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Quadrat
A quadrat is a frame used in ecology, geography, and biology to isolate a standard unit of area for study of the distribution of an item over a large area. Quadrats typically occupy an area of 0.25 m2 and are traditionally square, but modern quadrats can be rectangular, circular, or irregular. A quadrat is suitable for sampling or observing plants, slow-moving animals, and some aquatic organisms. A photo-quadrat is a photographic record of the area framed by a quadrat. It may use a physical frame to indicate the area, or may rely on fixed camera distance and lens field of view to automatically cover the specified area of substrate. Parallel laser pointers mounted on the camera can also be used as scale indicators. The photo is taken perpendicular to the surface, or as close as possible to perpendicular for uneven surfaces. History The systematic use of quadrats was developed by the pioneering plant ecologists Roscoe Pound and Frederic Clements between 1898 and 1900. The method w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frederic Clements
Frederic Edward Clements (September 16, 1874 – July 26, 1945) was an American plant ecologist and pioneer in the study of both plant ecology and vegetation succession. Biography Born in Lincoln, Nebraska, he studied botany at the University of Nebraska, graduating in 1894 and obtaining a doctorate in 1898. One of his teachers was botanist Charles Bessey, who inspired Clements to research topics such as microscopy, plant physiology, and laboratory experimentation. He was also classmate of Willa Cather and Roscoe Pound. While at the University of Nebraska, he met Edith Gertrude Schwartz (1874–1971), also a botanist and ecologist, and they were married in 1899. In 1905 he was appointed full professor at the University of Nebraska, but left in 1907 to head the botany department at the University of Minnesota in Minneapolis. From 1917 to 1941 he was employed as an ecologist at the Carnegie Institution of Washington in Washington, D.C., where he was able to carry out dedicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat
In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ecological niche. Thus "habitat" is a species-specific term, fundamentally different from concepts such as Biophysical environment, environment or vegetation assemblages, for which the term "habitat-type" is more appropriate. The physical factors may include (for example): soil, moisture, range of temperature, and Luminous intensity, light intensity. Biotic index, Biotic factors include the availability of food and the presence or absence of Predation, predators. Every species has particular habitat requirements, habitat generalist species are able to thrive in a wide array of environmental conditions while habitat specialist species require a very limited set of factors to survive. The habitat of a species is not necessarily found in a ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecology Terminology
Ecology () is the natural science of the relationships among living organisms and their environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere levels. Ecology overlaps with the closely related sciences of biogeography, evolutionary biology, genetics, ethology, and natural history. Ecology is a branch of biology, and is the study of abundance, biomass, and distribution of organisms in the context of the environment. It encompasses life processes, interactions, and adaptations; movement of materials and energy through living communities; successional development of ecosystems; cooperation, competition, and predation within and between species; and patterns of biodiversity and its effect on ecosystem processes. Ecology has practical applications in fields such as conservation biology, wetland management, natural resource management, and human ecology. The word ''ecology'' () was coined in 1866 by the German scientist Ern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stand Level Modelling
A forest stand is a contiguous Plant community, community of trees sufficiently uniform in composition, structure, Forest inventory#Timber metrics, age, size, class, distribution, spatial arrangement, condition, or location on a Site quality (forestry), site of uniform quality to distinguish it from adjacent communities. A forest is a "collection of stands" also utilizing the practices of forestry. Stand level modelling is a type of modelling in the forest sciences in which the main unit is a forested stand. Stand description A forest stand is commonly described as in 10ths or 10%s. Thus a ratio could be given of: 3 Ponderosa pines, 2 mangrove trees, 5 silver spruces. If there was a mixed stand that stand mix could be described as mixed up to 10%, mixed 10–40% and a mixed stand over that amount. The form of mixing of the tree types is commonly given as: * individuals – when there are a few unconnected trees of a type. * troop – up to 5 trees connected of one type. * grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Differential GPS
Differential Global Positioning Systems (DGPSs) supplement and enhance the positional data available from global navigation satellite systems (GNSSs). A DGPS can increase accuracy of positional data by about a thousandfold, from approximately to . DGPSs consist of networks of fixed position, ground-based reference stations. Each reference station calculates the difference between its highly accurate known position and its less accurate satellite-derived position. The stations broadcast this data locally—typically using ground-based transmitters of shorter range. Non-fixed (mobile) receivers use it to correct their position by the same amount, thereby improving their accuracy. The United States Coast Guard (USCG) previously ran DGPS in the United States on longwave radio frequencies between and near major waterways and harbors. It was discontinued in March 2022. The USCG's DGPS was known as NDGPS (Nationwide DGPS) and was jointly administered by the Coast Guard and the United ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodolite
A theodolite () is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building and infrastructure construction, and some specialized applications such as meteorology and rocket launching. It consists of a moveable telescope mounted so it can rotate around horizontal and vertical axes and provide angular readouts. These indicate the orientation of the telescope, and are used to relate the first point sighted through the telescope to subsequent sightings of other points from the same theodolite position. These angles can be measured with accuracies down to microradians or seconds of arc. From these readings a plan can be drawn, or objects can be positioned in accordance with an existing plan. The modern theodolite has evolved into what is known as a total station where angles and distances are measured electronicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Total Station
A total station or total station theodolite is an electronic/optical instrument used for surveying and building construction. It is an electronic transit theodolite integrated with electronic distance measurement (EDM) to measure both vertical and horizontal angles and the slope distance from the instrument to a particular point, and an on-board computer to collect data and perform triangulation calculations. Robotic or motorized total stations allow the operator to control the instrument from a distance via remote control. In theory, this eliminates the need for an assistant staff member, as the operator holds the retroreflector and controls the total station from the observed point. In practice, however, an assistant surveyor is often needed when the surveying is being conducted in busy areas such as on a public carriageway or construction site. This is to prevent people from disrupting the total station as they walk past, which would necessitate resetting the tripod and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Botanist And Students Examining The Species Distribution Using Quadrat
Botany, also called plant science, is the branch of natural science and biology studying plants, especially their anatomy, taxonomy, and ecology. A botanist or plant scientist is a scientist who specialises in this field. "Plant" and "botany" may be defined more narrowly to include only land plants and their study, which is also known as phytology. Phytologists or botanists (in the strict sense) study approximately 410,000 species of land plants, including some 391,000 species of vascular plants (of which approximately 369,000 are flowering plants) and approximately 20,000 bryophytes. Botany originated as prehistoric herbalism to identify and later cultivate plants that were edible, poisonous, and medicinal, making it one of the first endeavours of human investigation. Medieval physic gardens, often attached to monasteries, contained plants possibly having medicinal benefit. They were forerunners of the first botanical gardens attached to universities, founded from the 1540s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selection Bias
Selection bias is the bias introduced by the selection of individuals, groups, or data for analysis in such a way that proper randomization is not achieved, thereby failing to ensure that the sample obtained is representative of the population intended to be analyzed. It is sometimes referred to as the selection effect. The phrase "selection bias" most often refers to the distortion of a statistical analysis, resulting from the method of collecting samples. If the selection bias is not taken into account, then some conclusions of the study may be false. Types of bias Sampling bias Sampling bias is systematic error due to a non-random sample of a population, causing some members of the population to be less likely to be included than others, resulting in a biased sample, defined as a statistical sample of a statistical population, population (or non-human factors) in which all participants are not equally balanced or objectively represented. It is mostly classified as a subtype of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur Tansley
Sir Arthur George Tansley FLS, FRS (15 August 1871 – 25 November 1955) was an English botanist and a pioneer in the science of ecology. Educated at Highgate School, University College London and Trinity College, Cambridge, Tansley taught at these universities and at Oxford, where he served as Sherardian Professor of Botany until his retirement in 1937. Tansley founded the ''New Phytologist'' in 1902 and served as its editor until 1931. He was a pioneer of the science of ecology in Britain, being heavily influenced by the work of Danish botanist Eugenius Warming, and introduced the concept of the ecosystem into biology. Tansley was a founding member of the first professional society of ecologists, the Central Committee for the Survey and Study of British Vegetation, which later organised the British Ecological Society, and served as its first president and founding editor of the '' Journal of Ecology''. Tansley also served as the first chairman of the British Nature Conse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Ernst Weaver
John Ernst Weaver ( 5 May 1884 – 8 June 1966) was an American botanist, prairie ecologist, and university professor. Biography Weaver was born in Villisca, Iowa. He obtained a PhD in Biology and Botany at the University of Minnesota, 1916. He was "Instructor of Botany" at Washington State College from 1912 to 1913. In 1915 he became "Assistant professor of Botany" at the University of Nebraska where he was a plant ecology professor from 1917 until his retirement in 1952. Weaver published many works regarding vegetation and ecology of prairies. According to his biography in ''Nebraska Authors'': In 1929 Weaver and Henry Chandler Cowles published the first American ecology textbook. According to his obituary at the Ecological Society of America, which he served as both vice president and president (1924–1925 and 1930 respectively): He was also a member of the Botanical Society of America, and the Nebraska Academy of Sciences. Books *Study of ''Amygdalus persica''. Unpublish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
