Jimmy Le Bec - EURAF

TRUNK – CROWN GROWTH TRADE OFF IN POLLARDED TREES: INFLUENCE ON WOOD PRODUCTION

© Jimmy LE BEC , 2015, marais poitevin, France

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Modern agroforestry Keeping trees within crops but reducing competition for light

© Davis Dellas, Arbres & Paysages 32

3rd European Agroforestry conferance

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Pollarding agroforestry trees? Why and When?

crown trunk

How to maximize wood production? © Davis Dellas, Arbres & Paysages 32

3rd European Agroforestry conferance

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© Jimmy LE BEC , 2015

1 year old crown

© Jimmy LE BEC , 2015

© Jimmy LE BEC , 2015

4 years old crown

6 years old crown

Fast re-growth of the crowb after pollarding Jimmy LE BEC

3rd European Agroforestry conferance

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Assessing trunk and crown biomass growth

•Dry weight of ~ 50 branches => allomerty

=> Cross-sectional approach

•Tree ring width => dendrochronology

=>Longitudinal approach

Pressler increment borer Jimmy LE BEC

3rd European Agroforestry conferance

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Marais poitevin : a sylvopastoral region Mostly ash trees (Fraxinus excelsior)

Jimmy LE BEC

3rd European Agroforestry conferance

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Radial growth (mm.year-1)

1 cm

Crown harvest

Pollarding episode may be detected thanks to ring width but also from wood anatomy Jimmy LE BEC

3rd European Agroforestry conferance

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crown trunk

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biomass growth (kg.year-1)

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Simulated trunk (2 m height) and crown biomass growth

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time since first cut (years) Jimmy LE BEC

3rd European Agroforestry conferance

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1250 1200 1150 1100

simulated crown biomass (kg)

15 pollarding scenarios over a 100 years growth cycle

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simulated trunk biomass (kg) Jimmy LE BEC

3rd European Agroforestry conferance

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Further research • Does pollarding increases wood production? • How partial pruning (fodder) affects tree growth? • What about the wood quality?

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Jimmy LE BEC

3rd European Agroforestry conferance

Your questions???

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