title: Concordance and discordance between taxonomic and functional homogenization: responses of soil mite assemblages to forest conversion.
abstract: The compositional characteristics of ecological assemblages are often simplified; this process is termed "biotic homogenization." This process of biological reorganization occurs not only taxonomically but also functionally. Testing both aspects of homogenization is essential if ecosystem functioning supported by a diverse mosaic of functional traits in the landscape is concerned. Here, we aimed to infer the underlying processes of taxonomic/functional homogenization at the local scale, which is a scale that is meaningful for this research question. We recorded species of litter-dwelling oribatid mites along a gradient of forest conversion from a natural forest to a monoculture larch plantation in Japan (in total 11 stands), and collected data on the functional traits of the recorded species to quantify functional diversity. We calculated the taxonomic and functional β-diversity, an index of biotic homogenization. We found that both the taxonomic and functional β-diversity decreased with larch dominance (stand homogenization). After further deconstructing β-diversity into the components of turnover and nestedness, which reflect different processes of community organization, a significant decrease in the response to larch dominance was observed only for the functional turnover. As a result, there was a steeper decline in the functional β-diversity than the taxonomic β-diversity. This discordance between the taxonomic and functional response suggests that species replacement occurs between species that are functionally redundant under environmental homogenization, ultimately leading to the stronger homogenization of functional diversity. The insights gained from community organization of oribatid mites suggest that the functional characteristics of local assemblages, which support the functionality of ecosystems, are of more concern in human-dominated forest landscapes.
authors.affiliation: Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya, Yokohama, 240-8501, Japan. akira.s.mori@gmail.com.
authors.forename: Akira S
authors.initials: AS
authors.lastname: Mori
authors.affiliation: Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya, Yokohama, 240-8501, Japan.
authors.forename: Aino T
authors.initials: AT
authors.lastname: Ota
authors.affiliation: Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya, Yokohama, 240-8501, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Fujii
authors.affiliation: Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan.
authors.forename: Tatsuyuki
authors.initials: T
authors.lastname: Seino
authors.affiliation: Forestry and Forest Products Research Institute, 1 Matsunosato, Tsukuba, Ibaraki, 305-8687, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kabeya
authors.affiliation: Forestry and Forest Products Research Institute, 1 Matsunosato, Tsukuba, Ibaraki, 305-8687, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Okamoto
authors.affiliation: Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya, Yokohama, 240-8501, Japan.|Faculty of Economics and Management, Surugadai University, Azu 698, Hanno, Saitama, 357-8555, Japan.
authors.forename: Masamichi T
authors.initials: MT
authors.lastname: Ito
authors.affiliation: Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya, Yokohama, 240-8501, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Kaneko
authors.affiliation: Forestry and Forest Products Research Institute, 1 Matsunosato, Tsukuba, Ibaraki, 305-8687, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Hasegawa
mesh_terms: D000818:Animals; D044822:Biodiversity; D017753:Ecosystem; D065928:Forests; D007564:Japan; D028221:Larix; D008925:Mites / Q000145:classification / Q000502:physiology*; D012987:Soil; D013045:Species Specificity
chemical_list: D012987:Soil
keywords: Community reassembly; Ecosystem functioning; Forest restoration; Oribatid mites; Soil arthropods; Taxonomic and functional homogenization