Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Sci Total Environ. 2017 Jul 15;590-591:242-248. doi: 10.1016/j.scitotenv.2017.02.229. Epub 2017 Mar 3.
Soil respiration is the largest terrestrial carbon flux into the atmosphere, and different tree species could directly influence root derived respiration and indirectly regulate soil respiration rates by altering soil chemical and microbial properties. In this study, we assessed the small scale spatial heterogeneity of soil respiration and the microbial community below the canopy of three dominant tree species (Korean pine (Pinus koraiensis), Mongolian oak (Quercus mongolica), and Manchuria ash (Fraxinus mandshurica)) in a temperate mixed forest in Northeast China. Soil respiration differed significantly during several months and increased in the order of oak<ash<pine, while soil temperature was greater in the order of pine<oak<ash, suggesting that soil respiration variations among tree species were not mainly regulated by soil temperature. In addition, the lower N and higher C concentrations of pine litter resulted in a higher C/N ratio than ash and oak, which might lead to a higher recalcitrance and slower decomposition rate, and decreased heterotrophic respiration under pine. By contrast, fine root biomass was significantly higher under pine than ash and oak, which induced higher soil autotrophic respiration under pine compared to ash and oak. Tree species sharply regulated the bacterial communities through altering the litter and soil properties, while the fungal communities were relatively consistent among tree species. This study revealed the connection between species specific traits and soil respiration, which is crucial for understanding plant-soil feedbacks and improving forecasts of the global carbon cycle.
土壤呼吸是最大的陆地碳通量进入大气，不同的树种可以通过改变土壤化学和微生物特性直接影响根衍生呼吸，并间接调节土壤呼吸速率。在这项研究中，我们评估了三种主要树种（红松（Pinus koraiensis）、蒙古栎（Quercus mongolica）和东北枫（Fraxinus mandshurica））下冠层下土壤呼吸和微生物群落的小尺度空间异质性在东北温带混合林中。土壤呼吸在几个月内差异显著，顺序为橡木<灰烬<pine，而土壤温度顺序为pine<oak<ash，表明树种间土壤呼吸的变化不是主要由土壤温度调节的。此外，较低的氮和较高的 C 浓度导致松木凋落物的 C/N 比高于灰烬和橡木，这可能导致更高的抗逆性和更慢的分解率，并降低了松木下的异养呼吸。相比之下，松木下的细根生物量明显高于灰烬和橡木，这导致松木下的土壤自养呼吸高于灰烬和橡木。树种通过改变凋落物和土壤特性强烈调节细菌群落，而真菌群落在树种间相对一致。本研究揭示了特定物种特征与土壤呼吸之间的联系，这对于理解植物-土壤反馈和改善全球碳循环预测至关重要。
