Phytoplankton (mg fwt l
–1
)
0
4
8
12
80
160
X 10
0 500 1000 1500 2000 2500
Bacteria (mg fwt l
–1
)
0
2
4
6
8
Nutrients (
μmol l
–1
)
0
15
30
45
100
200
0 500 1000 1500 2000 2500
Detritivores (mg fwt l
–1
)
0.0
0.2
0.4
0.6
2.5
5.0
d e
g
Herbivores (m
g fwt l
–1
)
0
4
8
12
60
120
c
Time [days] Time [days]
f
Cyclopoids (mg fwt l
–1
)
0.0
0.2
0.4
0.6
1.0
2.0
3.0
b
a
Detritus
Picophyto–
plankton
Cyclopoids
Protozoa Rotifers Calanoids
Ostracods Harpacticoids
Nanophyto–
plankton
Nutrients
Filamentous
diatoms
Bacteria
Figure 2.6Description of a plankton community in a mesocosm experiment. (a) Food web structure of the mesocosm
experiment. The thickness of the arrows gives a first indication of the food preferences of the species, as derived from
general knowledge of their biology. (b–g) Time series of the functional groups in the food web (measured as
freshweight biomass). (b) Cyclopoid copepods; (c) calanoid copepods (red), rotifers (blue) and protozoa (dark green);
(d) picophytoplankton (black), nanophytoplankton (red) and filamentous diatoms (green); note that the diatom biomass
should be magnified by 10; (e) dissolved inorganic nitrogen (red) and soluble reactive phosphorus (black);
(f) heterotrophic bacteria; (g) harpacticoid copepods (violet) and ostracods (light blue). Reproduced with permission
from Benincaet al.(2008). See plate 1.
TROPHIC DYNAMICS OF COMMUNITIES 31