Baseline isotope data for Spirodela sp.: nutrient differentiation in aquatic systems
- Hill, Jaclyn M, Kaehler, Sven, Hill, Martin P
- Authors: Hill, Jaclyn M , Kaehler, Sven , Hill, Martin P
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444502 , vital:74246 , https://doi.org/10.1016/j.watres.2012.03.063
- Description: The excessive addition of nitrogen to watersheds is recognized as one of the main causes of the global deterioration of aquatic ecosystems and an increasing number of studies have shown that δ15N signatures of macrophytes may reflect the N-loading of the system under investigation. This study investigated isotopic equilibration rates and concentration level effects of KNO3 and cow manure nutrient solutions on the δ15N and δ13C signatures, C/N ratios, % N and % C of Spirodela sp. over time, to determine the feasibility of their use in monitoring anthropogenic N-loading in freshwater systems. Spirodela δ15N signatures clearly distinguished between nutrient types within 2 days of introduction, with plants grown in KNO3 showing extremely depleted δ15N values (−15.00 to −12.00‰) compared to those growing in cow manure (14.00–18.00‰). Isotopic equilibration rates could not be determined with certainty, but plant isotopic differentiation between nutrient regimes became apparent after 2 days and started to equilibrate by day 4. Concentration level effects were also apparent, with Spirodela tissue displaying more depleted and enriched δ15N values in higher concentrations of KNO3 and cow manure respectively.
- Full Text:
- Date Issued: 2012
- Authors: Hill, Jaclyn M , Kaehler, Sven , Hill, Martin P
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444502 , vital:74246 , https://doi.org/10.1016/j.watres.2012.03.063
- Description: The excessive addition of nitrogen to watersheds is recognized as one of the main causes of the global deterioration of aquatic ecosystems and an increasing number of studies have shown that δ15N signatures of macrophytes may reflect the N-loading of the system under investigation. This study investigated isotopic equilibration rates and concentration level effects of KNO3 and cow manure nutrient solutions on the δ15N and δ13C signatures, C/N ratios, % N and % C of Spirodela sp. over time, to determine the feasibility of their use in monitoring anthropogenic N-loading in freshwater systems. Spirodela δ15N signatures clearly distinguished between nutrient types within 2 days of introduction, with plants grown in KNO3 showing extremely depleted δ15N values (−15.00 to −12.00‰) compared to those growing in cow manure (14.00–18.00‰). Isotopic equilibration rates could not be determined with certainty, but plant isotopic differentiation between nutrient regimes became apparent after 2 days and started to equilibrate by day 4. Concentration level effects were also apparent, with Spirodela tissue displaying more depleted and enriched δ15N values in higher concentrations of KNO3 and cow manure respectively.
- Full Text:
- Date Issued: 2012
A stable isotope approach for the early detection and identification of N loading in aquatic ecosystems
- Hill, Jaclyn M, Kaehler, Sven, Hill, Martin P, Coetzee, Julie A
- Authors: Hill, Jaclyn M , Kaehler, Sven , Hill, Martin P , Coetzee, Julie A
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444491 , vital:74245 , https://www.wrc.org.za/wp-content/uploads/mdocs/KV 280.pdf
- Description: Global increases in urbanization and anthropogenic activity within wa-tersheds and catchment areas have resulted in excessive nitrogen loads in aquatic ecosystems. South Africa is deeply dependent on nat-ural resources for its economic health and as a consequence is particu-larly vulnerable to the degradation of its natural capital. Increased nitro-gen loading can result in widespread aquatic ecosystem degradation including: harmful algal blooms, increased turbidity, hypoxia, loss of aquatic vegetation and habitat and fish kills, it is also one of the mecha-nisms driving aquatic weed invasions. Understanding the fate and pro-cessing of anthropogenic nutrients in natural systems is therefore criti-cal for both preserving the well-being and biotic heritage for future gen-erations as well as providing a tremendous opportunity to improve the management driven by science. The objectives of this study were to evaluate the feasibility of mapping anthropogenic pollution through sta-ble isotopes signatures of aquatic plants, to investigate the potential for identifying different pollution sources, concentrations and distributions in a freshwater environment and to determine the utility of these tech-niques in indentifying early eutrophication.
- Full Text:
- Date Issued: 2011
- Authors: Hill, Jaclyn M , Kaehler, Sven , Hill, Martin P , Coetzee, Julie A
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444491 , vital:74245 , https://www.wrc.org.za/wp-content/uploads/mdocs/KV 280.pdf
- Description: Global increases in urbanization and anthropogenic activity within wa-tersheds and catchment areas have resulted in excessive nitrogen loads in aquatic ecosystems. South Africa is deeply dependent on nat-ural resources for its economic health and as a consequence is particu-larly vulnerable to the degradation of its natural capital. Increased nitro-gen loading can result in widespread aquatic ecosystem degradation including: harmful algal blooms, increased turbidity, hypoxia, loss of aquatic vegetation and habitat and fish kills, it is also one of the mecha-nisms driving aquatic weed invasions. Understanding the fate and pro-cessing of anthropogenic nutrients in natural systems is therefore criti-cal for both preserving the well-being and biotic heritage for future gen-erations as well as providing a tremendous opportunity to improve the management driven by science. The objectives of this study were to evaluate the feasibility of mapping anthropogenic pollution through sta-ble isotopes signatures of aquatic plants, to investigate the potential for identifying different pollution sources, concentrations and distributions in a freshwater environment and to determine the utility of these tech-niques in indentifying early eutrophication.
- Full Text:
- Date Issued: 2011
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