Temperature and soil moisture interactively affected soil net N mineralization in temperate grassland in Northern China
Temperature and soil moisture interactively affected soil net N mineralization in temperate grassland in Northern China
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DOI：
10.1016/j.soilbio.2005.09.009
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发表时间：
2006-05
影响因子：
9.7
通讯作者：
Changhui Wang;S. Wan;X. Xing;Lei Zhang;Xingguo Han
中科院分区：
文献类型：
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作者：
Changhui Wang;S. Wan;X. Xing;Lei Zhang;Xingguo Han
在实验室中培养了3个相邻样地（放牧样地A、围栏封育4年的样地B和围栏封育24年的样地C）的完整土芯，研究了温度、土壤水分及其交互作用对北方内蒙古草原净硝化和氮矿化速率的影响。孵化温度显着影响净硝化和氮矿化速率在所有三个草地网站。在较低温度（-10 ° C、0 ° C和5°C）下，净硝化或氮矿化速率没有差异，而在较高温度（15 ° C、25 ° C和35°C）下则存在显著差异。土壤水分深刻影响净硝化和氮矿化速率在所有三个网站。温度和水分的交互作用显著影响站点B和C的净硝化和矿化速率，但不影响站点A。净硝化作用和氮矿化作用的温度敏感性因土壤水分和草地立地而异。我们的研究结果表明，更大的净氮矿化率和较低的无机氮浓度在放牧的网站比围栏的网站，这表明放牧对土壤氮库和净初级生产力的负面影响。
Intact soil cores from three adjacent sites (Site A: grazed, Site B: fenced for 4 years, and Site C: fenced for 24 years) were incubated in the laboratory to examine effects of temperature, soil moisture, and their interactions on net nitrification and N mineralization rates in the Inner Mongolia grassland of Northern China. Incubation temperature significantly influenced net nitrification and N mineralization rates in all the three grassland sites. There were no differences in net nitrification or N mineralization rates at lower temperatures (−10, 0, and 5°C) whereas significant differences were found at higher temperatures (15, 25, and 35°C). Soil moisture profoundly impacted net nitrification and N mineralization rates in all the three sites. Interactions of temperature and moisture significantly affected net nitrification and mineralization rates in Site B and C, but not in Site A. Temperature sensitivity of net nitrification and N mineralization varied with soil moisture and grassland site. Our results showed greater net N mineralization rates and lower concentrations of inorganic N in the grazed site than those in the fenced sites, suggesting negative impacts of grazing on soil N pools and net primary productivity.