Does landscape heterogeneity modify the trade-off between production and biodiversity? Muriel Tichit

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

muriel.tichit@agroparistech.fr