The effects of elevated atmospheric humidity on soil respiration components in a young silver birch forest
The effects of elevated atmospheric humidity on soil respiration components in a young silver birch forest
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DOI：
10.1016/j.agrformet.2014.04.003
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发表时间：
2014-08
影响因子：
6.2
通讯作者：
M. Kukumägi;I. Ostonen;P. Kupper;M. Truu;I. Tulva;M. Varik;J. Aosaar;J. Sõber;K. Lõhmus
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文献类型：
--
作者：
M. Kukumägi;I. Ostonen;P. Kupper;M. Truu;I. Tulva;M. Varik;J. Aosaar;J. Sõber;K. Lõhmus
预计北纬地区降水量增加是影响森林生态系统功能的重要因素，但大气湿度增加对森林生态系统碳循环的影响仍然很大程度上未知。我们的目标是在自由空气湿度操纵实验设施 (FAHM) 中确定大气湿度升高对白桦 (Betula pendulaRoth.) 种植园土壤呼吸的影响。 2008 年和 2009 年，从 5 月到 10 月，每月对三个对照区和三个雾化区的土壤呼吸进行监测；同时测量土壤温度和土壤湿度。通过连续的土芯测量林下细根和根茎生物量。使用压力呼吸计测量土壤微生物生物量和基础呼吸。经过头两年的操作，加湿导致土壤呼吸降低。土壤温度是影响土壤呼吸季节动态的主要因素，占土壤呼吸总变化的75%。土壤湿度对土壤呼吸有较弱的负影响。加湿导致地下生物量和林下植被产量显着增加，微生物的基础呼吸增加了 28%。然而，地上生物量和林下根系周转率几乎没有变化。因此，大气湿度升高显着影响落叶林的碳循环。然而，为了更好地了解土壤呼吸对大气湿度变化的响应，以便预测气候条件变化下的碳平衡，还需要进一步的研究。
The predicted increase in precipitation at northern latitudes is an important factor affecting the functioning of forest ecosystems, yet the influence of increased atmospheric humidity on the forest ecosystem carbon cycle is still largely unknown. Our objectives were to determine the effect of elevated atmospheric humidity on soil respiration in silver birch (Betula pendulaRoth.) plantations in a Free Air Humidity Manipulation experimental facility (FAHM). Soil respiration was monitored monthly from May to October, in 2008 and 2009 in three control and in three misting plots; soil temperature and soil moisture were measured simultaneously. Fine-root and rhizome biomass of the understory was measured by sequential soil cores. Soil microbial biomass and basal respiration were measured using manometric respirometers. After the first two years of manipulation, humidification led to lower soil respiration. Soil temperature was the main factor influencing seasonal dynamics of soil respiration, describing up to 75% of the total variation of soil respiration. Soil moisture had a weak negative effect on soil respiration. Humidification caused a remarkable increase in below-ground biomass and the production of the understory, and a 28% increase in the basal respiration of microbes. However, above-ground biomass and root turnover rate of the understory were almost unchanged. Hence, elevated atmospheric humidity significantly affects carbon cycle of deciduous forest. However, further studies are necessary for a better understanding of soil respiration response to changes in atmospheric humidity, in order to predict carbon balance in changing climate conditions.