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标题：Interacting Controls of Pyrolysis Temperature and Plant Taxa on the Degradability of PyOM in Fire-Prone Northern Temperate Forest Soil
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作者：Christy D. Gibson ; Pierre-Joseph Hatton , Jeffrey A. Bird ; Knute Nadelhoffer 等
期刊名称：Soil Systems
电子版ISSN：2571-8789
出版年度：2018
卷号：2
期号：3
页码：48-64
DOI：10.3390/soilsystems2030048
出版社：MDPI AG
摘要：Tree taxa and pyrolysis temperature are the major controllers of the physicochemical properties of the resultant pyrogenic organic matter (PyOM) produced in fire-prone forests. However, we know little about how these controls determine the residence time of PyOM once introduced to soil. In this study, we tracked the fate of 13C-enriched red maple (RM) or jack pine (JP) wood and PyOM, produced over a range of temperatures (200, 300, 450, or 600 °C) added to soil from a northern temperate forest in Michigan, USA. Pyrolysis temperature was the main controller of PyOM-C mineralization rates, with mean residence times (MRT) ranging from ~4 to 450 years for both taxa. The PyOM-C mineralization rates for both taxa and the pyrolysis temperature correlated positively with PyOMw (leachable C content); however, the potential PyOMw contribution to net PyOM-C mineralization was lower for JP (14–65%) than RM (24–84%). The correlation between PyOMw and mineralization rate was strongest where carbonization and the thermochemical conversion of carbohydrates and non-lignin phenols was most pronounced during pyrolysis for each taxa (300 °C for JP and 450 °C for RM). Contrary to expectations, the addition of a labile C source, sucrose, to the soil did not enhance the decomposition of PyOM, indicating that soil microbes were not energy limited in the soil-PyOM system studied (regardless of pyrolysis temperature). Our results showed that while the first-order control on PyOM decomposition in this soil is pyrolysis temperature, wood taxa did affect PyOM-C MRT, likely in part due to differences in the amount of reactive water-soluble C present in PyOM.
关键词：pyrogenic organic matter; decomposition; stabilization; soil organic matter; recalcitrance; labile organic matter; fire; forest soil pyrogenic organic matter ; decomposition ; stabilization ; soil organic matter ; recalcitrance ; labile organic matter ; fire ; forest soil