Global evidence on nitrogen saturation of terrestrial ecosystem net primary productivity
The continually increasing nitrogen (N) deposition is expected to increase ecosystem aboveground net primary production (ANPP) until it exceeds plant N demand, causing a nonlinear response and N saturation for ANPP. However, the nonlinear response of ANPP to N addition gradient and the N saturation...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2016-01-01
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| Series: | Environmental Research Letters |
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| Online Access: | https://doi.org/10.1088/1748-9326/11/2/024012 |
| _version_ | 1797748643464216576 |
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| author | Dashuan Tian Hong Wang Jian Sun Shuli Niu |
| author_facet | Dashuan Tian Hong Wang Jian Sun Shuli Niu |
| author_sort | Dashuan Tian |
| collection | DOAJ |
| description | The continually increasing nitrogen (N) deposition is expected to increase ecosystem aboveground net primary production (ANPP) until it exceeds plant N demand, causing a nonlinear response and N saturation for ANPP. However, the nonlinear response of ANPP to N addition gradient and the N saturation threshold have not been comprehensively quantified yet for terrestrial ecosystems. In this study, we compiled a global dataset of 44 experimental studies with at least three levels of N treatment. Nitrogen response efficiency (NRE, ANPP response per unit N addition) and the difference in NRE between N levels (ΔNRE) were quantified to test the nonlinearity in ANPP response. We found a universal response pattern of N saturation for ANPP with N addition gradient across all the studies and in different ecosystems. An averaged N saturation threshold for ANPP nonlinearity was found at the N addition rates of 5–6 g m ^−2 yr ^−1 . The extent to which ANPP approaches N saturation varied with ecosystem type, N addition rate and environmental factors. ANPP in grasslands had lower NRE than those in forests and wetlands. Plant NRE decreased with reduced soil C:N ratio, and was the highest at intermediate levels of rainfall and temperature. These findings suggest that ANPP in grassland or the ecosystems with low soil C:N ratio (or low and high rainfall or temperature) is easier to be saturated with N enrichment. Overall, these results indicate that the beneficial effect of N deposition on plant productivity likely diminishes with continuous N enrichment when N loading surpasses the N saturation threshold for ANPP nonlinearity. |
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| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T16:07:43Z |
| publishDate | 2016-01-01 |
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| spelling | doaj.art-9b7ece899d5c4a9687b90791df06ea0d2023-08-09T14:17:23ZengIOP PublishingEnvironmental Research Letters1748-93262016-01-0111202401210.1088/1748-9326/11/2/024012Global evidence on nitrogen saturation of terrestrial ecosystem net primary productivityDashuan Tian0Hong Wang1Jian Sun2Shuli Niu3Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, People’s Republic of ChinaSemiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, Box 1030, Swift Current, SK S9H 3X2, CanadaKey Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, People’s Republic of ChinaKey Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, People’s Republic of ChinaThe continually increasing nitrogen (N) deposition is expected to increase ecosystem aboveground net primary production (ANPP) until it exceeds plant N demand, causing a nonlinear response and N saturation for ANPP. However, the nonlinear response of ANPP to N addition gradient and the N saturation threshold have not been comprehensively quantified yet for terrestrial ecosystems. In this study, we compiled a global dataset of 44 experimental studies with at least three levels of N treatment. Nitrogen response efficiency (NRE, ANPP response per unit N addition) and the difference in NRE between N levels (ΔNRE) were quantified to test the nonlinearity in ANPP response. We found a universal response pattern of N saturation for ANPP with N addition gradient across all the studies and in different ecosystems. An averaged N saturation threshold for ANPP nonlinearity was found at the N addition rates of 5–6 g m ^−2 yr ^−1 . The extent to which ANPP approaches N saturation varied with ecosystem type, N addition rate and environmental factors. ANPP in grasslands had lower NRE than those in forests and wetlands. Plant NRE decreased with reduced soil C:N ratio, and was the highest at intermediate levels of rainfall and temperature. These findings suggest that ANPP in grassland or the ecosystems with low soil C:N ratio (or low and high rainfall or temperature) is easier to be saturated with N enrichment. Overall, these results indicate that the beneficial effect of N deposition on plant productivity likely diminishes with continuous N enrichment when N loading surpasses the N saturation threshold for ANPP nonlinearity.https://doi.org/10.1088/1748-9326/11/2/024012plant growthterrestrial ecosystemmeta-analysisnitrogen depositionnitrogen response efficiencysaturation threshold |
| spellingShingle | Dashuan Tian Hong Wang Jian Sun Shuli Niu Global evidence on nitrogen saturation of terrestrial ecosystem net primary productivity Environmental Research Letters plant growth terrestrial ecosystem meta-analysis nitrogen deposition nitrogen response efficiency saturation threshold |
| title | Global evidence on nitrogen saturation of terrestrial ecosystem net primary productivity |
| title_full | Global evidence on nitrogen saturation of terrestrial ecosystem net primary productivity |
| title_fullStr | Global evidence on nitrogen saturation of terrestrial ecosystem net primary productivity |
| title_full_unstemmed | Global evidence on nitrogen saturation of terrestrial ecosystem net primary productivity |
| title_short | Global evidence on nitrogen saturation of terrestrial ecosystem net primary productivity |
| title_sort | global evidence on nitrogen saturation of terrestrial ecosystem net primary productivity |
| topic | plant growth terrestrial ecosystem meta-analysis nitrogen deposition nitrogen response efficiency saturation threshold |
| url | https://doi.org/10.1088/1748-9326/11/2/024012 |
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