The ecosystem of the oligotrophic Lake Pääjärvi 3. Secondary production and an ecological energy budget of the lake

Sarvala, Jouko; Ilmavirta, Veijo; Paasivirta, Lauri; Salonen, Kalevi

doi:10.1080/03680770.1980.11897022

Cited by 20 publications

(25 citation statements)

References 4 publications

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“…In this lake, 2/3 of secondary production is based on the microbial utilization of allochthonous DOC (Sarvala et al 1981), and therefore the biodegradation of DOC is a key for understanding the functioning of the Lake Pääjärvi ecosystem. For the bioassay, surface water (0-1.2 m) was collected with a Limnos-sampler from the middle of Lake Pääjärvi, southern Finland (61°04 0 N, 25°08 0 E) on 4 June 2007.…”

Section: Bioassaymentioning

confidence: 99%

Biodegradability continuum and biodegradation kinetics of natural organic matter described by the beta distribution

2010

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We followed a long-term (up to 503 days) microbial mineralization of dissolved organic carbon (DOC) from lake water in a bioassay and described the kinetics of biodegradation with a new model based on a reactivity continuum approach. The biodegradability of DOC was expressed as the probability of biodegradation, which was assumed to follow a beta distribution. We compared the performance of our beta model to five earlier models: the simplest first order kinetic model, two G models, the power model and the gamma model. The simplest first order kinetic model described the decreasing microbial mineralization of DOC poorly (r 2 = 0.73), but the other models explained the observed kinetics of biodegradation well (r 2 [ 0.95). When we assessed the extrapolation power of models beyond the length of the bioassay by reducing the amount of data, the predictive power of the G models was poor. Instead, the beta model predicted the biodegradation kinetics consistently and correctly based on even only three observations in time. The beta model provided also long-term predictions (up to 5,000 years) along the observed long-term mineralization trajectory of organic carbon in sediments. Additionally, the beta model formulated the biodegradability continuum of DOC, which was skewed towards low biodegradability. During the bioassay, the skew towards low biodegradability increased as the most biodegradable parts of DOC were consumed. The beta model describes the biodegradability continuum quantitatively and can predict biodegradation in a realistic manner, thus, improving our understanding about the biodegradability and the role of natural organic matter in the environment.

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Section: Bioassaymentioning

confidence: 99%

Biodegradability continuum and biodegradation kinetics of natural organic matter described by the beta distribution

2010

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“…Humphreys (1979) suggested a NPE of 0.3-0.4 for invertebrates. Sarvala et al (1981) used a NPE of 0.3 in computation of an energy budget for zoobenthos in the Finnish Lake Paajarvi Strayer & Likens (1986) found a NPE of 0.42 by using a variety of literature sources (compiled by Walter (1976)) to estimate community respiration in Mirror Lake. However, Lindegaard (1992b) found -by using the same equations as for M!…”

Section: Respiration and Assimilation Efficiencymentioning

confidence: 99%

The role of zoobenthos in energy flow in two shallow lakes

Lindegaard

1994

Hydrobiologia

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Net production of zoobenthos in two shallow and eutrophic lakes, i.e. the S-basin of Myvatn, Iceland (maximum depth 4.2 m, mean depth 2.3 m) and Hjarbek Fjord, Denmark (maximum depth 6.5 m, mean depth 1.9 m) were calculated as 878 and 1093 kJ m-2 yr-', respectively. The zoobenthos in both lakes was dominated by Chironomidae (Diptera) living partly as filtrators feeding on suspended particles (phytoplankton) and partly as surface feeders foraging on benthic algae and/or seston. Respiration and consumption were estimated from the literature. Net production efficiency averaged 0.41 and 0.48 in Hjarbaek Fjord and Myvatn, respectively. Ingestion was dominated by herbivorous chironomids, while detritivorous tubificids were insignificant. Zoobenthic production made up 86% of total secondary production (zooplankton plus zoobenthos) in both lakes. The trophic efficiency between net primary production and benthic net secondary production was 8 % and 11 % in Hjarbaek Fjord and Lake Myvatn S-basin, respectively.

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“…(1) HSs impoverish and modify the underwater light climate (Jackson & Hecky, 1980) which, in turn, may affect phototrophic organisms; (2) upon irradiation and subsequent photolysis, HSs may serve as an external energy source to heterotrophic microorganisms (Sarvala et al, 1981); (3) HSs may form complexes with inorganic cations (Kullberg et al, 1993) and organic compounds (Münster, 1985), thus indirectly affecting aquatic biota by exerting strong control on the surrounding biogeochemical conditions and nutrient bioavailability.…”

Section: Introductionmentioning

confidence: 99%

Selected coccal green algae are not affected by the humic substance Huminfeed® in term of growth or photosynthetic performance

et al. 2012

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Humic substances (HSs) have been shown to influence growth, photophysiology, and redox homeostasis in phototrophs. However, many ecological studies deliver controversial results indicating inhibitory or stimulating effects depending on the kind of phototrophic organism or type of HSs applied. Here we analyzed the effect of Huminfeed Ò (HF), a preparation from leonardite associated with lignite deposits, on growth and photosynthetic performance of three different coccal green algae. Concentrations of HF in the range of 2-20 mg l -1 dissolved organic carbon (DOC) did neither affect the growth rate nor the light-adapted photosynthetic electron transport. Even photoinhibitory light intensities of 1,600 lmol photons m -2 s -1 , representing the tenfold of growth light intensity, did not result in a decline of the maximal photosynthetic rate in HF-treated algae. In HF-grown algae, a very subtle decrease by about 10% could be observed in thermoluminescent light emission, a sensitive method to detect changes in photosystem II (PSII) chemistry. However, thermoluminescence (TL) represents only 3% of the light-induced charge separated states in PSII. Hence, rather small changes will not have significant effects on overall photosynthetic performance and growth. Therefore, the physiological effect of HSs on freshwater phototrophs has to be revisited.

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The ecosystem of the oligotrophic Lake Pääjärvi 3. Secondary production and an ecological energy budget of the lake

Cited by 20 publications

References 4 publications

Biodegradability continuum and biodegradation kinetics of natural organic matter described by the beta distribution

Biodegradability continuum and biodegradation kinetics of natural organic matter described by the beta distribution

The role of zoobenthos in energy flow in two shallow lakes

Selected coccal green algae are not affected by the humic substance Huminfeed® in term of growth or photosynthetic performance

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