title: Sample storage-induced changes in the quantity and quality of soil labile organic carbon.
abstract: Effects of sample storage methods on the quantity and quality of labile soil organic carbon are not fully understood even though their effects on basic soil properties have been extensively studied. We studied the effects of air-drying and frozen storage on cold and hot water soluble organic carbon (WSOC). Cold- and hot-WSOC in air-dried and frozen-stored soils were linearly correlated with those in fresh soils, indicating that storage proportionally altered the extractability of soil organic carbon. Air-drying but not frozen storage increased the concentrations of cold-WSOC and carbohydrate in cold-WSOC, while both increased polyphenol concentrations. In contrast, only polyphenol concentration in hot-WSOC was increased by air-drying and frozen storage, suggesting that hot-WSOC was less affected by sample storage. The biodegradability of cold- but not hot-WSOC was increased by air-drying, while both air-drying and frozen storage increased humification index and changed specific UV absorbance of both cold- and hot-WSOC, indicating shifts in the quality of soil WSOC. Our results suggest that storage methods affect the quantity and quality of WSOC but not comparisons between samples, frozen storage is better than air-drying if samples have to be stored, and storage should be avoided whenever possible when studying the quantity and quality of both cold- and hot-WSOC.
authors.affiliation: Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, No. 9, Block 4, South Renmin Rd., Chengdu, 610041 China.|Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada.
authors.forename: Shou-Qin
authors.initials: SQ
authors.lastname: Sun
authors.affiliation: Center for Ecological Research, Northeast Forestry University, No.26 Hexing Rd., Xiangfang Dist., Harbin, 150040 China.|Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada.
authors.forename: Hui-Ying
authors.initials: HY
authors.lastname: Cai
authors.affiliation: Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada.
authors.forename: Scott X
authors.initials: SX
authors.lastname: Chang
authors.affiliation: Canadian Forest Service, Northern Forestry Centre, 5320 122nd St. Edmonton, AB, T6H 3S5 Canada.
authors.forename: Jagtar S
authors.initials: JS
authors.lastname: Bhatti