関: defoliation、leaf abscission

WordNet

the loss of foliage
causing the leaves of trees and other plants to fall off (as by the use of chemicals)
yield to temptation or sin; "Adam and Eve fell"
the season when the leaves fall from the trees; "in the fall of 1973" (同)autumn
come as if by falling; "Night fell"; "Silence fell" (同)descend, settle
be born, used chiefly of lambs; "The lambs fell in the afternoon"
begin vigorously; "The prisoners fell to work right away"
go as if by falling; "Grief fell from our hearts"
occur at a specified time or place; "Christmas falls on a Monday this year"; "The accent falls on the first syllable"
pass suddenly and passively into a state of body or mind; "fall into a trap"; "She fell ill"; "They fell out of favor"; "Fall in love"; "fall asleep"; "fall prey to an imposter"; "fall into a strange way of thinking"; "she fell to pieces after she lost her work"
a lapse into sin; a loss of innocence or of chastity; "a fall from virtue"
a sudden decline in strength or number or importance; "the fall of the House of Hapsburg" (同)downfall
when a wrestlers shoulders are forced to the mat (同)pin
a movement downward; "the rise and fall of the tides"
come under, be classified or included; "fall into a category"; "This comes under a new heading" (同)come
lose an upright position suddenly; "The vase fell over and the water spilled onto the table"; "Her hair fell across her forehead" (同)fall down
fall to somebody by assignment or lot; "The task fell to me"; "It fell to me to notify the parents of the victims" (同)light
be inherited by; "The estate fell to my sister"; "The land returned to the family"; "The estate devolved to an heir that everybody had assumed to be dead" (同)return, pass, devolve
touch or seem as if touching visually or audibly; "Light fell on her face"; "The sun shone on the fields"; "The light struck the golden necklace"; "A strange sound struck my ears" (同)shine, strike
assume a disappointed or sad expression; "Her face fell when she heard that she would be laid off"; "his crest fell"
be captured; "The cities fell to the enemy"
be cast down; "his eyes fell"
be due; "payments fall on the 1st of the month"
come out; issue; "silly phrases fell from her mouth"
descend in free fall under the influence of gravity; "The branch fell from the tree"; "The unfortunate hiker fell into a crevasse"
die, as in battle or in a hunt; "Many soldiers fell at Verdun"; "Several deer have fallen to the same gun"; "The shooting victim fell dead"
drop oneself to a lower or less erect position; "She fell back in her chair"; "He fell to his knees"
lose office or power; "The government fell overnight"; "The Qing Dynasty fell with Sun Yat-sen"
lose ones chastity; "a fallen woman"
move in a specified direction; "The line of men fall forward"
slope downward; "The hills around here fall towards the ocean"
suffer defeat, failure, or ruin; "We must stand or fall"; "fall by the wayside"
to be given by assignment or distribution; "The most difficult task fell on the youngest member of the team"; "The onus fell on us"; "The pressure to succeed fell on the youngest student"
to be given by right or inheritance; "The estate fell to the oldest daughter"
turn over pages; "leaf through a book"; "leaf a manuscript"
the main organ of photosynthesis and transpiration in higher plants (同)leafage, foliage
produce leaves, of plants
hinged or detachable flat section (as of a table or door)
a sheet of any written or printed material (especially in a manuscript or book) (同)folio
having leaves or leaves as specified; often used in combination; "a fully leafed tree"; "broad-leafed"; "four-leaved clover" (同)leaved
decreasing in amount or degree; "falling temperature"
becoming lower or less in degree or value; "a falling market"; "falling incomes"
the syllable naming the fourth (subdominant) note of the diatonic scale in solmization

PrepTutorEJDIC

落葉
《しばしば副詞[句]を伴って》『落下する』,落ちる / 〈人・物が〉『倒れる』《+『down』(『over』)》 / 傷ついて倒れる,倒れて死ぬ / (…まで)垂れ下がる,〈道などが〉下降する《+『to』+『名』》 / 〈目・顔などが〉下を向く,うつむく,沈む / 〈暗やみ・静けさなどが〉(…に)たれ込める;〈災害・責任・病気・眠けなどが〉(…に)降りかかる《+『on』(『upon, over』)+『名』》 / 〈程度・数量・値段などが〉(…まで)『下がる』,減少する《+『to』+『名』》 / 誘惑に負ける,墜落する / (勢力・威信・人望などを)失う《+『from』(『in』)+『名』》 / 〈政権などが〉倒れる,〈要塞などが〉陥落する;(…の手に)落ちる《+『to』+『名』》 / 『なる』,陥る / 〈時・事が〉(…に)当たる,起こる,(しかるべき位置に)来る《+『on』(『upon』)+『名』》 / 〈光線・視線などが〉(…に)向けられる《+『on』(『upon』)+『名』 / (…に)分かれる《+『into』+『名』》 / 〈言葉などが〉(…から)漏れる《+『from』》 / 〈C〉(…から)『落ちること』,落下《+『from』+『名』》;(…への)落下《+『to』(『toward』)+『名』》 / 〈C〉(雨・雪などの)降った量《+『of』+『名』》 / 《複数形で》《固有名詞としては単数扱い》滝 / 〈C〉(…から…までの)落差《+『from』+『名』+『to』+『名』》 / 〈C〉倒れること,転倒 / 〈C〉(程度・数量・値段などの)下落,減少,衰退《+『in』+『名』》 / 《単数形で》(…の)陥落,崩壊《+『of』+『名』》 / 〈U〉堕落 / 〈C〉傾斜
『秋』(autumn)
〈C〉(木・草の)『葉』 / 〈C〉花びら / 〈C〉(本などのページの裏表)『1枚』 / 〈U〉(金属の)薄片,箔(はく) / 〈C〉(折りたたみ式テーブルの)補助板 / 《おもに米》〈木が〉葉を出す《+『out』》 / (本などの)ページをばらばらとめくる,内容にざっと目を通す》+『through』+『名』》
=leaved
ファ(全音階の第4音)

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/03/09 09:46:54」(JST)

wiki en

[Wiki en表示]

Second-growth deciduous forest, Pennsylvania, United States

Deciduous forest in autumn, Germany

Deciduous forest in winter, Denmark

Deciduous means "falling off at maturity"^[1] or "tending to fall off",^[2] and it is typically used in order to refer to trees or shrubs that lose their leaves seasonally (most commonly during autumn) and to the shedding of other plant structures such as petals after flowering or fruit when ripe. In a more general sense, deciduous means "the dropping of a part that is no longer needed" or "falling away after its purpose is finished". In plants it is the result of natural processes. "Deciduous" has a similar meaning when referring to animal parts, such as deciduous antlers in deer,^[3] deciduous teeth, also known as baby teeth, in some mammals (including humans); or decidua, the uterine lining that sheds off after birth.

Botany

In botany and horticulture, deciduous plants, including trees, shrubs and herbaceous perennials, are those that lose all of their leaves for part of the year.^[4] This process is called abscission.^[5] In some cases leaf loss coincides with winter—namely in temperate or polar climates.^[6] In other parts of the world, including tropical, subtropical, and arid regions, plants lose their leaves during the dry season or other seasons, depending on variations in rainfall.

The converse of deciduous is coniferous, where foliage is shed on a different schedule from deciduous trees, therefore appearing to remain green year round.^[7] Plants that are intermediate may be called semi-deciduous; they lose old foliage as new growth begins.^[8] Other plants are semi-evergreen and lose their leaves before the next growing season, retaining some during winter or dry periods.^[9] Some trees, including a few species of oak, have desiccated leaves that remain on the tree through winter; these dry persistent leaves are called marcescent leaves and are dropped in the spring as new growth begins.

Like a number of other deciduous plants, Forsythia flowers during the leafless season

Many deciduous plants flower during the period when they are leafless, as this increases the effectiveness of pollination. The absence of leaves improves wind transmission of pollen for wind-pollinated plants and increases the visibility of the flowers to insects in insect-pollinated plants. This strategy is not without risks, as the flowers can be damaged by frost or, in dry season regions, result in water stress on the plant. Nevertheless, there is much less branch and trunk breakage from glaze ice storms when leafless, and plants can reduce water loss due to the reduction in availability of liquid water during cold winter days.^[10]

Leaf drop or abscission involves complex physiological signals and changes within plants. The process of photosynthesis steadily degrades the supply of chlorophylls in foliage; plants normally replenish chlorophylls during the summer months. When autumn arrives and the days are shorter or when plants are drought-stressed,^[11] deciduous trees decrease chlorophyll pigment production, allowing other pigments present in the leaf to become apparent, resulting in non-green colored foliage. The brightest leaf colors are produced when days grow short and nights are cool, but remain above freezing.^[12] These other pigments include carotenoids that are yellow, brown, and orange. Anthocyanin pigments produce red and purple colors, though they are not always present in the leaves. Rather, they are produced in the foliage in late summer, when sugars are trapped in the leaves after the process of abscission begins. Parts of the world that have showy displays of bright autumn colors are limited to locations where days become short and nights are cool. In other parts of the world, the leaves of deciduous trees simply fall off without turning the bright colors produced from the accumulation of anthocyanin pigments.

The beginnings of leaf drop starts when an abscission layer is formed between the leaf petiole and the stem. This layer is formed in the spring during active new growth of the leaf; it consists of layers of cells that can separate from each other. The cells are sensitive to a plant hormone called auxin that is produced by the leaf and other parts of the plant. When auxin coming from the leaf is produced at a rate consistent with that from the body of the plant, the cells of the abscission layer remain connected; in autumn, or when under stress, the auxin flow from the leaf decreases or stops, triggering cellular elongation within the abscission layer. The elongation of these cells break the connection between the different cell layers, allowing the leaf to break away from the plant. It also forms a layer that seals the break, so the plant does not lose sap.

A number of deciduous plants remove nitrogen and carbon from the foliage before they are shed and store them in the form of proteins in the vacuoles of parenchyma cells in the roots and the inner bark. In the spring, these proteins are used as a nitrogen source during the growth of new leaves or flowers.^[13]

Function

Deciduous plants in mid- to high latitudes shed their leaves as temperatures drop in autumn.^[14]

Plants with deciduous foliage have advantages and disadvantages compared to plants with evergreen foliage. Since deciduous plants lose their leaves to conserve water or to better survive winter weather conditions, they must regrow new foliage during the next suitable growing season; this uses resources which evergreens do not need to expend. Evergreens suffer greater water loss during the winter and they also can experience greater predation pressure, especially when small. Losing leaves in winter may reduce damage from insects; repairing leaves and keeping them functional may be more costly than just losing and regrowing them.^[15] Removing leaves also reduces cavitation which can damage xylem vessels in plants. This then allows deciduous plants to have xylem vessels with larger diameters and therefore a greater rate of transpiration (and hence CO₂ uptake as this occurs when stomata are open) during the summer growth period.

Deciduous woody plants

The deciduous characteristic has developed repeatedly among woody plants. Trees include maple, many oaks and nothofagus, elm, aspen,and birch, among others, as well as a number of coniferous genera, such as larch and Metasequoia. Deciduous shrubs include honeysuckle, viburnum, and many others. Most temperate woody vines are also deciduous, including grapes, poison ivy, Virginia creeper, wisteria, etc. The characteristic is useful in plant identification; for instance in parts of Southern California and the American Southeast, deciduous and evergreen oak species may grow side by side.

Periods of leaf fall often coincide with seasons: winter in the case of cool-climate plants or the dry-season in the case of tropical plants,^[16] however there are no deciduous species among tree-like monocotyledonous plants, e.g. palms, yuccas, and dracaenas.

Regions

Forests where a majority of the trees lose their foliage at the end of the typical growing season are called deciduous forests. These forests are found in many areas worldwide and have distinctive ecosystems, understory growth, and soil dynamics.^[17]

Two distinctive types of deciduous forest are found growing around the world.

Temperate deciduous forest biomes are plant communities distributed in North and South America, Asia, Southern slopes of the Himalayas, Europe and for cultivation purposes in Oceania. They have formed under climatic conditions which have great seasonable temperature variability with growth occurring during warm summers and leaf drop in autumn and dormancy during cold winters. These seasonally distinctive communities have diverse life forms that are impacted greatly by the seasonality of their climate, mainly temperature and precipitation rates. These varying and regionally different ecological conditions produce distinctive forest plant communities in different regions.

Tropical and subtropical deciduous forest biomes have developed in response not to seasonal temperature variations but to seasonal rainfall patterns. During prolonged dry periods the foliage is dropped to conserve water and prevent death from drought. Leaf drop is not seasonally dependent as it is in temperate climates, and can occur any time of year and varies by region of the world. Even within a small local area there can be variations in the timing and duration of leaf drop; different sides of the same mountain and areas that have high water tables or areas along streams and rivers can produce a patchwork of leafy and leafless trees.^[18]

Lesser celandine (Ranunculus ficaria) dominates deciduous woodland in early spring.
Dry-season deciduous tropical forest
Mixed deciduous forest in spring, Texas, United States

References

^ William Dwight Whitney; Century Dictionary. The Century Dictionary and Cyclopedia: Dictionary. books.google.com. p. 1484.
^ Debra J. Housel; Capstone Publishers (2009). Ecosystems. books.google.com. ISBN 9780756540685.
^ Gause, John Taylor (1955). The complete word hunter. A Crowell reference book. New York: Crowell. p. 465.
^ University of the Western Cape. "Trees that lose their leaves". botany.uwc.ac.za. Archived from the original on 25 March 2013.
^ Dr. Kim D. Coder; University of Georgia (1999). "Falling Tree Leaves: Leaf Abscission" (PDF). forestry.uga.edu. Archived from the original (PDF) on 18 May 2013.
^ Science Daily. "Science Reference: Deciduous". sciencedaily.com.
^ J. Robert Nuss; Pennsylvania State University (2007). "Evergreen Shrubs and Trees for Pennsylvania" (PDF). psu.edu.
^ "The Illinois - North Carolina Collaborative Environment for Botanical Resources: Openkey Project. Glossary of Botanical Terms. Page 22." (PDF). Retrieved 2013-07-17.
^ Weber, William. 2001. African rain forest ecology and conservation an interdisciplinary perspective. New Haven: Yale University Press. page 15.
^ Lemon, P. C. (1961). "Forest ecology of ice storms". Bulletin of the Torrey Botanical Club. Bulletin of the Torrey Botanical Club, Vol. 88, No. 1. 88 (21): 21. doi:10.2307/2482410. JSTOR 2482410.
^ Mohammad Pessarakli (2005). Handbook of photosynthesis. CRC Press. pp. 725–. ISBN 978-0-8247-5839-4. Retrieved 9 October 2010.
^ Donald W. Linzey (1 April 2008). A natural history guide to Great Smoky Mountains National Park. Univ. of Tennessee Press. pp. 27–. ISBN 978-1-57233-612-4. Retrieved 9 October 2010.
^ Srivastava, Lalit M. (2002). Plant growth and development. Hormones and environment. Amsterdam: Academic Press. p. 476. ISBN 0-12-660570-X.
^ Bonan, Gordon (2015). Ecological Climatology: Concepts and Applications. Cambridge University Press. p. 294. ISBN 9781316425190.
^ Labandeira, C. C.; Dilcher, D. L.; Davis, D. R.; Wagner, D. L. (1994). "Ninety-seven million years of angiosperm-insect association: paleobiological insights into the meaning of coevolution". Proceedings of the National Academy of Sciences of the United States of America. 91 (25): 12278–12282. Bibcode:1994PNAS...9112278L. doi:10.1073/pnas.91.25.12278. PMC 45420. PMID 11607501.
^ Cundall, Peter (2005). Flora: The Gardener’s Bible: Over 20,000 Plants. Ultimo, NSW, Australia: ABC Publishing. ISBN 0-7333-1094-X.
^ Röhrig, Ernst; Ulrich, Bernhard, eds. (1991). Temperate deciduous forests. Ecosystems of the world, 7. Amsterdam: Elsevier. ISBN 0-444-88599-4.
^ Bullock, Stephen H.; J. Arturo Solis-Magallanes (March 1990). "Phenology of Canopy Trees of a Tropical Deciduous Forest in Mexico". Biotropica. 22 (1): 22–35. doi:10.2307/2388716. JSTOR 2388716.

External links

The dictionary definition of deciduous at Wiktionary
Media related to Deciduous forests at Wikimedia Commons

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 小児における転落の防止 prevention of falls in children
2. 転倒：一般社会で生活する高齢者における防止 falls prevention in community dwelling older persons
3. 高齢者における転倒：危険因子および患者評価 falls in older persons risk factors and patient evaluation
4. 高齢者における高度後弯症の概要 overview of hyperkyphosis in older persons
5. 転倒：介護施設および病院内での予防 falls prevention in nursing care facilities and the hospital setting

English Journal

Characterization of a cassiicolin-encoding gene from Corynespora cassiicola, pathogen of rubber tree (Hevea brasiliensis).

Déon M, Bourré Y, Gimenez S, Berger A, Bieysse D, de Lamotte F, Poncet J, Roussel V, Bonnot F, Oliver G, Franchel J, Seguin M, Leroy T, Roeckel-Drevet P, Pujade-Renaud V.SourceCIRAD, UMR AGAP, F-63000 Clermont-Ferrand, France.
Plant science : an international journal of experimental plant biology.Plant Sci.2012 Apr;185-186:227-37. Epub 2011 Oct 25.
Corynespora Leaf Fall (CLF) is a major disease of rubber tree (Hevea brasiliensis) caused by the Ascomycota Corynespora cassiicola. Here we describe the cloning and characterization of a gene encoding cassiicolin (Cas), a glycosylated cystein-rich small secreted protein (SSP) identified as a potenti
PMID 22325885

Tree litter and forest understorey vegetation: a conceptual framework to understand the effects of tree litter on a perennial geophyte, Anemone nemorosa.

Baltzinger M, Archaux F, Dumas Y.SourceIrstea, Les Barres, 45290 Nogent sur Vernisson, France.
Annals of botany.Ann Bot.2012 Mar 14. [Epub ahead of print]
Background and AimsLitter is a key factor in structuring plant populations, through positive or negative interactions. The litter layer forms a mechanical barrier that is often strongly selective against individuals lacking hypocotyle plasticity. Litter composition also interacts with plant growth b
PMID 22419760

Japanese Journal

The Improvement of Sleep by Oral Intake of GABA and Apocynum venetum Leaf Extract

, , , , ,
Journal of Nutritional Science and Vitaminology 61(2), 182-187, 2015
… The effects of two food materials, γ-aminobutyric acid (GABA) produced by natural fermentation and Apocynum venetum leaf extract (AVLE), on the improvement of sleep were investigated in humans. … These results mean that GABA can help people to fall asleep quickly, AVLE induces deep sleep, and they function complementarily with simultaneous intake. …
NAID 130005074118

アカマツ林と落葉広葉樹林における林冠から林地への放射性セシウムの移行

岡田直紀,中井渉,大橋伸太 [他],田中厚志
日本森林学会誌 97(1), 57-62, 2015
森林に降下した放射性セシウムの林冠から林地への移行の動態と，森林の違いがこれに及ぼす影響を明らかにする目的で，東京電力福島第一原子力発電所事故後の2012年10月から2013年12月まで，福島県内のアカマツ林と落葉広葉樹林においてリターフォールと降水に含まれる137Csの観測を行った。林冠から林地への137Csの移行には季節性があり，優占樹種の落葉期，降雨の多い時期にそれぞれリターフォールと林内雨 …
NAID 130005063858