Solid-State 13C Nuclear Magnetic Resonance Spectroscopic Characterization of Soil Organic Matter Fractions in a Forest Ecosystem Subjected to Prescribed Burning and Thinning  

作　　者：thilini d.ranatunga zhongqi he kamala n.bhat junyan zhong 

机构地区：[1]Department of Biological&Environmental Sciences,Alabama A&M University,Normal AL 35762(USA) [2]USDA-ARS,Southern Regional Research Center,New 0rlcans LA 70124(USA) [3]Department of Physics,Chemistry and Mathematics,Alabama A&M University,Normal AL 35762(USA) [4]College of Sciences,0ld Dominion University,Norfolk VA 23529(USA) [5]Intertek,Allentown PA 18195(USA)

出　　处：《Pedosphere》2017年第5期901-911,共11页土壤圈（英文版）

基　　金：supported by the USDA National Institute of Food and Agriculture(NIFA),Evans Allen Grant,USA(No.224120);the National Science Foundation(NSF-CREST-CFEA),USA(No.1036600);the Agricultural Experimental Station,Alabama A&M University,Alabama,USA(Journal#:660)

摘　　要：Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter （SOM）. In this study, surface softs from field plots in the Bankhead National Forest, Alabama, USA, were used to investigate possible SOM transformations induced by thinning and burning. Elemental analysis and solid-state 13C cross polarization magic angle spinning nuclear magnetic resonance （13C CPMAS NMR） spectroscopy were used to characterize SOM fractions in whole soils, humic substances, and density fractions. Our data revealed that the changes in SOM fractions due to the repeated burning carried out in the forest ecosystem studied were involved mainly with alkyl C, O-alkyl C, and carbohydrate functional groups, implying that most prominent reactions that occurred involved dehydrogenation, de-oxygenation, and decarboxylation. In addition, burning and thinning might have also affected the distribution and composition of free and occluded particulate SOM fractions. The limited structural changes in SOM fractions suggested that low-intensity prescribed fire in the forest ecosystem studied will not create major structural changes in SOM fractions.Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter(SOM). In this study, surface soils from field plots in the Bankhead National Forest, Alabama, USA, were used to investigate possible SOM transformations induced by thinning and burning. Elemental analysis and solid-state ^(13)C cross polarization magic angle spinning nuclear magnetic resonance(^(13)C CPMAS NMR) spectroscopy were used to characterize SOM fractions in whole soils, humic substances, and density fractions. Our data revealed that the changes in SOM fractions due to the repeated burning carried out in the forest ecosystem studied were involved mainly with alkyl C, O-alkyl C, and carbohydrate functional groups, implying that most prominent reactions that occurred involved dehydrogenation, de-oxygenation, and decarboxylation. In addition, burning and thinning might have also affected the distribution and composition of free and occluded particulate SOM fractions. The limited structural changes in SOM fractions suggested that low-intensity prescribed fire in the forest ecosystem studied will not create major structural changes in SOM fractions.

关 键 词：density fractionation forest fires forest management practices forest soils fulvic acids humic acids HUMIN particulateorganic matter 

分 类 号：S714[农业科学—林学]