Changes in soil microbial biomass carbon and enzyme activities under elevated CO2 affect fine root decomposition processes in a Mongolian oak ecosystem
Changes in soil microbial biomass carbon and enzyme activities under elevated CO2 affect fine root decomposition processes in a Mongolian oak ecosystem
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CO2升高下土壤微生物生物量碳和酶活性的变化影响蒙古栎生态系统的细根分解过程
DOI：
10.1016/j.soilbio.2010.03.007
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发表时间：
2010-07
影响因子：
9.7
通讯作者：
Xin, Lihua
中科院分区：
文献类型：
--
作者：
Li, Xuefeng;Han, Shijie;Guo, Zhongling;Shao, Diankun;Xin, Lihua
人们对二氧化碳浓度升高下土壤微生物特性与细根分解过程之间的关系知之甚少。为了解决这个问题，我们测定了2006年至2007年蒙古橡树中土壤微生物生物量碳（SMB-C）和氮（SMB-N）、与土壤碳（C）和氮（N）循环相关的酶、可培养的固氮细菌和纤维素分解真菌的丰度、细根有机质、木质素和全纤维素分解以及氮矿化。 中国东北地区的蒙古栎 (Quercus mongolica Fischer ex Ledebour) 生态系统。该实验包括三种处理：高架二氧化碳室、环境二氧化碳室和无室试验区。在二氧化碳浓度升高的情况下，细根的有机物分解率显着提高。这与显着更高的 SMB-C 相对应。 CO2升高下蛋白酶和酚氧化酶活性的变化不能分别解释细根氮释放和木质素分解速率的变化，而全纤维素分解速率与纤维素酶活性对实验处理的响应相同。实验处理对可培养固氮细菌和纤维素分解真菌丰度的变化分别与氮矿化和木质素分解率的变化相同，表明这两个指标与细根氮矿化和木质素分解密切相关。我们的结果表明，在 CO2 浓度升高的情况下，细根有机质、木质素和全纤维素分解以及氮矿化率的增加可以通过 SMB-C 的变化以及纤维素分解真菌和固氮细菌的丰度来解释。酶活性对于细根分解的评估并不可靠，应更多地关注特定细菌和真菌群落的测量。
The relationships between soil microbial properties and fine root decomposition processes under elevated CO2are poorly understood. To address this question, we determined soil microbial biomass carbon (SMB-C) and nitrogen (SMB-N), enzymes related to soil carbon (C) and nitrogen (N) cycling, the abundance of cultivable N-fixing bacteria and cellulolytic fungi, fine root organic matter, lignin and holocellulose decomposition, and N mineralization from 2006 to 2007 in a Mongolian oak (Quercus mongolica Fischer ex Ledebour) ecosystem in northeastern China. The experiment consisted of three treatments: elevated CO2chambers, ambient CO2chambers, and chamberless plots. Fine roots had significantly greater organic matter decomposition rates under elevated CO2. This corresponded with significantly greater SMB-C. Changes in the activities of protease and phenol oxidase under elevated CO2could not explain the changes in fine root N release and lignin decomposition rates, respectively, while holocellulose decomposition rate had the same response to experimental treatments as did cellulase activity. Changes in cultivable N-fixing bacterial and cellulolytic fungal abundances in response to experimental treatments were identical to those of N mineralization and lignin decomposition rates, respectively, suggesting that the two indices were closely related to fine root N mineralization and lignin decomposition. Our results showed that the increased fine root organic matter, lignin and holocellulose decomposition, and N mineralization rates under elevated CO2could be explained by shifts in SMB-C and the abundance of cellulolytic fungi and N-fixing bacteria. Enzyme activities are not reliable for the assessment of fine root decomposition and more attention should be given to the measurement of specific bacterial and fungal communities.
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影响因子：
9.7
作者：
K. V. van Groenigen;A. Gorissen;J. Six;D. Harris;P. Kuikman;J. V. van Groenigen;C. van Kessel
通讯作者：
K. V. van Groenigen;A. Gorissen;J. Six;D. Harris;P. Kuikman;J. V. van Groenigen;C. van Kessel
影响因子：
9.7
作者：
A. Sowerby;H. Blum;T. Gray;A. Ball
通讯作者：
A. Sowerby;H. Blum;T. Gray;A. Ball
影响因子：
2.9
作者：
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通讯作者：
J. Larson;D. Zak;R. Sinsabaugh
影响因子：
4.9
作者：
Des J. Ross;K. Tate;P. Newton;Harry Clark
通讯作者：
Des J. Ross;K. Tate;P. Newton;Harry Clark
影响因子：
2.7
作者：
King, JS;Pregitzer, KS;Schmidt, K
通讯作者：
Schmidt, K