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Elevated CO2 and nutrient addition after soil N cycling and N trace gas fluxes with early season wet-up in a California annual grassland
| Content Provider | Semantic Scholar |
|---|---|
| Author | Hungate, Bruce A. Lund, Christopher P. Pearson, H. Lennart Chapin, F. Stuart Iii |
| Copyright Year | 1997 |
| Abstract | We examined the effects of growth carbon dioxide (CO2)concentration and soil nutrient availability on nitrogen (N)transformations and N trace gas fluxes in California grasslandmicrocosms during early-season wet-up, a time when rates of Ntransformation and N trace gas flux are high. After plant senescenceand summer drought, we simulated the first fall rains and examined Ncycling. Growth at elevated CO2 increased root productionand root carbon:nitrogen ratio. Under nutrient enrichment, elevatedCO2 increased microbial N immobilization during wet-up,leading to a 43% reduction in gross nitrification anda 55% reduction in NO emission from soil. ElevatedCO2 increased microbial N immobilization at ambientnutrients, but did not alter nitrification or NO emission. ElevatedCO2 did not alter soil emission of N2O ateither nutrient level. Addition of NPK fertilizer (1:1:1) stimulatedN mineralization and nitrification, leading to increased N2Oand NO emission from soil. The results of our study support a mechanisticmodel in which elevated CO2 alters soil N cycling and NOemission: increased root production and increased C:N ratio in elevatedCO2 stimulate N immobilization, thereby decreasingnitrification and associated NO emission when nutrients are abundant.This model is consistent with our basic understanding of how C availabilityinfluences soil N cycling and thus may apply to many terrestrial ecosystems. |
| Starting Page | 89 |
| Ending Page | 109 |
| Page Count | 21 |
| File Format | PDF HTM / HTML |
| DOI | 10.1023/A:1005747123463 |
| Volume Number | 37 |
| Alternate Webpage(s) | http://ecoss.nau.edu/wp-content/uploads/2016/04/art3A10.10232FA3A1005747123463.pdf |
| Alternate Webpage(s) | https://doi.org/10.1023/A%3A1005747123463 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
