Deciduous forest in autumn
|
Deciduous forest in winter
|
Deciduous forest in spring
|
Deciduous means "falling off at maturity" or "tending to fall off" (deriving from the Latin word decidere, to fall off)[1] and is typically used in reference to trees or shrubs that lose their leaves seasonally and to the shedding of other plant structures such as petals after flowering or fruit when ripe. Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. In a more specific 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; in other fields the word has a similar meaning, including deciduous antlers in deer or deciduous teeth, also known as baby teeth, in some mammals, including human children. Antlers are the usually large and complex horn -like appendages of most Deer species mostly worn by males only for some species such as Caribou by both A deer is a Ruminant Mammal belonging to the family Cervidae. See also Deciduous. "Baby teeth" redirects here For the band of that name see Baby Teeth (band. [2]
Contents |
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. Botany, plant science(s, phytology, or plant biology is a branch of Biology and is the scientific study of plant Life Horticulture is the art and science of plant cultivation Horticulturists (or horticuluralists) work and conduct research in the fields of Plant propagation Plants are living Organisms belonging to the kingdom Plantae. A tree is a perennial Woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or A shrub or Bush is a horticultural rather than strictly botanical category of Woody plant, distinguished from a Tree A herbaceous plant (or in botanical use a Herb) is a Plant that has leaves and stems that die down at the end of In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis. This process is called abscission. Abscission (from Latin abscindere from ab- ‘off away’ + scindere ‘to cut’ is the shedding of a body part In some cases leaf loss coincides with winter - namely in temperate or polar climates. Regions with a polar climate are characterized by a lack of warm summers (specifically no month having an average temperature of 10 °C or higher While in other areas of the world, plants lose their leaves during the dry season or during other seasonal variations in rainfall, including tropical, subtropical and arid regions of the world. The dry season is a term commonly used when describing the weather in the Tropics. Rain is Liquid precipitation. On Earth it is the condensation of atmospheric Water vapor into drops heavy enough to fall often making it to
The converse of deciduous is evergreen, where green foliage is persistent year round. In Botany, an Evergreen plant is a plant having leaves all year round Plants that are intermediate may be called semi-deciduous, and lose old foliage as new growth begins, others are semi-evergreen[3] and lose their leaves before the next growing season but retain some during winter or during dry periods. Semi-deciduous is a botanical term which refers to Plants that lose their Foliage. [4] Some trees, including a few Oak species 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. The term oak can be used as part of the common name of any of about 400 species of Trees and Shrubs in the Genus Quercus (from Latin Marcescence is the retention of dead plant organs that normally are shed
Many deciduous plants flower during the period when they are leafless as this increases the effectiveness of pollination. Forsythia is of Flowering plants in the family Oleaceae (olive family A flower, also known as a bloom or Blossom, is the reproductive structure found in Flowering plants (plants of the division Magnoliophyta, also Pollination in angiosperms and Gymnosperms is the process that transfers pollen grains, which contain the male Gametes (sperm to where the female 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. In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis. Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described 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 the cold winter days. [5]
Leaf drop or abscission involves complex physiological signals and changes within plants. Abscission (from Latin abscindere from ab- ‘off away’ + scindere ‘to cut’ is the shedding of a body part The process of photosynthesis steadily degrades the supply of chlorophylls in foliage; plants normally replenish chlorophylls during the summer months. When days grow short and nights are cool, or when plants are drought stressed, deciduous trees decrease chlorophyll pigment production allowing other pigments present in the leaf to become apparent, resulting in fall color. These other pigments include carotenoids that are yellow, brown, and orange. Carotenoids are organic Pigments that are naturally occurring in Chromoplasts of plants and some other photosynthetic Organisms Anthocyanin pigments produce reds and purple colors, though they are not always present in the leaves but are produced in the foliage in late summer when sugars are trapped in the leaves after the process of abscission begins. Not to be confused with Anthocyanidin, their sugar free counterparts Parts of the world that have showy displays of bright fall 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 beginning of leaf drop starts when an abscission layer is formed between the leaf petiole and the stem. In Botany, the petiole is the small stalk attaching the Leaf blade to 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. Plant hormones (also known as phytohormones) are chemicals that regulate plant growth Auxins are a class of Plant growth substance (often called Phytohormone or Plant hormone) When the auxin coming from the leaf is produced at a rate consistent with that of the auxin from the body of the plant, the cells of the abscission layer remain connected; in the fall 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. Parenchyma is a term used to describe a bulk of a substance It is used in different ways in Animals and in Plants. In the spring these proteins are used as a nitrogen source during the growth of new leaves or flowers. [6]
Plants with deciduous foliage have both 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 more resources which evergreens do not need to expend. Evergreens suffer greater water lose 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. [7]
Deciduous woody plants
The deciduous characteristic has developed repeatedly among woody plants. Trees include Maple, many Oaks, Elm, Aspen, and Birch, among others, as well as a number of coniferous genera, such as Larch and Metasequoia. Acer ( maple) is a Genus of Trees or Shrubs They are variously classified in a family of their own the Aceraceae, or Elms are Deciduous and Semi-deciduous Trees comprising the genus Ulmus, family Ulmaceae, found Aspens are Trees of the willow family and comprise a section of the Poplar genus Populus sect Birch is the name of any Tree of the genus Betula ( Bé-tu-la) in the family Betulaceae, closely related to the A genus (plural genera from Γένος Latin genus "descent family type gender" is a low-level Taxonomic Larches are Conifers in the genus Larix, in the family Pinaceae. Metasequoia ( Dawn Redwood) is a fast growing Tree genus in the conifer family Cupressaceae of which Metasequoia glyptostroboides Deciduous shrubs include honeysuckle, poison oak, and many others. Most temperate woody vines are also deciduous, including grapes, poison ivy, virginia creeper, wisteria, etc. For the Tokyo University supercomputer see Gravity Pipe. GRAPE, or GRA phics P rogramming E nvironment is Virginia Creeper redirects here For the trail see Virginia Creeper Trail. Wisteria is a Genus of about ten species of woody climbing Vines native to the eastern United States and the East Asian states of China 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[8] , however there are no deciduous species among tree-like monocotyledonous plants, e. g. palms, yuccas, and dracenas.
Regions
Deciduous forests can be found in sections of: North America, South America, Europe, Asia, Australia, and Africa (Madagascar)(Bahamas). South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a For a topic outline on this subject see List of basic Australia topics. Madagascar, or Republic of Madagascar (older name Malagasy Republic) is an Island nation in the Indian Ocean off the southeastern The Bahamas, officially the Commonwealth of The Bahamas, is an independent sovereign English -speaking country consisting of two thousand Cays and Forests with a majority of tree species that lose their foliage at the end of the typical growing season are called deciduous forests. These forests have distinctive ecosystems, understory growth, and soil dynamics. [9]
Two distinctive types of deciduous forest are found growing around the world.
Temperate deciduous forest biomes are plant communities distributed in America, Asia and Europe. The Temperate deciduous forest is a Biome found in the eastern United States, Canada, central Mexico, southern South America, The have formed under climatic conditions which have great seasonable temperature variability with growth occurring during warm summers and leaf drop in fall 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. The tropical and subtropical dry broadleaf forest Biome, also known as tropical dry forest, is located at tropical and subtropical latitudes 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 none leaf trees. [10]
References
- ^ Online Etymology Dictionary. Retrieved on 2008-02-08. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 421 - Constantius III becomes co- Emperor of the Western Roman Empire.
- ^ Gause, John Taylor (1955). The complete word hunter, A Crowell reference book. New York: Crowell, p. 456.
- ^ http://www.ibiblio.org/openkey/intkey/web/glossary.pdf page 22.
- ^ 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 88 (21).
- ^ Srivastava, Lalit M. (2002). Plant growth and development. Hormones and environment. Amsterdam: Academic Press, p. 476. ISBN 0-12-660570-X.
- ^ 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. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ Cundall, Peter (2005). Flora: The Gardener’s Bible: Over 20,000 Plants. Ultimo, NSW, Australia: ABC Publishing. ISBN 073331094X.
- ^ Röhrig (ed. ), Ernst; Bernhard Ulrich (ed. ) (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): pp. 22–35.
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic