Adaptation of mountain regions
to drought recurrence in a
context of global change
Sandra LAVOREL
Pénélope Lamarque, LECA
Benoît Courbaud, Laurent Dobremez, Baptiste Nettier,
François Véron, Irstea, Grenoble
Recent climatic trends in the Central French Alps
The case of Vercors
Precipitation
T min
T max
Sylvain Bigot, Sandra Rome
Jean-Paul Laurent
Pierre-Eymard Biron
Perception by farmers and shepherds
of consequences of droughts since 2003
•
•
•
•
Signs of climate change - “Fewer storms in summer"
Decrease in pastoral resources
Decrease in water availability for summering herds
Vegetation dynamics – “Invasions” by undersirable species,
superficial soil degradation
 Adaptations at farm scale
– Pastoral systems have integrated the hypothesis of
increasingly frequent droughts into their fucntioning
– BUT: tactic responses without long-term adaptation
– Impacts and adaptation options differ widely across farming
systems (level of reliance on winter fodder)
– Given a scenario of increasing drought recurrence, only
strong system transformations would allow persistance of
livestock systems
– Drought is only one risk among others for livestock systems:
socio-économic context, structural constraints
Nettier et al., Journal of Alpine Research 2010
Perception by foresters
of consequences of droughts since 2003
2003
2004-5
• 2003: strong defoliation on drier / thinner
soils, but not in productive stands; good
recovery with only limited mortality
• Beetle damage on sprice in 2004-5
• Foresters are aware of climate change and
the risk of recurring droughts, but are yet
to see climate change effects
• Adaptation responses are limited:
– Manage stands towards species and
structural diversity
– Reduce the share of spruce in regional plans
– Infrastructure for increased fire risk
– Inconclusive attemps to plant more southern
species (frost)
– No consideration of the forest – grassland
interface
A high uncertainty on expected
climate trends
Mean max summer T
Number of days of heat wave
Mean annual precipitation
Length of drought
SECALP project
Objective: To analyse adaptation mechanisms for
mountain regions in the face of climate change,
especially recurring droughts
– Mechanisms of ecosystem resilience and transformation
– Processes of adaptation for livestock farming and forestry
– Expected effects of climate change scenarios, in the
context of social transformations
 Guidelines for supporting managers through policy and
infrastructure
 Strategies for long term observation
SECALP: An integrated conceptual framework
Ecosystem
adaptation
Land use
adaptation
Scenarios and
pathways to
sustainable
management
Long-term
observation system
The Central French Alps LTSER
Transdisciplinary network
40 scientists, 25 PhD & postdocs
1 national & 1 regional park
Vercors high plateaux
Villar d’Arène
Queige
5
15
10
25
15
Lanslebourg
0
0
5
Mortality rate
35
Are there discernable effects of drought
years on tree mortality?
1940
1960
1980
2000
mortality rate
CI
1920
1940
1960
1980
2000
1940
1960
1980
2000
Méaudre
0.0
1
0.5
2
1.0
3
Engins
1900
1.5
1920
0
Mortality rate
4
1900
1900
1920
1940
1960
1980
2000
1900
1920
• Overall low mortality rates and no long term trend
• Links to climate variables:
– Strongly predominant effects of storms (yr n or n-1)
– No effect of the Palmer Drought Severity Index (Climatic Research
Unit, Norwich)
– 2nd order effect of increased precipitation
Seignobosc et al. in prep.
Experimental simulation of the combined effects of
drought and management
- 80% reduction in summer precipitation + 1 C night time warming
- One extreme event: one month of total drought + 6 C warming
- Mowing (0/1) – split plot design within the climate manipulation
 Complex interactions and surprises ?
Measurements over 3 years
• Plant level: leaf senescence, photosynthetic stress, growth, leaf traits
• Community structure: species diversity & composition
• Ecosystem functioning: standing biomass, litter depth & decomposition
Slow climate effects vs.
rapid management effects
CLIMATE CHANGE
Limited impacts of climate
manipulation on plantand community-level
parameters
# plant functions
 leaf senescence
 plant development
# litter decomposition
Longer term effects?
MOWING
Importance of competition
Dominance by F. paniculata
 competition intensity
 above-ground biomass
 litter production
 changes in composition
 species diversity
From field data to projections
of ecosystem services
Step 1
Environmental
drivers
Step 2
Response and
effects traits
Step 3
Ecosystem
properties
Step 4
Ecosystem
services
Plant
Microbial
NNI= LUT+ β1*Altitude
VegHt = LUT+ β1*N
Green biomass =
β0 + β1 *NNI
+ β2 *VgHt – β3 *LDMC
Stakeholders’
perceptions
Lavorel, Grigulis, Lamarque et al (2011), J Ecol
PLANT TRAITS (CWM and FD)
Vegetative height
LDMC, SLA
LNC, LCC, C/N
MICROBIAL TRAITS
NEA : Km, Vmax
AOB, AOA, Ns, nrxA
DEA, nirS, nirK,
Fungi:Bacteria
REML
ECOSYSTEM PROPERTIES
Green herbage mass
Litter mass
Litter decomposition
Microbial biomass N
Potential Leached NO3 and NH4
N Mineralization Potential (NMP)
Ecosystem
services
Linear mixed model with restricted maximum likelihood estimations
Relative contributions of plant and microbial traits to a range of
above- and belowground processes under complex field conditions
with diverse plant communities
Direct and indirect abiotic effects
on C and N stocks across the landscape
Altitude
RESPONSE
- EFFECT TRAITS
e
NNI
CWM_VgHt
PNI
CWM_LNC
e
Green biomass
Litter
e
e
ECOSYSTEM
FUNCTION
e
0 - 0.2
0.2 - 0.4
0.4 - 0.6
0.6 - 0.8
Positive - Negative
C
N
Propagation of ABIOTIC effects to TRAITS and
ECOSYSTEM FUNCTION
ENVIRONMENT
e
Lavorel & Grigulis J. Ecol. 2012
A functional continuum from plant to microbial control of
ecosystem functioning, associated with plant responses
to grassland management intensity
Exploitative
PLANTS
Bacterial
Dominance
MICROBIAL
ABUNDANCES
Fast
Conservative
Fungal
Dominance
MICROBIAL PROCESSES
Slow
Microbial control
Plant control
Biomass
Production
Carbon
sequestration
Nutrient
retention
Lavorel & Grigulis J.Ecol. 2012; Grigulis et al. J. Ecol. in press
Modelling framework for climate and
management impacts on ecosystem services
Plant and microbial
functional traits
VgHeight
Ecosystem properties
Ecosystem services
Biomass
Fodder quantity
Fodder N concentration
Fodder quality
Soil fertility
Leaf P
Potential N
mineralization
Nitrif
Vmax
Nitrate retention
Water quality
Leaf N
Leaf DM
Denit DEA
Abiotic
parameters
Soil organic matter
Carbon sequestration
Flowering date
Pollination
Litter mass
Esthaetic value
Plant diversity
Plant diversity
conservation
WHC
Sol NO3
Altitude
Lamarque et al., in prep.
Participatory scenario development
1
3
Co-building of 4 highly detailed storylines with regional experts
- 2 drought frequencies x 2 socio-economic contexts
=> storylines
Biophysical model
parameter changes
- Field experiments
and scientific experts
4
2
Co-building of land management
adaptation maps with farmers
Modelling of effects on ecosystem services of DIRECT climate
effects and INDIRECT effects through farmers adaptation
Lamarque et al., submitted – see presentation by Pénélope Lamarque Wed. 2:40 p.m.
Model parameterisation for ecosystem
service projections
Plant and microbial
functional traits
VgHeight
Ecosystem properties
Ecosystem services
Biomass
Fodder quantity
Fodder N concentration
Fodder quality
Soil fertility
Leaf P
Potential N
mineralization
Nitrif
Vmax
Nitrate retention
Water quality
Leaf N
v
Leaf DM
Denit DEA
Abiotic
parameters
Soil organic matter
Carbon sequestration
Flowering date
Pollination
Litter mass
Esthaetic value
Plant diversity
Plant diversity
conservation
WHC
Sol NO3
v
Altitude
Ecosystem services supply according to
stakeholder criteria
Ecosystem properties
Green biomass
Fodder crude
protein content
+
Ecosystem services
=
Agronomic value
Plant diversity
=
Pollination
Mean flowering
onset date
Litter Mass
+ +=
Cultural value
Lavorel, Grigulis, Lamarque et al. J. Ecol. 2011
Projected ecosystem services change
Scenarios
Intermittent international
Current
Land use
Intermittent local
Drastic international
Carbon sequestration
Soil fertility
Drastic local
Water quality
Plant
diversity
Green
biomass
Litter
mass
Flowering
onset
Carbon sequestration
Soil fertility
Water quality
Plant
diversity
Green
biomass
Forage quality
Litter mass
Flowering onset
 Under more drastic scenarios, shift from
provisioning and cultural services of local interest
to regulation services of larger scale interest
Forage quality
Lamarque et al., in prep.
Implications
• Current climate impacts are difficult to detect through
observations or experiments, especially for forests
• Greater concern within the pastoral than the forestry
sector, but limited adaptation / adaptability for both
• Basic understanding of ecological constraints :
– Guidelines for policy and management for the maintenance of
multifunctional landscapes and of local livelihoods
– Payments for non-marketed ecosystem services or subsidies
– Need to take into account trade-offs between ES
• Enhance adaptation and sustainable delivery of ES
– An integrated observation system of (i) climate and extreme
weather events, (ii) management systems and practices, and (iii)
ecosystems
– Training material tailored for managers and extension officers