Labile substrate availability controls temperature sensitivity of organic carbon decomposition at different soil depths

	Labile substrate availability controls temperature sensitivity of organic carbon decomposition at different soil depths
	Pang, Xueyong; Zhu, Biao; Lu, Xiaotao; Cheng, Weixin
刊名	BIOGEOCHEMISTRY
	2015
卷号	126 期号:42371 页码:85-98
关键词	MICROBIAL CO2 PRODUCTION MATTER DECOMPOSITION INDUCED RESPIRATION VERTICAL-DISTRIBUTION COMMUNITY STRUCTURE SUBSURFACE SOIL FOREST SOILS BIOMASS-C QUALITY RATES
通讯作者	Cheng, WX (reprint author), Univ Calif Santa Cruz, Dept Environm Studies, Santa Cruz, CA 95064 USA.
产权排序	1
合作状况	国内
英文摘要	The decomposition of soil organic carbon (SOC) is intrinsically sensitive to temperature. However, the degree to which the temperature sensitivity of SOC decomposition (as often measured in Q(10) value) varies with soil depth and labile substrate availability remain unclear. This study explores (1) how the Q(10) of SOC decomposition changes with increasing soil depth, and (2) how increasing labile substrate availability affects the Q(10) at different soil depths. We measured soil CO2 production at four temperatures (6, 14, 22 and 30 A degrees C) using an infrared CO2 analyzer. Treatments included four soil depths (0-20, 20-40, 40-60 and 60-80 cm), four sites (farm, redwood forest, ungrazed and grazed grassland), and two levels of labile substrate availability (ambient and saturated by adding glucose solution). We found that Q(10) values at ambient substrate availability decreased with increasing soil depth, from 2.0-2.4 in 0-20 cm to 1.5-1.8 in 60-80 cm. Moreover, saturated labile substrate availability led to higher Q(10) in most soil layers, and the increase in Q(10) due to labile substrate addition was larger in subsurface soils (20-80 cm) than in surface soils (0-20 cm). Further analysis showed that microbial biomass carbon (MBC) and SOC best explained the variation in Q(10) at ambient substrate availability across ecosystems and depths (R-2 = 0.37, P < 0.001), and MBC best explained the variation in the change of Q(10) between control and glucose addition treatment (R-2 = 0.14, P = 0.003). Overall, these results indicate that labile substrate limitation of the temperature sensitivity of SOC decomposition, as previously shown in surface soils, is even stronger for subsoils. Understanding processes controlling the labile substrate availability (e.g., with rising atmospheric CO2 concentration and land use change) should advance our prediction of the fate of subsoil SOC in a warmer world.
学科主题	Environmental Sciences & Ecology; Geology
类目[WOS]	Environmental Sciences ; Geosciences, Multidisciplinary
语种	英语
内容类型	期刊论文
源URL	[http://210.75.237.14/handle/351003/27486]
专题	成都生物研究所_生态研究
推荐引用方式 GB/T 7714	Pang, Xueyong,Zhu, Biao,Lu, Xiaotao,et al. Labile substrate availability controls temperature sensitivity of organic carbon decomposition at different soil depths[J]. BIOGEOCHEMISTRY,2015,126(42371):85-98.
APA	Pang, Xueyong,Zhu, Biao,Lu, Xiaotao,&Cheng, Weixin.(2015).Labile substrate availability controls temperature sensitivity of organic carbon decomposition at different soil depths.BIOGEOCHEMISTRY,126(42371),85-98.
MLA	Pang, Xueyong,et al."Labile substrate availability controls temperature sensitivity of organic carbon decomposition at different soil depths".BIOGEOCHEMISTRY 126.42371(2015):85-98.