Reply to: Data do not support large-scale oligotrophication of terrestrial ecosystems.
Hiltbrunner et al. apply a reductionist approach to argue that the evidence for widespread terrestrial oligotrophication2 should be replaced with a two-factor explanation (growth dilution and depositional signatures) that does not invoke reductions in N availability, that is, the supply of N relativ...
| Autores principales: | , , , , , , , , , , , , , |
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| Formato: | info:ar-repo/semantics/artículo |
| Lenguaje: | Inglés |
| Publicado: |
Springer Nature
2021
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| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12123/9044 https://www.nature.com/articles/s41559-019-0949-4 https://doi.org/10.1038/s41559-019-0949-4 |
| Sumario: | Hiltbrunner et al. apply a reductionist approach to argue that the evidence for widespread terrestrial oligotrophication2 should be replaced with a two-factor explanation (growth dilution and depositional signatures) that does not invoke reductions in N availability, that is, the supply of N relative to plant demand. Contrary to any “adjustment of leaf photosynthetic capacity and a widening of leaf C:N ratios,” there is little evidence that observed declines in foliar [N] are caused solely by photosynthetic downregulation. Photosynthetic downregulation is not universal and probably could be caused by reduced N availability. A comprehensive synthesis of data on responses of plant productivity and N acquisition to elevated CO2 in free-air carbon dioxide enrichment (FACE) experiments demonstrated that there were declines in N uptake in low-N ecosystems as a result of decreased ‘access’ to N, not reduced demand4. The growth dilution hypothesis was ‘refuted’ as an explanation for these declines. |
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