Differences in temperature, organic carbon and oxygen consumption among lowland streams

Sand‐Jensen, Kaj; Pedersen, Niels Lagergaard

doi:10.1111/j.1365-2427.2005.01436.x

Cited by 36 publications

(28 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Respiration was lowest when both temperature and O 2 were low at dawn and much higher in the afternoon when O 2 and temperature peaked. The importance of both temperature and O 2 for respiration rates accords with experimental studies on freshwater plants (Sand‐Jensen & Frost‐Christensen, ) and heterotrophic bacteria (Sand‐Jensen & Pedersen, ).…”

Section: Discussionsupporting

confidence: 79%

Fluctuating water levels control water chemistry and metabolism of a charophyte‐dominated pond

2013

Self Cite

View full text Add to dashboard Cite

Summary To investigate seasonal variability and importance of environmental drivers of ecosystem metabolism in a shallow pond characterised by low and fluctuating water depth, clear water and shortage of nutrients, we measured primary production and respiration during May–September and examined their relationships to environmental parameters (light, temperature and pH). Using a combination of free water measurements of O2, pH, temperature and conductivity, in situ mesocosm and laboratory bottle experiments, we documented extreme daily variations in environmental variables (e.g. 0–700 mmol O2 m−3, pH 7.5–9.5, 18–32 °C) and high and variable areal rates of gross primary production (GPP, 30–316 mmol O2 m−2 day−1) and community respiration (R, 26–318 mmol O2 m−2 day−1). These rates of benthic charophytes under oligotrophic conditions are comparable to those obtained by pelagic phytoplankton communities under highly eutrophic conditions. By using sediment resources, benthic charophytes can achieve high biomasses and high metabolic rates. Pond metabolism reflected the physiology of the dominant charophyte, with light‐saturated photosynthesis occurring during 55% of the light hours. Experiments and photosynthetic models showed inorganic carbon limitation of GPP at pHs above 9.5 during mid‐summer periods of low water levels, while R was strongly influenced by temperature. According to open water measurements of O2, the pond was net autotrophic (mean NEP = 12 ± 13 (SD) mmol O2 m−2 day−1) but net heterotrophic when based on dissolved inorganic carbon (DIC) dynamics (10 ± 29 mmol CO2 m−2 day−1), suggesting that the significant input of DIC in inflowing water from the surrounding limestone soils mimics elevated respiration.

show abstract

Section: Discussionsupporting

confidence: 79%

Fluctuating water levels control water chemistry and metabolism of a charophyte‐dominated pond

2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…Oxygen consumption rates during organic carbon mineralization have been shown to be related to POC concentrations more than DOC concentrations in long‐term models of lowland streams, as well as positively correlated to temperature owing to enhanced biological activity (Jennerjahn et al, ; Sand‐Jensen & Pedersen, ). Oxygen is more soluble in cold water (Williams & Boorman, ), and molar ratios of DOC:O 2 photochemical consumption may be close to 1:1 (Amon & Benner, ).…”

Section: Discussionmentioning

confidence: 99%

Controls on fluvial carbon efflux from eroding peatland catchments

Brown

Goulsbra

Evans

2018

Hydrological Processes

View full text Add to dashboard Cite

Global peatlands store an unparalleled proportion of total global organic carbon but it is vulnerable to erosion into fluvial systems. Fluvial networks are being recognized as areas of carbon transformation, with eroded particulate organic carbon processed to dissolved organic carbon and CO2. Existing studies indicate biodegradation and photodegradation as key processes controlling the transformation of organic carbon in fluvial systems, with initial concentrations of dissolved organic carbon (DOC) identified as a control on the rate of carbon mineralization. This study manipulates temperature and incident light intensity to investigate carbon mineralization rates in laboratory simulations of peatland sediment transport into fluvial systems. By directly measuring gaseous CO2 emissions from sampled stream water, the relationship of temperature and light intensity with carbon efflux is identified. In simulations where sediment (as particulate organic matter, POM) is absent, temperature is consistently the dominant factor influencing carbon efflux rates. This influence is independent of the initial DOC concentration of the water sample. In simulations where POM was added, representing a peatland river receiving eroded terrestrial sediment, initial DOC concentration predicts 79% of the variation in total gaseous carbon efflux whereas temperature and light intensity predict 12% and 3%, respectively. When sampled stream water's mineralization rates in the presence of added POM are analysed independently, removing DOC as a model variable, the dominant variable affecting CO2 efflux is opposite for each sample. This study presents novel data suggesting peatland erosion introduces further complexity to dynamic stream systems where rates of carbon transformation processes and the influence of specific environmental variables are interdependent. Anthropogenic climate change is identified as a leading risk factor perpetuating peatland erosion; therefore, understanding the fate of terrestrial sediment in rivers and further quantifying the benefits of protecting peatland soils will be of increasing importance to carbon budgeting and ecosystem function studies.

show abstract

“…In contrast, a study of the temperature dependence of oxygen consumption in the water column in lowland Danish rivers by Sand-Jensen & Pedersen (2005) found no significant differences among study sites or seasons. In contrast, a study of the temperature dependence of oxygen consumption in the water column in lowland Danish rivers by Sand-Jensen & Pedersen (2005) found no significant differences among study sites or seasons.…”

Section: Temperature Dependence Of Rmentioning

confidence: 70%

Temperature dependence of stream benthic respiration in an Alpine river network under global warming

et al. 2008

View full text Add to dashboard Cite

Summary 1. Global warming has increased the mean surface temperature of the Earth by 0.6 °C in the past century, and temperature is probably to increase by an additional 3 °C by 2100. Water temperature has also increased, which in turn can affect metabolic rate in rivers. Such an increase in metabolic rate could alter the role of river networks in the global C cycle, because the fraction of allochthonous organic C that is respired may increase. 2. Laboratory‐based incubations at increasing water temperature were used to estimate the temperature dependence of benthic respiration in streams. These experiments were performed on stones taken from seven reaches with different thermal conditions (mean temperature ranging 8–19 °C) within the pre‐alpine Thur River network in Switzerland, June–October 2007. 3. The activation energy of respiration in different reaches along the river network (0.53 ± 0.12 eV, n = 94) was similar, indicating that respiration was constrained by the activation energy of the respiratory complex (E = 0.62 eV). Water temperature and the thickness of the benthic biofilm influence the temperature dependence of respiration and our results suggest that an increase of 2.5 °C will increase river respiration by an average of 20 ± 1.6%.

show abstract

Differences in temperature, organic carbon and oxygen consumption among lowland streams

Cited by 36 publications

References 26 publications

Fluctuating water levels control water chemistry and metabolism of a charophyte‐dominated pond

Fluctuating water levels control water chemistry and metabolism of a charophyte‐dominated pond

Controls on fluvial carbon efflux from eroding peatland catchments

Temperature dependence of stream benthic respiration in an Alpine river network under global warming

Contact Info

Product

Resources

About