Appendix
Supplementary material for Matthiessen B, Ptacnik R, Hillebrand H. Diversity
and biomass production depend on dispersal and disturbance in microalgal
communities.
Obs.
Obs.
Obs.
Obs.
Local
disturbance
A) Local community
patches
no
B) Surrounding
region
low
high
Obs
local patches for observation
over the course of experiment
Figure S1: One aquarium with A) 16 local community patches of benthic microalgae
located in plastic tubes. Local communities are differentially disturbed by removing
biomass with different frequencies, i.e. three times per week in the high, and once a
week in the low disturbance treatments. No biomass was removed in the none
disturbed treatments. B) shows the surrounding region comprising all species which
can enter local communities by dispersal (see Figure S2).
1
Figure S2: One aquarium with benthic algae in the surrounding regional pool which
disperse into local community patches when the water is stirred. For simplicity only
eight out of 16 local patches are displayed.
2
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
no
enhanced
dispersal
o
o
Disturbance
no
low
high
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
daily
dispersal
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
Dispersal rate
o
o
o
o
o
o
o
o
o
obs.
Aquarium
Figure S3:
Experimental design with six levels of dispersal and three levels of disturbance. Each
dispersal level is replicated in independent aquaria whereas the disturbance levels
are all situated in each aquarium with a given dispersal rate. Local community
patches marked with an ‘o’ are for observation over the course of the experiment.
3
Table S4
The table gives species used in the experimental communities, their abbreviations in
the text, mean cell sizes, description of life-forms, and growth rates of five of the
species. Growth rates derive from another study (Matthiessen et al. 2010) with the
same microalgal community growing under similar light and nutrient conditions.
Total
Abbrev.
species pool
Mean
Mobility and life-form
Growth rate
biovolume/cell
(µm3)
Achnanthes
(ACH)
1712
brevipes
Amphora
chain-forming, flexed
(AMP)
173
Coffaeiformes
Cocconeis sp.
Pennate, stalked and
Pennate, highly mobile,
1.28
solitary, amphora-shaped
(COC)
357
Pennate, mobile but
strongly attached, solitary,
very flat
Entomoneis
(ENT)
4293
paludosa
Pennate, mobile and little
attached, solitary, very
irregular form
Melosir
(MEL)
304
varians
Navicula
Centric, chain-forming,
non-attached, floating
(NAV)
979
ramosissima
Pennate, mobile, medium
1.2
attached, solitary, regular
diatom form
Nitzschia sp.
(NITZ I)
62
Pennate, mobile, medium
1.62
attached, solitary, regular
4
diatom form
Nitzschia
(NITZ
oblongella
II)
2175
Pennate, mobile, medium
attached, solitary,
elongated, erect growth
Nitzschia
sigma
(NITZ
3597
III)
Pennate, mobile, medium
1.2
attached,
solitary, S-shaped, erect
growth
Stauroneis
(STA)
3387
constricta
Pennate, mobile, medium
1.35
attached, solitary,
constricted
Synedra sp.
(SYN)
532
Pennate, mobile, solitary,
elongated, erect growth
5
Regional pool species richness
10
8
6
Regression models:
4
Linear:
R² = 0.06; F = 0.05; p = 0.83
Quadratic: R² = 0.03; F = 0.77; p = 0.48
2
0
0
0.2
0.4
0.6
0.8
Dispersal rate (LN X / 56 + 1)
Figure S5: This figure shows that regional pool species richness is not affected by
potential disturbance created by the dispersal treatments in the regional pool. Results
of regressions show that species richness was neither affected in a linear nor in a
non-linear way.
6
high
low
no
2
6x108
1
4x10
0
2x108
-1
0x100
80
2x1010
60
1x10
40
8x109
20
4x10
0
0x100
8
ACH
10
AMP
9
8x107
COC
4x107
0x100
3x109
0
12
9
2x10
8
4
109
0
0x100
ENT
0.3
4x107
0.2
2x107
0.1
0
0x100
5
4
3
2
1
0
2x109
MEL
9
1x10
8x108
NAV
8
4x10
0x100
1x109
12
8
8x10
8
NITZ I
4x108
4
0x100
0
5
4
3
2
1
0
Total biovolume (µm2 *cm-1 ± SE)
Relative Biomass (% ± SE)
0.4
2x109
8x108
NITZ II
0x100
5
4
3
2
1
0
2x109
NITZ III
8x108
0x100
80
60
4x1010
40
2x1010
STA
20
0x100
0
0.4
0.3
8x106
0.2
4x106
SYN
0.1
0x100
0
Dispersal rate (ln x / 56 +1)
7
Figure S6: Dispersal rate plotted versus species relative and total biomass
contribution at high and low disturbance rates and without disturbance. The black
circles and left y-axis represents relative biomass production (calculated from
Biovolumes µm³/cm²).The white circles and the right y-axis represents species total
biomass production.
8
high
low
no
2
100
80
60
40
20
0
1
0
-1
80
100
80
60
40
20
0
60
40
20
0.4
0.4
0.3
0.2
0.1
0
-0.1
100
80
60
40
20
0
5
4
3
2
1
0
100
80
60
40
20
0
0.2
0.1
0
12
8
Relative Biomass (% ± SE)
4
AMP
COC
ENT
MEL
NAV
0
100
80
60
40
20
0
5
4
3
2
1
0
100
80
60
40
20
0
5
4
3
2
1
0
100
80
60
40
20
0
80
100
80
60
40
20
0
STA
100
80
60
40
20
0
SYN
12
8
4
60
40
20
0.4
0.3
0.2
0.1
0
Occupancy (%)
0
100
80
60
40
20
0
100
80
60
40
20
0
0.3
ACH
NITZ I
NITZ II
NITZ III
Dispersal rate (ln x / 56 +1)
9
Figure S7: Dispersal rate plotted versus species relative biomass contribution and
occupancy frequency at high and low disturbance rates and without disturbance. The
black circles and left y-axis represent relative biomass production (calculated from
Biovolumes µm³/cm²).The grey bars and the right y-axis represent species
occupancy calculated from all pseudoreplicates.
Reference
Matthiessen B, Mielke E, Sommer U (2010) Dispersal decreases diversity in
heterogeneous metacommunities by enhancing regional competition. Ecology
in press
10