Cold storage and laboratory incubation of intact soil cores do not reflect in-situ nitrogen cycling rates of tropical forest soils
Cold storage and laboratory incubation of intact soil cores do not reflect in-situ nitrogen cycling rates of tropical forest soils
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DOI：
10.1016/j.soilbio.2008.06.001
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发表时间：
2008-09
影响因子：
9.7
通讯作者：
J. Arnold;M. Corre;E. Veldkamp
中科院分区：
文献类型：
--
作者：
J. Arnold;M. Corre;E. Veldkamp
热带森林土壤氮素转化速率的测定通常在实验室中从扰动或完整的土芯进行。在巴拿马和厄瓜多尔的古老森林下的4个Andisol土壤站点上，我们比较了在冷藏（5°C）一段时间后从实验室培养（在站点的土壤温度下）测量的完整土芯的氮转化率与原位测量。从储存的土壤芯的实验室测量结果表明，较低的总氮矿化和NH4+消耗率和较高的总硝化和NO3−固定率比原位测量。我们的结论是，冷藏和实验室培养改变土壤到这样的程度，N循环速率不反映现场条件。测定热带森林土壤氮素转化率的唯一可靠方法是原位培养和野外提取矿质氮。
Measurements of N transformation rates in tropical forest soils are commonly conducted in the laboratory from disturbed or intact soil cores. On four sites with Andisol soils under old-growth forests of Panama and Ecuador, we compared N transformation rates measured from laboratory incubation (at soil temperatures of the sites) of intact soil cores after a period of cold storage (at 5°C) with measurements conducted in situ. Laboratory measurements from stored soil cores showed lower gross N mineralization and NH4+consumption rates and higher gross nitrification and NO3−immobilization rates than the in-situ measurements. We conclude that cold storage and laboratory incubation change the soils to such an extent that N cycling rates do not reflect field conditions. The only reliable way to measure N transformation rates of tropical forest soils is in-situ incubation and mineral N extraction in the field.