Linking planktonic biomass and metabolism to net gas fluxes in northern temperate lakes

Journal Article · Tue Jun 01 04:00:00 EDT 1999 · Ecology

DOI:https://doi.org/10.1890/0012-9658(1999)080[1422:LPBAMT]2.0.CO;2· OSTI ID:355569

Giorgio, P.A. del ^[1]; Cole, J J; Caraco, N F ^[2]; Peters, R H ^[3]

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1. Univ. of Maryland Center for Environmental Science, Cambridge, MD (United States). Horn Point Lab.
2. Inst. of Ecosystem Studies, Millbrook, NY (United States)
3. McGill Univ., Montreal, Quebec (Canada). Dept. of Biology

Plankton communities in oligotrophic waters are characteristically dominated by the biomass of heterotrophs, including bacteria, micro-, and macrozooplankton. It has been generally assumed that these inverted biomass pyramids are the direct result of high specific production rates of phytoplankton and a tight coupling between producers and consumers. There are, however, at least two alternative hypotheses: (1) heterotrophic biomass turnover is much slower in oligotrophic than eutrophic systems; and (2) oligotrophic planktonic communities are significantly subsidized by allochthonous organic matter. In this study the authors assessed these hypotheses by establishing the relationship between plankton biomass structure, plankton function, and whole-lake gas (O{sub 2} and CO{sub 2}) fluxes in 20 temperate lakes that span a large range in primary production. The authors show that the balance of phytoplankton production and community respiration (P/R ratio) is always below unity in unproductive lakes where heterotrophic biomass (H) is high relative to autotrophic biomass (A), suggesting that these planktonic food webs function as heterotrophic systems and must be subsidized by allochthonous organic matter. Further, rates of phytoplankton specific production are not highest in communities characterized by dominance of heterotrophic biomass. All except the most productive lakes were supersaturated in CO{sub 2} and undersaturated in O{sub 2}.

• Sponsoring Organization: USDOE
• OSTI ID: 355569
• Journal Information: Ecology, Journal Name: Ecology Journal Issue: 4 Vol. 80; ISSN 0012-9658; ISSN ECOLAR
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
AQUATIC ECOSYSTEMS
CARBON CYCLE
CARBON DIOXIDE
ENERGY TRANSFER
LAKES
METABOLISM
PLANKTON
WATER QUALITY