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Approaching Planktonic Food Webs: Competition, Coexistence, and Chaos
cling. This makes it likely that fluctuations in resource supply rates generated by simple prey-predator cycles are insufficient to maintain the
observed diversity of phytoplankton communities. In other words, the
original theory put forward by Hutchinson (1961), that physical disturbances prevent plankton communities from reaching an equilibrium situation leading to competitive exclusion, still remains a strong candidate for
explaining the paradox of the plankton.
6.6 Symbols, Definitions, and Units
Symbol Defmition
Unit
a'
Specific nutrient uptake affinity
I (mg C)"I day"1
C
Food carbon biomass
(mgC)r l
C.
Algal carbon biomass
(mgCn l
Cb
Bacterial carbon biomass
(mgC)r l
C~
Particulate detritus carbon
(mgC)r l
C'
Incipient limiting food concentration
(mgC)r l
,5
Specific grazer mortality rate
day"1
D
Dilution rate
day"1
&
Grazer food carbon assimilation efficiency
e,.
Bacterial carbon assimilation efficiency
f.
Fraction extracellular release of total primary production
f,
Particulate fraction of grazer organic C release
F
Specific grazer clearance rate
I (mg C)"I day"1
Fi
Specific clearance rate on prey species i
I (mg Cr l day"1
' "
Grazer feeding selectivity index
"' "
Critical feeding selectivity for a pair of algal competitors
g
Grazer growth rate
day"1
g'
Maximum grazer growth rate on optimally composed food
day"1
I
Specific food ingestion rate
day"1
I'
Maximum specific ingestion rate at saturating food
day"1