Different nitrogen saturation thresholds for above-, below-, and total net primary productivity in a temperate steppe
© 2023 John Wiley & Sons Ltd.
| Veröffentlicht in: | Global change biology. - 1999. - 29(2023), 16 vom: 02. Aug., Seite 4586-4594 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2023
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| Zugriff auf das übergeordnete Werk: | Global change biology |
| Schlagworte: | Journal Article N saturation threshold ammonium toxicity nitrogen deposition production semi-arid grassland soil N concentration Nitrogen N762921K75 Soil |
| Zusammenfassung: | © 2023 John Wiley & Sons Ltd. Identifying the thresholds for the positive responses of total net primary productivity (NPP) to nitrogen (N) enrichment is an essential prerequisite for predicting the benefits of N deposition on ecosystem carbon sequestration. However, the responses of below-ground NPP (BNPP) to N enrichment are unknown in many ecosystems, which limits our ability to understand the carbon cycling under the scenario of increasing N availability. We examined the changes in above-ground NPP (ANPP), BNPP, and NPP of a temperate meadow steppe across a wide-ranging N addition gradient (0, 2, 5, 10, 20, and 50 g N m-2 year-1 ) during 5 years. Both ANPP and NPP increased nonlinearly with N addition rates. The N saturation threshold for ANPP (TA ) and NPP (TN ) was at the rate of 13.11 and 6.70 g N m-2 year-1 , respectively. BNPP decreased with increasing N addition when N addition rates ˃5 g N m-2 year-1 , resulting in much lower TN than TA . Soil N enrichment played a key role in driving the negative impacts of high N addition rates on BNPP, and consequently on the earlier occurrence of N saturation threshold for NPP. Our results highlight the negative effects of soil N enrichment on NPP in natural grasslands super-saturated with N. Furthermore, by considering ANPP and BNPP simultaneously, our results indicate that previous findings from above-ground might have over-estimated the positive effects of N deposition on primary productivity |
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| Beschreibung: | Date Completed 17.07.2023 Date Revised 16.11.2023 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1365-2486 |
| DOI: | 10.1111/gcb.16803 |