中科院海岸带环境过程与生态修复重点实验室知识库

Nutrient availability greatly regulates ecosystem processes in salt-affected soils. However, few studies have explored the impacts of nitrogen (N), phosphorus (P) and N×P interactions on CO₂ and N₂O emissions from salt-affected soils in the Yellow River Delta (YRD), which is one of the three biggest deltas in China. An incubation study was conducted to test the effects of N or P addition alone, as well as combined NP application, on CO₂ and N₂O emissions from the soils taken from four sites: bare land (BL) with no vegetation cover and three adjacent vegetation communities, Tamarix chinensis (TC), Suaeda salsa (SS) and Phragmites australis (PA) in the YRD. The results showed that N and its interaction with P showed significant and identical effects on both CO₂ and N₂O emissions in all soils. Nevertheless, the significant effect of P on CO₂ production was found in soils covered with vegetation. N addition tended to augment CO₂ and N₂O emissions. However, the significant positive correlation between cumulative CO₂ emissions and P addition was only found in soils collected from different communities. Compared with soils collected from BL, soils from different vegetation communities emitted more CO₂ and more N₂O. Moreover, soils of woody communities produced more CO₂ than those of herbaceous communities. On the contrary, N₂O emissions in soils of herbaceous communities were higher than in woody communities. Therefore, more attention, should be paid to the pulse GHG emissions that result from nutrient addition during the reclamation of saline soils, especially those covered with vegetation.