SOIL MICROSITES AS A SOURCE OF DENITRIFICATION VARIABILITY
SOIL MICROSITES AS A SOURCE OF DENITRIFICATION VARIABILITY
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DOI：
10.2136/sssaj1987.03615995005100050019x
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发表时间：
1987-09-01
影响因子：
2.9
通讯作者：
PARKIN, TB
中科院分区：
文献类型：
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作者：
PARKIN, TB
土壤脱硝率的空间变异性很大。作为典型的自然反硝化速率测量，一个给定的数据集的大多数样品的个别率是低的，但是，少数样品往往表现出极高的速率。这些数据的特点是样本频率分布高度偏斜。本研究旨在研究导致这些观察结果的潜在机制。结果发现，高比反硝化活性的“热点”与土壤中的颗粒有机碳物质。这些热点的高比活性（在有氧条件下孵育，没有修正案）是类似于在厌氧条件下测量的散装土壤与葡萄糖和NO3的dentrification活性。这一观察结果作为计算机模型的基础，该模型评估了这些高活性位点的密度和分散模式对测得的反硝化速率的影响。从计算机模拟生成的直方图非常相似的直方图获得的真实的数据，支持的概念，颗粒有机材料在土壤中的斑片状分散是一个主要因素，影响自然dentrification率的变化。
The spatial variability exhibited by soil dentrification rates is high. As is typical for natural denitrification rate measurements, the individual rates of most samples of a given data set are low; however, a few samples often exhibit extremely high rates. Such data are characterized by highly skewed sample frequency distributions. This study was initiated to investigate the underlying mechanisms responsible for these observations. It was found that "hot-spots" of high specific denitrification activity were associated with particulate organic C material in the soil. The high specific activities of these hot-spots (incubated under aerobic conditions with no amendments) were similar to the dentrification activity of the bulk soil measured under conditions of anerobiosis with added glucose and NO3. This observation served as the basis of a computer model that evaluates the influence of the density and dispersion pattern of these high activity sites on the measured rates of denitrification. Histograms generated from computer simulations are very similar to histograms obtained for real data, supporting the concept that the patchy dispersion of particulate organic material in soil is a major factor influencing the variability of natural dentrification rates.