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为探讨氮硫沉降对华北暖温带森林土壤呼吸的影响规律以及与温度、湿度的关系,在落叶松人工林中开展了野外模拟氮硫沉降试验.结果表明:在生长季,各氮硫水平样地月平均土壤呼吸有明显的季节变化特征,模拟氮硫复合沉降对华北落叶松林土壤呼吸产生显著影响(P<0.05).生长季内,氮沉降促进土壤呼吸速率,其中高氮与CK产生显著差异(P<0.05).土壤呼吸速率与硫沉降水平呈正相关关系(P<0.05).氮硫复合沉降促进了土壤呼吸速率,高氮高硫与CK土壤呼吸速率产生显著差异(P<0.05),而中氮中硫水平抑制土壤呼吸速率,但未达到显著水平(P>0.05).中氮和中硫对土壤呼吸速率的影响大于二者的共同作用,产生拮抗作用,而高氮高硫产生协同作用.各处理土壤呼吸速率与5 cm土壤温度呈极显著正相关关系.土壤温湿度双因子模型预测土壤呼吸的准确性和稳定性高于单因子模型.模拟氮硫沉降增加了土壤Q_(10)值,而高氮高硫降低了土壤Q_(10)值.试验结果揭示了太岳山华北落叶松林土壤呼吸特征对氮硫复合沉降的响应,即除中氮中硫外,复合沉降不同程度地促进了土壤呼吸速率,其复杂的响应机制仍有待进一步研究.
In order to investigate the influence of nitrogen and sulfur deposition on soil respiration in warm temperate forests in North China and its relationship with temperature and humidity, simulated field tests of nitrogen and sulfur in the larch plantation were carried out. The results showed that during the growing season, The mean monthly soil respiration had obvious seasonal variations, and the simulated N-S composite sedimentation had a significant effect on soil respiration in the Larix principis-rupprechtii forest (P <0.05) .In the growing season, N deposition promoted the soil respiration rate, (P <0.05) .The soil respiration rate was positively correlated with the level of sulfur deposition (P <0.05) .Sulphurization combined with nitrogen and sulfur promoted the soil respiration rate, high nitrogen and sulfur and CK soil respiration rate significant difference (P <0.05) , While the level of sulfur in middle nitrogen inhibited the respiration rate of soil, but did not reach the significant level (P> 0.05). The effect of medium and medium sulfur on soil respiration rate was greater than that of both, which resulted in antagonism, And there was a significant positive correlation between soil respiration rate and soil temperature at 5 cm.The accuracy and stability of soil respiration predicted by soil temperature and humidity two-factor model were higher than those of single factor model.The simulated nitrogen and sulfur Sedimentation increased Q_ (10) value of soil, while high N and S decreased soil Q_ (10) value.The results revealed that soil respiration characteristics of Larix principis - rupprechtii Forest in Taiyue Mountain responded to N and S composite sedimentation, In addition, the composite sedimentation promotes the soil respiration rate to varying degrees, and its complex response mechanism remains to be further studied.