Effects of long-term increases in atmospheric CO2 concentration, precipitation, temperature and N deposition on gross N mineralization and nitrification rates in California annual grassland soil
Abstract
We have studied the effects of long-term increases in atmospheric CO2 concentration, precipitation, temperature and N deposition on soil inorganic N content, and gross and net N transformation rates in Californian grassland. We sampled soil (0-10 cm) from the Jasper Ridge Global Change Experiment plots in February and April 2005, and determined the gross N mineralization and nitrification rates using the 15N isotope dilution methodology. Statistical analysis revealed significant interactions between multiple climate change factors, making mechanistic interpretations difficult. Consistent effects of N deposition and an interaction between atmospheric CO2 concentration and temperature treatments on N cycling were observed. These results demonstrate the importance of studying interactions between multiple climate change factors in order to provide realistic predictions of C and N cycling under realistic future environmental conditions.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFM.B54B..04H
- Keywords:
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- 0428 Carbon cycling (4806);
- 0469 Nitrogen cycling;
- 0486 Soils/pedology (1865);
- 1600 GLOBAL CHANGE