title: Spatial variations in the molecular diversity of dissolved organic matter in water moving through a boreal forest in eastern Finland.
abstract: Dissolved organic matter (DOM) strongly affects water quality within boreal forest ecosystems. However, how the quality of DOM itself changes spatially is not well understood. In this study, to examine how the diversity of DOM molecules varies in water moving through a boreal forest, the number of DOM molecules in different water samples, i.e., rainwater, throughfall, soil water, groundwater, and stream water was determined using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in Norway spruce and Scots pine stands in eastern Finland during May and June 2010. The number of molecular compounds identified by FT-ICR MS (molecular diversity) ranged from 865 to 2,194, revealing large DOM molecular diversity in the water samples. Additionally, some of the molecular compounds were shared between different water samples. The DOM molecular diversity linearly correlated with the number of low-biodegradable molecules, such as, lignin-like molecules (lignins), but not with dissolved organic carbon concentration. The number of lignins shared between different sampling locations was larger than that of any other biomolecular class. Our results suggest that low-biodegradable molecules, especially lignins, regulate spatial variations in DOM molecular diversity in boreal forests.
authors.affiliation: Institute of Decision Science for a Sustainable Society, Kyushu University, Fukuoka 811-2415, Japan.
authors.forename: Jun'ichiro
authors.initials: J
authors.lastname: Ide
authors.affiliation: Graduate School of Human Science and Environment, University of Hyogo, Hyogo 670-0092, Japan.
authors.forename: Mizue
authors.initials: M
authors.lastname: Ohashi
authors.affiliation: National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, Japan.
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Graduate School of Human Science and Environment, University of Hyogo, Hyogo 670-0092, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sugiyama
authors.affiliation: Natural Resources Institute Finland, P.O. Box 68, FIN-80101 Joensuu, Finland.
authors.forename: Sirpa
authors.initials: S
authors.lastname: Piirainen
authors.affiliation: Finnish Environment Institute, P.O. Box 140, FIN-00251 Helsinki, Finland.
authors.forename: Pirkko
authors.initials: P
authors.lastname: Kortelainen
authors.affiliation: Faculty of Agriculture, Kobe University, Kobe 657-0013, Japan.
authors.forename: Nobuhide
authors.initials: N
authors.lastname: Fujitake
authors.affiliation: Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries, Forestry and Forest Products Research Institute, Hyogo 671-2515, Japan.
authors.forename: Keitaro
authors.initials: K
authors.lastname: Yamase
authors.affiliation: Department of Social Informatics, Graduate School of Informatics, Kyoto University, Kyoto 606-8501, Japan.
authors.forename: Nobuhito
authors.initials: N
authors.lastname: Ohte
authors.affiliation: Graduate School of Human Science and Environment, University of Hyogo, Hyogo 670-0092, Japan.
authors.forename: Mina
authors.initials: M
authors.lastname: Moritani
authors.affiliation: Graduate School of Human Science and Environment, University of Hyogo, Hyogo 670-0092, Japan.
authors.forename: Miyako
authors.initials: M
authors.lastname: Hara
authors.affiliation: Natural Resources Institute Finland, P.O. Box 68, FIN-80101 Joensuu, Finland.
authors.forename: Leena
authors.initials: L
authors.lastname: Finér