Community Ecology Processes, Models, and Applications

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