Can nitrogen isotopes be used to detect the effects of burning on nitrogen cycling? : a study on Pinus resinosa in Minnesota, USA
| dc.contributor.advisor | Craine, Joseph M | en_ZA |
| dc.contributor.author | Ballantyne, Fiona | en_ZA |
| dc.date.accessioned | 2017-11-10T06:30:28Z | |
| dc.date.available | 2017-11-10T06:30:28Z | |
| dc.date.issued | 2004 | en_ZA |
| dc.date.updated | 2017-03-10T14:41:30Z | |
| dc.description.abstract | Pinus resinosa stands in Minnesota, USA were surveyed and fine and coarse roots from stands were analysed for nitrogen isotopes in an attempt to determine if fire effects nitrogen cycling. Fire increased the % nitrogen of coarse roots and changed the ratio of C: N. It may also decrease the depth of the A-horizon. It did not however affect the nitrogen isotope ratio of stands. Isotope values of coarse roots were affected by the depth of the A-horizon, which is consistent with other studies. A correlation between the ¹⁵N values of coarse and fine roots was found however fine roots were enriched proportionately to coarse roots. This suggests that they may be using a more enriched source of nitrogen such as ammonia although this is not conclusive. A PCA performed on site variables and isotope values determined the two major axes for sites were bum history and nitrogen cycle openness but that burning did not affect the second axis. A stepwise backwards regression showed the best predictors of a roots isotope value were, in decreasing order, the isotope value of coarse roots for fine roots and vice versa, the % nitrogen of roots and the age of stands. Coarse and fine roots showed opposite trends with % nitrogen. As the % nitrogen increased, fine roots were more ¹⁵N enriched, again pointing to different nitrogen sources for coarse and fine roots. Older stands do appear to have a more open nitrogen cycle, as roots were ¹⁵N enriched in these stands. The availability of different forms of nitrogen may influence the ¹⁵N signal of roots especially if fine roots are preferentially using ammonia. Therefore, it is not possible to say if isotope values are due to stand openness, or due to different resources use by roots. | en_ZA |
| dc.identifier.apacitation | Ballantyne, F. (2004). <i>Can nitrogen isotopes be used to detect the effects of burning on nitrogen cycling? : a study on Pinus resinosa in Minnesota, USA</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/26118 | en_ZA |
| dc.identifier.chicagocitation | Ballantyne, Fiona. <i>"Can nitrogen isotopes be used to detect the effects of burning on nitrogen cycling? : a study on Pinus resinosa in Minnesota, USA."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2004. http://hdl.handle.net/11427/26118 | en_ZA |
| dc.identifier.citation | Ballantyne, F. 2004. Can nitrogen isotopes be used to detect the effects of burning on nitrogen cycling? : a study on Pinus resinosa in Minnesota, USA. University of Cape Town. | en_ZA |
| dc.identifier.ris | TY - Thesis / Dissertation AU - Ballantyne, Fiona AB - Pinus resinosa stands in Minnesota, USA were surveyed and fine and coarse roots from stands were analysed for nitrogen isotopes in an attempt to determine if fire effects nitrogen cycling. Fire increased the % nitrogen of coarse roots and changed the ratio of C: N. It may also decrease the depth of the A-horizon. It did not however affect the nitrogen isotope ratio of stands. Isotope values of coarse roots were affected by the depth of the A-horizon, which is consistent with other studies. A correlation between the ¹⁵N values of coarse and fine roots was found however fine roots were enriched proportionately to coarse roots. This suggests that they may be using a more enriched source of nitrogen such as ammonia although this is not conclusive. A PCA performed on site variables and isotope values determined the two major axes for sites were bum history and nitrogen cycle openness but that burning did not affect the second axis. A stepwise backwards regression showed the best predictors of a roots isotope value were, in decreasing order, the isotope value of coarse roots for fine roots and vice versa, the % nitrogen of roots and the age of stands. Coarse and fine roots showed opposite trends with % nitrogen. As the % nitrogen increased, fine roots were more ¹⁵N enriched, again pointing to different nitrogen sources for coarse and fine roots. Older stands do appear to have a more open nitrogen cycle, as roots were ¹⁵N enriched in these stands. The availability of different forms of nitrogen may influence the ¹⁵N signal of roots especially if fine roots are preferentially using ammonia. Therefore, it is not possible to say if isotope values are due to stand openness, or due to different resources use by roots. DA - 2004 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2004 T1 - Can nitrogen isotopes be used to detect the effects of burning on nitrogen cycling? : a study on Pinus resinosa in Minnesota, USA TI - Can nitrogen isotopes be used to detect the effects of burning on nitrogen cycling? : a study on Pinus resinosa in Minnesota, USA UR - http://hdl.handle.net/11427/26118 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/26118 | |
| dc.identifier.vancouvercitation | Ballantyne F. Can nitrogen isotopes be used to detect the effects of burning on nitrogen cycling? : a study on Pinus resinosa in Minnesota, USA. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2004 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/26118 | en_ZA |
| dc.language.iso | eng | en_ZA |
| dc.publisher.department | Department of Biological Sciences | en_ZA |
| dc.publisher.faculty | Faculty of Science | en_ZA |
| dc.publisher.institution | University of Cape Town | |
| dc.subject.other | Botany | en_ZA |
| dc.subject.other | Plant Ecology | en_ZA |
| dc.title | Can nitrogen isotopes be used to detect the effects of burning on nitrogen cycling? : a study on Pinus resinosa in Minnesota, USA | en_ZA |
| dc.type | Bachelor Thesis | |
| dc.type.qualificationlevel | Honours | |
| dc.type.qualificationname | BSc (Hons) | en_ZA |
| uct.type.filetype | ||
| uct.type.filetype | Text | |
| uct.type.filetype | Image | |
| uct.type.publication | Research | en_ZA |
| uct.type.resource | Thesis | en_ZA |