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Plant Communities
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] |
Association (ecology)
In phytosociology and community ecology an association is a type of ecological community with a predictable species composition and consistent physiognomy (structural appearance) which occurs in a particular habitat type. The term was first coined by Alexander von Humboldt and formalised by the International Botanical Congress in 1910. An association can be viewed as a real, integrated entity shaped either by species interactions or by similar habitat requirements, or it can be viewed as merely a common point along a continuum. The former view was championed by American ecologist Frederic Clements, who viewed the association as a whole that was more than the sum of its parts, and by Josias Braun-Blanquet, a Swiss-born phytosociologist. On the other end of the argument was American ecologist Henry Gleason, who saw these groupings of plant species as a coincidence produced by the "fluctuation and fortuitous immigration of plants, and an equally fluctuating and variable environment". ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Ornduff
Robert Ornduff (1932–2000) was an American botanist. He was Director of the University and Jepson Herbaria, Director of the University of California Botanical Garden, Executive Director of the Miller Institute for Basic Research in Science, and Chair of the (former) Department of Botany and Professor of Integrative Biology at the University of California at Berkeley. Botanist Phyllis M. Faber said of him following his death, "his extensive knowledge and love of the California flora remains unmatched." Robert Ornduff, Phyllis M. Faber, Todd Keeler-Wolf; 2003 revised ed.; Preface, p. x He was a specialist in the systematics of various plant groups in California, particularly the |
Pinus Hwangshanesis
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts 187 species names of pines as current, together with more synonyms. The American Conifer Society (ACS) and the Royal Horticultural Society accept 121 species. Pines are commonly found in the Northern Hemisphere. ''Pine'' may also refer to the lumber derived from pine trees; it is one of the more extensively used types of lumber. The pine family is the largest conifer family and there are currently 818 named cultivars (or trinomials) recognized by the ACS. Description Pine trees are evergreen, coniferous resinous trees (or, rarely, shrubs) growing tall, with the majority of species reaching tall. The smallest are Siberian dwarf pine and Potosi pinyon, and the tallest is an tall ponderosa pine located in southern Oregon's Rogue River-Si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygonum Aviculare
''Polygonum aviculare'' or common knotgrass is a plant related to buckwheat and dock. It is also called prostrate knotweed, birdweed, pigweed and lowgrass. It is an annual found in fields and wasteland, with white flowers from June to October. It is widespread across many countries in temperate regions, apparently native to Eurasia, naturalized in temperate parts of the Southern Hemisphere. Description Common knotgrass is an annual herb with a semi-erect stem that may grow from high. The leaves are hairless and short-stalked. They are longish-elliptical with short stalks and rounded bases; the upper ones are few and are linear and stalkless. The stipules are fused into a stem-enclosing, translucent sheath known as an ochrea that is membranous and silvery. The flowers are regular, green with white or pink margins. Each has five perianth segments, overlapping at the base, five to eight stamens and three fused carpels. The fruit is a dark brown, three-edged nut. The seeds need l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
