Precipitation regime drives warming responses of microbial biomass and activity in temperate steppe soils
Precipitation regime drives warming responses of microbial biomass and activity in temperate steppe soils
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降水状况驱动温带草原土壤微生物量和活动的变暖响应
DOI：
10.1007/s00374-016-1087-7
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发表时间：
2016-05-01
影响因子：
6.5
通讯作者：
Wan, Shiqiang
中科院分区：
文献类型：
--
作者：
Liu, Weixing;Allison, Steven D.;Wan, Shiqiang
虽然许多变暖实验已经研究了温度升高对土壤微生物活动的影响，但大多数都是基于单一地点的响应。为了研究降水制度如何调节气候变暖对碳循环的影响，我们沿着降水梯度对中国北方荒漠草原、典型草原和草甸草原进行了人为增温实验。测定了2006 ~ 2009年土壤温度、湿度、微生物生物量C （MBC）、N （MBN）和微生物呼吸。增温对典型草原土壤湿度有显著影响，而对荒漠草原和草甸草原没有影响。4年间，增温对荒漠和典型草原的MBC和微生物呼吸均有降低作用，而对草甸草原没有影响。气候变暖导致的MBC和微生物呼吸减少幅度随着站点降水的增加而减小。3个样地土壤MBC、MBN和微生物呼吸变化均与年降水量和地下净初级生产力变化呈正相关。我们的研究结果表明，降水制度可能通过调节土壤水分和基质有效性来控制土壤微生物活性和生物量对变暖的响应。随着降水的增加，增温对土壤微生物活性和生物量的促进作用大于土壤水分下降的抑制作用。
Although numerous warming experiments have examined the impacts of elevated temperature on soil microbial activities, most are based on responses from a single site. To investigate how precipitation regime regulates warming effects on the carbon cycle, we conducted manipulative warming experiments in desert steppe, typical steppe, and meadow steppe along a precipitation gradient in northern China. Soil temperature, moisture, microbial biomass C (MBC), N (MBN), and microbial respiration were measured from 2006 to 2009. Soil moisture was significantly reduced by warming in the typical steppe but not affected in the desert and meadow steppe. Across the 4 years, warming decreased MBC and microbial respiration in the desert and typical steppe but not in the meadow steppe. The magnitude of warming-induced reductions in MBC and microbial respiration declined as site precipitation increased. Across the three sites, the changes in soil MBC, MBN, and microbial respiration were all positively correlated with annual precipitation and changes in belowground net primary productivity. Our results suggest that precipitation regime controls the response of soil microbial activity and biomass to warming, possibly by regulating soil moisture and substrate availability. With increasing precipitation, the stimulatory effects of warming on soil microbial activity and biomass outweigh the inhibitory effects due to declining soil moisture.