Multi-scale spatial variability of amphipod assemblages from the foliar stratum of the Posidonia oceanica (L.) Delile meadow Nicolas Sturaro1, Gilles Lepoint1, Loïc Michel2,
Download ReportTranscript Multi-scale spatial variability of amphipod assemblages from the foliar stratum of the Posidonia oceanica (L.) Delile meadow Nicolas Sturaro1, Gilles Lepoint1, Loïc Michel2,
Slide 1
Multi-scale spatial variability of amphipod
assemblages from the foliar stratum of the
Posidonia oceanica (L.) Delile meadow
Nicolas Sturaro1, Gilles Lepoint1, Loïc Michel2, Sylvie Gobert1
1Laboratoire
d’Océanologie, University
of Liège, Liège, Belgium
2Laboratoire
de Systématique et
Diversité Animale, University of
Liège, Liège, Belgium
Liège 2008
Slide 2
Context of the Study
• Ecological communities are patchy
• Several spatial and temporal scales
• Studying spatial patterns is of ecological importance
understand the causes of the distribution and
abundance of organisms
provide valuable basis for management and
conservation
Slide 3
Context of the Study
• Posidonia oceanica
- forms large meadows
- important habitat for
Egidio Trainito
- endemic species of seagrass
mobile invertebrates
- large number of species
- considerable abundance/biomass
- important trophic ressource
Peter Bryant
• Amphipods
Slide 4
Amphipods
Vertical spatial variability of amphipods is better
known in P. oceanica meadows
Horizontal spatial variability ?
At different spatial scales ?
Slide 5
Objective
Assess the spatial variability, at different scales, of
amphipods living in the P. oceanica meadows
Explore the relationship between the amphipod
assemblages and habitat structure
Slide 6
Material & Methods
Study site : Revellata Bay (NW of Corsica)
www.biomedcentral.com
Slide 7
Material & Methods
Hierarchical spatial sampling design
10 m
Zone
Z1
Sites
S2
S1
(~ 100 m)
Frames
F1
F2
F1
F2
F3
F4
X
X
X
X
X
X
X
X
X
X
X
X
(~ 10 m)
Samples
(~ 1 m)
Constant depth: 12-13 m
F3
F4
Slide 8
Material & Methods
Air-Lift
collecting nylon bag
- non destructive method
- quantitative estimation
100 cm
- capture samples at small
PVC suction tube
pressure regulator
compressed air injector
flexible suction tube
spatial scale ~ 1 m
Slide 9
Material & Methods
• Sampling area of the meadow
is previously delimited by a
PVC cylinder (0,129 m2)
• Aspiration of the leaves
included in the cylinder, with
the vagile fauna (2 min)
• Sampling was realized between
10h30 am and 3h00 pm
(March 2007)
Egidio Trainito
Slide 10
Results and Discussion
Slide 11
Community Structure
General Characteristics
- Abundance :
727 amphipods
- Sample richness :
30 species
- Variable diversity : low to medium (H´: 0,45 - 1,88)
- Dominant species :
Apherusa chiereghinii
(46,1 %)
Aora spinicornis
(18,4 %)
Amphilochus neapolitanus
(5,3%)
1 mm
Slide 12
Variations at different spatial scales
Abundance
(number of individuals per sample)
120
100
80
60
40
20
0
0
1
*
10
100
110
Distance
(~ m)
Slide 13
Variations at different spatial scales
Biomass
(in mg AFDW per m2 of the meadow)
45
40
35
30
25
20
15
10
5
0
0
1
10
*
High heterogeneity of the meadow
100
110
Distance
(~ m)
Slide 14
Variations at different spatial scales
Density of the meadow
(number of shoots per m2)
1200
1000
800
600
400
200
0
0
1
10
High heterogeneity of the meadow
100
110
Distance
(~ m)
Slide 15
Variations at different spatial scales
Species richness
(number of species)
14
12
10
8
6
4
2
0
0
1
10
*
100
110
Distance
(~ m)
Slide 16
Variations at different spatial scales
Diversity
(Shannon-Wiener index, H´)
2,0
1,5
1,0
0,5
0,0
0
1
10
*
100
110
Distance
(~ m)
Habitat complexity…lower density of the meadow
and litter accumulations
Slide 17
Non-metric Multidimensional scaling
Stress : 0,13
Frame 1
Frame 2
Frame 3
Frame 4
Slide 18
Summary
Influence
No Influence
Scales
~1m
~ 10 m
~ 100 m
Abundance
Biomass
Species richness
Diversity
Specific composition
No clear pattern
Slide 19
Conclusions
Our results showed
• Amphipod community associated with the
P.oceanica meadow : abundant, rich in species,
moderately diversify
• Community dominated by a few species
• Important spatial variability at different scales
Slide 20
Conclusions
Our results showed
• Some scales influenced the characteristics of the
community more than others
- Small spatial scale >> abundance and biomass
- Medium scale >> species richness and diversity
Slide 21
Egidio Trainito, AMP Tavolara-Punta Coda Cavallo
Thank you for your attention
Slide 22
Acknowledgments
We are very thankful to the staff of
the oceanographic station STARESO
(CORSICA) for their hospitality and
assistance during field work.
This study was supported by F.R.I.A.
(Fonds pour la formation à la Recherche dans
l’industrie et dans l’agriculture)
FRIA Grant – FC 77010
Contact : [email protected]
www.ulg.ac.be/oceanbio
Multi-scale spatial variability of amphipod
assemblages from the foliar stratum of the
Posidonia oceanica (L.) Delile meadow
Nicolas Sturaro1, Gilles Lepoint1, Loïc Michel2, Sylvie Gobert1
1Laboratoire
d’Océanologie, University
of Liège, Liège, Belgium
2Laboratoire
de Systématique et
Diversité Animale, University of
Liège, Liège, Belgium
Liège 2008
Slide 2
Context of the Study
• Ecological communities are patchy
• Several spatial and temporal scales
• Studying spatial patterns is of ecological importance
understand the causes of the distribution and
abundance of organisms
provide valuable basis for management and
conservation
Slide 3
Context of the Study
• Posidonia oceanica
- forms large meadows
- important habitat for
Egidio Trainito
- endemic species of seagrass
mobile invertebrates
- large number of species
- considerable abundance/biomass
- important trophic ressource
Peter Bryant
• Amphipods
Slide 4
Amphipods
Vertical spatial variability of amphipods is better
known in P. oceanica meadows
Horizontal spatial variability ?
At different spatial scales ?
Slide 5
Objective
Assess the spatial variability, at different scales, of
amphipods living in the P. oceanica meadows
Explore the relationship between the amphipod
assemblages and habitat structure
Slide 6
Material & Methods
Study site : Revellata Bay (NW of Corsica)
www.biomedcentral.com
Slide 7
Material & Methods
Hierarchical spatial sampling design
10 m
Zone
Z1
Sites
S2
S1
(~ 100 m)
Frames
F1
F2
F1
F2
F3
F4
X
X
X
X
X
X
X
X
X
X
X
X
(~ 10 m)
Samples
(~ 1 m)
Constant depth: 12-13 m
F3
F4
Slide 8
Material & Methods
Air-Lift
collecting nylon bag
- non destructive method
- quantitative estimation
100 cm
- capture samples at small
PVC suction tube
pressure regulator
compressed air injector
flexible suction tube
spatial scale ~ 1 m
Slide 9
Material & Methods
• Sampling area of the meadow
is previously delimited by a
PVC cylinder (0,129 m2)
• Aspiration of the leaves
included in the cylinder, with
the vagile fauna (2 min)
• Sampling was realized between
10h30 am and 3h00 pm
(March 2007)
Egidio Trainito
Slide 10
Results and Discussion
Slide 11
Community Structure
General Characteristics
- Abundance :
727 amphipods
- Sample richness :
30 species
- Variable diversity : low to medium (H´: 0,45 - 1,88)
- Dominant species :
Apherusa chiereghinii
(46,1 %)
Aora spinicornis
(18,4 %)
Amphilochus neapolitanus
(5,3%)
1 mm
Slide 12
Variations at different spatial scales
Abundance
(number of individuals per sample)
120
100
80
60
40
20
0
0
1
*
10
100
110
Distance
(~ m)
Slide 13
Variations at different spatial scales
Biomass
(in mg AFDW per m2 of the meadow)
45
40
35
30
25
20
15
10
5
0
0
1
10
*
High heterogeneity of the meadow
100
110
Distance
(~ m)
Slide 14
Variations at different spatial scales
Density of the meadow
(number of shoots per m2)
1200
1000
800
600
400
200
0
0
1
10
High heterogeneity of the meadow
100
110
Distance
(~ m)
Slide 15
Variations at different spatial scales
Species richness
(number of species)
14
12
10
8
6
4
2
0
0
1
10
*
100
110
Distance
(~ m)
Slide 16
Variations at different spatial scales
Diversity
(Shannon-Wiener index, H´)
2,0
1,5
1,0
0,5
0,0
0
1
10
*
100
110
Distance
(~ m)
Habitat complexity…lower density of the meadow
and litter accumulations
Slide 17
Non-metric Multidimensional scaling
Stress : 0,13
Frame 1
Frame 2
Frame 3
Frame 4
Slide 18
Summary
Influence
No Influence
Scales
~1m
~ 10 m
~ 100 m
Abundance
Biomass
Species richness
Diversity
Specific composition
No clear pattern
Slide 19
Conclusions
Our results showed
• Amphipod community associated with the
P.oceanica meadow : abundant, rich in species,
moderately diversify
• Community dominated by a few species
• Important spatial variability at different scales
Slide 20
Conclusions
Our results showed
• Some scales influenced the characteristics of the
community more than others
- Small spatial scale >> abundance and biomass
- Medium scale >> species richness and diversity
Slide 21
Egidio Trainito, AMP Tavolara-Punta Coda Cavallo
Thank you for your attention
Slide 22
Acknowledgments
We are very thankful to the staff of
the oceanographic station STARESO
(CORSICA) for their hospitality and
assistance during field work.
This study was supported by F.R.I.A.
(Fonds pour la formation à la Recherche dans
l’industrie et dans l’agriculture)
FRIA Grant – FC 77010
Contact : [email protected]
www.ulg.ac.be/oceanbio