shrub species:
-> Case study summary: management options to aid persistence of ash-associated biodiversity if ash is lost
Site IDCurrent 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
Incr
easi
ng c
hang
e in
site
m
anag
emen
t
phot
o R
Har
mer
photo M Mackinnon
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!
Thank [email protected]
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