scholarly journals Uptake of dissolved inorganic nitrogen, urea and amino acids in the Scheldt estuary: comparison of organic carbon and nitrogen uptake

2006 ◽  
Vol 44 ◽  
pp. 303-315 ◽  
Author(s):  
MGI Andersson ◽  
P van Rijswijk ◽  
JJ Middelburg
Keyword(s):  
Amino Acids ◽  
Organic Carbon ◽  
Nitrogen Uptake ◽  
Inorganic Nitrogen ◽  
Scheldt Estuary ◽  
Dissolved Inorganic Nitrogen ◽  
Carbon And Nitrogen

scholarly journals Forest defoliator outbreaks alter nutrient cycling in northern waters

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Samuel G. Woodman ◽  
Sacha Khoury ◽  
Ronald E. Fournier ◽  
Erik J. S. Emilson ◽  
John M. Gunn ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Water Chemistry ◽  
Inorganic Nitrogen ◽  
Biogeochemical Cycles ◽  
Dissolved Inorganic Nitrogen ◽  
Insect Outbreaks ◽  
Receiving Waters ◽  
North Temperate Lakes ◽  
Lake Waters ◽  
Terrestrial Biomass

AbstractInsect defoliators alter biogeochemical cycles from land into receiving waters by consuming terrestrial biomass and releasing biolabile frass. Here, we related insect outbreaks to water chemistry across 12 boreal lake catchments over 32-years. We report, on average, 27% lower dissolved organic carbon (DOC) and 112% higher dissolved inorganic nitrogen (DIN) concentrations in lake waters when defoliators covered entire catchments and reduced leaf area. DOC reductions reached 32% when deciduous stands dominated. Within-year changes in DOC from insect outbreaks exceeded 86% of between-year trends across a larger dataset of 266 boreal and north temperate lakes from 1990 to 2016. Similarly, within-year increases in DIN from insect outbreaks exceeded local, between-year changes in DIN by 12-times, on average. As insect defoliator outbreaks occur at least every 5 years across a wider 439,661 km2 boreal ecozone of Ontario, we suggest they are an underappreciated driver of biogeochemical cycles in forest catchments of this region.

Proteins: Amino Acids and Amines

2011 ◽  
Author(s):  
Thomas S. Bianchi ◽  
Elizabeth A. Canuel
Keyword(s):  
Amino Acids ◽  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Particulate Organic Carbon ◽  
Nitrogen Cycle ◽  
Organic Nitrogen ◽  
Building Blocks ◽  
Marine Organisms ◽  
Carbon And Nitrogen

This chapter discusses proteins, which make up approximately 50% of organic matter and contain about 85% of the organic nitrogen in marine organisms. Peptides and proteins comprise an important fraction of the particulate organic carbon (13–37%) and particulate organic nitrogen (30–81%), as well as dissolved organic nitrogen (5–20%) and dissolved organic carbon (3–4%) in oceanic and coastal waters. In sediments, proteins account for approximately 7 to 25% of organic carbon and an estimated 30 to 90% of total nitrogen. Amino acids are the basic building blocks of proteins. This class of compounds is essential to all organisms and represents one of the most important components in the organic nitrogen cycle. Amino acids represent one of the most labile pools of organic carbon and nitrogen.

High resilience of soils to re-grazing in a long-term abandoned alpine pasture

2020 ◽  
Author(s):  
Alix Vidal ◽  
Anne Schucknecht ◽  
Paul Toechterle ◽  
Diana Rocio Andrade Linares ◽  
Noelia Garcia-Franco ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Microbial Communities ◽  
Inorganic Nitrogen ◽  
Bare Soil ◽  
European Alps ◽  
Short Term ◽  
Carbon And Nitrogen ◽  
Nitrogen Turnover ◽  
Grazing Effects

<p>Grazed alpine pastures have shaped landscapes of the European Alps for millennia. However, especially steep alpine areas have largely been abandoned since the 1950s, resulting in a fast re-forestation of mountain pastures in the last decades, which is accelerated by climate change. Re-grazing of abandoned pastures could preserve the cultural landscape of the European Alps with its high species diversity, but there is a lack of information on the response of the soil system to re-grazing. We investigated short-term effects of re-grazing of an abandoned pasture in the German Alps on soil organic carbon and nitrogen biochemistry, soil microbial communities, and water quality. In May 2018, we set up a pilot grazing experiment at Brunnenkopfalm (1500-1700 m a.s.l.), abandoned since 1955. Four ha were fenced and a herd of rustic, local and endangered breeds (ca 1/ha) was introduced. Two and five months after the beginning of grazing, we investigated the short-term re-grazing effects, considering grazing-induced heterogeneity, as well as the distribution of vegetation types. In order to gain a functional understanding of soil responses to re-grazing, we used a wide array of techniques to characterize soil biogeochemical properties (salt-extractable and total organic carbon, gross nitrogen turnover rates, soil mineral nitrogen availability), as well as the abundance and characteristics of microbial communities (microbial biomass, phospholipid-derived fatty acids analysis, abundance of nitrogen-related microbial communities). A few months after re-grazing started, extractable organic carbon, gross nitrogen mineralisation rates and inorganic nitrogen concentrations were increased only in intensively grazing-affected areas with bare soil. Bare soils represented a small fraction of the study area (~ 1 %), and the grazing effects on these areas could at least partially also be driven by the initial site heterogeneity (soil and vegetation) rather than solely by recent grazing activities. Re-grazing did not affect the microbial abundance, but induced a community shift towards a smaller proportion of fungi compared to bacteria and an increase of ammonia oxidizers (archaea/bacteria). Concentrations of dissolved organic carbon and nitrate in the draining creek remained very low. Overall, re-grazing of pastures in the first season had very limited effects on microbial communities and associated carbon and nitrogen turnover and concentrations, highlighting the initial resilience of alpine soils to extensive re-grazing. However, a slight increase in nitrifier abundances at bare soil spots, as well as the low organic carbon:nitrogen ratios of soils suggest that a future increase in inorganic nitrogen accumulation is possible at least at bare soil areas. This could possibly endanger some biodiverse grassland biotopes via eutrophication and result in environmental nitrogen losses along hydrological or gaseous pathways. Thus, long-term studies are needed to verify whether soils are also resilient to re-grazing in the long-term. On the short-term, undesired re-grazing effects can be avoided by extensive, guided grazing with adapted cattle breeds targeted to avoid trampling-induced bare soil areas.</p>

The effect of land use on dissolved organic carbon and nitrogen uptake in streams

2009 ◽  
Vol 54 (11) ◽  
pp. 2335-2350 ◽  
Author(s):  
LAURA T. JOHNSON ◽  
JENNIFER L. TANK ◽  
CLAY P. ARANGO
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Nitrogen Uptake ◽  
Carbon And Nitrogen

Carbon and nitrogen budgets of two Ascidians and their symbiont, Prochloron, in a tropical seagrass meadow

1993 ◽  
Vol 44 (1) ◽  
pp. 173 ◽  
Author(s):  
I Koike ◽  
M Yamamuro ◽  
PC Pollard
Keyword(s):  
Organic Carbon ◽  
Organic Nitrogen ◽  
Carbon Budget ◽  
Seagrass Meadow ◽  
Inorganic Nitrogen ◽  
Host Animal ◽  
Nitrogen Budgets ◽  
Carbon And Nitrogen ◽  
Respiration Rates ◽  
Surrounding Environment

Two species of ascidian, Didemnum molle Herdman and Lissoclinum voeltzkowi Michaelsen, were collected from a Fijian seagrass meadow. The primary production of their symbiont (Prochloron), the inorganic nitrogen metabolism and the filtration rate were measured to assess the nutritional coupling between the symbiont and the host animal. The loss of organic carbon due to the respiration of D. molle (1.1 �g at. C (mg dry wt)-1 day-1) was greater than that supplied through photosynthesis of the Prochloron (0.69 �g at. C (mg dry wt)-1 day,-1). The carbon supplied through filter-feeding appeared to supplement the ascidian's carbon budget. In contrast, organic carbon from the Prochloron of L. voeltzkowi appeared to meet the colony's respiration needs. The nitrogen budgets of both ascidian colonies were estimated from their respiration rates, the nitrogen requirement of the Prochloron, and the uptake of inorganic nitrogen and particulate organic nitrogen uptake from the water column. The nitrogen incorporated from the surrounding environment could contribute to the net nitrogen gain of the colony. However, our estimate of the nitrogen needed by the Prochloron was much greater than that which could be supplied externally. The amount of nitrogen released by the ascidians was also greater than that which could be supplied externally. This suggests that nitrogen is efficiently recycled within the symbiotic Prochloron-ascidian relationship.

Dissolved inorganic nitrogen uptake kinetics and δ15N of Zostera marina L. (eelgrass) in a coastal lagoon with oyster aquaculture and upwelling influence

2015 ◽  
Vol 472 ◽  
pp. 1-13 ◽  
Author(s):  
Jose Miguel Sandoval-Gil ◽  
Víctor F. Camacho-Ibar ◽  
María del Carmen Ávila-López ◽  
Julieta Hernández-López ◽  
José A. Zertuche-González ◽  
...  
Keyword(s):  
Nitrogen Uptake ◽  
Coastal Lagoon ◽  
Zostera Marina ◽  
Inorganic Nitrogen ◽  
Uptake Kinetics ◽  
Dissolved Inorganic Nitrogen ◽  
Oyster Aquaculture
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