The Effects Of Warming And Nitrogen Deposition On Soil Carbon And Nitrogen Processes In Vegetation Restored Medow Of Wugong Mountain, China

The widely-distributed and low-altitude mountain meadow in Wugong Mountain of Jiangxi province along the East China, is an important indicative vegetation type for climate change. However, human disturbances and excessive tourism development have made the mountain meadows being serious degradation. Mountain meadows soils represent large carbon?C? and nitrogen?N? pools, thereby, different grass species used for degradation ecosystem restorations can impact soil carbon and nitrogen processes,especially carbon dioxide?CO₂? and nitrous oxide?N₂O? emissions which are important greenhouse gases. In other hand, because of extreme sensitivity of the Wugong mountain meadows to climate change, it may produce significant amounts of carbon and nitrogen processes depending on the warming and nitrogen deposition. Hence, warming and nitrogen deposition depend on different plant species in restored meadows may impact soil carbon and nitrogen processes.We collected soils from degraded meadows?Bare soil? and plots restored using three different plant species?Miscanthus sinensis, Fimbristylis dichotoma and Carex chinensis?at Wugong Mountain?Jiangxi,China?. We measured soil CO₂ and N₂ O emissions rate and N mineralization rate when soils were incubated at different temperature?15°C, 25°C or35°C? and N additions(control vs. 4 gN m^-2) to simulate the climate warming and nitrogen deposition and understand their responses to warming and N deposition.The result showed that dissolved organic C was higher in restored plots?Miscanthus sinensis, Fimbristylis dichotoma and Carex chinensis? compared to non-restored?Bare soils? and available N was lower. CO₂ emission rates were increased by vegetation restorations, decreased?Miscanthus sinensis? by N deposition, and increased by warming.CO₂ emission rates were similar for the three grass species at 15°C and 25°C, dominant specie Miscanthu sinensiss at 35°C have the lowest CO₂ emission rates compare to other restoration species. Q10 of CO₂ emission of Fimbristylis dichotoma increasing by N deposition. Soils from non-dominant species?Fimbristylis dichotoma and Carex chinensis?plots had higher N₂ O emissions than Bare soil or dominant specie?Miscanthus sinensis?plots, especially at 25°C. Q10 of N₂ O emissions of dominant specie?Miscanthus sinensis?is significantly higher than the non-dominant species?Carex chinensis and Fimbristylis?.Dominant specie Miscanthus sinens not only have the lowest soil N mineralization rate?both 15°C,25°C or 35°C?, but also not have affected by N deposition.In conclusion, the effects of ecosystem restorations on soil greenhouse gas emissions depended on plant species. In addition, these differences varied with temperature and N deposition suggesting that future climate change and dominant specie should be consideredwhen choosing plant species in restorations to predict soil CO₂ and N₂ O emissions and global warming potential.