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Kyoichi Otsuki - One of the best experts on this subject based on the ideXlab platform.

  • a nitrogen saturated plantation of cryptomeria japonica and Chamaecyparis obtusa in japan is a large nonpoint nitrogen source
    Journal of Environmental Quality, 2015
    Co-Authors: Masaaki Chiwa, Hiroaki Kato, Takami Saito, Hirokazu Haga, Kyoichi Otsuki, Yuichi Onda
    Abstract:

    Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa) plantations account for approximately 30% of the total forested area in Japan. Both are arbuscular mycorrhizal trees that leach more NO₃⁻ in response to nitrogen (N) deposition than do forests of ectomycorrhizal trees. However, little information is available about the size of N exports from these plantations. The aim of this study was to evaluate nonpoint source N exports from a N-saturated plantation. We collected stream water samples in base-flow (25 samples) and storm-flow conditions (20 events) in a watershed (2.98 ha) where Japanese cypress and Japanese cedar were planted in 1969 (41 yr old). The annual NO₃⁻ export was calculated from load–discharge relationships. Atmospheric N deposition was also determined. The stream water contained high NO₃⁻ concentrations (160 and 165 μmol L⁻¹ during base flow and storm flow, respectively), indicating N saturation in the watershed. High bulk atmospheric N deposition (16.5 kg N ha⁻¹ yr⁻¹) could explain the N saturation. There were only small variations in NO₃⁻ concentrations in stream water in response to discharge volume, because of the N saturation of the forest ecosystem. Consequently, there were only small errors in estimating annual NO₃⁻ exports from the studied watershed. The annual NO₃⁻ export was high (36.1 kg N ha⁻¹ yr⁻¹), comparable to values reported for agricultural and urbanized areas. These results suggest that N-saturated forest plantations can become important nonpoint N sources. Our results also suggest that N exports from forest plantations across Japan should be quantified to evaluate nonpoint source N accurately.

  • the effect of strip thinning on tree transpiration in a japanese cypress Chamaecyparis obtusa endl plantation
    Agricultural and Forest Meteorology, 2014
    Co-Authors: Xinchao Sun, Hiroaki Kato, Yuichi Onda, Kyoichi Otsuki, Akiko Hirata, Takashi Gomi
    Abstract:

    This study analyzes the effect of strip thinning on tree transpiration (Et) in a dense and mature Japanese cypress (Chamaecyparis obtusa Endl.) plantation in central Japan. Strip thinning, which removed 50% of stems, was conducted in a headwater basin in October 2011. Xylem sap flow densities (Fd) were measured using thermal dissipation (Granier-type) sensors in a 156-m2 plot before and after thinning. The canopy conductance (Gc) was calculated on the basis of Et values. The results revealed that the Fd at the outer xylem (0–20 mm) increased remarkably, whereas the Fd at the inner xylem (20–40 mm) had no significant change after thinning. Mean stand sap flow density (JS) values were higher in the post-thinning period than in the pre-thinning period, and the differences significantly increased with increasing vapor pressure deficit (VPD) values. Furthermore, the daily single tree Et increased, particularly in the small tree class. Unlike the daily tree Et, the daily stand Et decreased from 1.29 ± 0.60 to 1.00 ± 0.40 mm d−1 during the growing season or decreased from 1.23 ± 0.48 to 0.74 ± 0.42 mm d−1 on the annual scale. The total stand Et decreased by 23.0%, from 214.9 to 165.5 mm, during the growing season or decreased by 38.3%, from 441.0 to 272.1 mm, on the annual scale. Gc decreased after thinning, which implies lower stand Et and photosynthesis. Gc was primarily related to the VPD and would be an effective model to predict Et from these Japanese cypress plantations. This study provides useful information for understanding the Et responses at individual tree and stand levels to strip thinning and contributes to obtaining a thorough understanding of the change in tree water use under different management strategies.

  • effects of antecedent rain history on particulate phosphorus loss from a small forested watershed of japanese cypress Chamaecyparis obtusa
    Journal of Hydrology, 2008
    Co-Authors: Junichiro Ide, Masaaki Chiwa, Hirokazu Haga, Kyoichi Otsuki
    Abstract:

    Summary This study aimed to clarify the effects of antecedent rain history on particulate phosphorus (PP) loss in a small mountainous watershed covered primarily with a plantation forest of Japanese cypress (Chamaecyparis obtusa). We analyzed stream discharge and PP concentration at 15–60 min intervals during 24 h in eight rain events with different discharge levels. The PP concentration versus stream discharge (PPC–Q) relationships exhibited clockwise hysteresis loops for each of the eight events monitored. Discharge could explain changes in PP concentration on the falling but not rising limb of the hydrograph. On the rising limb, a positive relationship between the rate of changes in discharge (dQ/dt) and the PP load (dL/dt) was found for each event. This indicates that a large amount of PP is strongly pulsed at times of rapidly increased discharge. These results suggest that dQ/dt is the driving force behind PP supply and the primary control on the clockwise hysteresis loop of PPC–Q relationship. There was a strong negative correlation between the antecedent precipitation index and the slope of the dL/dt versus dQ/dt relationship. This shows that a rapid increase in PP load occurs even with slight increases in discharge as antecedent moisture conditions become drier. The soil water repellency and rapid runoff response following dry conditions support that soil desiccation increases the PP supply associated with soil erosion via overland flow. Therefore, we concluded that the antecedent rain history affects the mobility of PP via soil desiccation. The findings of this study will fill gaps in our understanding of temporal variations in released fine sediment and associated PP as reported in previous studies.

  • sources of error in estimating stand transpiration using allometric relationships between stem diameter and sapwood area for cryptomeria japonica and Chamaecyparis obtusa
    Forest Ecology and Management, 2005
    Co-Authors: Tomoomi Kumagai, Hisami Nagasawa, Tetsuya Mabuchi, Shigeru Ohsaki, Katsuyoshi Kubota, Kimio Kogi, Yasuhiro Utsumi, Shinya Koga, Kyoichi Otsuki
    Abstract:

    Abstract Estimations of stand sapwood area (AS_stand) are among the most critical factors for determining stand transpiration (E) using sap flux measurements. AS_stand is generally estimated using stem diameter (DBH) data measured for all trees in a stand and an allometric equation that describes the relationship between DBH and sapwood area (AS_tree) based on available allometric data. To examine the errors in E that are generated when using the allometric equation with a small sample size, the Monte Carlo sampling technique was used with an original allometric data set. In this study, all trees (921 Cryptomeria japonica and 1226 Chamaecyparis obtusa) in the studied stands provided the original allometric data (DBH and AS_tree). Monte Carlo simulations allow the number of sample trees required for an appropriate E estimate to be derived. The results revealed that potential errors in the E estimate were almost stable with a sample size of over 20 for both Cr. japonica and Ch. obtusa. This implies that at least, but not more than, 20 trees are necessary for the allometric equation when estimating E for both species.

  • sources of error in estimating stand transpiration using allometric relationships between stem diameter and sapwood area for cryptomeria japonica and Chamaecyparis obtusa
    Forest Ecology and Management, 2005
    Co-Authors: Tomoomi Kumagai, Hisami Nagasawa, Tetsuya Mabuchi, Shigeru Ohsaki, Katsuyoshi Kubota, Kimio Kogi, Yasuhiro Utsumi, Shinya Koga, Kyoichi Otsuki
    Abstract:

    Estimations of stand sapwood area (AS_stand) are among the most critical factors for determining stand transpiration (E) using sap flux measurements. AS_stand is generally estimated using stem diameter (DBH) data measured for all trees in a stand and an allometric equation that describes the relationship between DBH and sapwood area (AS_tree) based on available allometric data. To examine the errors in E that are generated when using the allometric equation with a small sample size, the Monte Carlo sampling technique was used with an original allometric data set. In this study, all trees (921 Cryptomeria japonica and 1226 Chamaecyparis obtusa) in the studied stands provided the original allometric data (DBH and AS_tree). Monte Carlo simulations allow the number of sample trees required for an appropriate E estimate to be derived. The results revealed that potential errors in the E estimate were almost stable with a sample size of over 20 for both Cr. japonica and Ch. obtusa. This implies that at least, but not more than, 20 trees are necessary for the allometric equation when estimating E for both species. # 2004 Elsevier B.V. All rights reserved.

Yueh-hsiung Kuo - One of the best experts on this subject based on the ideXlab platform.

  • cytotoxic and novel skeleton compounds from the heartwood of Chamaecyparis obtusa var formosana
    Tetrahedron Letters, 2007
    Co-Authors: Shih-chang Chien, Jang Yang Chang, Chingchuan Kuo, Chengchih Hsieh, Ningsun Yang, Yueh-hsiung Kuo
    Abstract:

    Abstract The novel skeleton compounds, chamaecypanone C ( 3 ) and obtunorlignan A ( 4 ) were isolated from the heartwood of Chamaecyparis obtusa var. formosana . The structure of 3 was elucidated as a dimeric of monoterpene and norlignan with tricyclo[5.2.2.0 2.6 ]undecane and the structure of 4 was elucidated as a norlignan skeleton by spectroscopic methods. Compound 3 exhibits potent cytotoxic activity against several human cancer cells with IC 50 values ranging from 0.19 to 0.52 μM, whereas 4 has no activity.

  • yatein from Chamaecyparis obtusa suppresses herpes simplex virus type 1 replication in hela cells by interruption the immediate early gene expression
    Antiviral Research, 2006
    Co-Authors: Y H Kuo, Yueh-hsiung Kuo, Yuanglian Lin, Weijern Tsai
    Abstract:

    Inhibitory effects of methanolic extracts from nine Chinese herbs on herpes simplex virus type 1 (HSV-1) replication were studied. By a bioassay-guided fractionation procedure, yatein (C(22)H(23)O(7); M.W.399) was isolated from Chamaecyparis obtusa; yatein significantly suppressed HSV-1 multiplication in HeLa cells without apparent cytotoxicity. To further localize the point in the HSV-1 replication cycle where arrest occurred, a set of key regulatory events leading to the viral multiplication was examined, including viral immediate-early (alpha) and late (gamma) gene expression and DNA replication. Results indicated that levels of glycoprotein B (gB) and gC mRNA expression in HeLa cells were impeded by yatein. Data from polymerase chain reaction showed that replication of HSV-1 DNA in HeLa cells was arrested by yatein. Furthermore, yatein decreased ICP0 and ICP4 gene expression in HeLa cells. Results of an electrophoretic mobility shift assay demonstrated that yatein interrupted the formation of alpha-trans-induction factor/C1/Oct-1/GARAT multiprotein complex. The mechanisms of antiviral action of yatein seem to be mediated, by inhibiting HSV-1 alpha gene expression, including expression of the ICP0 and ICP4 genes, and by arresting HSV-1 DNA synthesis and structural protein expression in HeLa cells. These results suggest that yatein is an antiviral agent against HSV-1 replication.

  • Novel diterpenes from the heartwood of Chamaecyparis obtusa var. formosana.
    Chemical & pharmaceutical bulletin, 2004
    Co-Authors: Yueh-hsiung Kuo, Chia‐hsien Chen, Shih-chang Chien, Hsiu-chuan Lin
    Abstract:

    Two novel diterpenes, obtusanal B (1) and obtusadione (2), along with obtusanal A (3), obtunone (4), 12-hydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial, 8,12-dihydroxydielmentha-5,9-diene-7,11-dione and myrcene, isolated from the heartwood of Chamaecyparis obtusa var. formosana, were characterized by spectroscopic means, including 2D-NMR techniques. Compounds 1 and 2 are 7(6→2)abeoabietane and 14(8→9)abeoabietane type diterpenes, respectively. Their biosyntheses were proposed.

  • New lignans from the heartwood of Chamaecyparis obtusa var. formosana.
    Chemical & pharmaceutical bulletin, 2002
    Co-Authors: Yueh-hsiung Kuo, Chia‐hsien Chen, Yun-lian Lin
    Abstract:

    Four new lignans, 3′,4′-O,O-demethylenehinokinin (1), chamalignolide (2), 8′β-hydroxyhinokinin (3) and 7β,8β-epoxyzuonin A (4), as well as (−)-hinokinin (5), and (−)-zuonin A (6), were isolated from the heartwood of Chamaecyparis obtusa var. formosana. The structures of these lignans were unambiguously determined by spectroscopic methods. And the absolute configuration of 1 was elucidated with a circular dichroism (CD) spectrum.

  • five new cadinane type sesquiterpenes from the heartwood of Chamaecyparis obtusa var formosana
    Journal of Natural Products, 2002
    Co-Authors: Yueh-hsiung Kuo, Chia-hsien Chen, Shih-chang Chien, Yun-lian Lin
    Abstract:

    Muurola-4,10(14)-dien-3-one (1), 10-O-acetyl-15-oxo-α-cadinol (2), 15-hydroxy-α-cadinol (3), 4α-hydroxy-5β-ethoxy-epi-cubenol (4), and 4α-hydroxy-5β-acetoxy-epi-cubenol (5), five new bicyclic sesquiterpenes, have been isolated from the heartwood of Chamaecyparis obtusa var. formosana along with the known compounds epi-cubenol, T-cadinol, T-muurolol, δ-cadinol, and α-cadinol. The structures of the new constituents were elucidated through chemical and spectral studies.

Akio Hagihara - One of the best experts on this subject based on the ideXlab platform.

  • temperature effect on maintenance and growth respiration coefficients of young field grown hinoki cypress Chamaecyparis obtusa
    Ecological Research, 1997
    Co-Authors: Stephen Adubredu, Taketo Yokota, Akio Hagihara
    Abstract:

    Respiration measurements were made on the entire aboveground parts of young, field-grown hinoki cypress (Chamaecyparis obtusa) trees at monthly intervals over a 5-year period, to examine the effect of temperature on maintenance and growth respiration coefficients. The respiration rate of the trees was grouped on a monthly basis and then partitioned into maintenance and growth components. The maintenance respiration coefficient increased exponentially with air temperature. The maintenance respiration coefficient at a temperature of 0°C and itsQ 10 value were 0.205 mmol CO2 g−1 d.w. month−1 and 1.81, respectively. The growth respiration coefficient, which was virtually independent of temperature, had a mean value of 38.06±1.95 (SE) mmol CO2g−1 d.w. The growth rate increased exponentially with increasing temperature up to a peak at around 18°C, and thereafter declined, thereby resulting in the growth respiration rate being increasingly less sensitive to increasing air temperature. The reported decreases in theQ 10 value of total respiration with increasing air temperature is due to the way in which the growth component of respiration responds to temperature.

  • maintenance and growth respiration of the aboveground parts of young field grown hinoki cypress Chamaecyparis obtusa
    Tree Physiology, 1995
    Co-Authors: Taketo Yokota, Akio Hagihara
    Abstract:

    : Aboveground respiration of five 8-year-old trees of field-grown hinoki cypress (Chamaecyparis obtusa (Sieb. et Zucc.) Endl.) was nondestructively measured at monthly intervals over 1 year with an enclosed standing tree method. The relationship between monthly specific respiration rate and monthly mean relative growth rate at the individual tree level was described by a linear equation. During the dormant season, respiration was used mainly for maintenance purposes, whereas during the growing season, more than 40% of the respiration was used for growth purposes, i.e., 60 to 70% in May. We conclude that annual maintenance and growth respiration of a tree are directly proportional to the aboveground phytomass and its annual increment, respectively. The maintenance coefficient was estimated to be 0.504 +/- 0.039 (SE) kg kg(-1) year(-1), indicating that the amount respired for maintaining already existing phytomass was equivalent to about half of the existing phytomass. The growth coefficient was estimated to be 0.772 +/- 0.043 (SE) kg kg(-1), indicating that the amount respired for constructing new phytomass was equivalent to about three-fourths of the annual phytomass increment. The annual stand maintenance and growth respiration were, respectively, 8.8 Mg ha(-1) year(-1) for an aboveground biomass of 17.4 Mg ha(-1) and 5.0 Mg ha(-1) year(-1) for an annual stand aboveground biomass increment of 6.5 Mg ha(-1) year(-1). About two-thirds of the total respiration was used to maintain already existing biomass, and about one-third was used to construct new biomass.

Hajime Utsugi - One of the best experts on this subject based on the ideXlab platform.

Ning-hua Tan - One of the best experts on this subject based on the ideXlab platform.

  • Sesquiterpenoids and Diterpenes from Chamaecyparis obtusa var. breviramea f. crippsii.
    ChemInform, 2014
    Co-Authors: Guang-zhi Zeng, Yi-mei Liu, Ke-li Chen, Zhang-hua Sun, Yu-mei Zhang, Ning-hua Tan
    Abstract:

    Four new sesquiterpenoids (I)-(III) are isolated from the branches and leaves of Chamaecyparis obtusa var.

  • sesquiterpenoids and diterpenes from Chamaecyparis obtusa var breviramea f crippsii
    Zeitschrift für Naturforschung B, 2014
    Co-Authors: Guang-zhi Zeng, Yi-mei Liu, Ke-li Chen, Zhang-hua Sun, Yu-mei Zhang, Ning-hua Tan
    Abstract:

    Four new sesquiterpenoids, 1 alpha-hydroxymethyl-3 beta-hydroxy-7,8-dihydro-ionol (1), 1 alpha-hydroxymethyl-3 beta-hydroxy-7,8-dihydro-ionol-9-O-beta-D-glucopyranoside (2), (1 alpha,5 beta,7 beta)-3,10(14)-guaiadien-11,12-diol (3), and (6S)-13-O-beta-D-glucopyranosyl-abscisic acid (4), together with 10 known sesquiterpenoids and 5 diterpenes were isolated from the branches and leaves of Chamaecyparis obtusa var. breviramea f. crippsii. Their structures were mainly determined on the basis of MS, IR, 1D and 2D NMR spectral evidence. Compound 13-epi-toruolsol (17) showed cytotoxicities against BGC-823 and Hela cancer cell lines with IC50 values of 23.0 and 49.9 mu M, and compound 3-epi-triptobenzene B (19) showed cytotoxicities against BGC-823, Hela and A549 cancer cell lines with IC50 values of 19.1, 30.3 and 24.5 mu M, respectively.

  • a new lignan glycoside from Chamaecyparis obtusa var breviramea f crippsii
    Natural Product Communications, 2014
    Co-Authors: Guang-zhi Zeng, Yi-mei Liu, Ke-li Chen, Zhang-hua Sun, Ning-hua Tan, Yu-mei Zhang
    Abstract:

    A new phenolic glycoside, 3-methoxyphenol 1-O-alpha-L-rhamnopyranosyl-(1 -> 6)-O-beta-D-glucopyranoside (1), was isolated from the 90% acetone extract of the branches and leaves of Chamaecyparis obtusa var. breviramea f. crippsii along with another 10 known phenolics 2-11. Their structures were determined mainly by means of MS, 1D- and 2D-NMR data. Cytotoxicities of compounds 3 and 5-11 were tested on BGC-823, Hela and A549 cancer cell lines, the results showed that compound 8 was bioactive and its IC50 values were 6.9, 29.7 and 52.9 mu M, respectively.

  • a new phenolic glycoside from Chamaecyparis obtusa var breviramea f crippsii
    Molecules, 2013
    Co-Authors: Yu-mei Zhang, Guang-zhi Zeng, Zhang-hua Sun, Lin Xiao, Ning-hua Tan
    Abstract:

    A new phenolic glycoside, 3-methoxyphenol 1-O-α-L-rhamnopyranosyl-(1→6)- O-β-D-glucopyranoside (1), was isolated from the 90% acetone extract of the branches and leaves of Chamaecyparis obtusa var. breviramea f. crippsii along with another 10 known phenolics 2–11. Their structures were determined mainly by means of MS, 1D- and 2D-NMR data. Cytotoxicities of compounds 3 and 5–11 were tested on BGC-823, Hela and A549 cancer cell lines, the results showed that compound 8 was bioactive and its IC50 values were 6.9, 29.7 and 52.9 μM, respectively.

  • Chamobtusin A, a novel skeleton diterpenoid alkaloid from Chamaecyparis obtusa cv. tetragon.
    Organic letters, 2007
    Co-Authors: Yu-mei Zhang, Ning-hua Tan, Ying Chang, Rui-rui Jia
    Abstract:

    The novel diterpenoid alkaloid chamobtusin A (1) was isolated from the branches and leaves of Chamaecyparis obtusa cv. tetragon. Its structure and relative stereochemistry were mainly determined by MS, 2D NMR, and X-ray methods. The methanol extracts, total alkaloids of C. obtusa cv. tetragon, and chamobtusin A were tested for their cytotoxicities against A549 and K562 human tumor cell lines.