Temperate Japan Research Articles

How far do forest container mosquitoes (Diptera: Culicidae) invade rural and urban areas in Japan? - Simple landscape ecology with comparison of the invasive Aedes ecology between native and invasive ranges.

The distribution of container mosquitoes in relation to distances from forests was studied in temperate Japan. Mosquito larvae were collected between May and September in 4 years from tree holes, bamboo stumps, riverine rock pools, and artificial containers; sampling ranged spatially from the mountain forest across the deforested plain developed as agriculture and urban areas to the seacoast. Although tree holes, bamboo stumps, and artificial containers existed throughout the deforested plain area, 10 container species of 6 genera were found virtually only within 5 km from the nearest forest edge. Worldwide invasive Aedes albopictus (Skuse) and Aedes japonicus (Theobald) of Asian origin showed unique occurrence patterns different from other container species and from each other. Ae. japonicus was dominant in artificial containers in and near the forest but minor in forest natural containers and only occurred within 5 km from the forest. Ae. albopictus was minor in the forest irrespective of container types but not bound to the forest and dominant in natural and artificial containers throughout rural and urban areas. The 5-km range was designated as the circum-forest zone for container mosquitoes (except Ae. albopictus) in Japan, and an expanded concept, circum-boundary zone, is proposed. The widths of these zones primarily depend on the dispersal traits of mosquitoes. Whether the relation of Ae. albopictus and Ae. japonicus to forests we observed are common in the native and invasive ranges is discussed. The study of across-ecosystem dispersal is important for mosquito management under anthropogenically changing environments due to either deforestation or green restoration.

Comparison of prey fauna in tropical red traps versus temperate whitish traps in carnivorous Drosera indica complex (Droseraceae)

AbstractCertain carnivorous plant species display geographical variation in trap coloration, which may impact interactions with prey. Our study focused on Drosera indica (Droseraceae) in tropical Thailand and its phylogenetically related species Drosera toyoakensis in temperate Japan. Drosera indica in Thailand has green leaf blades with red tentacles when flowering, making the entire trap appear red. In contrast, D. toyoakensis in Japan has green leaf blades with green‐white tentacles when flowering, and the entire trap appears white. Field observations revealed statistically significant differences in taxa and size of prey caught by D. indica and D. toyoakensis. Both species caught small flies, but D. toyoakensis additionally caught larger flies and butterflies, including pollinators. These differences in prey composition may reflect differences in trap coloration that evolved under different selection pressures for capturing prey. However, trap coloration and prey assemblages were influenced by various factors, and further research is required to elucidate their evolutionary significance.

A new genus and species of the Assimineidae (Caenogastropoda: Truncatelloidea) from temperate mainland Japan

ABSTRACT Xenassiminea nana n. gen. and n. sp. is described from estuaries of temperate mainland Japan (central to western Honshū, Shikoku and Kyūshū). This species has a minute, colourless, translucent, depressed and helicoid shell and resembles some so-called skeneimorphs. However, the anatomical characters of the head–foot, radula and reproductive system indicate that this species belongs to the Assimineidae, in spite of the dissimilarity in shell features. The presence of basal cusps of the central radular teeth and the extremely rudimentary cephalic tentacles indicate that it should be assigned to the subfamily Assimineinae. The shell size (0.8 mm in length, 1.1 mm in diameter) is the smallest among known assimineids. It lives beneath stones deeply buried in sandy mud flats at the innermost parts of large bays and can be regarded as threatened by the rapid loss of these habitats in recent years.

Flowering shift due to climate warming in cool temperate Japan

Biological processes can be disrupted by global climate warming, causing phenological mismatching and mistiming. On Hokkaido Island (Japan), which has a cool temperate climate, warmer and shorter winters affect plant flowering phenology. Rapid changes in flowering phenology suggest that shorter winters will result in earlier flowering. Flowering phenology patterns were recorded for nine years (2013–2021), and nine species were selected for analysis. I analyzed climate variables that affect plant flowering phenology, including annual changes in aerial temperature, snow depth, and snowmelt timing. The results indicated that winters are getting shorter and that the accumulated degree hours of aerial temperature have not significantly changed over nine years for these plant species except one species. Plant responses to these changes differed between species, with the first flowering day occurring earlier (1.5–1.8 days per year) for two species, although that of the other seven not. If climate warming continues, it will have diverse, complex, and unpredictable effects on various individual organisms and biological relationships among species. Detailed studies are needed to link climate change predictions to the predicted degree of mismatch in species interactions and networks.

Fish otolith record reveals possible tropical-subtropical fish community in temperate Japan during the exceptionally warm Last Interglacial period

ABSTRACT Glacial-interglacial cycles are characteristic of the large-scale reorganisation of global climate during the Quaternary. Therefore, records of warmer-than-present periods, such as the Marine Isotope Stage (MIS) 5e, draw particular interest as they may aid scientists to predict how marine ecosystems may change in the future. However, fish fossil records during such warming periods are less clear. Here, we aim to reconstruct local fish fauna during the MIS 5e by describing fossil otoliths from two localities in central Japan belonging to the Otsu Sand and Mud Member of the Yokosuka Formation. A total of 544 otoliths were analysed, revealing the presence of at least 35 taxa. The fish assemblages reflect a mixture of coastal to oceanic epi-mesopelagic species. In addition, the remarkable occurrences of two present-day tropical species and its species composition demonstrate a possible complex tropical to subtropical-like fish fauna in the higher latitude Palaeo-Tokyo Bay during the warmer-than-present last interglacial period.

Notes on Diptera Pupipara of the eastern Palaearctic region 1. The taxonomic status of species and subspecies of Hippoboscidae and Nycteribiidae described from temperate Japan and the Republic of Korea

The taxonomic status of subspecies and species of Diptera Pupipara described from Japan and the Republic of Korea was investigated. Two subspecies of Hippoboscidae and three subspecies of Nycteribiidae described based on Japanese specimens are treated as new synonyms of respective nominotypical subspecies: Ornithomya avicularia (Linnaeus, 1758) (Syn. n.: O. avicularia aobatonis Matsumura, 1905); Ornithomya chloropus (Bergroth, 1901) (Syn. n.: O. chloropus extensa Maa, 1967); Nycteribia allotopa (Speiser, 1901) (Syn. n.: N. allotopa mikado Maa, 1967); Basilia rybini Hurka, 1969 (Syn. n.: B. rybini japonica Theodor, 1973; B. truncata Theodor, 1966 (Syn. n.: B. truncata endoi Mogi, 1977). Two species described from Korean specimens are treated as new synonyms: Nycteribia formosana (Karaman, 1939) (Syn. n. Nycteribia uenoi Maa, 1968); Nycteribia quasiocellata Theodor, 1966 (Syn. n. Nycteribia pleuralis Maa, 1968).

Notes on Diptera Pupipara of the eastern Palaearctic region. 2. Identity of <i>Ornithoica momiyamai</i> (Hippoboscidae)

The louse fly,Ornithoica momiyamai, is ectoparasitic on a variety of bird species in Japan and the Republic of Korea (ROK). However, its species status has been controversial for many years. We investigated its morphological and ecological traits to clarify further its species status. Morphology of gynandromorphs, which has been regarded as useful in distinguishing related Ornithoica species, was reported for the first time. Gynandromorphs in Japan have a tri-lobed infra-anal plate similar to Ornithoica tridens (endemic to Taiwan) but distinct from several related tropical species. Collection records of O. momiyamai compiled from literature were compared with O. tridens, Ornithoica exilis (a tropical species carried to the temperate region by migratory birds), and Ornithomya avicularia (a Palaearctic species overwintering in the temperate region primary as puparia). The records indicate that O. momiyamai is relatively common throughout temperate Japan and the ROK, found on a number of bird species irrespective of their seasonality, and collected annually and locally if collection efforts are done. Records also document population increases during summer months concurrently with Ornithomya avicularia in warm-temperate Japan. These results demonstrate that O. momiyamai is a temperate species that overwinters as puparia at least in warm-temperate Japan.

Small-scale heterogeneity of fish diversity evaluated by environmental DNA analysis in eelgrass beds

Seagrass beds are a target for conservation worldwide and are frequently the focus of bioassessment and biomonitoring surveys. However, these surveys often employ destructive methods and involve considerable effort and cost. Recently, environmental DNA (eDNA) techniques have been attracting attention as a low-impact alternative for evaluating species diversity. However, the relationship between the detection ability of eDNA metabarcoding and the ecology of the organisms from which eDNA is derived has not been explicitly investigated. In this study, we examined this relationship for fishes in 2 eelgrass Zostera marina beds in temperate Japan, with a focus on 2 ecological characteristics (swimming position and appearance frequency in seagrass beds). We used eDNA metabarcoding to identify fish DNA collected from seawater samples and compared species inventories between 2 sampling positions (within vs. above eelgrass meadows) and 2 survey methods (eDNA vs. sledge-net sampling). Our results show that eDNA metabarcoding is much more effective than sledge-net sampling in detecting fish species, and that the detection ability of eDNA metabarcoding differs with water-sampling position. In particular, the relationship between fish ecology and survey detection ability appears to differ between the 2 eelgrass beds. Our results indicate that prior consideration of the spatial structure and fish communities of eelgrass beds is necessary for a reliable estimation of fish diversity in vegetated marine habitats.

Seed Morphology and Dispersibility of Orchids in Warm Temperate Japan

Seed Morphology and Dispersibility of Orchids in Warm Temperate Japan

Seed morphology and dispersibility of orchid in warm temperate Japan

Seed morphology and dispersibility of orchid in warm temperate Japan

Vegetative Reproduction Is More Advantageous Than Sexual Reproduction in a Canopy-Forming Clonal Macroalga under Ocean Warming Accompanied by Oligotrophication and Intensive Herbivory.

Ocean warming and the associated changes in fish herbivory have caused polarward distributional shifts in the majority of canopy-forming macroalgae that are dominant in temperate Japan, but have little effect on the alga Sargassum fusiforme. The regeneration ability of new shoots from holdfasts in this species may be advantageous in highly grazed environments. However, little is known about the factors regulating this in Sargassum species. Moreover, holdfast tolerance to high-temperature and nutrient-poor conditions during summer has rarely been evaluated. In the present study, S. fusiforme holdfast responses to the combined effects of temperature and nutrient availability were compared to those of sexually reproduced propagules. The combined effects of holdfast fragmentation and irradiance on regeneration were also evaluated. Propagule growth rate values changed from positive to negative under the combination of elevated temperature (20 °C–30 °C) and reduced nutrient availability, whereas holdfasts exhibited a positive growth rate even at 32 °C in nutrient-poor conditions. The regeneration rate increased with holdfast fragmentation (1 mm segments), but was unaffected by decreased irradiance. These results suggest that S. fusiforme holdfasts have a higher tolerance to high-temperature and nutrient-poor conditions during summer than propagules, and regenerate new shoots even if 1-mm segments remain in shaded refuges for fish herbivory avoidance.

Mapping of a Major QTL, <i>qHD6-SD</i> Responsible for Days to heading Under Natural Short Day Conditions to Develop Rice Varieties adaptable to Tropical Regions

In the tropics (Southeast Asian countries), indica rice is more common than japonica. Japonica rice is mainly cultivated in temperate regions, including Korea, Japan, and China (northeast regions) due to its poor adaptation to tropical areas. To develop tropically-adapted high-yielding japonica rice, breeders should overcome the challenges, including extremely early flowering, low biomass accumulation, and inferior panicle traits. This study investigated 180 F9 recombinant inbred lines (RILs) developed from a cross between Ilpum (temperate japonica) and Zenith (indica) as a case population to identify quantitative trait loci (QTLs) that influence the said traits. Here we identified two major QTLs, qHD6-SD and qHD6- LD, conferring days to heading under short day (SD) and long day (LD) conditions, respectively. Finer mapping revealed that both qHD6-SD and qHD6-LD located in the similar 98 kb region harbored the Hd1 gene. Days to heading in the RILs harboring the Zenith allele type of qHD6-SD under SD conditions were significantly longer than those in the RILs harboring the Ilpum allele type. On the contrary, days to heading in the RILs harboring the Zenith allele type of qHD6-SD under LD conditions were significantly shorter than those in the RILs harboring the Ilpum allele type. This bi-functionality of qHD6-SD upon heading strongly support the claim that both qHD6-SD and qHD6-LD might be the Hd1 gene. Our findings further support the claim that the functional allele type of Hd1 gene delays long-day heading and promotes extremely early short-day heading. Therefore, a non-functional Hd1 type is critical to tropical adaptation of japonica rice since it delays the heading date, which is essential to attain prolonged vegetative state in order to achieve optimum biomass, increased spikelet number, and grain filling capacity.

Road preference of ants in a Japanese warm temperate forest and its implications for the regeneration of myrmecochorous sedges

AbstractIn warm temperate forests where light availability is generally low, roadsides often provide a refuge for myrmecochores. Therefore, whether or not ants disperse seeds along the roadsides should critically affect the regeneration of myrmecochores. Nonetheless, the dispersal behaviors of ants along roadsides have rarely been investigated in warm temperate forests. This study examined the road preference of two seed dispersing ants in warm temperate Japan, Formica japonica and Pheidole nodus. We located ant nests using baits placed at the vicinity of myrmecochorous sedges and examined the road preferences of ants and their consequences for seed dispersal by comparing the observed road proximity of ant nests with the simulated value assuming a random dispersal direction. Nests of both ant species were significantly closer to the road than in those simulated assuming random dispersal, which confirmed their road preferences. The road preference of F. japonica reduced the risk of seed loss into the forest interior to one‐ninth of the random dispersal. This trend was not observed in P. nodus due to its short dispersal distance relative to roadside width. Although light availability was higher around nests of P. nodus due to their closer proximity to the road than nests of F. japonica, adult sedges were located farther from the road than the nests of P. nodus. This implies that nests of P. nodus are unsuitable microhabitats for sedges. These results suggest that ants can disperse seeds along forest roadsides in warm temperate forests, but the efficiency vary among ant species.

Review on Pharmacological and Phytochemical Prospects of Traditional Medicinal Plant: Persicaria hydropiper (Smartweed).

Persicaria hydropiper (L.) Delarbre (family Polygonacea), commonly known as Polygonum hydropiper, is a popular medicinal plant used in traditional medicine. The plant is indigenous to the tropical northern hemisphere and temperate zone, including China, Bangladesh, India, and Japan. The plant is used in folk medicine for numerous ailments such as hemorrhoids, antifertility, diarrhea, and dyspepsia. Its medicinal usage in Unani, Ayurveda, Siddha, and other traditional medicine is well-recognized. So far, a wide range of active phytochemicals of this plant has been identified, such as flavonoids, sulphated flavonoids, terpenoids, anthraquinones, steroids, coumarin, simple phenolics, and others. Pharmacological data reported in the literature suggest that various parts of P. hydropiper exhibit antimicrobial, antioxidant, hypoglycemic, antidepressant, cardioprotective, hepatoprotective, anticancer, and antifertility effects. The present review aims to compile the coherently document research on the phytochemical, pharmacological, and biological activities of P. hydropiper from different parts of the globe.

Aculeate wasp assemblages in naturally regenerating broad-leaved forests and conifer plantations in temperate Japan (Insecta, Hymenoptera)

Aculeate wasp assemblages in naturally regenerating broad-leaved forests and conifer plantations in temperate Japan (Insecta, Hymenoptera)

Genome-Wide Identification, Phylogeny, and Expressional Profiles of the Mitogen-Activated Protein Kinase Kinase Kinase (MAPKKK) Gene Family in Pyropia yezoensis

Mitogen-activated protein kinase kinase kinases (MAPKKKs) are pivotal components of MAPK cascades. Pyropia yezoensis, belonging to Rhodophyta, is an important macroalga growing in the intertidal zone of temperate Japan and China. At present, little is known about MAPKKKs and their potential regulatory mechanisms in response to environmental stressors in red algae, particularly with regard to how this gene family retained its ancient characteristics. In this study, we identified 33 MAPKKK genes in P. yezoensis by bioinformatics analysis. Phylogenetic analysis classified them into Raf, MEKK and ZIK groups, which contained conserved kinase motif with minor variations. The number of intron of all PyMAPKKK is few, up to 3. Regulatory elements prediction indicated that the cis-acting elements included many motifs involved in the stress response. Furthermore, expression analysis of PyMAPKKKs under different stress conditions revealed that numerous PyMAPKKK genes were involved in various signaling pathways with different expression patterns. Additionally, 16 PyMAPKKK genes were validated their expression patterns by Realtime-PCR analysis. An interactome network of PyMAPKKK was constructed to show that most of the interacting proteins were serine/threonine protein kinases, MAPKs, and ubiquitin-binding proteins. Our study provided helpful information for understanding the evolution and function of the MAPKKK family in P. yezoensis.

A new species of the Spirobranchus kraussii-complex (Annelida, Serpulidae) from the Persian Gulf and Gulf of Oman.

A recent study (Simon et al. 2019) confirmed that Spirobranchus kraussii is neither a widely distributed tropical species of Indo-Pacific origin nor a Lessepsian migrant to the Mediterranean, but a large complex of species, some of which might be indeed invasive. Thus, a common intertidal gregarious serpulid, previously attributed to S. kraussii in the Persian Gulf and Gulf of Oman, is described herein as Spirobranchus sinuspersicus sp. nov., using a combination of morphological and molecular data. The new species differs from S. kraussii by smaller size, fewer abdominal chaetigers, arrangement of abdominal chaetae and shape of opercular endplate talon. Results of phylogenetic analyses of a dataset combining 18S nucleotide and Cyt-b amino-acid sequences of S. sinuspersicus sp. nov. and Spirobranchus spp. available from GenBank supported monophyly of S. kraussii complex (including S. cariniferus) nested within Spirobranchus and thus, provided molecular support for synonymy of Pomatoleios with Spirobranchus proposed based on morphological criteria. The new species forms a well-supported clade with (S. kraussii (sp. 2 Hawaii + sp. 3 Australia)) clade, which in turn forms a clade with Spirobranchus sp.1 from temperate Japan, while S. cariniferus from New Zealand forms a basal grade. Evidence of substitution saturation of Cyt-b nucleotide sequences suggests that using translated amino-acid sequences to exclude non-informative substitutions should provide a better phylogenetic resolution for the genus Spirobranchus. Further studies are required to determine the invasive status of S. sinuspersicus sp. nov. as well as taxonomic and invasive status of S. cf. kraussii populations from the Mediterranean Sea, Suez Bay, Pakistan, India, Sri Lanka, Philippines, Singapore, and Panama.

Association between myxomycetes and the decay stage of coarse woody debris in an evergreen broadleaf forest in warm temperate Japan

Abstract Myxomycetes inhabit coarse woody debris in varying stages of decay; however, their ecology in the dead wood of evergreen broadleaf trees is not well known. In this study, we examined the relationships between myxomycete species and the decay stage of wood from fallen trees in an evergreen broadleaf forest in Japan. Myxomycete species richness and abundance were calculated for eight stages of decay in fallen logs, according to the appearance and wood hardness of log portions. A total of 70 myxomycete species (including varieties) were found on the logs. Moderately decayed wood was the preferred habitat of myxomycetes (57 species; 81% of the total) and most species inhabited moist decayed wood. Analysis by nonmetric multidimensional scaling enabled the differentiation of myxomycete assemblages, with five groupings recognized across the progression of decay. Forty-two species preferred a particular decay stage, represented by the decay index. Physarum viride and Stemonitis splendens particularly preferred the less-decayed wood and Stemonitopsis typhina var. similis especially inhabited the well-decayed wood. Species from the order Physarales dominated the less-decayed wood, whereas Trichiales and Liceales species dominated the softer well-decayed wood. Myxomycetes diversity was high in and varied among logs with various stages of decay in a typical Japanese evergreen forest.

The effect of substrate disturbance on benthic invertebrates in old-growth broad-leaved forest and planted conifer forest basin streams in Japan

ABSTRACTDisturbances such as heavy rainfall impact benthic invertebrate assemblages in streams and other lotic systems. In temperate Japan, the steep topography means that even modest rainfall can result in significant substrate disturbance. Impacts of this disturbance on benthic invertebrates were examined in the following 1 week and compared in streams of an old-growth broad-leaved forest (OBF) and a planted conifer forest (PCF). Disturbance in this study occurred by kicking the stream substrate. The number of individuals and genera in both forest types decreased after disturbance and gradually recovered over time, but no difference in recovery was observed between the OBF and PCF streams. Benthic invertebrate assemblage composition in both forest types changed depending on the days from disturbance, and differences in recovery between the OBF and PCF streams were observed in the composition of benthic invertebrate assemblages. Recovery patterns of individual taxa after disturbance were also different. Complete recovery was not observed 1 week after disturbance in either forest type, suggesting more time was required to reestablish pre-disturbance invertebrate community composition.

Interactions among dwarf bamboo, litter and consumption by small vertebrates place multiple constraints on the establishment of native tree seedlings in a Japanese agricultural landscape

Faunal assemblage alterations due to anthropogenic impacts have changed herbivore–vegetation relationships in various ecosystems, but the influences of small vertebrates on revegetation processes remain unclear. In a peri-urban agricultural landscape in eastern Japan that lacks large ungulates but supports small generalist herbivores, fewer native seedlings have become established in thickets dominated by native dwarf bamboo, Pleioblastus chino (Franch. et Sav.) Makino. The mechanisms limiting tree seedling establishment are unknown. Our aim here was to evaluate the influence of interactions among the dwarf bamboo, its litter cover and small vertebrate herbivores on the microsite conditions governing the establishment of native tree seedlings from different successional stages in an old field in temperate Japan. First, seedling emergence and survival of seeded Pinus densiflora Siebold et Zucc., Celtis sinensis Pers., Aphananthe aspera (Thunb.) Planch., Quercus serrata Murray, Quercus myrsinifolia Blume and Castanopsis sieboldii (Makino) Hatus. ex T. Yamaz. et Mashiba were observed in a factorial design that accounted for the presence or absence of dwarf bamboo and its litter cover, as well as the exclusion or access of small vertebrate fauna, in 2009 and 2010. To identify small vertebrate herbivores that reduced the emergence or survival of tree seedlings in the first experiment, reseeding experiments using P. densiflora, C. sinensis, A. aspera and Q. myrsinifolia were conducted by video trapping in 2011 and video and still-camera trapping in 2012. The abiotic conditions under the dwarf bamboo were lethal to early- to mid-successional P. densiflora, C. sinensis, A. aspera and Q. serrata but led to better survival—although spindly growth—of late-successional Q. myrsinifolia and C. sieboldii. The main consumers and the plants they found palatable differed between the bamboo thickets and the intervening gaps. Predation by mice appeared to have severely limited the emergence of all species, particularly in the bamboo thickets but occasionally in the gaps, whereas litter cover slightly mitigated this limitation. However, bamboo litter cover reduced the emergence of P. densiflora in the gaps. Chinese bamboo partridge (Bambusicola thoracicus Temminck), an introduced game bird, selectively and severely fed on the cotyledons—and probably seeds—of A. aspera and moderately preyed upon those of P. densiflora in the gaps. Apparent consumption of seedlings in the gaps by the Japanese hare (Lepus brachyurus Temminck) suppressed the growth of all species but apparently did not severely affect emergence and survival. Thus, the net balance of positive and negative interactions at the bamboo thicket scale (i.e. the presence of dominant dwarf bamboo cover or intervening gaps and the herbivore behaviours in these two environments) and at the microsite level (i.e. litter cover) shapes the early establishment patterns of native tree seedlings, and this balance differs among tree seedling species.