Castanopsis Sieboldii Research Articles

Analysis of Molecular Diversity in Castanopsis sieboldii with Felt Disease Caused by Septobasidium sp.

In 2020, within the Dongbaekdongsan area in Jeju Island, a Septobasidium sp. associated with a felt disease in <i>Castanopsis sieboldii</i> (Makino) Hatus. ex T. Yamaz. & Mashiba was identified. The symptom included the presence of brown, thin, and silk-like mycelial mats attached to the tree's bark, displaying variations in size from large to small. To induce hyphal growth, the samples collected were incubated in a moist chamber, and the newly formed hyphae were subjected to genomic DNA extractions. The nucleotide sequences of the internal transcribed spacer and small subunit rDNA genes were determined, and molecular characteristics among the isolates were investigated through polymerase chain reaction-based restriction fragment length polymorphism analysis. This <i>Septobasidium</i> sp. exhibited distinct morphological and phylogenetic features compared to those that were previously reported in South Korea. Consequently, this strain is taxonomically classified as a provisionally novel species of <i>Septobasidium</i>. Furthermore, the observed felt disease exhibited a high degree of host specificity, as it was exclusively identified in <i>C. sieboldii</i> without occurrence in other tree species at the time of observation.

Castanopsis sieboldii Extract Alleviates Acute Liver Injury by Antagonizing Inflammasome-Mediated Pyroptosis.

Castanopsis sieboldii (CS), a subtropical species, was reported to have antioxidant and antibacterial effects. However, the anti-inflammatory effects of CS have not been studied. This study aimed to investigate whether the 70% ethanol extract of the CS leaf (CSL3) inhibited lipopolysaccharide (LPS)-induced inflammatory responses and LPS and ATP-induced pyroptosis in macrophages. CSL3 treatment inhibited NO release and iNOS expression in LPS-stimulated cells. CSL3 antagonized NF-κB and AP-1 activation, which was due to MAPK (p38, ERK, and JNK) inhibition. CSL3 successfully decreased NLRP3 inflammasome activation and increased IL-1β expression. CSL3 treatment diminished LPS and ATP-induced pore formation in GSDMD. The in vivo effect of CSL3 on acute liver injury was evaluated in a CCl4-treated mouse model. CCl4 treatment increased the activity of serum alanine aminotransferase and aspartate aminotransferase, which decreased by CSL3. In addition, CCl4-induced an increase in TNF-α, and IL-6 levels decreased by CSL3 treatment. Furthermore, we verified that the CCl4-induced inflammasome and pyroptosis-related gene expression in liver tissue and release of IL-1β into serum were suppressed by CSL3 treatment. Our results suggest that CSL3 protects against acute liver injury by inhibiting inflammasome formation and pyroptosis.

Evaluation of water use characteristics focusing on isohydry and anisohydry for an evergreen broad-leaved species, <i>Castanopsis sieboldii</i> (Makino) Hatus., based on sap flow measurements

Evaluation of water use characteristics focusing on isohydry and anisohydry for an evergreen broad-leaved species, <i>Castanopsis sieboldii</i> (Makino) Hatus., based on sap flow measurements

Hundreds of billions of silent outbreaks: A historic outbreak record of the gall midge Schizomyia castanopsisae (Diptera: Cecidomyiidae) on the Izu Islands, Tokyo, Japan, and its potential mechanism

AbstractHerbivore outbreaks cause serious damage to forest trees. In recent decades, outbreaks of the gall midge Schizomyia castanopsisae (Diptera: Cecidomyiidae) inducing inflorescence galls on Castanopsis sieboldii (Fagaceae) occurred in the Izu Islands, Tokyo, Japan. We investigated the gall density on the islands and estimated the larval population on Miyakejima Island. We also surveyed seasonal changes in larval age structure, presence of natural enemies, larval cold tolerance, and thermal effects on the adult emergence. In addition, we conducted molecular phylogenetic analyses of S. castanopsisae populations among different localities. The gall density was particularly high in southern parts (from Miyakejima to Aogashima) of the Izu Islands. The gall midge seemed to have been expanding its range toward northern parts in recent years. On Miyakejima, the larval population was estimated to be approximately 158 and 36 bn in 2017 and 2018, respectively. Parasitoids were not found in the dissection of galls. A cold temperature treatment did not affect the percentage of adult emergence. Developmental zero and thermal constant during the period from larval departure to adult emergence were estimated to be 4.7°C and 588.2°C‐days in males and 7.4°C and 476.2°C‐days in females, and the adults were predicted to emerge in April. Populations in Kyushu were genetically distinct from those in Okinawajima and the Izu Islands, but a common haplotype was found between the latter two localities. These imply that S. castanopsisae on the Izu Islands may be a recent invasion, and the absence of natural enemies causes its outbreaks.

Regeneration of tree species after 11 years of canopy gap creation and deer exclusion in a warm temperate broad-leaved forest over-browsed by sika deer.

Deer overpopulation is a major threat to forest ecosystems worldwide resulting in loss of natural vegetation cover and increased sapling mortality. To resolve this problem of deer overpopulation, different strategies such as deer exclusion and gap creation have been explored to determine more efficient methods to restore deer-damaged forest ecosystems. In the current study, we applied a 2×2 factorial design of four different treatment groups in warm temperate secondary forests: closed canopy with deer as control, closed canopy without deer, clearcut with deer and clearcut without deer. We compared the decadal change in tree foliar cover and tree species richness among treatment groups to assess tree regeneration success. We also selected six tree species (Abies firma, Quercus acuta, Eurya japonica, Cinnamomum tenuifolium, Castanopsis sieboldii and Neolitsea sericea) that are common in the studied region and compared their regeneration success among the treatment groups. In the absence of deer, clearcutting increased the diversity of tree species and accelerated sapling growth, while under closed canopy conditions sapling heights did not exceed two meters. Tree saplings tended to be less abundant in treatments with deer compared to their counterpart, suggesting limited successful recruitment of saplings at the current deer density (10-13.5 deer km-2). In clearcut-with-deer treatment, non-tree species became abundant, and negatively affected recruitment of tree species as was suggested by regression analysis. However, these general trends were not equal for all tree species. Although clearcut-without-deer treatment facilitated sapling recruitment of all six tree species, Q. acuta, C. tenuifolium and C. sieboldii required deer exclusion for sapling recruitment while A. firma, N. sericea and E. japonica required increased light availability. Consequently, informed decisions can be made by identifying whether certain tree species are capable of naturally recruiting without human intervention and how best to ensure successful recruitment if necessary. By implementing effective strategies, time and resources will be saved, and management goals such as reestablishing tree cover rapidly and increasing tree species diversity can be achieved.

Mammal and bird species using cavities among forests of different ages on Okinawajima Island in the Ryukyu Archipelago, Japan

ABSTRACT Various animals use tree cavities in the northern forest of Okinawajima Island in the Ryukyu Archipelago. However, the cavity characteristics and forest types used by cavity users are not well known. The aim of this study was to reveal the cavity users in natural forests of different ages in northern Okinawajima Island. Camera trap surveys were conducted to identify the utilization of cavities in four Castanopsis sieboldii dominated forests; one 40-year-old, one 70-year-old, and two mature forests. Only a few cavities were recorded in the 40-year-old forest and these locations were limited to the lower part of the trees. Consequently, cavity users were limited to two ground-foraging bird species. In contrast, cavities of various sizes were located at various heights above the ground in the other three types of forests, although endangered mammals such as Ryukyu long-furred rat (Diplothrix legata) and Ryukyu tube-nosed bat (Murina ryukyuana) only used cavities in mature forests. The greatest number of cavity-using bird species were recorded in the 70-year-old forest, and a Ryukyu robin (Larvivora komadori) built a nest in a cavity. These results show that mature forests provide various types of cavities with various functions which are important for diverse animal taxa, and that cavity users differ among forests of different ages. Furthermore, it was observed that cavity availability and use does not recover in 70 years. Cavity users should be considered in forest management not only in the core area, but also in the buffer zone of the protected areas in the future.

Insect fauna visiting flowers of the entomophilous broadleaf evergreen trees Castanopsis sieboldii, Castanopsis cuspidata, and their hybrid in fragmented urban woods in Aichi Prefecture, Japan

Insect fauna visiting flowers of the entomophilous broadleaf evergreen trees <i>Castanopsis sieboldii</i>, <i>Castanopsis cuspidata</i>, and their hybrid in fragmented urban woods in Aichi Prefecture, Japan

Tree-cavity formation in the mature subtropical forests of Yambaru, Okinawa Island

ABSTRACT Tree-cavities are considered as key components that support multiple species, including endemic ones, in subtropical forests in Yambaru, the northern area of Okinawa Island, Japan. Here, we established two study plots in mature subtropical forests in Yambaru and surveyed for tree-cavities with depths ≥ 10 cm. The density of tree-cavities was 198 per ha, which is exceptionally high compared with tree-cavity densities reported by other studies. Among the three key tree species (Castanopsis sieboldii, Schima wallichii, and Distylium racemosum), no tree-cavities were observed in S. wallichii in the study plots. In both C. sieboldii and D. racemosum, the probability of tree-cavity presence increased as the diameter at breast height (DBH) increased. In addition, the probability of tree-cavity presence on D. racemosum started to increase at smaller DBH stage compared with that on C. sieboldii. Distylium racemosum often had multiple tree-cavities per stem. Excavated cavities were rare across all species, and decay cavities were dominant. We detected the activity of the endangered Ryukyu long-haired rat (Diplothrix legata) in two cavities, both of which had similar features: a stem DBH of about 43 cm and volumes of 0.09–0.16 m3. In the Yambaru area, the preservation of large-diameter stems that will form tree-cavities is critically important for maintaining forest ecosystem health and should be considered when implementing forest management plans, especially for D. racemosum, which is rich in cavities and likely plays multiple ecological roles.

The ectomycorrhizal fungal communities react differently to climatic, edaphic and spatial variables depending on their host species

AbstractAimEctomycorrhizal (ECM) fungal community structures can vary across sites at a regional scale (&gt;1,000 km), affected by abiotic and biotic environments, dispersal abilities of the fungi, or ecological drift, even among forests of the same host tree species. The spatial patterns of such variation may differ among associated host species and their growth environments, but our knowledge about this remains limited. In the present study, we aimed to investigate whether the ECM fungal community structures (i.e. species richness and species composition) at the regional scale and their driving factors vary across hosts.LocationJapan.TaxonECM fungi associated with Fagus crenata and Castanopsis sieboldii.MethodsUsing DNA metabarcoding of fine roots, the ECM fungal communities of 15 Fagus crenata forests across their distribution range were characterised. The resultant community structure of ECM fungi, as well as the relative effects of edaphic, climatic and spatial factors on community composition were compared with those of 12 Castanopsis sieboldii forests investigated in a previous study.ResultsECM fungal community composition differed between the two Fagaceae hosts. The spatial pattern of ECM fungal community composition also differed between hosts. Specifically, the spatial variation in community composition across sites was smaller in F. crenata forests than in C. sieboldii forests. The spatial pattern of ECM fungal communities of F. crenata forests was explained by climatic and edaphic factors, while that of C. sieboldii forests was explained by spatial and edaphic factors.Main conclusionsOn a regional scale in Japan, the spatial pattern of ECM fungal communities and its driving factors varied between two Fagaceae host species. Our results provide an example that the difference in associated host leads to the difference in environmental response among ECM fungal communities.

The complete chloroplast genome of Castanopsis sieboldii (Makino) Hatus (Fagaceae)

Castanopsis sieboldii (Makino) Hatus is an evergreen tree that distributes in Eastern Asia including Islands of Korea and Japan. The chloroplast genome of C. sieboldii was successfully sequenced. Its length is 160,705 bp long (GC ratio is 36.8%) and has four subregions: 90,821 bp of large single copy (34.6%) and 19,014 bp of small single copy (30.8%) regions are separated by 25,075 bp of inverted repeat (42.8%) regions including 134 genes (89 protein-coding genes, eight rRNAs, and 37 tRNAs). Interspecific variations of Castanopsis are at a moderate level in comparison to those of the other genera. Phylogenetic trees show that C. sieboldii chloroplast genome was clustered with the other two Castanopsis species.

屋久島，黒島，口之島，中之島に分布するシイ型照葉樹林の種組成および種多様性

屋久島，黒島，口之島，中之島に分布するシイ型照葉樹林の種組成および種多様性

Landforms and distribution patterns of giant Castanopsis sieboldii trees in urban areas and western suburbs of Tokyo, Japan

Combining both biological diversity and cultural significance, populations of big trees in Japan are considered important. Furthermore, individual specimens, often with broken and unusual tree form, are highly striking and create a ‘sense of place’ in a locale. The giant Castanopsis sieboldii trees belonging to the family Fagaceae have a trunk circumference of over 3 m. These trees are distributed on various landforms in Tokyo and its western suburbs. In this study, we conducted field surveys to determine the distribution pattern and geographical conditions of giant C. sieboldii trees growing in urban areas and western suburbs of Tokyo. The topography of Tokyo is variable, comprising mountainous areas, hills, plateaux, lowlands, and reclaimed lands with large rivers or streams. The places where giant C. sieboldii trees grew were classified into 13 categories using cluster analysis of geomorphic landscape sections. The lowest point of the area within a 2-km radius surrounding the giant trees was determined through field surveys and based on geomorphic sections in four directions. Trees growing on slopes, plateaux, and hilltops or mountain tops, or along the edges of plateaux represented 80 % of the total recorded trees. Two categories were an exception to this, where the height difference between the lowest and highest altitude was less than 10 m. Giant trees were mostly distributed above the 10-m contour line, on plateaux or hills and especially on slopes along the edges of 10, 30, 120, 170, and 210-m contour lines on flat uplands. Altitude appeared to be a significant factor for giant tree distribution, with only a few giant trees located below the 10-m contour line in low lying or reclaimed lands. Finally, we discuss the reasons underlying this unique distribution of C. sieboldii in the light of the physical characteristics of different landforms.

Vegetation structure and distribution characteristics of Symplocos prunifolia, a rare evergreen broad-leaved tree in Korea

BackgroundIn Korea, Symplocos prunifolia Siebold. & Zucc. is only found on Jeju Island. Conservation of the species is difficult because little is known about its distribution and natural habitat. The lack of research and survey data on the characteristics of native vegetation and distribution of this species means that there is insufficient information to guide the management and conservation of this species and related vegetation. Therefore, this study aims to identify the distribution and vegetation associated with S. prunifolia.ResultsAs a result of field investigations, it was confirmed that the native S. prunifolia communities were distributed in 4 areas located on the southern side of Mt. Halla and within the evergreen broad-leaved forest zones. Furthermore, these evergreen broad-leaved forest zones are themselves located in the warm temperate zone which are distributed along the valley sides at elevations between 318 and 461 m. S. prunifolia was only found on the south side of Mt. Halla, and mainly on south-facing slopes; however, small communities were found to be growing on northwest-facing slopes. It has been confirmed that S. prunifolia trees are rare but an important constituent species in the evergreen broad-leaved forest of Jeju. The mean importance percentage of S. prunifolia community was 48.84 for Castanopsis sieboldii, 17.79 for Quercus acuta, and 12.12 for Pinus thunbergii; S. prunifolia was the ninth most important species (2.6).ConclusionsS. prunifolia can be found growing along the natural streams of Jeju, where there is little anthropogenic influence and where the streams have caused soil disturbance through natural processes of erosion and deposition of sediments. Currently, the native area of S. prunifolia is about 3300 m2, which contains a confirmed population of 180 individual plants. As a result of these low population sizes, it places it in the category of an extremely endangered plant in Korea. In some native sites, the canopy of evergreen broad-leaved forest formed, but the frequency and coverage of species were not high. Negative factors that contributed to the low distribution of this species were factors such as lacking in shade tolerance, low fruiting rates, small native areas, and special habitats as well as requiring adequate stream disturbance. Presently, due to changes in climate, it is unclear whether this species will see an increase in its population and habitat area or whether it will remain as an endangered species within Korea. What is clear, however, is that the preservation of the present native habitats and population is extremely important if the population is to be maintained and expanded. It is also meaningful in terms of the stable conservation of biodiversity in Korea. Therefore, based on the results of this study, it is judged that a systematic evaluation for the preservation and conservation of the habitat and vegetation management method of S. prunifolia should be conducted.

Diversity and Geographic Distribution of Ligninolytic Fungi Associated With Castanopsis sieboldii Leaf Litter in Japan.

The diversity and geographic pattern of ligninolytic fungi were investigated within the distribution range of an evergreen tree, Castanopsis sieboldii (Fagaceae), in Japan. Fungal isolates obtained from 18 sites in subtropical and temperate regions in Japan were classified into 50 operational taxonomic units in Ascomycota and Basidiomycota according to the base sequence of the rDNA internal transcribed spacer region. Ordination by nonmetric multidimensional scaling showed the separation of fungal compositions between the study sites which was significantly related to the latitude, longitude, and mean annual temperature (MAT) of the study sites. We applied variation partitioning to separate the magnitude of the climatic, spatial, and leaf property factors and found the roles of MAT and spatial factors in structuring fungal assemblages, suggesting the importance of both niche processes and such non-niche processes as priority effect and dispersal limitation. The bleached area on leaf litter was greater at sites with higher MAT and precipitation located at lower latitudes and at sites where some major ligninolytic fungi occurred at greater relative frequencies, indicating that not only the climatic conditions but also the biogeographic patterns of distribution of ligninolytic fungi influence the decomposition of lignin in leaf litter.

Effects of soil physical and chemical properties on the growth of Castanopsis sieboldii

Effects of soil physical and chemical properties on the growth of <i>Castanopsis sieboldii</i>

Visualization and Localization of Submicron-Sized Ammonium Sulfate Particles on Needles of Japanese Larch (Larix kaempferi) and Japanese Cedar (Cryptomeria japonica) and Leaves of Japanese Beech (Fagus crenata) and Japanese Chinquapin (Castanopsis sieboldii) after Artificial Exposure

We applied a method combining field-emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectrometry (EDX) to visualize the deposition and localization of the submicron-sized ammonium sulfate (AS) particles. The AS particles emitted from an aerosol generator in the laboratory were spherical in shape and individually deposited without aggregation on the surface of a silicon substrate. We determined the AS particles on the surfaces of the needles of Japanese larch (Larix kaempferi) and Japanese cedar (Cryptomeria japonica), and the leaves of Japanese beech (Fagus crenata) and Japanese chinquapin (Castanopsis sieboldii), using EDX. The particles were deposited on either the adaxial or abaxial side of the leaves and needles. The AS particles deposited on the surfaces of the leaves and needles did not aggregate, and they were deposited on the surfaces of the leaves and needles in the same manner, regardless of leaf structure. These results, using a new method, highlight the early stages of the deposition and localization of submicron-sized AS particles on the surfaces of the leaves and needles of forest trees.

Characteristics of vegetation succession on the Pinus thunbergii forests in warm temperate regions, Jeju Island, South Korea

BackgroundTo investigate the trends of succession occurring at the Pinus thunbergii forests on the lowlands of Jeju Island, we quantified the species compositions and the importance values by vegetation layers of Braun-Blanquet method on the Pinus thunbergii forests. We used multivariate analysis technique to know the correlations between the vegetation group types and the location environmental factors; we used the location environment factors such as altitudes above sea level, tidal winds (distance from the coast), annual average temperatures, and forest gaps to know the vegetation distribution patterns.ResultsAccording to the results on the lowland of Jeju Island, the understory vegetation of the lowland Pinus thunbergii forests was dominated by tall evergreen broad-leaved trees such as Machilus thunbergii, Neolitsea sericea, and Cinnamomum japonicum showing a vegetation group structure of the mid-succession, and the distribution patterns of vegetation were determined by the altitudes above sea level, the tidal winds on the distance from the coast, the annual average temperatures, and the forest gaps. We could discriminate the secondary succession characteristics of the Pinus thunbergii forests on the lowland and highland of Jeju Island of South Korea.ConclusionsIn the lowland of Jeju Island, the secondary succession will progress to the form of Pinus thunbergii (early successional species)→Machilus thunbergii, Litsea japonica (mid-successional species)→Machilus thunbergii (late-successional species) sequence in the temperate areas with strong tidal winds. In the highland of Jeju Island, the succession will progress to the form of Pinus thunbergii (early successional species)→Neolitsea sericea, Eurya japonica (mid-successional species)→Castanopsis sieboldii (late-successional species) sequence in the areas where tidal winds are weak and temperatures are relatively low. However, local differences between lowland and highland of Jeju Island will be caused by the micro-environmental factors resulting from the topographic differences and the supply of tree seeds. From the characteristics of succession study, we could properly predict and manage the Pinus thunbergii forest ecosystem on lowland and highland of Jeju Island.

Assessment of Broad-Leaved Forest Stand Management

There are many broad-leaved forests in Japan that were formerly managed for charcoal production, which have been abandoned for decades. Appropriate thinning can revitalize these forests if the cost balance of the management is positive. Two critical elements are the construction of spur roads to facilitate mechanized harvesting operations and management planning that considers stand properties such as the growing stock, species, and tree size distribution. We surveyed three abandoned former broad-leaved coppice stands; one coastal, one cool temperate and one warm temperate. The stock in all three stands exceeded 300 m3 ha-1, two- to three-fold the official forest registry data estimates. The dominant species in terms of tree numbers are Castanopsis sieboldii, Pieris japonica, and Quercus glauca. Medium-sized trees involve those well suited for firewood, i.e., Quercus acuta, Quercus glauca, Quercus serrata, etc. Each plot contained a few large trees that potentially have a high market value, e.g., Cinnamomum camphora, Zelkova serrata, Abies firma, etc. The average income from harvested trees was estimated to be 10200 JPY (Japanese Yen) m-3, whereas the thinning costs would be 3200 to 5400 JPY m-3, with the additional spur road construction costs. The management cost balance of a broad-leaved stand in a 60 year rotation was evaluated with both Net Present Value (NPV) (for interest rates of 1, 2, 3, and 4%) and Internal Rate of Return (IRR). This balance was compared with that of a typical plantation stand of Japanese cedar (Cryptomeria japonica) and of a fast-growing plantation stand of Chinese fir (Cunninghamia lanceolata). The estimated NPVs were largest for the fast-growing plantation stand, second largest for the typical plantation stand, and lowest for the broad-leaved stand with a NPV interest rate of 1 + %. However, the IRR of the broad-leaved stand was the highest, followed by that of the fast-growing plantation stand, while the IRR of the typical plantation stand was the lowest. This order was the same for NPVs assuming higher interest rates. 1 JPY=0.0086 € on April 29, 2019.

Relationships between growing characteristics and soil chemistry of Castanopsis sieboldii

Relationships between growing characteristics and soil chemistry of <i>Castanopsis sieboldii</i>

Comparison of allometric equations and biomass expansion factors for six evergreen broad-leaved trees in subtropical forests in southern Korea

ABSTRACTThis study was conducted to compare the allometric equations and biomass expansion factors (BEFs) of six dominant evergreen broad-leaved trees (Camellia japonica L, Castanopsis sieboldii Hatus, Quercus acuta Thunb, Q. glauca Thunb, Machilus thunbergii S. et Z., and Neolitsea sericea Koidz) in subtropical forests. A total of 86 trees were destructively sampled to quantify the aboveground biomass of each tree component (i.e., leaves, branches, and stem). Species-specific or generalized allometric equations and species-dependent BEFs were developed for each tree component of the six broad-leaved forest trees. Species-specific allometric equations were significant (P < 0.05), with the diameter at breast height (DBH) accounting for 68–99% of the variation, whereas generalized allometric equations explained 64–96% of the variation. The values of stem density ranged broadly from 0.49 g cm−3 for C. sieboldii to 0.79 g cm−3 for Q. glauca, with a mean value of 0.68 g cm−3. The BEFs were significantly (P < 0.05) lower for C. sieboldii (1.25) than for M. thunbergii (2.02). Stem density and aboveground BEFs had a significant negative relationship with tree ages. The results indicate that species-specific allometric equations and species-dependent BEFs are applicable for obtaining accurate biomass estimates of subtropical evergreen broad-leaved forests.