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Dryas Integrifolia
''Dryas integrifolia'' is a species of flowering plant in the rose family known by the common names arctic avens,Louis-Marie, P. ND. Flore-Manuel de la Province de Québec, Canada (3e édition). Cooperative Harpell's Press, Gardenvale, PQ. entireleaf mountain-avens, white mountain-avens, northern white mountain avens,''Dryas integrifolia''. NatureServe. and mountain avens.Aiken, S.G., et al. 2007 NRC Research Press, National Research Council of Canada, Ottawa. It is native to northern parts of North America, where it occurs from across |
Martin Vahl
Martin Henrichsen Vahl (10 October 1749 – 24 December 1804) was a Danish-Norwegian botanist, herbalist and zoologist. Biography Martin Vahl was born in Bergen, Norway and attended Bergen Cathedral School. He studied botany at the University of Copenhagen and at Uppsala University under Carl Linnaeus. He edited ''Flora Danica'' fasc. XVI-XXI (1787–1799), ''Symbolæ Botanicæ'' I-III (1790–1794), ''Eclogæ Americanæ'' I-IV (1796–1807) and ''Enumeratio Plantarum'' I-II (1804–1805). He lectured at the University of Copenhagen Botanical Garden from 1779 to 1782. Vahl made several research trips in Europe and North Africa between 1783 and 1788. He became professor at the Society for Natural History at the University of Copenhagen in 1786 and was a full professor of botany from 1801 to his death. In 1792, he was elected a foreign member of the Royal Swedish Academy of Sciences. He died in Copenhagen, Denmark at age 55. His son Jens Vahl also became a botanist. Authorit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anther
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament and an anther which contains ''microsporangia''. Most commonly anthers are two-lobed and are attached to the filament either at the base or in the middle area of the anther. The sterile tissue between the lobes is called the connective, an extension of the filament containing conducting strands. It can be seen as an extension on the dorsal side of the anther. A pollen grain develops from a microspore in the microsporangium and contains the male gametophyte. The stamens in a flower are collectively called the androecium. The androecium can consist of as few as one-half stamen (i.e. a single locule) as in '' Canna'' species or as many as 3,482 stamens which have been counted in the saguaro (''Carnegiea gigantea''). The androecium in var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carex
''Carex'' is a vast genus of more than 2,000 species of grass-like plants in the family Cyperaceae, commonly known as sedges (or seg, in older books). Other members of the family Cyperaceae are also called sedges, however those of genus ''Carex'' may be called true sedges, and it is the most species-rich genus in the family. The study of ''Carex'' is known as caricology. Description All species of ''Carex'' are perennial, although some species, such as '' C. bebbii'' and '' C. viridula'' can fruit in their first year of growth, and may not survive longer. They typically have rhizomes, stolons or short rootstocks, but some species grow in tufts (caespitose). The culm – the flower-bearing stalk – is unbranched and usually erect. It is usually distinctly triangular in section. The leaves of ''Carex'' comprise a blade, which extends away from the stalk, and a sheath, which encloses part of the stalk. The blade is normally long and flat, but may be folded, inrolled, c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Community
A plant community is a collection or association of plant species within a designated geographical unit, which forms a relatively uniform patch, distinguishable from neighboring patches of different vegetation types. The components of each plant community are influenced by soil type, topography, climate and human disturbance. In many cases there are several soil types present within a given plant community. This is because the soil type within an area is influenced by two factors, the rate at which water infiltrates or exits (via evapotranspiration) the soil, as well as the rate at which organic matter (any carbon-based compound within the environment, such as decaying plant matter) enters or decays from the soil. Plant communities are studied substantially by ecologists, due to providing information on the effects of dispersal, tolerance to environmental conditions, and response to disturbance of a variety of plant species, information valuable to the comprehension of various plant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heath
A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a cooler and damper climate. Heaths are widespread worldwide but are fast disappearing and considered a rare habitat in Europe. They form extensive and highly diverse communities across Australia in humid and sub-humid areas where fire regimes with recurring burning are required for the maintenance of the heathlands.Specht, R.L. 'Heathlands' in 'Australian Vegetation' R.H. Groves ed. Cambridge University Press 1988 Even more diverse though less widespread heath communities occur in Southern Africa. Extensive heath communities can also be found in the Texas chaparral, New Caledonia, central Chile, and along the shores of the Mediterranean Sea. In addition to these extensive heath areas, the vegetation type is also found in scattered locations acro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dominance (ecology)
Ecological dominance is the degree to which one or several species have a major influence controlling the other species in their ecological community (because of their large size, population, productivity, or related factors) or make up more of the biomass. Most ecological communities are defined by their dominant species. *In many examples of wet woodland in western Europe, the dominant tree is alder ('' Alnus glutinosa''). *In temperate bogs, the dominant vegetation is usually species of ''Sphagnum'' moss. *Tidal swamps in the tropics are usually dominated by species of mangrove (''Rhizophoraceae'') *Some sea floor communities are dominated by brittle stars. *Exposed rocky shorelines are dominated by sessile organisms such as barnacles and limpets. See also * National Vegetation Classification, a system for classifying British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Sheet
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at Last Glacial Maximum, the Laurentide Ice Sheet covered much of North America, the Weichselian ice sheet covered Northern Europe and the Patagonian Ice Sheet covered southern South America. Ice sheets are bigger than ice shelves or alpine glaciers. Masses of ice covering less than 50,000 km2 are termed an ice cap. An ice cap will typically feed a series of glaciers around its periphery. Although the surface is cold, the base of an ice sheet is generally warmer due to geothermal heat. In places, melting occurs and the melt-water lubricates the ice sheet so that it flows more rapidly. This process produces fast-flowing channels in the ice sheet — these are ice streams. The present-day polar ice sheets are relatively young in geol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pioneer Species
Pioneer species are hardy species that are the first to colonize barren environments or previously biodiverse steady-state ecosystems that have been disrupted, such as by wildfire. Pioneer flora Some lichens grow on rocks without soil, so may be among the first of life forms, and break down the rocks into soil for plants.LICHEN BIOLOGY AND THE ENVIRONMENT, LICHENS OF NORTH AMERICA, Sylvia and Stephen Sharnoff/ref> Since some uninhabited land may have thin, poor quality soils with few nutrients, pioneer species are often hardy plants with adaptations such as long roots, root nodes containing Diazotroph, nitrogen-fixing bacteria, and leaves that employ transpiration. Note that they are often photosynthetic plants, as no other source of energy (such as other species) except light energy is often available in the early stages of succession, thus making it less likely for a pioneer species to be non-photosynthetic. The plants that are often pioneer species also tend to be wind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scree
Scree is a collection of broken rock fragments at the base of a cliff or other steep rocky mass that has accumulated through periodic rockfall. Landforms associated with these materials are often called talus deposits. Talus deposits typically have a concave upwards form, where the maximum inclination corresponds to the angle of repose of the mean debris particle size. The exact definition of scree in the primary literature is somewhat relaxed, and it often overlaps with both ''talus'' and ''colluvium''. The term ''scree'' comes from the Old Norse term for landslide, ''skriða'', while the term ''talus'' is a French word meaning a slope or embankment. In high-altitude arctic and subarctic regions, scree slopes and talus deposits are typically adjacent to hills and river valleys. These steep slopes usually originate from late-Pleistocene periglacial processes. Notable scree sites in Eastern North America include the Ice Caves at White Rocks National Recreation Area in southern Ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tundra
In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mountain tract". There are three regions and associated types of tundra: Arctic tundra, alpine tundra, and Antarctic tundra. Tundra vegetation is composed of dwarf shrubs, sedges, grasses, mosses, and lichens. Scattered trees grow in some tundra regions. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline. The tundra soil is rich in nitrogen and phosphorus. The soil also contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide in the permafrost, making the tundra soil a carbon sink. As global warming heats the ecosystem and causes soil thawing, the permafrost carbon cycle accelerates and releases much of these soil-contained g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycorrhiza
A mycorrhiza (from Greek μύκης ', "fungus", and ῥίζα ', "root"; pl. mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, its root system. Mycorrhizae play important roles in plant nutrition, soil biology, and soil chemistry. In a mycorrhizal association, the fungus colonizes the host plant's root tissues, either intracellularly as in arbuscular mycorrhizal fungi (AMF or AM), or extracellularly as in ectomycorrhizal fungi. The association is sometimes mutualistic. In particular species or in particular circumstances, mycorrhizae may have a parasitic association with host plants. Definition A mycorrhiza is a symbiotic association between a green plant and a fungus. The plant makes organic molecules such as sugars by photosynthesis and supplies them to the fungus, and the fungus supplies to the plant water and mineral nutrients, such as phosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hebeloma Cylindrosporum
''Hebeloma cylindrosporum'' is a species of mushroom-forming fungus in the family Hymenogastraceae. It was species description, described as new to science in 1965 by French mycologist Henri Romagnesi. See also *List of Hebeloma species, List of ''Hebeloma'' species References Hebeloma, cylindrosporum Fungi described in 1965 Fungi of Europe Fungus species {{Hymenogastraceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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