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To investigate the reproductive traits of the dioecious canopy tree Cercidiphyllum japonicum, we performed visual surveys from 2000 to 2007 to assess the flowering and fruiting of 59 individuals in...

Prevailing directions of seed and pollen dispersal may induce anisotropy of the fine‐scale spatial genetic structure (FSGS), particularly in wind‐dispersed and wind‐pollinated species. To examine the separate effects of directional seed and pollen dispersal on FSGS, we conducted a population genetics study for a dioecious, wind‐pollinated, and wind‐dispersed tree species, Cercidiphyllum japonicum Sieb. et Zucc, based on genotypes at five microsatellite loci of 281 adults of a population distributed over a ca. 80 ha along a stream and 755 current‐year seedlings. A neighborhood model approach with exponential‐power‐von Mises functions indicated shorter seed dispersal (mean = 69.1 m) and much longer pollen dispersal (mean = 870.6 m), effects of dispersal directions on the frequencies of seed and pollen dispersal, and the directions with most frequent seed and pollen dispersal (prevailing directions). Furthermore, the distance of effective seed dispersal within the population was estimated to depend on the dispersal direction and be longest at the direction near the prevailing direction. Therefore, patterns of seed and pollen dispersal may be affected by effective wind directions during the period of respective dispersals. Isotropic FSGS and spatial sibling structure analyses indicated a significant FSGS among the seedlings generated by the limited seed dispersal, but anisotropic analysis for the seedlings indicated that the strength of the FSGS varied with directions between individuals and was weakest at a direction near the directions of the most frequent and longest seed dispersal but far from the prevailing direction of pollen dispersal. These results suggest that frequent and long‐distance seed dispersal around the prevailing direction weakens the FSGS around the prevailing direction. Therefore, spatially limited but directional seed dispersal would determine the existence and direction of FSGS among the seedlings.

The general trends in the purity changes of the environment in connection with the urbanistic technogenesis were analyzed on the example of the largest city of Western Ukraine – Lviv – and its outskirts, Dublyany. The characteristic changes of some parameters of the main environmental factors – transformed ecosystems, including biogeochemical properties of edaphotope and pollution by heavy metals are described. Urbanization leads to a tendency of parkerising, alkalinization and significant measure of green zone soil contamination with heavy metals. The increase of the complex pressure of urban anthropogenic environment on vegetation is revealed and current changes of the chemical composition of dry matter of leaves of trees in terms of heavy metal content and structure-energy metabolites are analyzed. A significant accumulation of some chemical elements in the assimilation system of Quercus robur L. and Cercidiphyllum japonicum Siebold et Zucc. was found, their species-specific features of ash accumulative ability were revealed. Cercidiphyllum japonicum is proved to be a promising and effective, in terms of cleaning the environment from man-made pollution, decorative plant in the green belt of cities in the regions of Roztochchia and Pasmove Pobuzhya. Under the influence of edaphotope transformation and pollution in the assimilation bodies of woody plants some structural and metabolic changes occur to adapt to the new to their species environment. Oak as autochthonous species, has signs of stability of the metabolic system of assimilation to the urban genic changes. Cercidiphyllum’s structure demonstrates plasticity of dry matter of leaves, designed to adapt to the new environment acclimatization of exotic species, and thus performs an effective metal storage function in a green area of the city.

Premise Water stored in the xylem of woody plants is important for supporting the transpiration stream under prolonged drought, yet the source of stored water within the xylem during drought remains unclear. Insights into xylem water utilization during drought will uncover the adaptation strategies of the test species to stress. Methods To fill the existing knowledge gap, we excised twigs of Abies firma (Japanese fir, conifer), Cercidiphyllum japonicum (katsura tree, diffuse-porous) and Quercus serrata (konara oak, ring-porous) to quantify interspecific variation of water transfer in xylem corresponding with increasing cumulative water release (CWR) using micro x-ray computed tomography and cryo-SEM. Results For all species studied, the main components of water storage within the operating range of water potential were not living cells but cavitation release and capillaries. Abies firma maintained water in the earlywood-like cells, for possible maintenance of the transpiration stream. Cercidiphyllum japonicum maintained water in its vessels over 200 kg m-3 of CWR, while Q. serrata lost most of its water in vessels with increasing CWR up to 100 kg m-3 . Cercidiphyllum japonicum exhibited a higher water storage capacity than Q. serrata. Under high CWR, narrow conduits stored xylem water in C. japonicum and imperforate tracheary elements in Q. serrata. Conclusions Among the species examined, increasing CWR appears to indicate differential utilization of stored water in relation to variation of xylem structure, thereby providing insight into the interspecific responses of tree species to drought.

Approach for reducing the growth-inhibiting effects of endogenous phenolic compounds in katsuratree (Cercidiphyllum japonicum). An approach for reducing the growth-inhibiting effects of endogenous phenolic compounds in katsuratree (Cercidiphyllum japonicum Sieb. & Zucc.) was developed to assist with clonal micropropagation of the species. A quantitative phenolic profile of Cercidiphyllum spp. was undertaken to provide further evidence of metabolic diversity within the genus. In order to mitigate the growth-inhibiting effects of preformed and induced polyphenols in katsura microshoot cultures, a range of sequestering treatments and carbon sources were compared. Cultures were compared by presoaking nodal explants in aqueous solutions for 12 or 24 h as well as incorporating sequestering agents into initiation media. The carbon source treatments, sucrose and d-(+)-glucose, were compared at concentrations of 0%, 1.5%, 3%, and 5% (w/v), and 1:1 (w/v) mixtures of d-(+)-glucose and sucrose over 4 weeks on a bulked, half-sib C. japonicum family. Eight major phenolic compounds were identified in varying concentrations and presence within and among species. Presoaking solutions significantly outperformed all other treatments for shoot growth traits. Incorporation of l-ascorbic acid at 40 μM showed similar performance. The carbon source d-(+)-glucose at 3% (w/v) was determined to be the most effective treatment for improving microshoot growth.

Conservation for endangered medicinal plant species is important and urgent. Cercidiphyllum japonicum is an endangered and nationally protected medicinal plant species. We use multivariate methods to study ecological relations of C. japonicum communities in the Shennongjia Nature Reserve, Central China. Fifty-eight 10 m x 20 m quadrats of C. japonicum communities were randomly set up along an altitudinal gradient. Data for species composition and environmental variables were measured and recorded for each quadrat. Two-way indicator species analysis (TWINSPAN) and canonical correspondence analysis (CCA) was used in analyses. Moreover, species diversity indices were used to analyze the relationships between species diversity and environmental variables. The results showed that there were eight types of C. japonicum communities. Each community had its own compositional, structural and environmental characteristics. Variation of C. japonicum communities was significantly correlated to elevation and slope. Community variations were also related to aspect and litter thickness. Elevation and slope were revealed as important factors that influence community distribution and diversity. Species diversity showed a quadratic and negative correlation with elevation. The importance values of C. japonicum also showed a quadratic and negative correlation with species diversity. For conservational purposes, species diversity should be maintained within a reasonable range.

4 Figuras; 2 Tablas; 25 Páginas, Although several chlorophyll metabolites have been shown to exert prominent benefits to human health when consumed, the battery of linear chlorophyll derivatives (phyllobilins) presents in fruits is poorly understood. Yellow chlorophyll catabolites (YCCs) are a new kind of phyllobilins recently identified in senescent leaves, probably arising from an oxidative process of the terminal chlorophyll catabolites, NCCs (non-fluorescent chlorophyll catabolites). This work deals with the characterization by first time of this kind of phytochemicals in edible fruits. Two YCCs have been identified in yellow Japanese plums, one (Ps-YCC1) previously described in the senescent leaves of Cercidiphyllum japonicum Siebold & Zucc. and Ps-YCC2, a chlorophyll catabolite structure described by first time in the edible parts of Japanese plum fruits. These YCCs were characterized by high-resolution MS/MS, describing the specific fragmentation (ring A) and the absence of the typical cleavage of phyllobilins (ring D), as a consequence of the unsaturated bond at C15–16 typical of YCCs, allowing the differentiation from NCCs. To the already known array of phenolic acids, anthocyanins and carotenoids, NCCs and YCCs may contribute to the antioxidant potential of these fruits, a potential that deserves attention and future research, considering the photochemical and photophysical behaviour of this group of tetrapyrrolic breakdown products., This work was supported by the Comisión Interministerial de Ciencia y Tecnología (CICYT-EU, Spanish and European Government, AGL 2015-63890-R).

'Living fossils' are testimonies of long-term sustained ecological success, but how demographic history and natural selection contributed to their survival, resilience, and persistence in the face of Quaternary climate fluctuations remains unclear. To better understand the interplay between demographic history and selection in shaping genomic diversity and evolution of such organisms, we assembled the whole genome of Cercidiphyllum japonicum, a widespread East Asian Tertiary relict tree, and resequenced 99 individuals of C. japonicum and its sister species, Cercidiphyllum magnificum (Central Japan). We dated this speciation event to the mid-Miocene, and the intraspecific lineage divergence of C. japonicum (China vs Japan) to the Early Pliocene. Throughout climatic upheavals of the late Tertiary/Quaternary, population bottlenecks greatly reduced the genetic diversity of C. japonicum. However, this polymorphism loss was likely counteracted by, first, long-term balancing selection at multiple chromosomal and heterozygous gene regions, potentially reflecting overdominance, and, second, selective sweeps at stress response and growth-related genes likely involved in local adaptation. Our findings contribute to a better understanding of how living fossils have survived climatic upheaval and maintained an extensive geographic range; that is, both types of selection could be major factors contributing to the species' survival, resilience, and persistence.

Long-term ecological research (LTER) began at the Ooyamazawa riparian forest research site in 1983. Ooyamazawa comprises a representative cool-temperate zone old-growth riparian forest that is species-rich and contains complex topography. The Ooyamazawa river basin comprises at least 230 species of vascular plants, including 46 woody tree species that are found within the research site. Researchers have used this site to study forest structure and tree life histories over a 35-year period. In particular, research has focused on the life histories of the dominant canopy species Fraxinus platypoda, Pterocarya rhoifolia, and Cercidiphyllum japonicum. After the research site was registered as a Core Site of the Monitoring Sites 1000 Project, research began on avifauna and ground beetles, in addition to ongoing forest research.

The canopy tree species Fraxinus platypoda, Pterocarya rhoifolia, and Cercidiphyllum japonicum coexist at the Ooyamazawa riparian forest research site. In this chapter, we clarify the coexistence mechanisms of riparian tree species as they pertain to disturbance regimes, life-history strategies, and responses to environmental factors. Reproductive strategies, e.g., seed production and germination, differ widely among these three species and we observed probable reproductive trade-offs in each species. Canopy-height individuals of F. platypoda are recruited from advanced saplings, and P. rhoifolia and C. japonicum both established following large-scale disturbance events. Basal sprouting, i.e., vegetative reproduction, is likely the mechanism by which C. japonicum survives and attains co-dominance in riparian forests. F. platypoda had greater shade and water tolerance than the other two species. Each of these species is well-adapted to the various disturbances typical of riparian zones. Therefore, the coexistence mechanisms among them are likely a combination of random chance and niche partitioning.

Cercidiphyllum japonicum, a Tertiary relict, recolonized areas north of the Yangtze River after the last glacial; however, little is known about its specific colonization corridors. Together with distribution models, the least cost path (LCP) analysis has been used to reveal the landscape connectivity of species. In this study, we utilized the categorical LCP method, combining the species distribution with genetic data from cpDNA and nuclear markers, to identify the possible dispersal routes of C. japonicum after the LGM. Across time periods and genetic markers, the results revealed that the species generally spread from the western edge of the Sichuan Basin, while the highest degree of dispersal potential corresponds with the year 2080 and the cpDNA haplotype. Furthermore, shifts in the species' range and the indication of an area of low genetic divergence further support the existence of a dispersal corridor. Overall, we believe that a dispersal route from the western edge of the Sichuan Basin through the Qinling Mountains and further to the northeast could exist, and therefore, the results are an important supplement to the evolutionary history of C. japonicum. In the future, we believe species distribution models (SDM) and connectivity assessment in relation to climate change will provide increasingly useful information and new implications for prioritizing the conservation of the endangered species.

Xylem tension relaxation is an important procedure that closely resembles the in vivo xylem water distribution when measuring conductivity or observing water distribution of plant tissue samples by cryo-scanning electron microscopy (cryo-SEM). Recent studies have shown that partial xylem embolism occurs when samples under tension are cut under water and that gas-filled vessels are refilled during tension relaxation. Furthermore, the frequency of gas-filled vessels has been reported to increase in samples without tension relaxation before cryo-fixation by liquid nitrogen, particularly in samples with significant tension. Here, we examined the effect of tension relaxation on these artifacts in Carpinus tschonoskii and Cercidiphyllum japonicum using magnetic resonance imaging. We observed that xylem embolism rarely occurs in bench-dried samples cut under water. In both species, a small portion of the xylem was refilled within ~1 h after tension relaxation. Cryo-SEM observations revealed that short-time (

This publication covers the physical and main features, plant needs, functions, care, and additional information for Katsuratree, Cercidiphyllum japonicum.

The phylogenetic relationships among Chrysanthemum and its related genera (Anthemideae, Asteraceae) is poorly understood. In the present study, these relationships were investigated using 45S and 5S ribosomal DNA (rDNA)-targeted fluorescent in situ hybridization. The results showed that there were two 45S rDNA signals present in Crossostephium chinense, four 45S rDNA signals in Cercidiphyllum japonicum, Artemisia sieversiana, Artemisia annua and Artemisia absinthium, six 45S rDNA signals in Chrysanthemum boreale and Pyrethrum parthenium, eight 45S rDNA signals in Chrysanthemum nankingense, Chrysanthemum dichrum, Chrysanthemum lavandulifolium and Tanacetum vulgare, and ten 45S rDNA signals in Ajania przewalskii. For the 5S rDNA locus, two 5S rDNA signals were present in C. nankingense, C. dichrum, C. lavandulifolium, C. boreale, C. japonicum, C. chinense and P. parthenium, four in A. sieversiana, A. annua, A. absinthium and A. przewalskii, and six 5S in T. vulgare. In addition, karyotypes of the 12 species were investigated. From this study, we inferred that Chrysanthemum was closely related to Ajania, and that Chrysanthemum species originating from China and Japan may have evolved differently. These findings add a new level to the understanding of the phylogenetic relationships of Chrysanthemum and related genera.

Cercidiphyllum japonicum leaves were collected, air-dried and extracted with 70% aqueous acetone, then concentrated and sequentially fractionated using n-hexane, methylene chloride (CH 2 Cl 2 ), ethylacetate (EtOAc), and H 2 O. A portion of EtOAc fraction (10 g) was chromatographed on a Sephadex LH-20 column, by the suc-cessively elution with various aqueous MeOH-H 2 O (1:9, fraction 1-2 → 3:7, fraction 3-5 → 1:1, fraction 6-9 → 7:3, fraction 10-13 → 9:1, fraction 14-16). Compound 2 was isolated from fraction 6 and compound 1 was separated from fraction 11 and 12. Compound 3 and 4 were purified from fraction 13. The isolated compounds were elucidated as quercetin-3-O-α-L-rhamnopyranoside (1), chlorogenic acid (2), quercetin-3-O-α-L-arabinofur-anoside (3) and quercetin-3-O-β-D-xylopyranoside (4) by the spectral and literature data, and by comparison with the authentic samples. These compounds were reported, for the first time, from the extracts of C. japoni-cum leaves. Also chlorogenic acid (2) has never been reported before in domestic tree species and can be used as an index compound for C. japonicum.Keywords : Cercidiphyllum japonicum leaves, phenolic glycosides, ethyl acetate fraction, column chromatography,structure elucidation

Katsura tree (Cercidiphyllum japonicum Sieb. Et Zucc) leaves were collected, air-dried and extracted with 70% aqueous acetone, then concentrated and sequentially fractionated using n-hexane, methylene chloride (CH2Cl2), ethylacetate (EtOAc), and H2O. The EtOAc fraction was chromatographed on a Sephadex LH-20 column with various aqueous MeOH eluting solvents and finally treated with acetone-H2O (7:3, v/v) to isolate a gallotannin. According to the NMR analysis, including HSQC and HMBC, and with the comparison of authentic literature data, the isolate was elucidated as 6-m-digalloyl-1,2,3,4-tetra-O-galloyl β-D-(+)-glucose, one of hydrolyzable tannins and one of gallotannins. The compound was only gallotannin which was firstly isolated from the extracts of Katsura tree leaves, and has not been reported before in domestic tree sources.

Katsura tree (Cercidiphyllum japonicum Sieb. Et Zucc) leaves were collected, air-dried and extracted with 70% aqueous acetone, then concentrated and sequentially fractionated using n-hexane, , EtOAc, and to be freeze dried for antioxidant and -glucosidase inhibition activity tests. The antioxidant activity of the extracts was evaluated using DPPH (1,1-diphenyl 2-picrylhydrazyl) free radical scavenging assay. The test concentrations were adjusted to 500, 250, 125, 62.5, 31.25, 15.62, 7.81, 3.9, 1.95 and 0.97 ppm. The and EtOAc fractions showed higher activities compared with the control, -tocopherol, at all concentrations. The crude fraction also gave better activity at the concentrations lower than 62.5 ppm. However, the nonpolar n-hexane and fractions gave prominently lower activities compared with the control at all concentrations. The values of the crude, EtOAc, and fractions exhibited 11.78, 4.29 and , respectively, compared with of the control. But the n-hexane and fractions indicated 300 and of , respectively. -Glucosidase inhibition activity was evaluated at the concentrations of 50, 25, 12.5, 6.3, 3.1, 1.6 and 0.8 ppm. The inhibition activities were increased according to as the increase of sample concentrations. However, the nonpolar n-hexane and fractions indicated very low inhibition activities compared with acarbose, a positive control. The EtOAc fraction showed very good capability as almost 100% compared with the control at the higher concentrations than 12.5 ppm and the crude fraction also indicated good potential as 95% and 100% at 25 and 50 ppm, respectively. The fraction gave good inhibition value as 90% at 50 ppm although the value was lower than the control. These results showed that the polar fractions had better -glucosidase inhibition activities. The values of the nonpolar fractions, n-hexane and , showed very lower values as 468 and , respectively, than the control. -Glucosidase Inhibition Activity of the Extracts of Katsura Tree (Cercidiphyllum japonicum Sieb. Et Zucc) Leaves However, the polar fractions, crude, EtOAc and , showed 7.1, 3.7 and , respectively, indicating that these fractions can be used as natural bioresources for treating diabetes mellitus. Also -glucosidase inhibition activity had a positive correlation with antioxidant activity of the extracts.

Development of xylem embolism during water stress in two diffuse-porous hardwoods, Katsura (Cercidiphyllum japonicum) and Japanese white birch (Betula platyphylla var. japonica), was observed non-destructively under a compact magnetic resonance imaging (MRI) system in addition to conventional quantitation of hydraulic vulnerability to cavitation from excised stem segments. Distribution of white and dark areas in MR images corresponded well to the distribution of water-filled/embolized vessels observed by cryo-scanning electron microscopy in both species. Water-filled vessels were observed in MR images as white areas in Katsura and as white dots in Japanese white birch, respectively, and embolisms could be detected as a change to dark areas. The increase in the relative embolized area (REA: %) in the cross-sectional area of total xylem during water stress, which was estimated from the binarized MR images, was consistent with the hydraulic vulnerability curves of these species. From the non-destructive MRI observations, cavitation induced by water stress was shown to develop earlier in 1- or 2-year-old xylem than in the current-year xylem in both species; that is, the vulnerability to cavitation differs between vessels in the current-year xylem and those in older annual rings.

Functional diversity is significant to ecological processes of plant communities. We analyzed the variation of functional diversity of endangered species, Cercidiphyllum japonicum, communities along an elevational gradient in the Shennongjia Reserve, central China. Sixty plots of 10 × 20 m from 1,350 to 2,050 m were set up and species composition, traits and environmental variables were measured and recorded. These data were analyzed using five functional diversity indices, functional attribute diversity, modified functional attribute diversity, plot based functional diversity, community based functional diversity and Rao’s functional diversity indices (Rao’s index), Functional diversities of C. japonicum communities were rich and varied greatly. Functional diversity declined non-linearly with increasing elevation. Functional diversity was significantly correlated with species richness and heterogeneity. Elevation was a key environmental variable influencing functional diversity and species diversity. The five functional diversity indices were all effective for measuring functional diversity of communities. Functional diversity can be used as an indicator of conservation efficiency of endangered species such as C. japonicum.

Cercidiphyllum, the only member of Cercidiphyllaceae, contains two extant species: Cercidiphyllum japonicum and Cercidiphyllum magnificum. Here, we reported their complete chloroplast genomes by de...

Summary Cercidiphyllum Sieb. & Zucc. comprises two very similar living species, Cercidiphyllum japonicum Sieb. & Zucc. and Cercidiphyllum magnificum (Nakai) Nakai, both commonly referred to as the katsura tree. The systematic placement and fossil history of Cercidiphyllum are described, and aspects of its cultivation and conservation are discussed. Cercidiphyllum magnificum is illustrated.

Premise of research. Several key morphological and anatomical features are found in temperate deciduous hardwood taxa that undergo seasonal dormancy, including long-shoot/short-shoot differentiation, heterophylly, and diffuse-porous wood. These features, when found together in the fossil record, can serve as indicators suggesting that fossil plants had physiological responses to changing photoperiod and chilling similar to those present today in temperate deciduous forests. We measured heterophyllous leaves on branches of extant Cercidiphyllum trees and used these data as a profile with which to compare fossil leaves of the family Trochodendraceae.Methodology. We recorded frequency distributions of L∶W ratios of leaves from short and long shoots on branches of live Cercidiphyllum japonicum (Cercidiphyllaceae) trees and compared them with fossil leaves of late Paleocene Zizyphoides flabellum of Almont, North Dakota, of Zizyphoides type 1 from the late early Eocene “upland” Okanogan Highlands locality at Re...

Whether soaking or injected by BSA, low to intermediate (≦ 7.58 μ M) concentrations of BSA improved rooting rate of cuttings and higher (≧ 15.15 μ M) concentrations of BSA significantly decreased the rooting rate of cuttings. The effect on the rooting rate by the method of BSA injected are significant than that of BSA soaking cuttings. Both of soaked and injected cuttings with low to intermediate (≦ 7.58 μ M) concentrations of BSA markedly increased the average number of lateral roots and the average root length. The treatment of the injection had a remarkable effect on the average number of lateral roots and average root length than that of soaking whether the low or high concentration of BSA. The magnitude of changes of the endogenous GA, ABA, ZR and IAA of the cuttings were bigger in the cuttings treated by injecting than that of soaking in each stage after cutting. This study adds the understanding that organic nitrogen effects on the cuttings root formation, growth and endogenous hormone changes.

Cercidiphyllum japonicum is a rare endemic species of East Asia flora and a common component in riparian forests. Dendrochronological techniques were employed to trace radial growth of C. japonicum in the Shennongjia area of central China and examine its relationships with local climate. Effects of precipitation on width of C. japonicum annual rings were negligible except for some temporary negative impacts in prior winter. The variables most strongly controlling radial growth were temperatures in the previous December and during the current summer. Relationships for most pairs of ring-width and monthly/seasonal climate variables were temporally unstable but occasionally significant. Radial growth–climate relationships for C. japonicum were likely shaped by riparian site characteristics, root habits, and regional climatic regimes.

Euptelea pleiospermum and Cercidiphyllum japonicum are dominant relictual tree species of the riparian plant communities in the subtropical region of Shennongjia Mountains, central China. Community survey and multivariate analysis were carried out to characterize their ecological ranges and regeneration characteristics, and further to explore the factors determining their present distribution boundaries and the barriers restricting their range expansion. We recorded 303 woody species, among which there were 14 relictual, rare and/or endemic woody species. Results obtained from cluster analysis corroborated the results from non-metric multidimensional scaling (NMS) ordination, classifying the 42 plots into three well-defined associations. Correlation analysis revealed that variation in species composition among associations was partly explained by some physical (altitude, slope, soil temperature) and chemical (available K, NH4, pH) properties. Multiple regression analyses with data of adults and seedlings with physical and chemical variables revealed contrasting patterns of the two dominant relictual species. Both taxa have a high resprouting rate that keeps the stands stable irrespective of scarcity of seedlings. However, expansion of the distribution range is difficult in such a situation. E. pleiospermum prefers riparian habitats with poor nutrients in the south-facing slope of the Shennongjia Mountains, which may indicate that this species is light-demanding at some life stages and well adapted to a nutrient-poor habitat where competition from other species is limited. The Cercidiphyllum japonicum population was more scattered and fragmented, and preferred riparian habitats on gentle slopes. Both species are favored by the mild and moist microclimate, but the current conditions in these subtropical mountain riparian habitats probably do not really provide optimal ecological conditions for the two relictual species.

Cercidiphyllum japonicum and C. magnificum are deciduous tree species that produce large numbers of sprouts. They are found mainly in riparian and/or disturbed areas. C. japonicum is distributed in the montane zone in Japan, whereas C. magnificum is distributed mostly in the subalpine zone of central Japan. However, the two species sometimes coexist, e.g., on the talus slope at the valley head of the Chichibu Mountains. We investigated differences in sprouting traits in these two species by comparing class distributions of sprout diameter at breast height (DBH) and heights of individuals on the talus slope. Sprout DBH and individual height were smaller in C. magnificum as compared to C. japonicum. Moreover, the analysis of the DBH-class distribution of each species indicated that C. magnificum had numerous small sprouts and experienced high mortality, whereas C. japonicum had fewer small sprouts and low mortality. It is likely that the sprouting traits of C. magnificum make it more adapted to severe conditions in the subalpine zone than those of C. japonicum.

Uniaxial compression tests were conducted using specimens of agathis (Agathis sp.) and katsura (Cercidiphyllum japonicum Sieb. et Zucc.) with various values of off-axis angle, defined as the angle between the grain axis and the axis along the loading direction. The obtained stress-strain relation was regressed into Ramberg–Osgood’s equation, and it was predicted by approximating the relationship between the parameters contained in the regressed equation and off-axis angle into Hankinson’s formula. The comparisons between the stress-strain relations obtained by the experiment and prediction revealed that the off-axis compression stress-strain relation can be predicted effectively using the relations in the orthotropic axes.

Here we describe the detection and identification of a yellow chlorophyll catabolite (Cj-YCC) in fresh extracts of senescent leaves of Cercidiphyllum japonicum. In addition, we report its partial synthesis by oxidation of Cj-NCC-1, the major (colourless) "nonfluorescent" chlorophyll catabolite (NCC) found in degreened leaves of C. japonicum. The spectroscopic analysis and structural characterization indicated Cj-YCC to be a simple dehydrogenation product of Cj-NCC-1 (by formal removal of a hydrogen atom at the C(20)- and C(1)-positions). Indeed, NCCs are easily oxidized and were first called "rusty pigments", as they had a tendency to turn brown upon storage on a dry silica gel plate. The yellow tetrapyrrole Cj-YCC may thus come about by oxidation of Cj-NCC-1 in the leaves. Its presence in the yellow leaves of a deciduous tree provides the first evidence for the contribution of a coloured chlorophyll catabolite to the fall colours.

To clarify effects of lignin on the thermal-softening properties of water-swollen wood, dynamic viscoelasticities of water-swollen wood were measured in the temperature range from 5°C to 100°C. The results obtained were as follows. 1) Delignified wood and moso bamboo did not show thermal softening around 60∼80°C which was found for untreated wood and moso bamboo. From this result, it was found that the thermal softening of lingo-cellulosic materials around 60∼80°C were attributable to lignin. Decrease in storage elastic moduli (E') of wood and moso bamboo from 20 to 100°C remarkably decreased with decreasing in their lignin contents. From this result, it can be concluded that the degree of thermal softening around 60∼80°C largely depends on lignin contents. 2) The thermal-softening temperatures were different among many kind of wood species (softwood, Japanese hardwood, Tropical hardwood) and between an untreated katsura (Cercidiphyllum japonicum) sample and a sample slightly delignified. Consequently, it is deduced that the thermal-softening behaviors of water-swollen wood were largely affected by cross-linking of lignin. 3) The thermal softening behaviors of katsura were quite different among specimens experienced cooling with different rates. This suggests that the thermal-softening behaviors of water-swollen wood largely depend on the conformation of lignin.

Boreal hardwood species, including Japanese white birch ( Betula platyphylla Sukat. var. japonica Hara), Japanese chestnut ( Castanea crenata Sieb. et Zucc.), katsura tree ( Cercidiphyllum japonicum Sieb. et Zucc.), Siebold’s beech ( Fagus crenata Blume), mulberry ( Morus bombycis Koidz.), and Japanese rowan ( Sorbus commixta Hedl.), had xylem parenchyma cells (XPCs) that adapt to subfreezing temperatures by deep supercooling. Crude extracts from xylem in all these trees were found to have anti-ice nucleation activity that promoted supercooling capability of water as measured by a droplet freezing assay. The magnitude of increase in supercooling capability of water droplets in the presence of ice-nucleation bacteria, Erwinia ananas , was higher in the ranges from 0.1 to 1.7 °C on addition of crude xylem extracts than freezing temperature of water droplets on addition of glucose in the same concentration (100 mosmol/kg). Crude xylem extracts from C. japonicum provided the highest supercooling capability of water droplets. Our additional examination showed that crude xylem extracts from C. japonicum exhibited anti-ice nucleation activity toward water droplets containing a variety of heterogeneous ice nucleators, including ice-nucleation bacteria, not only E. ananas but also Pseudomonas syringae (NBRC3310) or Xanthomonas campestris , silver iodide or airborne impurities. However, crude xylem extracts from C. japonicum did not affect homogeneous ice nucleation temperature as analyzed by emulsified micro-water droplets. The possible role of such anti-ice nucleation activity in crude xylem extracts in deep supercooling of XPCs is discussed.