- Title
- Growth metrics and δ15N values of water hyacinth, Eichhornia crassipes, in relation to biological control
- Creator
- Hill, Jaclyn M
- Subject
- To be catalogued
- Date
- 2014
- Type
- text
- Type
- article
- Identifier
- http://hdl.handle.net/10962/444744
- Identifier
- vital:74264
- Identifier
- https://www.cabidigitallibrary.org/doi/pdf/10.5555/20173070900
- Description
- The success of classical biological control against Eichhornia crassipes (Pontederiaceae) in South Africa has been varied, with failures attributed to numerous factors, predominantly the high levels of eutrophication of many freshwater systems. Studies have shown that increased N-loads are associated with enriched δ15N values of aquatic biota. Stable isotope analyses may therefore help to assess the nutrient status of invaded ecosystems and predict the success of classical biological control. A combination of controlled greenhouse experiments and in-situ observations were used: to quantify the δ15N equilibration rate of E. crassipes leaf tissue (ie the time span of the information on environmental N-loading); to confirm the ability of plant tissue to reflect ecosystem N-loading; and to compare standard water hyacinth growth metrics with δ15N and C/N ratios to evaluate how well they described eutrophication. Using both δ15N values and C/N ratios, it was possible to distinguish clearly between manure-, fertilizer-and control-regimes, and plant tissue provided information on ecosystem N-loading over approximately 16 days. Interpretations were complicated by the plant’s capacity for N storage. Strong correlations between petiole length of E. crassipes and δ15N values indicate that petiole length may be linked to N-loading. Weaker (or a lack of) correlations between δ15N or C/N ratios and remaining growth metrics suggest that generalisations and, or, predictions of eutrophication based on growth metrics should be avoided. A combination approach using plant tissue δ15N and C/N ratios along with maximum petiole length of E. crassipes plants may provide a time-integrated assessment of ecosystem eutrophication and help to identify areas where classical biological control may face significant obstacles in the regulation of water hyacinth populations.
- Format
- 1 pages, pdf
- Language
- English
- Relation
- CABI Digital Library, Hill, J.M., 2014. Growth metrics and δ15N values of water hyacinth, Eichhornia crassipes, in relation to biological control, CABI Digital Library volume 2014 number 1 1 1 2014
- Rights
- Publisher
- Rights
- Use of this resource is governed by the terms and conditions of the CABI Direct Terms and Conditions Statement (http://www.cabi.org/terms-and-conditions)
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Collections
Hill, Jaclyn Marie (Ms)
RU DST/NRF SARChI for Insects in Sustainable Agricultural Ecosystems
RU Department of Zoology and Entomology
SDG 14. Life Below Water
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