担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：International Society for Horticultural Science (ISHS)  

DOI： 10.17660/actahortic.2018.1222.19

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Informa UK Limited  

DOI： 10.1080/13416979.2017.1320207

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担当区分：筆頭著者   記述言語：英語   出版者・発行元：日本沙漠学会  

<p>Juniperus sabina L. is an evergreen shrub with prostrate life form that may effectively stabilize sand dunes and moving sand. Therefore, it serves as an important woody species for revegetation in semiarid areas of China. The main root system of J. sabina can reach deep into soil while adventitious roots mostly extend into surface soil. To evaluate water movement between different soil-layers these root systems that is associated with rainfall-induced vertical heterogeneity in soil moisture, we measured changes in sap flow and soil moisture content as well as atmospheric temperature and humidity. The patch radius of twenty-four patches was also measured for 7 years to monitor changes in growth rate. Nighttime sap flow between the main root system and adventitious roots during periods of no rainfall was measured; nighttime sap flow decreased or disappeared after rainfall. The annual growth rate of the patch radius was significantly correlated with the annual deposition rate of sand and the amount of annual precipitation. It was suggested that water movement occurs from the deeper moist soil layer to dry surface soil layer via the main root system and adventitious roots by hydraulic redistribution (HR). This movement increased with the progression of drought in the surface soil layer after a rain event. J. sabina can effectively use both subsoil water during periods of drought and rainwater in surface soil layer after an occasional rain event through the HR. This allows the plant to survive and continuously grow under water-limited conditions and in a mobile sand environment in semiarid areas.</p>

DOI： 10.14976/jals.26.3_95

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer-Verlag Tokyo  

Unfortunately, the variable ab has changed globally as b in Table 2 and published incorrectly in the original publication of the article.The corrected Table 2 should read as given in this Erratum. The original article has also been updated.

DOI： 10.1007/s11355-016-0299-1

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER JAPAN KK  

Maintenance of water transport is very important for plant growth and survival. We studied seven woody species that inhabit the semi-arid Mu Us Sandy Land, China, to understand their strategies for maintaining hydraulic function. We evaluated water transport properties, including cavitation resistance, hydraulic recovery, and water loss regulation by stomatal control, which are associated with xylem structural and leaf physiological traits. We also discussed the water-use characteristics of these species by comparing them with those of species in other regions. Species with tracheids had higher levels of xylem resistance to cavitation and a smaller midday transpiration rate than the other species studied. Although species with vessels were less resistant to cavitation, some recovered hydraulic conductivity within 12 h of rehydration. Species with xylem tracheids could maintain their hydraulic function through resistance to cavitation and by relaxing xylem tension. Although species with vessels had less resistant xylem, they could maintain hydraulic function through hydraulic recovery even when xylem dysfunction occurred. Additionally, the species studied here were less resistant to cavitation than species in semi-arid environments, and equally or less resistant than species in humid environments. Rather than allow hydraulic dysfunction due to drought-induced dehydration, they may develop water absorption systems to avoid or recover quickly from hydraulic dysfunction. Thus, not only stem cavitation resistance to drought but also stem-root coordination should be considered when selecting plants for the revegetation of arid regions.

DOI： 10.1007/s11355-015-0290-2

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

It was recently reported that cutting artefacts occur in some species when branches under tension are cut, even underwater. We used non-destructive magnetic resonance imaging (MRI) to investigate the change in xylem water distribution at the cellular level in Vitis coignetiae standing stems before and after relaxing tension. Less than 3% of vessels were cavitated when stems under tension were cut under water at a position shorter than the maximum vessel length (MVL) from the MRI point, in three of four plants. The vessel contents remained at their original status, and cutting artefact vessel cavitation declined to &lt;1% when stems were cut at a position farther than the MVL from the MRI point. Water infiltration into the originally cavitated vessels after cutting the stem, i. e. vessel refilling, was found in &lt;1% of vessels independent of cutting position on three of nine plants. The results indicate that both vessel cavitation and refilling occur in xylem tissue under tension following stem cutting, but its frequency is quite small, and artefacts can be minimized altogether if the distance between the monitoring position and the cutting point is longer than the MVL.

DOI： 10.1111/pce.12617

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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.

DOI： 10.1111/pce.12510

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

Sustainable stomatal opening despite xylem cavitation occurs in ring-porous species and stomatal closure prior to cavitation in diffuse-porous species during soil drought.
To elucidate the relationship between water loss regulation and vulnerability to cavitation associated with xylem structure, stomatal conductance (g (s)), defoliation, vulnerability curves, and vessel features were measured on seedlings of ring-porous Zelkova serrata and Melia azedarach, and diffuse-porous Betula platyphylla var. japonica, Cerasus jamasakura and Carpinus tschonoskii. Under prolonged drought conditions, the percentage loss of hydraulic conductivity (PLC) increased and g (s) decreased gradually with decreasing predawn (I-pd) or xylem water potential (I-xylem) in Z. serrata. During the gentle increase of PLC in M. azedarach, g (s) increased in the early stages of dehydration while leaves were partly shed. A sharp reduction in g (s) was observed before the onset of an increase in the PLC for drying plants of the three diffuse-porous species, suggesting cavitation avoidance by stomatal regulation. In the ring-porous species, xylem-specific hydraulic conductivity (K (s)) was higher, whereas the vessel multiple fractions, the ratio of the number of grouped vessels to total vessels, was lower than that in the diffuse-porous species, suggesting that many were distributed as solitary vessels. This may explain the gradual increase in the PLC with decreasing I-xylem because isolated vessels provide less opportunity for air seeding. Different water loss regulation to soil drought was identified among the species, with potential mechanisms being sustainable gas exchange at the expense of xylem dysfunction or partial leaf shedding, and the avoidance of xylem cavitation by strict stomatal regulation. These were linked to vulnerability to cavitation that appears to be governed by xylem structural properties.

DOI： 10.1007/s00468-013-0963-0

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：OXFORD UNIV PRESS  

Woody species hydraulically vulnerable to xylem cavitation may experience daily xylem embolism. How such species cope with the possibility of accumulated embolism is unclear. In this study, we examined seven temperate woody species to assess the hypothesis that low cavitation resistance (high vulnerability to cavitation) is compensated by high recovery performance via vessel refilling. We also evaluated leaf functional and xylem structural traits. The xylem recovery index (XRI), defined as the ratio of xylem hydraulic conductivity in plants rewatered after soil drought to that in plants under moist conditions, varied among species. The xylem water potential causing 50% loss of hydraulic conductivity (Psi(50)) varied among the species studied, whereas only a slight difference was detected with respect to midday xylem water potential (Psi(min)), indicating smaller hydraulic safety margins (Psi(min) - Psi(50)) for species more vulnerable to cavitation. Cavitation resistance (vertical bar Psi(50)vertical bar) was negatively correlated with XRI across species, with cavitation-vulnerable species showing a higher performance in xylem recovery. Wood density was positively correlated with cavitation resistance and was negatively correlated with XRI. These novel results reveal that coordination exists between cavitation resistance and xylem recovery performance, in association with wood functional traits such as denser wood for cavitation-resistant xylem and less-dense but water-storable wood for refillable xylem. These findings provide insights into long-term maintenance of water transport in tree species growing under variable environmental conditions.

DOI： 10.1093/treephys/tpt010

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：OXFORD UNIV PRESS  

Xylem cavitation and its recovery were studied in 1-year-old stems of ring-porous Quercus serrata Thunb. and diffuse-porous Betula platyphylla var. japonica Hara. The Q. serrata had 5-100 mu m vessel diameter in the functional current xylem and 5-75 mu m in nonconducting 1-year-old xylem; B. platyphylla had a narrower range of vessel diameters of 5-55 mu m and more than double the number of vessels in both functional growth rings. Although hydraulic conductivity of Q. serrata appeared to decrease after release of moderate water stress of a half loss of native hydraulic conductivity-about -2 MPa in xylem water potential-no significant recovery of hydraulic conductivity was observed, probably because of intraspecific variation in vessel diameter distribution, which induced variable vulnerability to cavitation. Furthermore, in terms of xylem anatomy, larger and more efficient vessels of the current xylem did not show obvious refilling. In B. platyphylla, after release of water stress, rapid (1 h) recoveries of both hydraulic conductivity and water potential were apparent after rewatering: so-called &apos;novel refilling&apos;. During that time, a high degree of vessel refilling was observed in both xylems. At 12 h after rewatering, embolized vessels of the current xylem had refilled completely, although about 20% of vessels were still embolized in 1-year-old xylem. This different pattern of vessel refilling in relation to xylem age for B. platyphylla might be attributable to structural faults in the 1-year-old xylem, such as pit degradation or perhaps xylem aging itself. Results show that Q. serrata performs water conduction using highly efficient large vessels instead of unclear vessel refilling. In contrast, B. platyphylla transports water via less efficient but numerous vessels. If cavitation occurs, B. platyphylla improves water conduction by increasing the degree of vessel refilling.

DOI： 10.1093/treephys/tpq011

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY  

Juniperus sabinaL. is an evergreen coniferous shrub, with a widespread distribution in Asia and Europe. It is one of the key species for restoration of the ecosystem in desertification areas. In the present study, we isolated and characterized eight microsatellite loci of this species. The number of alleles per locus ranged from two to 27, with observed heterozygosity values ranging from 0.256 to 0.744 and expected heterozygosity from 0.276 to 0.939. The markers developed in this study could be useful for population genetics studies of J. sabina.

DOI： 10.1111/1442-1984.12152

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

© 2015, Springer-Verlag Berlin Heidelberg. Key message: Freezing with liquid nitrogen promotes the expansion of air in water columns of water-stressed, intact trees that are not transpiring. Abstract: In analyses of the distribution of water-filled and embolized conduits, xylem sap is frozen with liquid nitrogen and visualized using cryo-scanning electron microscopy (cryo-SEM). However, artifacts may be introduced during preparation of samples for these analyses. If the xylem is frozen intact, conduits may embolize during freezing when xylem water potential (Ψxylem) is substantially negative, whereas rehydration to release negative pressure may induce artifactual refilling. To evaluate these sampling phenomena during dehydration and rehydration, we monitored dynamic changes in xylem functional status in the stem of Dendropanax trifidus by compact magnetic resonance imaging (CMRI). We also visualized the water distribution in xylem (under low Ψxylem and with no transpiration) after freezing D. trifidus and Carpinus tschonoskii stems with liquid nitrogen. Artifactual refilling of embolized conduits was sometimes observed in D. trifidus samples cut underwater prior to freezing; however, the extent of refilling may have no influence on hydraulic measurements. Living cells in all samples were dramatically restored after rehydration by cutting underwater. In the current-year xylem, intact saplings of C. tschonoskii frozen with liquid nitrogen after dehydration had a greater number of embolized vessels than samples cut underwater. When a low Ψxylem (≤−2.5 MPa) was maintained, artifactual embolisms were rarely observed in samples directly frozen after rehydration. Thus, relaxation of negative Ψxylem and rehydration are important factors for consideration when assessing the distribution of embolized conduits by cryo-SEM.

DOI： 10.1007/s00468-015-1302-4

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

中国内蒙古自治区の毛烏素沙地において，緑化植物である落葉半灌木 Artemisia ordosica Krasch.の群落構造に，同じ固定砂丘上に分布する匍匐性針葉樹 Juniperus sabina L.と土壌表層の環境条件が与える影響について調査を行った。固定砂丘上の群落に調査区を設置し，株密度，株位置，株サイズ，結実状況を調査し，表層土壌の環境条件を測定した。その結果，両種は排他的な分布をしており，土壌表層の養分量が多く J. sabina と近い場所では群落の株密度と合計樹冠投影面積は小さい傾向があった。したがって，固定砂丘上では土壌表層の養分条件の差異よりも，J. sabina との資源を巡る競合が A. ordosica 群落に影響する可能性が示唆された。

DOI： 10.7211/jjsrt.41.56

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：METEOROLOGICAL SOC JAPAN  

A parameter set expressing the potential response used to simulate evapotranspiration was inferred from pooled data of leaf-level stomatal conductance in the Far East. We used Jarvis-type parameterization, which consists of restriction terms of light, air dryness, temperature, and soil water. Two parameter sets, pooled common (PC) and within-site (WS) sets, were determined using stomatal conductance data of eight species at nine sites. Seasonal changes of energy and water fluxes observed at four tower sites are well reproduced by a land surface model, despite using a different set of parameters. The results suggest that energy and water fluxes can be simulated using only one common parameter set with no parameter tuning, at least for forests in a wide region of the Far East.
We discuss why similar fluxes were simulated using PC and WS parameters despite the clear differences between these two parameter sets. Sensitivity experiments showed that the effects of maximum stomatal conductance and soil water content mutually cancel each other in Yakutsk and that an optimum temperature effect was added.

DOI： 10.2151/jmsj.2013-303

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

Arbuscular mycorrhizal fungi (AMF) have been observed in deep soil layers in arid lands. However, change in AMF community structure with soil depth and vertical distributions of the other root-associated microorganisms are unclear. Here, we examined colonization by AMF and dark septate fungi (DSF), as well as the community structure of AMF and endophytic fungi (EF) and endophytic bacteria (EB) in association with soil depth in a semiarid desert with shallow groundwater. Roots of Sabina vulgaris and soils were collected from surface to groundwater level at 20-cm intervals. Soil chemistry (water content, total N, and available P) and colonization of AMF and DSF were measured. Community structures of AMF, EF, and EB were examined by terminal restriction fragment length polymorphism analysis. AMF colonization decreased with soil depth, although it was mostly higher than 50%. Number of AMF phylotypes decreased with soil depth, but more than five phylotypes were observed at depths up to 100 cm. Number of AMF phylotypes had a significant and positive relationship with soil moisture level within 0-15% of soil water content. DSF colonization was high but limited to soil surface. Number of phylotypes of EF and EB were diverse even in deep soil layers, and the community composition was associated with the colonization and community composition of AMF. This study indicates that AMF species richness in roots decreases but is maintained in deep soil layers in semiarid regions, and change in AMF colonization and community structure associates with community structure of the other root-associated microorganisms.

DOI： 10.1007/s00572-011-0417-8

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER JAPAN KK  

The present paper shows simulated results of seasonal and inter-annual variations in energy and carbon exchanges and forest dynamics in a sub-boreal deciduous forest using a fully coupled atmosphere-vegetation interaction model [multilayered integrated numerical model of surface physics-growing plants interaction (MINoSGI)]. With careful adjustment of site-specific eco-physiological parameters, MINoSGI reproduced successfully stand biomass-tree density relationship based on the forest inventory data for 7 years (1999-2005) and seasonal and inter-annual variations in energy and CO2 fluxes measured by means of eddy covariance technique for 3 years (2003-2005) in the sub-boreal forest, northern Japan. In addition, MINoSGI estimated annual evapotranspiration (E (vt)) at 328.6 +/- A 25.8 mm year(-1), net primary production (NPP) at 372.1 +/- A 31.5 gC m(-2) year(-1) and net ecosystem exchange (NEE) at -224.2 +/- A 32.2 gC m(-2) year(-1). We found the estimate of annual NEE in our site lies among the estimates at other forest stands with the almost same climatic conditions in northern Japan, although the tree species and stand age of these forests are different from those of our site. Overall, MINoSGI was found useful to present simultaneous simulations of forest dynamics, surface energy, and carbon exchanges of a forest stand in the future from micro-meteorological and ecophysiological points of view.

DOI： 10.1007/s11284-010-0763-6

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

中国内モンゴル自治区毛烏素沙地において，A. squarrosum の分布を調査し，地下水面からの比高と形態，現存量を比較した。A. squarrosum は，地下水面からの比高として108 cm から532 cm の間で生育した。500 cm を超えるプロットでは，ほぼ優占種となリ，地下水面からの比高が大きく植物への水分供給が難しく他の樹種が生育しにくい環境で群落を形成した。主根長の到達状況から地下水を利用している可能性はなく，乾砂層下の水分，結露水を利用していた。A. squarrosum の形状T/R 比は，地下部の長さから1.00 以下となり，現存量T/R 比は地上部の現存量の大きさから1.00 以上となった。A. squarrosum の現存量は，根元直径との関係で表せた。

DOI： 10.7211/jjsrt.35.39

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.7211/jjsrt.34.636

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

ケネザサを異なる光条件で地下茎から生育させ,稈数と葉数の季節変化,褐変度,および葉の形態を調べた。稈の発生と生残では,分げつ稈を含めれば明るい処理区のほうが,稈の発生期間が長く,積算発生数が多い傾向があった。稈の枯死数は,1%区で特に多かった。明るい処理区ほど伸長終了時期の稈の生残数が多い傾向がみられた。稈の伸長成長では,明るい処理区ほど伸長速度が遅く,伸長終了後の稈の長さが短い傾向があった。したがって,明るい環境では稈の数を増やし水平方向に広がるように,暗い環境では稈のサイズを大きくして垂直方向に伸びるように成長し,それぞれ異なる侵入と優占の仕方で群落を発達させると考えられる。葉群動態では,明るい処理区ほど葉が早く褐変し,落葉が早かった。明るい処理区では,葉の寿命は短いが,稈の発生期間が長いために,葉の展葉期間が長いことによって葉群を維持し,暗い処理区では,葉の展葉期間は短いが,葉の寿命が長いことによって葉群を維持することが示唆された。葉の形態からは,明るい処理区ほど葉面積が小さく厚い陽葉的な葉をつけると考えられた。

DOI： 10.7211/jjsrt.34.524

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00337240629?from=CiNii

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.7211/jjsrt.35.51

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1007/s11355-008-0050-7

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その他リンク： http://link.springer.com/article/10.1007/s11355-008-0050-7/fulltext.html

記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

中国内モンゴル自治区毛烏素沙地において，家畜が喫食しないことから過放牧地に比較的大きな群落がみられる牛心朴子の分布と地下水面からの比高との関係を調査した。その結果，広域踏査調査において，牛心朴子は地下水面からの比高として68 cm から314 cm のプロットで出現していた。丘間低地から砂丘上部にかけて行ったトランセクト調査では，地下水面からの比高が140 cm のわずかに地形が変化する砂丘下部において現存量がもっとも多かった。また，砂丘下部では，他の出現種は少なかった。牛心朴子は，砂の堆積に対して茎を伸ばすことにより適応し，地下水を利用しながら生育しているものと考えられた。過放牧により他の植物による被覆が減り，喫食されずに残る本種は，飛砂を抑える砂丘固定植物として利用可能であることが示唆された。

DOI： 10.7211/jjsrt.34.33

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：岡山大学大学院環境生命科学研究科  

&nbsp;&nbsp;We compared effects of different growing water potential conditions on physiological and morphological water&ndash;use properties of Sabina vulgaris Ant., which is an evergreen shrub that is widely distributed in arid and semi-arid environments of the Mu Us Sandy Land, China. Measurements were taken of cuttings grown for eight years under -0.02 MPa (control), -0.10 MPa (moderate water stress), and -0.34 MPa (severe water stress) water potential conditions. The transpiration rate (T_r) under moderate stress was significantly lower than that under severe stress and control water conditions (49% and 45% lower, respectively, than severe stress and the control on average). The leaf-specific hydraulic conductivity (LSC) in shrubs growing under moderate water stress was also significantly lower than for those under the severe water potential condition. In contrast, S. vulgaris growing under severe water stress had less leaf biomass than under moderate stress or control conditions. These results suggest that S. vulgaris growing under moderate water stress tends to show a reduced transpiration rate derived from its low LSC; therefore it avoids water loss in response to chronic water stress, while plants growing under severe water stress tends to reduce water loss through decreased leaf biomass. These results suggest that S. vulgaris has a high capacity for acclimation to different water potential conditions through physiological and morphological flexibility.

DOI： 10.3107/jesss.2.27

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

放棄され拡大しつつあるハチク(Phyllostachys nigra var. henonis)林を対象として,竹林の林内,落葉広葉樹林と接し拡大しつつある竹林の林縁,およびその中間部分に区分し,稈の空間分布を比較検討した。空間分布解析のために, L関数を用い,距離にともなうL関数の変化を検討した。同じコホートの稈で,タケノコから当年生稈,当年生稈から5年生の古い稈へと生育段階が進む過程で,空間分布の変化を検討したところ,竹林の林内では,タケノコと当年生稈で集中分布, 5年生稈ではランダム分布し,林縁や中間部分では,タケノコの段階から5年生の稈まで常にランダム分布を示した。したがって,竹林の林内では,タケノコが稈となって以降に密度依存的な枯死が生じ,拡大しつつある部分では,タケノコの段階からランダムに分布して密度依存的な枯死を避けているものと考えられた。

DOI： 10.7211/jjsrt.33.65

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00299736628?from=CiNii

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

拡大しつつあるハチク林の動態を明らかにするため,落葉広葉樹二次林に隣接するハチク林で稈のセンサス調査を12年間継続した。落葉広葉樹二次林と接する部分では,稈の葉群が林冠木の樹冠より高い場合や樹冠と接する場合があり,ハチク林の拡大を可能としていると考えられる。ハチク林では,落葉広葉樹二次林へ稈を侵入させることによって,林分の稈密度と地上部バイオマスが増加し,最前線の稈の位置は落葉広葉樹二次林の方向へ12年間で7m距離を伸ばした。侵入している稈のサイズは,竹林内部の稈のサイズと異なっていなかった。一方,ハチク林拡大の過程で,ハチクによる被圧のため下層木の枯死が著しかった。

DOI： 10.7211/jjsrt.32.15

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00284128155?from=CiNii

記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

中国寧夏回族自治区銀川市の毛烏素沙地に造成され、その後15年間放置されてきた約50haの防風防砂林を対象として、樹木の生育状態を毎木調査と伐倒調査によって調べた。新彊楊は、植栽当初から激しい個体間競争によって間引きが起こり、生存個体数は植栽時の6割程度まで減少した。しかし、残存個体は多くの資源を獲得することができ、現在も旺盛な成長を持続し、樹高は現在の12mよりさらに高くなる傾向を示した。一方、合作楊、河北楊は15年間枯死がほとんど起こらず、共倒れ型の林分を形成し、どの個体の成長も悪く、多くの枯れ枝を持って、樹高は上限(7〜10m)に達していた。新彊楊が優占するプロットの土壌含水率は、合作楊、河北楊が優占するプロットよりも低かった。これは新彊楊は葉量が多く、水消費量が多いためと考えられた。

DOI： 10.7211/jjsrt.32.137

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00284128377?from=CiNii

記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

オマーン国の海岸線に成立する7つのヒルギダマシ林において, 地域集団の遺伝的変異について明らかにするために, RAPD法によりDNA多型解析を行った。その結果, 北中部と南部の集団間で遺伝的距離が遠いことが明らかとなった。そのようなヒルギダマシの植林を行う上で, 地域間での苗や種子の移動には配慮が必要であることが示唆された。遺伝的多様性と林分面積の間には正の相関があり, 林分面積が大きな集団ほど遺伝的多様性が高くなることが示唆された。ヒルギダマシ林の遺伝的多様性を保全するためには大きな林分面積を維持する必要がある。

DOI： 10.7211/jjsrt.31.92

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00256140826?from=CiNii

記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

光条件を相対照度100%,10%,5%,1%の4段階に設定し試験区を設け,ケネザサ(Pleioblastus pubescens Nakai)の地下茎を植栽した。稈発生後,稈の長さと直径,葉数,葉の長径と短径と厚さ,最大光合成速度,光合成の日変化,および掘り取りによる各器官の乾重を測定した。稈の成長では,明るい処理区でサイズが小さい稈を多く発生し,暗い処理区ではサイズが大きい稈を少なく発生した。個葉の形態では,100%区で,葉が厚く比葉面積が小さかった。最大光合成速度では処理区間で有意差がなかった。日光合成量は,100%区で最も大きく,1%区で最も小さかった。5%区および10%区ではその中間であった。現存量を比較すると,100%区では植栽した地下茎より大きな現存量に達し,新しい地下茎をつくっていた。5%区および10%区では植栽した地下茎とほぼ同様な現存量であり,1%区では現存量が減少していた。

DOI： 10.7211/jjsrt.30.175

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00242821470?from=CiNii

記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

土壌水分条件をpF1.8(対照区)とpF4.2(乾燥区)の2段階に設定したポットに植栽した臭柏とカイヅカイブキの苗木の蒸散速度と気孔コンダクタンスおよび根,茎,葉の水ポテンシャルを測定した。また,切り枝により気孔蒸散速度,クチクラ蒸散速度を求めた。臭柏は水ストレスを受けると気孔コンダクタンスを低下させ,葉の含水率が高いうちに素早く気孔を閉鎖した。また,地上部の高い水ポテンシャル勾配によって吸水力を確保した。一方,土壌水分が十分にある場合,気孔を開いて盛んに蒸散を行っていた。カイヅカイブキは水ストレスを受けるとクチクラ蒸散速度も気孔蒸散速度も低くし,高い含水率で気孔閉塞が起こった。また,地上部の水ポテンシャルの勾配は処理区間でほとんど差がなかった。しかし,地下部の水ポテンシャル勾配は乾燥区で大きく低下した。

DOI： 10.7211/jjsrt.30.98

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00242821340?from=CiNii

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

生育立地の違いがアカマツ(Pinus densiflora Sieb. et Zucc.)樹体の水利用調節に与える影響を明らかにするために,土壌水分が変動する際の葉,枝,および幹の諸機能について調べた。その結果,乾性な条件下で生育する斜面上部の個体は土壌の乾燥に対して,主に枝部の通水抵抗を調節して気孔を閉じ気味に保つことが示唆された。また,その際に枝および幹部の貯留水の利用が,通水抵抗の高さにより生じる一時的な水欠差を斜面下部の個体よりも相対的に高く補償していると考えられた。一方,相対的に湿潤な斜面下部に生育する個体は,常に気孔を開いており,土壌の乾燥に関わらず,活発に蒸散活動を行うことが示唆された。

DOI： 10.7211/jjsrt.30.104

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00242821357?from=CiNii

記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

マダケの葉量の季節変化,葉の形態,光合成速度に関する測定を行った。マダケの落葉と展葉は,4月から5月にかけて同時に起こった。齢の若い稈で多くの葉量を保ち,齢の古い稈では,少ない葉量を維持した。稈の齢が古くなるにつれて,古い葉を高い割合で残す傾向がみられ,葉替わりは緩やかになり葉の寿命が長くなると考えられる。葉の形態では,1年生の稈で最も大きく厚い葉をつけ,その後稈の齢の増加に伴い,より小さく薄い葉に変わっていた。光合成速度は,稈の齢が若いほど高かった。したがって,マダケでは稈の齢の違いによって,葉の寿命,あるいは葉の入れ替わりの早さと光合成速度の間には負の関係がみられ,トレードオフの関係のあることが示唆された。

DOI： 10.7211/jjsrt.30.181

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00242821487?from=CiNii

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.7211/jjsrt.30.110

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

In pine forests damaged by pine wilt disease, in western Japan, the effect of protection regimes of pine trees on the stand dynamics were examined in the following four stands: (1) lightly damaged stand (age 30-40 years) with no procedure in operation for protecting pine trees
(2) severely damaged stand (age 30-40 years) with no procedure in place for protecting pine trees
(3) severely damaged stand (age 50 years) with a selective cutting of infected trees
(4) severely damaged stand (age 30-40 years) with a selective cutting of infected trees. All the stands had been abandoned before the pine wilt disease damage. The understory structure of the severely damaged stand with no protection procedure was similar to that of the lightly damaged stand. Frequent invasion by tree species and acceleration in the growth of understory trees occurred after the dieback in the selective cutting stand. These results suggest that a deficiency in the canopy layer caused by the dieback resulted in low disturbance intensity in the early stages after the die-back, but the selective cutting increased the intensity by the reduction in the understory as well as the canopy layer. The intensity of the disturbance in the selective cutting stands was larger in the younger stand because it had a higher density of selectively cut pine trees. The different stand structure of pine forests occurred after the dieback because the intensity of the disturbance varied as a result of the selective cutting operation and the stand age.

DOI： 10.1007/s10310-003-0044-0

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

To elucidate the differences in the leaf water relations of Pinus densiflora Sieb, et Zucc. growing in different soil moisture conditions, we examined the pressure-volume curve and the diurnal changes in the stomatal conductance, the transpiration rate, and the leaf water potential. The leaf water relations were compared using field-grown 40-year-old pine trees growing on the upper and lower parts of a slope. We also compared the leaf water relations of potted 4-year-old saplings growing at pF 4.2 and pF 1.8 soil moisture levels for almost 1 year. The values of the ratio of symplasmic water at turgor loss point to symplasmic water at saturated point (V p/Vo) and bulk modulus of elasticity (ε) of both the adult trees on the upper part of the slope and the potted saplings growing on pF 4.2 soil moisture were higher than those values of both the adult trees on the lower part of the slope and the potted saplings growing on pF 1.8 soil moisture, respectively. The field-grown adult tree and the potted saplings growing under long-term water stress tended to reduce their stomatal conductance in response to the acute soil drying. It is suggested that P. densiflora growing under long-term water stress rapidly closed its stomata in response to soil drying and avoided losing water, and could also rapidly absorb water with reducing water loss because of the decrease in the leaf pressure potential derived from the high ε values.

DOI： 10.1007/s10310-002-0021-z

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担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

アラビア半島南部のオマーン湾沿岸に分布するヒルギダマシ(Avicennia marina (Forssk.) Vierh.)林において,林分構造の調査を行った。その結果,海に通じた水路沿いに発達したShinasのヒルギダマシ林では最大樹高は約6m,平均樹冠投影面積は1.21m^2であった。林床には多数の実生が生育していた。一方,水路が海とつながっておらず,陸封された状態にあるQuriyatでは,最大樹高は4.5m,平均樹冠投影面積は2.26m^2で,実生は全く見られなかった。両調査地ともに25m^2の大きさのコンパクトなコロニーがランダムに分布する空間分布の特性を示した。特に,実生が多数発生しているShinasではコロニー構造が顕著であった。

DOI： 10.7211/jjsrt.29.125

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00231954233?from=CiNii

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本緑化工学会  

生育土壌の水分条件が異なるアカマツ(Pinus densiflora Sieb.et Zucc.)苗木の生理特性の違いを明らかにすることを目的として,pF1.8とpF4,2の土壌水分条件下で育てたアカマツ苗木の気孔コンダクタンス,蒸散速度および純光合成速度の日変化を測定した。その結果,pF4.2処理区の個体は,水ストレスに対して気孔を閉鎖して失水を抑える日変化を示した。しかし,純光合成速度は一日中pF1.8処理区と同程度の値を維持していた。気孔開度が等しいときの純光合成速度を比較しても,pF4.2処理区の個体の方が有意に高かった。このことから,慢性的に水ストレスを受けて生育したpF4,2処理区の個体は,pF1.8処理区の個体よりも少ない水分消費で高い光合成活性を維持できる水分低消費型であることが示唆された。

DOI： 10.7211/jjsrt.28.103

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00158618645?from=CiNii

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

We examined the relationship between the incidence of pine wilt disease and moisture conditions in the stand level of Pinus densiflora Sieb. et Zucc. forests in the warm-temperate zone of the western part of Japan. For this analysis, pine trees killed by pine wilt disease were distinguished from the suppressed trees by their position in the layer of the pine forest stand. The drainage area, which is small in the upper part and large in the lower part of the slope, was adopted for representing the moisture conditions in the soil of the slope. The percentage of the pine trees killed by pine wilt disease increased as the size of the drainage area increased. This result suggested that the incidence of pine wilt disease tended to be high in areas with moist conditions. Pine trees attacked by the pinewood nematode die from extensive water deficit due to tracheid cavitations. Pine wilt disease mainly emerges in the summer when the soil water conditions become especially severe, and the radical water stress is thought to accelerate the disease. It was assumed that pine trees in the plots with the small drainage area resisted the influence of the attack of the pinewood nematode because pine trees in the plots with the small drainage area encountered long-term water stress and acquired drought tolerance. Pine trees in the plots with the large drainage area were presumed to be well established in the moist conditions and not to have acquired drought tolerance. The drought tolerance of pine trees was thought to be an important factor in resistance to pine wilt disease.

DOI： 10.1007/BF02767090

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記述言語：日本語   出版者・発行元：北海道大学低温科学研究所 = Institute of Low Temperature Science, Hokkaido University  

光合成活動に影響を与える要因の一つである葉の蒸散特性の評価法として，ガスチャンバー（同化箱）法による解析と重量法による解析がある．これらの解析は蒸散に関する種特性を評価する上で有効である．Gas chamber methods and gravimetric methods of dehydration from leaves can provide evaluation of transpiration properties, which are the factors affecting photosynthesis. These analyses would be suitable to evaluate inter-specific differences in transpiration properties in plant species.光合成研究法. 北海道大学低温科学研究所, 日本光合成研究会共編

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その他リンク： http://hdl.handle.net/2115/39111

担当区分：筆頭著者   記述言語：日本語   掲載種別：記事・総説・解説・論説等（その他）  

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