Large Scale Impacts of Grassland management and changes in livestock production...

Large scale impacts of grassland management and changes in livestock production systems

Susanne Rolinski, Isabelle Weindl, Jens Heinke, Benjamin Bodirsky,

Anne Biewald and Hermann Lotze-Campen

15.10.2014

Grassland productivity and livestock production

MAgPIE

global agro-economical model

• feed baskets for livestock production systems

• livestock products

• landuse pattern

LPJmL

global vegetation and crop model

• grass growth and yield

• management of pasture

Grass in LPJmL So far

• frequent mowing

• dependence on grass productivity

New

• mowing and grazing

• difference in frequency and intensity

• fate of NPP differs

feedback of grazing and mowing on productivity

Grass management options Default option • harvest when

leaf biomass > 100 g C m-2

• removed biomass is 50% of leaves

• goes to harvest removal from paddock

Grass management options Extensive grazing • during the entire

vegetation period grazing of biomass by cattle

• low density (~ 0.5 LSU ha-1)

• removed biomass goes to cattle, soil and atmosphere

Varying LSU ha-1

(g C m-2)

(g C m-2 a-1)

(g C m-2 a-1)

Average 1998 – 2002

Numbers: xx means x.x LSU ha-1

Varying LSU ha-1

(g C m-2 a-1)

(g C m-2 a-1)

(g C m-2)

Distribution per livestock density

Optimal LSU

maximum harvest under grazing

livestock density under which maximum harvest is achieved

(g C m-2 a-1)

(LSU ha-1)

Optimal LSU

maximum harvest under grazing

9.3 GT C

livestock density under which maximum harvest is achieved

13975 Mio LSU

(g C m-2 a-1)

(LSU ha-1)

Optimal LSU

… but the world is not only grassland

What is the potential compared to current numbers?

current landuse pattern

current numbers in land-based systems

current numbers in all systems

Livestock numbers (Mio LSU) 2754 44.7 256

Grass harvest (GT C) 1.75 0.07 0.32

multiply pasture area and sum

GLW data in production systems LGA, LGH, LGT and their grazing demand

same for all livestock production systems

Conclusion and Outlook

• Integrated assessment of livestock

• production

• feed demand

• impact on land use, water use, emissions, prices

• requires

• link of production system to feed baskets

• description of transitions in production systems and diets

Next steps:

grassland management link to production systems

transition between diets into landuse model

Special tribute to Pete Smith for sponsoring

Large Scale Impacts of Grassland management and changes in livestock production...

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