1. No category

Friday 17. April 2015
University of Copenhagen
Erik Aude, HabitatVision
Jacob Heilmann-Clausen, CMEC
Motivation
• A highly prioritised habitat-type in the EU.
”Alluvial forests with Alnus glutinosa and
Fraxinus excelsior”.
• Probably the most species rich forest type
in Denmark
2
Background
Alnus glutinosa
•Tolerates high water level most of the
year
•Tolerates coppicing for centuries
What was tested in the project?
The influence of
coppicing on the
diversity of vascular
plants and mosses.
Data
• 5 random sample plots per department
• Size of sample plots: 15x15 m og 5x5 m
• 53 departments and 262 sample plots
• 2-129 years since coppiced
• Vascular plants and mosses
• Light, water level and pH
• Forest structure (volume of dead wood,
Basal area)
6
13 yr since coppiced
60 yr since coppiced
100 yr since coppiced >100 yr since coppiced
Average number of plant species vs. yr. since coppice
38
36
34
32
30
28
26
24
22
20
<15
16-30
31-40
41-60
61-80
81-100
>100
Average number of plant species vs. yr. since coppice
38
36
34
32
30
Coppice cycle
28
26
24
22
20
<15
16-30
31-40
41-60
61-80
81-100
>100
Average number of plant species vs. yr. since coppice
38
36
34
32
30
28
26
24
22
20
<15
16-30
31-40
41-60
61-80
81-100
>100
Average number of plant species vs. yr. since coppice
38
36
34
32
30
28
26
24
22
20
<15
16-30
31-40
41-60
61-80
81-100
>100
Why?
•Continuity
•Increased micro-topographic
variation
•Natural disturbance (water, wind,
uprooted trees)
•Improved forest micro-climate
(humidity and light)
•More dead wood
Dead wood (m3/ha)
35
30
25
20
15
10
5
0
<10
11_40
41_60
Year since coppicing
61_90
>90
Light and Basalarea (BA)
35
30
25
Light (% )
20
> 90 yr.
0-9 yr.
15
50-89 yr.
10
5
10-49 yr.
0
0
10
20
30
40
BA (m²/ha)
50
60
70
NB: If you have spoiled the
Alnus swamps by lowering
the water level => coppice
or heavy grasing to
maintain the Alnus. But the
important biodiversity have
already disappeared.
Thanks to:
•The Danish Nature Agency for
economic support of the project.
•You for listening.
•Jacob Heilmann-Clausen
Threats
Ditches
22
Threats
Ditches
Water extraction
23
Threats
Ditches
Water extraction
?
24
Ordination og artssammensætning
Gradientanalyse af planter i felter
300
250
DCA2
200
150
Tørreste 25%
Vådeste 25%
100
50
0
0
25
50
100
150
200
DCA1
250
300
350
400
Ordination og artssammensætning
Gradientanalyse af planter i felter
300
250
DCA2
200
150
Tørreste 25%
Vådeste 25%
100
50
0
0
26
50
100
150
200
DCA1
250
300
350
400
Ordination og artssammensætning
Gradientanalyse af planter i felter
300
Drænede
250
DCA2
200
150
Tørreste 25%
Vådeste 25%
100
50
0
0
27
50
100
150
200
DCA1
250
300
350
400
Kontinuitet er vigtigt!
• Det giver mulighed for at opbygge
specielle økologiske forhold
28
Dødt ved
• Mosser har gavn af dødt ved
29
Forstyrrelse ser også ud til at foregå i de
urørte ellebevoksninger
• Væltede træer giver fx nye nicher (ved,
vand og lys).
• De ændrede levevilkår med opbygning af
organisk materiale kan anses som
forstyrrelse
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Driftsmæssige anbefalinger
til biologisk mangfoldighed i ellesumpe
1. Udlæg ellesumpebevoksninger til urørt skov
2. Vælg bevoksninger med længst kontinuitet
3. Ved stævningsdrift, foretages stævningen
hvert 4. årti eller oftere
4. Efterlad noget dødt ved
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