Improving the statistical preparation for measuring soil N2O flux by closed chamber.
Improving the statistical preparation for measuring soil N2O flux by closed chamber.
复制标题
改进密闭室测量土壤N2O通量的统计准备工作。
DOI：
10.1016/j.scitotenv.2013.02.032
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
L. Van Zwieten
中科院分区：
文献类型：
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作者：
S. Morris;S. Kimber;P. Grace;L. Van Zwieten
众所周知，土壤中的一氧化二氮排放在空间和时间上都是不稳定的。对特定时间和空间内排放量的可靠估计取决于足够强度的测量，但决定测量站的数量和观测频率可能令人烦恼。还出现了低频人工观测结果与高频自动采样结果可比的问题。从一个重复的现场实验收集的数据进行了深入研究，目的是在这些问题上提供一些统计上的强大的指导。实验中，在10 m × 2.5 m的地块内，通过自动密闭室以3 h的平均采样间隔和手动静态室以3 d的平均采样间隔监测氧化亚氮的土壤-空气通量，持续60 d。通过静态室观察到的通量随时间变化的趋势大多在自动室实验误差范围内。每个系统测量的累积一氧化二氮排放量也在误差范围内。在本实验的时间响应模式下，在各种低频场景下，对数据进行剔除以模拟结果后，没有观察到显著的信息损失。在本实验的范围内，从手动室观察到的距离在1米以上的空间上不相关。因此，由于每次处理的重复次数或每次重复次数的室数增加，统计功效得到改善。行动后仔细审查实验数据可以节省未来的工作。
Nitrous oxide emissions from soil are known to be spatially and temporally volatile. Reliable estimation of emissions over a given time and space depends on measuring with sufficient intensity but deciding on the number of measuring stations and the frequency of observation can be vexing. The question of low frequency manual observations providing comparable results to high frequency automated sampling also arises. Data collected from a replicated field experiment was intensively studied with the intention to give some statistically robust guidance on these issues. The experiment had nitrous oxide soil to air flux monitored within 10 m by 2.5 m plots by automated closed chambers under a 3 h average sampling interval and by manual static chambers under a three day average sampling interval over sixty days. Observed trends in flux over time by the static chambers were mostly within the auto chamber bounds of experimental error. Cumulated nitrous oxide emissions as measured by each system were also within error bounds. Under the temporal response pattern in this experiment, no significant loss of information was observed after culling the data to simulate results under various low frequency scenarios. Within the confines of this experiment observations from the manual chambers were not spatially correlated above distances of 1 m. Statistical power was therefore found to improve due to increased replicates per treatment or chambers per replicate. Careful after action review of experimental data can deliver savings for future work.