Effects of afforestation on species
richness of plants and animals in Iceland
Edda Sigurdis Oddsdottir
Icelandic Forest Research, Mogilsa
Asrun Elmarsdottir1, Bjarni D. Sigurdsson2, Bjarni E. Gudleifsson2, Brynja Hrafnkelsdottir3, Arne
Fjellberg4, Gudmundur Halldorsson5, Gudridur G. Eyjolfsdottir1, Gudmundur A. Gudmundsson1,
Kristinn H. Skarphedinsson1, Erling Olafsson1, Maria Ingimarsdóttir1,Olafur K. Nielsen1 and
Borgthor Magnusson1
1)
Icelandic Institute of Natural History 2) Agricultural University of Iceland 3) Icelandic Forest Research, Mogilsa 4) Entomological
Research, Tjöme, Norway; 5) Icelandic Soil Conservation Service.
Corresponding author: [email protected]
Afforestation may have several
consequences:
• Changes soil conditions
• Change ground vegetation
– Original vegetation replaced by woodland
vegetation
– Reduces plant species diversity
• Changes invertebrate fauna
– Depented on tree species used
• Dispersal of introduced species
• New pathogens and pests
Peterken 2001, Engelmark 2001,Cannell 1999
What is biodiversity?
• Species richness; the number of
species in a community, plot or sample
• Species eveness: the distribution of
individuals among the species
• Species diversity; a good measure of
diversity should take into account both
the number of species and the
evenness of individuals in the various
species
Until now, most biodiversity studies have
focused on one or few functional groups:
•Vascular plants
•Birds
•Beetles
Are those representative for the whole
ecosytem???
What about the rest???
Why Iceland??
• Limited native flora and fauna
• Only three native tree species,
– Birch (Betula pubescens) the only forest forming
• Very low forest cover (1.5%)
• Large scale afforestation programs
– Use of introduced conifers (larch, spruce, pine)
• Good opportunity to study the effects of
afforestation on species richness
The goal
• Study the the influence of afforestation on the
ecosystem
• Describe changes in biodiversity
– how communities of flora, fungi, arthropods, and
birds change when open land is converted to forest
• Are there differences between exotic and native
forest types?
More information..
• Posters
– Effects of afforestation by exotic conifers
and native birch on ground vegetation
composition in Iceland
– The effects of afforestation on Collembola
density and species number
• Talk
– Effects of afforestation on carbon stocks
and fluxes of previously grazed
heathlands in Iceland
What are the effects of
afforestation on species richness ?
What are changes in species richness?
Σ (vascular plants, non-vascular plants, fungi, arthropods, birds,)
or
Decreasing
or
Steady
Increasing
13-16 m
7-10 m
4-6 m
Study sites
2-4 m
1990
1985
1965
1952
Two study areas in Iceland, Fljótsdalshérað (East Iceland) and
Skorradalur (West Iceland)
Vegetation types
• grazed heathlands
• native forests (Betula pubescens)
• exotic forests (Larix sibirica, Picea sitchensis, Pinus contorta)
Conducted in chronosequences for each forest type
Study sites
•
•
•
•
Continuous forests larger than 300 ha
Each stand larger than 3 ha
Five plots in each stand
Replicated measurements conducted
on plots
– Except birds
Skorradalur- West Iceland
– Heathland
– Birch forests (Betula pubescens)
– Spruce forests (Picea sitchensis)
•
•
•
•
S-1, planted 1995;
S-2, planted 1970;
S-3, planted 1960-1961, unmanaged
S-4, planted in 1961, managed
– Pine forests
• P-1 planted in 1990
• P-2 planted in 1965-68
• P-3 planted in 1958-59
H-1 Heathland
S-1 Spruce (1995)
S-3 Spruce (1960-61)
Birch
Flora
Licens
Results
0
Moss
Vascular pl
Bushes
1
‐ 35%
‐47%
28
He
at
h
2
‐ 25%
‐ 42%
12
9
rc
h
7
e b
i
9
Na
tiv
9
ru
ce
_1
Sp
ru
ce
_2
Sp
ru
ce
_3
Sp
ru
ce
4
Sp
He
at
h
9
23
1
34
32
9
2
14
2
13
1
Sp
ru
ce
_1
Sp
ru
ce
_2
Sp
ru
ce
_3
Sp
ru
ce
4
Breeding birds
1
1
23
40
16
2
h
1
0
e b
irc
67
Na
tiv
59
Results
Surface insects (Beetles, spiders, flies, etc.)
101
85
th
a
He
71
ru
p
S
_1
e
c
ru
p
S
_2
e
c
ru
p
S
82
_3
e
c
ru
p
S
90
84
4
e
c
it ve
Na
h
rc
i
b
rc
h
18
ive
b
i
e 4
5
Na
t
ru
c
e_
3
5
Sp
ru
c
19
Sp
e_
2
+ 26%
ru
c
e_
1
Collembola
Sp
ru
c
h
5
Sp
He
at
4
rc
h
5
e b
i
4
20
tiv
Earthworms
Na
5
e 4
e_
3
e_
2
e_
1
14
14
ru
c
ru
c
ru
c
ru
c
h
14
Sp
Sp
Sp
Sp
He
at
Soil animals
Results
- 16%
Fungi
11
+ 300%
+ 420%
21
15
8
0
"Total" species richness in heathland, Sikta spruce and native birch
Soil anim.
He
at
h
5
19
Birds
9
67
9
34
101
71
0
18
8
19
9
23
9
32
7
40
82
84
90
18
24
21
24
15
16
h
85
Flora
Na
tiv
e bi
rc
59
Surface insects
Sp
ru
ce
_1
Sp
ru
ce
_2
Sp
ru
ce
_3
Sp
ru
ce
4
12
Fungi
Effects of Afforestation on Total Species Richness
300
#1 Start:
Heathland
200
Birch_E yng
Spruce_1
Larch_1
Larch_3
Larch_2
Heath_E
Heath_W
Spruce 4
Birch_W3
Birch_W1
Thicket stage
Thicket stage
Larch_5
Birch_E old
0
#3: Middle‐aged dense stands
Thinned or Past + Larch_4 Pine_2 Spruce_3
50
#4: OlderBirch or Conifer + Birch_W2
100
#2: YoungOpen Birch and Confer Stands
+
Less Grazing Pressure Pine_1
150
Pine_3
Spruce_2
Number of spp
250
Conclusions
• No difference in “total” species richness of
oldest age classes between conifers and
broadleaved
• Afforestation affects different functional
groups in different ways
• It is not possible to judge the effect of
afforestation on species richness based on
one or few functional group(s)
• Forest management is an important factor in
determinating species richness
Thank you for your attention
Icewood-ers