Plant community structure regulates responses of prairie soil respiration to decadal experimental warming
Plant community structure regulates responses of prairie soil respiration to decadal experimental warming
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DOI：
10.1111/gcb.12940
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发表时间：
2015-10
影响因子：
11.6
通讯作者：
Xia Xu;Z. Shi;Dejun Li;Xuhui Zhou;R. Sherry;Yiqi Luo
中科院分区：
文献类型：
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作者：
Xia Xu;Z. Shi;Dejun Li;Xuhui Zhou;R. Sherry;Yiqi Luo
土壤呼吸作用受温度、湿度和生态系统生产力的影响。然而，植物群落结构如何调节土壤呼吸对气候变化的响应却知之甚少。在这里，我们使用了13年的现场变暖实验，以探讨土壤呼吸对气候变化的反馈，在俄克拉荷马州，美国的高草草原植物群落调节的机制。自1999年11月以来，使用红外加热器将温度提高约2 °C。每年修剪被用来模拟干草收获。我们的研究结果表明，实验变暖显着增加土壤呼吸约从前7年（2000-2006年）的10%，在未来6年（2007-2012年）的30%。土壤呼吸的两个阶段变暖刺激与多年来变暖引起的生态系统生产力的增加密切相关。此外，我们发现，在整个13年中，变暖引起的土壤呼吸增加受到C3杂类植物贡献的地上净初级生产力（ANPP）的比例的积极影响。植物群落的功能组成通过向土壤输入的有机质的数量和质量以及分配到地下的光合碳（C）的量来调节变暖引起的土壤呼吸增加。刈割、刈割与增温的相互作用以及增温引起的土壤温度和水分变化对土壤呼吸的影响都很小（P均> 0.05）。我们的研究结果表明，气候变暖可能会通过改变草原生态系统中植物群落的组成来推动土壤呼吸的增加。
Soil respiration is recognized to be influenced by temperature, moisture, and ecosystem production. However, little is known about how plant community structure regulates responses of soil respiration to climate change. Here, we used a 13‐year field warming experiment to explore the mechanisms underlying plant community regulation on feedbacks of soil respiration to climate change in a tallgrass prairie in Oklahoma, USA. Infrared heaters were used to elevate temperature about 2 °C since November 1999. Annual clipping was used to mimic hay harvest. Our results showed that experimental warming significantly increased soil respiration approximately from 10% in the first 7 years (2000–2006) to 30% in the next 6 years (2007–2012). The two‐stage warming stimulation of soil respiration was closely related to warming‐induced increases in ecosystem production over the years. Moreover, we found that across the 13 years, warming‐induced increases in soil respiration were positively affected by the proportion of aboveground net primary production (ANPP) contributed by C3 forbs. Functional composition of the plant community regulated warming‐induced increases in soil respiration through the quantity and quality of organic matter inputs to soil and the amount of photosynthetic carbon (C) allocated belowground. Clipping, the interaction of clipping with warming, and warming‐induced changes in soil temperature and moisture all had little effect on soil respiration over the years (all P > 0.05). Our results suggest that climate warming may drive an increase in soil respiration through altering composition of plant communities in grassland ecosystems.