A Gram-staining-negative, strictly aerobic bacterium, designated strain SD10T, was isolated from a tidal flat of the Yellow Sea, South Korea. Cells were non-spore-forming rods that showed catalase- and oxidase-positive reactions. Growth of strain SD10T was observed at 15–40 °C (optimum, 25–30 °C), at pH 6.0–9.0 (optimum, pH 6.5–8.5) and in the presence of 1–10 % (w/v) NaCl. Strain SD10T contained ubiquinone-10 (Q-10) as a major isoprenoid quinone and C18 : 1ω7c (39.3 %), C16 : 0 (20.2 %), C17 : 0 (8.9 %) and C17 : 1ω6c (8.1 %) as major fatty acids. The cellular polar lipids were identified as phosphatidylglycerol, monoglycosyldiglyceride, glucuronopyranosyldiglyceride and two unidentified glycolipids. The G+C content of the genomic DNA was 55.2 mol%. Based on 16S rRNA gene sequence similarities, the strain was most closely related to Henriciella marina Iso4T and Maribaculum marinum P38T, with similarities of 97.8 and 97.0 %, respectively. The DNA–DNA relatedness between strain SD10T and H. marina Iso4T was 12.0±3.2 %. A phylogenetic analysis based on 16S rRNA gene sequences showed that M. marinum P38T and H. marina Iso4T formed a monophyletic cluster and that their 16S rRNA gene sequence similarity was 98.1 %. DNA–DNA hybridization between H. marina Iso4T and M. marinum LMG 24711T was 22.9±2.7 %, indicating that the two strains belong to separate species. On the basis of chemotaxonomic data and molecular properties, we propose that strain SD10T represents a novel species of the genus Henriciella, for which the name Henriciella litoralis sp. nov. is proposed. The type strain is SD10T ( = KACC 13700T  = DSM 22014T). In addition, we propose to transfer Maribaculum marinum Lai et al. 2009 to the genus Henriciella as Henriciella aquimarina nom. nov. (type strain P38T  = CCTCC AB 208227T  = LMG 24711T  = MCCC 1A01086T), and we present an emended description of the genus Henriciella.

The atmospheric carbon dioxide (CO2) level is expected to increase substantially, which may change the global climate and carbon dynamics in ecosystems. We examined the effects of an elevated atmospheric CO2 level on the growth of Quercus acutissima and Fraxinus rhynchophylla seedlings. We investigated changes in the chemical composition of leaf litter, as well as litter decomposition. Q. acutissima and F. rhynchophylla did not show differences in dry weight between ambient CO2 and enriched CO2 treatments, but they exhibited different patterns of carbon allocation, namely, lower shoot/root ratio (S/R) and decreased specific leaf area (SLA) under CO2-enriched conditions. The elevated CO2 concentration significantly reduced the nitrogen concentration in leaf litter while increasing lignin concentrations and carbon/nitrogen (C/N) and lignin/N ratios. The microbial biomass associated with decomposing Q. acutissima leaf litter was suppressed in CO2 enrichment chambers, while that of F. rhynchophylla was not. The leaf litter of Q. acutissima from the CO2-enriched chambers, in contrast with F. rhynchophylla, contained much lower nutrient concentrations than that of the litter in the ambient air chambers. Consequently, poorer litter quality suppressed decomposition.

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Litter decomposition involves multiple complex processes, including interactions between the physicochemical characteristics of litter species and various environmental factors. We selected four representative pine species in South Korea (Pinus densiflora Siebold & Zucc., Pinus thunbergii Parl., Pinus koraiensis Siebold & Zucc., and Pinus rigida Miller) to investigate the decay rate and effects of the physicochemical properties on decomposition. Needle litters were incubated in microcosms at 23 °C for 280 days and retrieved four times in about 70-day intervals. The mass loss showed significant differences among the species and was higher in the order of P. densiflora (30.5%), P. koraiensis (27.8%), P. rigida (26.5%), and P. thunbergii (23.6%). The needle litter decomposition showed a negative relationship with the initial surface area, volume, density, cellulose content, and lignin/nitrogen of the litter, and a positive relationship with the initial specific leaf area (SLA), surface-area-to-volume ratio (SA/V), and water- and ethanol-soluble substances. The decomposition rate was highly affected by the physical properties of litter when compared with the initial chemical litter quality, and it was strongly influenced by SLA and SA/V. Accordingly, the physical properties of pine needle litter, especially SLA and SA/V, may be the key factors, and they could be used as predictive indices for the decomposition rate of pine tree litters.

ABSTRACT. Gymnospermium microrrhynchum (Berberidaceae) is an ephemeral perennial herb with a limited distributional range in the Baekdudaegan mountain areas of the Korean Peninsula, and is designated a rare plant by the Korean Forest Service. Information about its genetic variation and structure is important for developing successful conservation strategies. To investigate the genetic variation within and among seven G. microrrhynchum populations, random amplified polymorphic DNA data were obtained for 207 individuals. The populations exhibited relatively low genetic diversity: the percentage of polymorphic bands (PPB) ranged from 32.1 to 66.7% (mean = 51.4%) and Nei's gene diversity (H E ) ranged from 0.116 to 0.248 (mean = 0.188). However, genetic diversity at the species level was relatively high (PPB = 98.7%, H E = 0.349). An analysis of molecular variance revealed high differentiation among populations (F ST = 0.6818), but the low gene flow value (N m = 0.117) suggests a low level of gene exchange occurs among populations. Principal coordinates analysis revealed that individuals were separated according to population. The high level of genetic differentiation and restricted gene flow among G. microrrhynchum populations, which resulted from their isolation in alpine areas after the Ice Age, indicates that it is essential to protect and manage all populations, rather than focus on specific populations, in order to maintain the genetic diversity of this species.