Light-induced mass turnover in a mono-species community of mixotrophs
Kooijman, S.A.L.M., Dijkstra, H.A. and Kooi, B.W. 2002.
Light-induced mass turnover in a mono-species community of mixotrophs.
J. Theoret. Biol., 214: 233 - 254.
We formulate a simple model for growth of a facultative
photoautotroph with chemoheterotrophic capabilities. The
organism is described by zero, one or three reserve components,
and one structural component, all taken to be generalized
compounds. The rules of Synthesizing Units are used for
interactions among the uptake processes of the various nutrients
and light (parallel processing), and for the merging of
autotrophic and heterotrophic activities (sequential processing).
For simplicity's sake, we focus on the assimilation of inorganic
carbon, inorganic nitrogen and light, and of two organic compounds
(dead reserves and dead structure) that originate from aging. The
process of resource recycling in a closed environment, as driven
by light, and its links with community's structure (amount of
biomass) is analysed in this simplest of all communities.
Explicit analytical expressions for the steady states show how
structure and function depend on the system parameters light,
total carbon and total nitrogen. The behaviour resembles the Monod
model for the Canonical Community, a three-species ecosystem
consisting of producers, consumers and decomposers. If trophic
preferences of a mixotroph are allowed to follow a random walk
across generations, a trophic structure evolves where mixotrophs
coexist with auto- and heterotrophs. Depth profiles are presented
for the implied steady state concentrations of dissolved inorganic
carbon and nitrogen.
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