Is single tree selection suited for Tasmania´s
Wet Eucalypt Forests?
Lessons from the European experience
Andreas Rothe
University of Applied Sciences Weihenstephan, Germany
Mark Neyland, John Hickey
Forestry Tasmania
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Rothe/Neyland/Hickey
Single Tree Selection
Overview:
•
How common is single tree selection in
Europe
•
Experiences with single tree selection in
Bavaria
•
Experiences with single tree selection in
Tasmania
•
Conclusions
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Rothe/Neyland/Hickey
Single Tree Selection
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Rothe/Neyland/Hickey
Single Tree Selection
Bavaria
Total area:
Inhabitants:
Forest area:
State forest:
Annual cut:
7.0 m ha
12 m
2.5 m ha
0.8 m ha total, 0.6 productive
5.0 m m3 = 8.3 m3 ha-1 y-1
(State forest)
Tasmania
Total area:
Inhabitants:
Forest area:
State forest:
Annual cut:
6.8
0.5
3.3
1.5
3.0
m ha
m
m ha
m ha, 0.7 productive
m3 = 4.3 m3 ha-1 y-1
(State forest)
Forest
State Forest
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Rothe/Neyland/Hickey
Single Tree Selection
Proportion of Plenterwald (Continuous cover forests)
(% of forest area)
Real Plenterwald
Europe
(Schütz 2001)
Continuous cover forestry
Germany
Continuous cover forestry
Bavaria
(National forest inventory 2002)
(Internal inventory)
Switzerland:
8.0 %
Real Plenterwald: 0.3 %
Real Plenterwald:
ca. 1 %
Slovenia:
4.1 %
Multilayered
9%
(continuous cover forests)
Continuous cover forests: 11%
Austria:
< 2%
Germany:
< 2%
France:
1.1 %
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Regeneration methods in Bavaria (State forests)
Rothe/Neyland/Hickey
(estimation)
Single Tree Selection
Single tree selection
10 %
Group selection, shelterwood, edge
cutting (<0.5 ha)
70%
Planned clear cuts
<1%
Clear cuts after storm/insects
20 %
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Rothe/Neyland/Hickey
Single Tree Selection
Shade tolerance of European tree species
Minimum rel. light intensity
for foliage (%) (Mischerlich 1982)
Ellenberg Indicator Value Light
0
2
4
6
8
1-2
Abies alba
Fagus sylvatica
“Plenterwald
species“
Picea abies
1-2
3-4
Quercus petraea
5
Pinus sylvestris
10
Larix decidua
20
?
Eucalyptus obliqua
27 (Alcorn 2002)
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Rothe/Neyland/Hickey
Single Tree Selection
Measurement of regeneration in the State Forests of Bavaria
(about 150,000 inventory plots total, sampling about 15,000/year)
understorey regeneration
(overstorey > 30% crown cover)
open regeneration
regeneration without overstorey
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Rothe/Neyland/Hickey
Single Tree Selection
Regeneration of beech (very shade tolerant)
(Lower Franconia, 100,000 ha, 30,000 inventory plots)
p ro p o tio n o f fo re s t c o v e r (% )
beech NW Bavaria
60
50
40
30
Nearly completely natural
regeneration
20
10
0
old forest
Trees
> 20y
understory
Understorey
Regeneration
regeneration
young
forest
Open
Regeneration
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Rothe/Neyland/Hickey
Single Tree Selection
Regeneration of pine (shade intolerant)
(Upper Palatinate, 100,000 ha, 40,000 inventory plots)
propotion of forest cover (% )
pine E Bavaria
35
30
25
20
15
Nearly completely natural
regeneration
10
5
0
Trees
> 20y
old
forest
Understorey
understory
Regeneration
regeneration
Open
young
forest
Regeneration
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Rothe/Neyland/Hickey
Single Tree Selection
Regeneration of oak (rel. shade intolerant)
propotion of forest cover (% )
(Lower Franconia, 100,000 ha, 30,000 inventory plots)
25
20
Mostly planting or sowing
15
10
5
0
old forest
Trees
> 20y
understory
Understorey
Regeneration
regeneration
young
forest
Open
Regeneration
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Rothe/Neyland/Hickey
Single Tree Selection
Standards method to regenerate light demanding oak
1. Planting on
windthrown areas
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Rothe/Neyland/Hickey
Single Tree Selection
Standard methods to regenerate light demanding oak
2. Rapid Shelterwood
System (0.5 – 4 ha)
- Harvesting about 70 %
of standing volume
- Sowing oak underneath
the retained trees
- Harvesting the retained
trees within 5 years
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Single Tree Selection
Area regenerated with oak (Spessart, Germany)
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Single Tree Selection
Economic outcome
1. Model calculation:
2. Reality:
Bavarian State Forest
Company:
Profit:
(2006/2007)
120 A$ ha-1 y-1
Profit/turnover ratio: 15 %
Even aged Even aged
with windthrow
Plenterwald Plenterwald
unfavourable
Net yield of different forest management systems
(Hanewinkel 1998)
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Rothe/Neyland/Hickey
Single Tree Selection
Conclusions for Bavaria:
1.
Continuous cover methods work
well for shade tolerant species like
beech, fir or spruce
2.
Continuous cover forests can yield
at least the same profits as evenaged forests
3.
Continuous cover methods strongly
disfavour light-demanding species
like pine or oak
4.
Regeneration of light-demanding
species usually uses openings
between 2-5 tree lengths in size
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Rothe/Neyland/Hickey
Single Tree Selection
And now moving to Tasmania …….
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Single Tree Selection
Eucalypt regeneration at Warra at age 3
(Neyland 2008)
Seedlings/ha
8000
6000
4000
2000
0
clearfell
stripfell
dispersed
SGS
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Single Tree Selection
Colonisation by rainforest seedlings
(Tabor , et al. 2007)
Avg. seedlings per hectare
3000
Celery Top Pine
2500
Leatherwood
Myrtle
2000
Sassafras
1500
1000
500
0
0
50
100
150
200
250
Distance from edge (m)
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Single Tree Selection
Economic outcome
Expectation value (revenues - costs) of different regeneration techniques at Warra
(Nyvold 2001)
12000
10000
8000
$/ha
6000
4000
2000
0
CBS
-2000
10%
Dispersed
30%
Aggregated
SGS-A
SGS-B
-4000
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Rothe/Neyland/Hickey
Single Tree Selection
Conclusions for Tasmania’s
Wet Eucalypt Forests:
1.No examples of successful selective
silviculture in Tall Wet Eucalypt
forests
2.Single tree selection leads to
inadequate eucalypt regeneration
3.Single tree selection is not sound
from an economic point of view
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Rothe/Neyland/Hickey
Single Tree Selection
Fagus
sylvatica
Natural
regeneration
shade
Quercus
petrea
Eucalyptus
obliqua
Small gaps
Tree height
Fire, Wind ? Infrequent
wildfires
Very tolerant Slightly
Intolerant
tolerant
< 40 m
< 35 m
< 80 m
Understorey
naked
grasses
Minimum
opening for
regeneration
1 tree
2 tree lengths 2 tree lengths
Standard
silviculture
Shelterwood, Rapid
shelterwood
group
selection
Trees and shrubs
Clearfell, Burn
and Sow
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Single Tree Selection
How small can we go ?
Group selection with openings of about 80 m (Warra 8G)
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Single Tree Selection
Overall conclusions:
1.
The transfer of silvicultural experiences must be
based on ecology of the site and the tree species.
2.
Continuous cover methods which are hardly used for
oak and pine in Europe are very unlikely to work for
tall wet Eucalypt forests in Tasmania.
3.
Forestry with light demanding species does not
require large clearcuts but needs minmum openings of
2 - 5 tree lengths.
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