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Does landscape heterogeneity modify the trade-off between production and
biodiversity?
Rodolphe Sabatier & Muriel Tichit
DIET A G R I C U L T U R E
E N V I R O N M E N T
INRA SAD – Sciences for Action and Development Division, PARIS
Stating the problem
Explaining ‘Landscape Heterogeneity’
com
posit
ionn
al h
eter
ogen
eity
+ +
+
structural heterogeneity + + +
200 m
afte
r Fa
hrig
201
1
200 m
Landscape simplification
Stating the problem
‘Biodiversity needs heterogeneity’
Benton 2003Tscharntke 2005
Fahrig 2011
– mechanization and field enlargement– use of chemical inputs in large areas– loss of semi natural elements– …
= qualitative reviews need for quantifications
biod
ivers
ity
production
To what extent can biodiversity be enhanced by increasing landscape heterogeneity?
Stating the problem
Case study
– A grassland landscape (5000 ha) with 50 beef cattle farms
Case study
– A grassland landscape (5000 ha) with 50 beef cattle farms
– Bird sp. which life cycle is deeply linked to management practices
fecundity survival
Spatially explicit dynamic model
Landscape
FieldFarm
50% 25%
25%
mowing heavy (productive) grazing light (ecological) grazing
Sabatier 2010 Teillard 2010
Bird
gro
wth
rate
herbage production (LU.days.ha-1)
bird
pop
ulat
ion
size
Relative effect of composition and structure
Sabatier 2010
Bird
gro
wth
rate
herbage production (LU.days.ha-1)
bird
pop
ulat
ion
size
Relative effect of composition and structure
Composition
mowing (39%) heavy (productive) grazing light (ecological) grazing
Sabatier 2010
Bird
gro
wth
rate
herbage production (LU.days.ha-1)
bird
pop
ulat
ion
size
Relative effect of composition and structure
Composition Structure
landscape structure
bird
pop
ulat
ion
size
mowing 39% heavy (productive) grazing light (ecological) grazing
Sabatier 2010
herbage production (LU.days.ha-1)
bird
pop
ulat
ion
size
Heterogeneity leverages the trade-off (in biodiversity)
heavy (productive) grazing light (ecological) grazing
Sabatier 2010
mowing 39%
herbage production (LU.days.ha-1)
bird
pop
ulat
ion
size
Heterogeneity leverages the trade-off (in production)
mowing heavy (productive) grazing light (ecological) grazing
Sabatier 2010
• Heterogeneity leverages the tradeoff
• The positive effect of heterogeneity derives from complementarities between management regimes
• Heterogeneity more important for mobile species
• Modifying landscape heterogeneity requires coordination between farmers
Conclusion
From possible landscapes to feasible
landscapes
Future challenges
Co-design of feasible landscapes with farmers and other stakeholders
Fundings 2009-2012 FarmBird project« Coviability models of FARMing and BIRD biodiversity »
Thank you for your attention
