Contrasting effects of exogenous phosphorus application on N2O emissions from two tropical forest soils with contrasting phosphorus availability.
Contrasting effects of exogenous phosphorus application on N2O emissions from two tropical forest soils with contrasting phosphorus availability.
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DOI：
10.1186/s40064-016-2587-5
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
Kitayama K
中科院分区：
文献类型：
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作者：
Mori T;Yokoyama D;Kitayama K
通过培养试验研究了不同母质[变质岩(MS)和超基性岩(UB)]上两种热带雨林土壤中添加磷(P)对土壤一氧化二氮(N2O)排放的影响。基纳巴鲁，婆罗洲。早期的研究表明，与MS土壤相比，UB土壤上的森林受到P的限制更强。在MS土壤中，磷的添加显著减少了N2O的排放。由于磷的添加既没有减少氨氮(NH_4+)，也没有减少硝酸盐(NO_3-−)的含量，我们推测N_2O排放的减少不是由于先前报道的机制：P的添加促进了微生物氮(N)的固定和伴随的无机N的消耗，从而减少了产生N_2O的资源。由于磷的添加提高了微生物生物量与CO2和N2O排放的比率(硝化和/或反硝化呼吸效率的指标)，因此表明硝化和/或反硝化细菌呼吸所需的N减少了，导致N2O排放减少。而施磷对UB土壤中N2O的排放没有影响。施磷量对土壤呼吸效率影响不大，可能是由于施磷量使土壤微生物群落发生了变化，从而提高了土壤的呼吸效率。我们的结论是：(1)磷的添加可能通过提高呼吸效率来控制N2O的排放，以及(2)不同的磷有效性的影响可能是不同的。
An incubation study was conducted to test the effects of phosphorus (P) addition on nitrous oxide (N2O) emissions from the soils taken from two tropical rain forests established on different parent materials [meta-sedimentary (MS) and ultrabasic (UB) rock] on Mt. Kinabalu, Borneo. Earlier studies suggest that the forest on UB soils is more strongly limited by P than that on MS soils is. In MS soils, P addition significantly reduced N2O emissions. Since neither ammonium (NH4+) nor nitrate (NO3−) contents were reduced by P addition, we assumed that the decrease in N2O emissions were not due to the previously-reported mechanism: P addition stimulated microbial nitrogen (N) immobilization and collateral inorganic N consumption, reducing resources for producing N2O. Since P addition enhanced the ratios of microbial biomass to CO2 and N2O emissions (indicators of nitrifying and/or denitrifying respiratory efficiency), it was suggested that the N required for the respiration of nitrifying and/or denitrifying bacteria was reduced, leading to reduced N2O emissions. On the other hand, P addition had no effects on N2O emissions in UB soils. The respiratory efficiency did not change significantly by P addition, possibly because the microbial community in the highly-P-depleted UB soils shifted by P addition, with which the enhancement of respiration efficiency did not co-vary. We concluded that (1) P addition may control N2O emissions through increasing respiratory efficiency, and (2) the effects may be different depending on the differences in P availability.