Description of Ruehmaphelenchus fujiensis n. sp. (Tylenchomorpha: Aphelenchoididae) isolated from dead wood of Quercus crispula from Yamanashi, Japan

Summary Three undescribed Ruehmaphelenchus species were isolated from dead wood of Quercus crispula collected in three different localities in Japan. One of these three species was successfully cultured using Botrytis cinerea as its food fungus and is described and figured as R. fujiensis n. sp. The new species is characterised by the following features: male tail, conical with or without a projection; female tail, conical with variously shaped terminal mucron or projection; and male spicule possessing a relatively long and triangular condylus. The new species is close to, or almost a cryptic species of R. digitulus, i.e., the typological characters and morphometric values of these two species are mostly overlapping. In a molecular phylogenetic relationship inferred from near-full-length small subunit (18S) and D2-D3 expansion segments of the large subunit (28S) of ribosomal RNA, the new species is close to R. asiaticus, R. digitulus, R. formosanus, and Ruehmaphelenchus sp. NKZ202; however, it was clearly separated from these species.

Five-year nitrogen addition affects fine root exudation and its correlation with root respiration in a dominant species, Quercus crispula, of a cool temperate forest, Japan

In forest ecosystems, fine root respiration directly contributes to belowground carbon (C) cycling. Exudation from fine roots indirectly affects C cycling via enhanced microbial decomposition of soil organic matter. Although these root-derived C fluxes are essential components of belowground C cycling, how nitrogen (N) addition affects these fluxes and their correlations remains unclear. In this study, fine root exudation, respiration and chemical/morphological traits were measured in a dominant canopy species, Quercus crispula Blume, found in a cool temperate forest, the Tomakomai Experimental Forest, Hokkaido University, which has undergone 5-year N addition. Soil-dissolved organic carbon (DOC) was also measured in both bulk and rhizosphere soils to evaluate the impact of fine root exudation on soil C cycling. Compared with a control plot with no N treatment, fine roots in the N addition plot exhibited larger diameters and higher N concentrations, but lower specific root lengths and areas. On a root-weight basis, respiration was not different between plots, but exudation was slightly higher under N addition. On a root-area basis, exudation was significantly higher in the N addition plot. Additionally, differences in DOC between rhizosphere and bulk soils were two times higher in the N addition plot than the control plot. Although fine root respiration was positively correlated with exudation in both the control and N addition plots, the ratio of exudation C to respiration C decreased after 5-year N addition. Nitrogen addition also affected absolute C allocation to fine root exudation and changed the C allocation strategy between exudation and respiration fluxes. These findings will help enhance predictions of belowground C allocation and C cycling under N-rich conditions in the future.

Characteristic Aromas of Quercus crispula (Japanese Oak)

Nature is important in Japanese culture. Many tree species produce diverse fragrances, making Japan's forests a botanical treasure. However, there have been no detailed investigations of the aroma characteristics of trees, a vital factor in forest bathing. Previously, we applied our analytical method to three tree species found mainly in Japan: Chamaecyparis pisifera, Lindera praecox, and Lindera obtusiloba Blume. In this paper, we report investigations of the aroma of Quercus crispula Blume (Japanese oak) using this analysis method. Japanese oak grows mainly in Japan. The odor compounds of Japanese oak were obtained by hexane extraction and monolithic material sorptive extraction and each extracted compound was identified by gas chromatography olfactometry and gas chromatography-mass spectrometry. Comparison of the aromas and compounds in the extracts resulted in the identification of important aroma compounds in Japanese oak: 10 (including eugenol) in the leaves and 15 (including 3-methyl-4-octanolide) in the wood.

Rinodina megistospora (Physciaceae) in the Russian Far East

The paper presents new data on distribution of the lichen Rinodina megistospora in the Russian Far East and its revealed range in eastern Asia. R. megistospora is recorded for the first time for the Sakhalin Region (Sakhalin and Iturup islands). It has been found on the territory of Russia in eight localities in the boreal and nemoral zones of Northeast Asia. The species grows in old-growth intact coniferous and oak forests on bark of Betula sp., Kalopanax septemlobus, Picea sp., Quercus crispula and Sorbus sp. Current data suggest that R. megistospora is one of the species belonging to the Eastern Asiatic — Western North American group of species, characterized by disjunctive range. The paper presents the anatomical and morphological description of Rinodina megistospora, based on the examined specimens.