ecology and silviculture of sycamore valbro acer ... · valbro ecology and silviculture of sycamore...

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ValBro ECOLOGY AND SILVICULTURE OF SYCAMORE (ACER PSEUDOPLATANUS L.) IN EUROPE Sebastian HEIN 1 , Catherine COLLET 2 , Christian AMMER 3 , Noël LE GOFF 2 , Jens Peter SKOVSGAARD 4 , Peter SAVILL 5 1 Forest Research Institute of Baden-Wuerttemberg, Freiburg & University of Applied Forest Sciences, Rottenburg, Email: [email protected] 2 UMR INRA-ENGREF 1092, Champenoux 3 Department of Silviculture and Forest Ecology of the Temperate Zones, Georg August University, Göttingen, 4 Forest and Landscape Denmark, University of Copenhagen, 5 Department of Plant Sciences, University of Oxford. Introduction Sycamore is a widespread but minor species that seldom occupies more than 3% of a forest area. Its natural range includes large parts of Europe. It has become widely naturalized beyond its native range. Site requirements Growth pattern Crown architecture Stand dynamics This poster was prepared under the COST action E42 "Growing Valuable Broadleaved species (ValBro)". This poster is a summary of Hein, S., Collet, C., Ammer, C., Le Goff, N., Skovsgaard, J.P., Savill, P.: A review on growth and stand dynamics of sycamore (Acer pseudoplatanus L.) in Europe: implications for silviculture, freely available on www.valbro.uni-freiburg.de The natural range of Sycamore in Europe (Rusanen & Myking 2003, EUFORGEN) For high productivity sycamore requires a deep, moist and freely draining soil. In Central Europe, it is characteristic of constantly moist loamy places on mountain slopes, gentle valley hollows, and narrow fresh valley floors. Sites to avoid are badly drained and waterlogged soils because of top dieback and premature deaths. Natural pruning of sycamore is fast due to its rapid early height growth. A two phase silvicultural system is recommended to control and reduce branch development and thus knottiness: slow diameter growth during the first phase (tending) and then free growth until the target diameter is reached. Production objectives for sycamore: Height growth curves for sycamore all share the characteristic of rapid early height growth (<20 – 25 years) that then slows. On the best sites sycamore reaches a height of 19.5 m at age 20 years. Compared to beech, sycamore is taller between 20 – 40 and similar to ash. This explains its vigor in mixed stands. Height growth of sycamore compared to beech and ash. Left: Knottiness for a mean rad. increment of 2-5 mm yr -1. Right: Knottiness in a two phase silvicultural system during the tending and thereafter free growth. 2 mm y -1 3 mm y -1 4 mm y -1 5 mm y -1 branch free 2 nd phase 1 st phase knotty core branch free branch free Sycamore is often a component of mixed broadleaved or conifer- broadleaved stands, where it may be found in small groups or in intimate mixtures with beech, silver fir, ash or oak. Sycamore regenerates relatively easily although, damage by browsers or bark stripping by grey squirrels may endanger production of valuable timber. Like many other species, light requirements increase as seedlings develop. Target DBH [cm] Mean radial Increment [mm yr -1 ] Prod. time (rotation) [yrs] Number of crop trees/ha [ - ] Length of clear bole (60yrs: H o =30 m) [m] 60 3 100 78 14.4 4 75 72 11.8 5 60 69 9.7 sycamore target tree: DBH 67 cm, clear bole length: 9.8 m, tree height: 29.2 m, crown diameter: 12.4 m, age: 85 yrs, Belgium. (Photo S. Hein) Production objectives sycamore beech sycamore ash

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Page 1: ECOLOGY AND SILVICULTURE OF SYCAMORE ValBro ACER ... · ValBro ECOLOGY AND SILVICULTURE OF SYCAMORE (ACER PSEUDOPLATANUS L.) IN EUROPESebastian HEIN1, Catherine COLLET2, Christian

ValBroECOLOGY AND SILVICULTURE OF SYCAMORE(ACER PSEUDOPLATANUS L.) IN EUROPE

Sebastian HEIN1, Catherine COLLET2, Christian AMMER3, Noël LE GOFF2, Jens Peter SKOVSGAARD4, Peter SAVILL5

1Forest Research Institute of Baden-Wuerttemberg, Freiburg & University of Applied Forest Sciences, Rottenburg, Email: [email protected] 2UMR INRA-ENGREF 1092, Champenoux 3Department of Silviculture and Forest Ecology of the Temperate Zones, Georg August University,

Göttingen, 4Forest and Landscape Denmark, University of Copenhagen, 5Department of Plant Sciences, University of Oxford.

IntroductionSycamore is a widespread but minor species that seldomoccupies more than 3% of a forest area. Its natural rangeincludes large parts of Europe. It has become widely naturalizedbeyond its native range.

Site requirements

Growth pattern

Crown architecture

Stand dynamics

This poster was prepared under the COST action E42 "Growing Valuable Broadleaved species (ValBro)".This poster is a summary of Hein, S., Collet, C., Ammer, C., Le Goff, N., Skovsgaard, J.P., Savill, P.: A review on growth and stand dynamics of

sycamore (Acer pseudoplatanus L.) in Europe: implications for silviculture, freely available on www.valbro.uni-freiburg.de

The natural range of Sycamore in Europe(Rusanen & Myking 2003, EUFORGEN)

For high productivity sycamore requires adeep, moist and freely draining soil. In CentralEurope, it is characteristic of constantly moistloamy places on mountain slopes, gentlevalley hollows, and narrow fresh valley floors.Sites to avoid are badly drained andwaterlogged soils because of top dieback andpremature deaths.

Natural pruning of sycamore is fast due to its rapidearly height growth. A two phase silviculturalsystem is recommended to control and reduce branchdevelopment and thus knottiness: slow diametergrowth during the first phase (tending) and then freegrowth until the target diameter is reached.

Production objectives for sycamore:

Height growth curves for sycamore all sharethe characteristic of rapid early heightgrowth (<20 – 25 years) that then slows. Onthe best sites sycamore reaches a height of19.5 m at age 20 years. Compared to beech,sycamore is taller between 20 – 40 andsimilar to ash. This explains its vigor inmixed stands.

Height growthof sycamorecompared to beechand ash.

Left:Knottiness for a

mean rad. incrementof 2-5 mm yr-1.

Right:Knottiness in

a two phasesilvicultural

system during the tending and thereafter free growth.

2 mm y-1

3 mm y-1

4 mm y-1

5 mm y-1

branchfree

2nd phase

1st phase

knottycore

branchfree

branchfree

Sycamore is often a component of mixed broadleaved or conifer-broadleaved stands, where it may be found in small groups or inintimate mixtures with beech, silver fir, ash or oak.

Sycamore regenerates relatively easily although, damage bybrowsers or bark stripping by grey squirrels may endangerproduction of valuable timber. Like many other species, lightrequirements increase as seedlings develop.

TargetDBH

[cm]

Meanradial

Increment

[mm yr-1]

Prod.time

(rotation)

[yrs]

Numberof croptrees/ha

[ - ]

Length ofclear bole

(60yrs:Ho=30 m)

[m]

603 100 78 14.4

4 75 72 11.8

5 60 69 9.7sycamore target tree:

DBH 67 cm,clear bole length: 9.8 m,

tree height: 29.2 m,crown diameter: 12.4 m,

age: 85 yrs, Belgium.

(Photo S. Hein)

Production objectives

sycamore

beech

sycamore

ash