Ecological Risks from Atmospheric Deposition of Nitrogen and Sulphur in Jack Pine forests of Northwestern Canada
Chronic elevated nitrogen (N) deposition can have adverse effects on terrestrial ecosystems. For large areas of northern Canada distant from emissions sources, long-range atmospheric transport of N may impact plant species diversity, even at low deposition levels. The objective of this study was to...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-02-01
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| Series: | Nitrogen |
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| Online Access: | https://www.mdpi.com/2504-3129/4/1/8 |
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| author | Nicole Vandinther Julian Aherne |
| author_facet | Nicole Vandinther Julian Aherne |
| author_sort | Nicole Vandinther |
| collection | DOAJ |
| description | Chronic elevated nitrogen (N) deposition can have adverse effects on terrestrial ecosystems. For large areas of northern Canada distant from emissions sources, long-range atmospheric transport of N may impact plant species diversity, even at low deposition levels. The objective of this study was to establish plant species community thresholds for N deposition under multiple environmental gradients using gradient forest analysis. Plant species abundance data for 297 Jack pine (<i>Pinus banksiana</i> Lamb.)-dominant forest plots across Alberta and Saskatchewan, Canada, were evaluated against 43 bioclimatic and deposition variables. Bioclimatic variables were overwhelmingly the most important drivers of community thresholds. Nonetheless, dry N oxide (DNO) and dry N dioxide deposition inferred a total deposited N (TDN) community threshold of 1.4–2.1 kg N ha<sup>−1</sup> yr<sup>−1</sup>. This range was predominantly associated with changes in several lichen species, including <i>Cladina mitis</i>, <i>Vulpicida pinastri</i>, <i>Evernia mesomorpha</i> and <i>Lecanora circumborealis</i>, some of which are known bioindicators of N deposition. A secondary DNO threshold appeared to be driving changes in several vascular species and was equivalent to 2.45–3.15 kg N ha<sup>−1</sup> yr<sup>−1</sup> on the TDN gradient. These results suggest that in low deposition ‘background’ regions a biodiversity-based empirical critical load of 1.4–3.15 kg N ha<sup>−1</sup> yr<sup>−1</sup> will protect lichen communities and other N-sensitive species in Jack pine forests across Northwestern Canada. Nitrogen deposition above the critical load may lead to adverse effects on plant species biodiversity within these forests. |
| first_indexed | 2024-03-11T06:05:22Z |
| format | Article |
| id | doaj.art-a78258da6ba6404aa1f049954c3af4a5 |
| institution | Directory Open Access Journal |
| issn | 2504-3129 |
| language | English |
| last_indexed | 2024-03-11T06:05:22Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nitrogen |
| spelling | doaj.art-a78258da6ba6404aa1f049954c3af4a52023-11-17T13:02:55ZengMDPI AGNitrogen2504-31292023-02-014110212410.3390/nitrogen4010008Ecological Risks from Atmospheric Deposition of Nitrogen and Sulphur in Jack Pine forests of Northwestern CanadaNicole Vandinther0Julian Aherne1School of Environment, Trent University, Peterborough, ON K9L 0G2, CanadaSchool of Environment, Trent University, Peterborough, ON K9L 0G2, CanadaChronic elevated nitrogen (N) deposition can have adverse effects on terrestrial ecosystems. For large areas of northern Canada distant from emissions sources, long-range atmospheric transport of N may impact plant species diversity, even at low deposition levels. The objective of this study was to establish plant species community thresholds for N deposition under multiple environmental gradients using gradient forest analysis. Plant species abundance data for 297 Jack pine (<i>Pinus banksiana</i> Lamb.)-dominant forest plots across Alberta and Saskatchewan, Canada, were evaluated against 43 bioclimatic and deposition variables. Bioclimatic variables were overwhelmingly the most important drivers of community thresholds. Nonetheless, dry N oxide (DNO) and dry N dioxide deposition inferred a total deposited N (TDN) community threshold of 1.4–2.1 kg N ha<sup>−1</sup> yr<sup>−1</sup>. This range was predominantly associated with changes in several lichen species, including <i>Cladina mitis</i>, <i>Vulpicida pinastri</i>, <i>Evernia mesomorpha</i> and <i>Lecanora circumborealis</i>, some of which are known bioindicators of N deposition. A secondary DNO threshold appeared to be driving changes in several vascular species and was equivalent to 2.45–3.15 kg N ha<sup>−1</sup> yr<sup>−1</sup> on the TDN gradient. These results suggest that in low deposition ‘background’ regions a biodiversity-based empirical critical load of 1.4–3.15 kg N ha<sup>−1</sup> yr<sup>−1</sup> will protect lichen communities and other N-sensitive species in Jack pine forests across Northwestern Canada. Nitrogen deposition above the critical load may lead to adverse effects on plant species biodiversity within these forests.https://www.mdpi.com/2504-3129/4/1/8community thresholdbiodiversitycritical loadlichensgradient forest analysis |
| spellingShingle | Nicole Vandinther Julian Aherne Ecological Risks from Atmospheric Deposition of Nitrogen and Sulphur in Jack Pine forests of Northwestern Canada Nitrogen community threshold biodiversity critical load lichens gradient forest analysis |
| title | Ecological Risks from Atmospheric Deposition of Nitrogen and Sulphur in Jack Pine forests of Northwestern Canada |
| title_full | Ecological Risks from Atmospheric Deposition of Nitrogen and Sulphur in Jack Pine forests of Northwestern Canada |
| title_fullStr | Ecological Risks from Atmospheric Deposition of Nitrogen and Sulphur in Jack Pine forests of Northwestern Canada |
| title_full_unstemmed | Ecological Risks from Atmospheric Deposition of Nitrogen and Sulphur in Jack Pine forests of Northwestern Canada |
| title_short | Ecological Risks from Atmospheric Deposition of Nitrogen and Sulphur in Jack Pine forests of Northwestern Canada |
| title_sort | ecological risks from atmospheric deposition of nitrogen and sulphur in jack pine forests of northwestern canada |
| topic | community threshold biodiversity critical load lichens gradient forest analysis |
| url | https://www.mdpi.com/2504-3129/4/1/8 |
| work_keys_str_mv | AT nicolevandinther ecologicalrisksfromatmosphericdepositionofnitrogenandsulphurinjackpineforestsofnorthwesterncanada AT julianaherne ecologicalrisksfromatmosphericdepositionofnitrogenandsulphurinjackpineforestsofnorthwesterncanada |