Interactive effects of temperature and precipitation on soil respiration in a temperate maritime pine forest.
Interactive effects of temperature and precipitation on soil respiration in a temperate maritime pine forest.
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DOI：
10.1093/treephys/23.18.1263
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发表时间：
2003-12
期刊：
影响因子：
4
通讯作者：
J. Curiel Yuste;I. Janssens;A. Carrara;L. Meiresonne;R. Ceulemans
中科院分区：
文献类型：
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作者：
J. Curiel Yuste;I. Janssens;A. Carrara;L. Meiresonne;R. Ceulemans
2001年对樟子松（Pinus sylvestris L.）位于比利时Campine地区。正如预期的温带海洋森林，温度是占主导地位的控制SR在一年中的大部分时间。而在春末和夏季土壤含水量有限时，SR对温度不敏感（Q（10）= 1.24）。我们观察到，在长时间无雨期间，当SWC小于15%（v/v），SR急剧下降（高达50%）和SWC接管SR的控制。然而，在这样的干旱期间，降雨事件有时刺激SR和恢复SR的温度控制，即使在矿质土壤中的SWC是低的。我们假设，只有当降雨事件充分重新润湿最上层土壤，其中大部分的呼吸活动发生时，才发生恢复的温度控制。为了量化降雨事件的再润湿能力，设计了一个指数（I（w）），该指数包括降雨强度、自上次降雨事件以来的时间和大气蒸汽压亏损（蒸发水损失的代理）。为了模拟SR通量，开发了一个模型，包括土壤温度的影响，在干旱和非再湿润条件下（I（w）和SWC <阈值），SWC响应函数。该模型解释了95%的时间变化，在夏季观察到的SR，而温度函数单独解释只有73%的这种变化。我们的研究结果表明，除了温度和SWC，降雨在确定土壤碳释放总量方面也发挥着重要作用，即使在海洋性气候中也是如此。
Soil respiration (SR) was monitored periodically throughout 2001 in a Scots pine (Pinus sylvestris L.) stand located in the Belgian Campine region. As expected for a temperate maritime forest, temperature was the dominant control over SR during most of the year. However, during late spring and summer, when soil water content (SWC) was limiting, SR was insensitive to temperature (Q(10) = 1.24). We observed that during prolonged rain-free periods, when SWC was less than 15% (v/v), SR decreased dramatically (up to 50%) and SWC took over control of SR. During such drought periods, however, rain events sometimes stimulated SR and restored temperature control over SR, even though SWC in the mineral soil was low. We hypothesize that restoration of temperature control occurred only when rain events adequately rewetted the uppermost soil layers, where most of the respiratory activity occurred. To quantify the rewetting capacity of rain events, an index (I(w)) was designed that incorporated rainfall intensity, time elapsed since the last rain event, and atmospheric vapor pressure deficit (a proxy for evaporative water losses). To simulate SR fluxes, a model was developed that included the effects of soil temperature and, under drought and non-rewetting conditions (I(w) and SWC < threshold), an SWC response function. The model explained 95% of the temporal variability in SR observed during summer, whereas the temperature function alone explained only 73% of this variability. Our results revealed that, in addition to temperature and SWC, rain plays a role in determining the total amount of carbon released from soils, even in a maritime climate.