"Quadrat A quadrat is a frame, traditionally square, used in ecology and geography to isolate a standard unit of area for study of the distribution of an item over a large area. Modern quadrats can for example be rectangular, circular, or irregular. The quadrat is suitable for sampling plants, slow-moving animals, and some aquatic organisms. The systematic use of quadrats was developed by the pioneering plant ecologists R. Pound and F. E. Clements between 1898 and 1900. The method was then swiftly applied for many purposes in ecology, such as the study of plant succession. Botanists and ecologists such as"
"might not give a sample that was representative of the whole field. It would be an unrepresentative, or biased, sample. One way one can sample randomly is to place the quadrats at coordinates on a numbered grid. Long-term studies may require that the same quadrats be revisited months or even years after initial sampling. Methods of relocating the precise area of study vary widely in accuracy, and include measurement from nearby permanent markers, use of total station theodolites, consumer-grade GPS, and differential GPS. Quadrat A quadrat is a frame, traditionally square, used in ecology and geography to isolate a standard"
"D vs q in ecology is the characterization of the abundance distribution of species. Traditionally the relative species abundances is calculated for an area without taking into account the positions of the individuals. An equivalent representation of relative species abundances are species ranks, used to generate a surface called the species-rank surface, which can be analyzed using generalized dimensions to detect different ecological mechanisms like the ones observed in neutral theory of biodiversity, metacommunity dynamics or niche theory. Multifractal spectra can be determined from box counting on digital images. First, a box counting scan is done to determine how the"
"square meters. This allows for more intensive, delimited studies of changes and inventories of biota. Transects are straight lines at which, at intervals, measurements are taken for a profile of the ecological community. Land lab A land lab is an area of land that has been set aside for use in biological studies. Thus, it is literally an outdoor laboratory based on an area of land. Studies may be elementary or advanced. For instance, students may simply be given the task of identifying all the tree species in a land lab, or an advanced student may be doing an intensive"
"Digital orthophoto quadrangle A digital orthophoto quadrangle (DOQ) is aerial photography or satellite imagery that has been corrected so that its pixels are aligned with longitude and latitude lines, and have a narrowly defined region of coverage. This is a widely used format introduced by United States Geological Survey (USGS). The correction technique is called image rectification and is a large part of photogrammetry. DOQs produced by the USGS cover an area measuring 7.5-minutes longitude by 7.5-minutes latitude (the same area covered by a USGS 1:24,000-scale topographic map, also known as a 7.5-minute quadrangle) or 3.75-minutes by 3.75-minutes. The second"
"by Carl Troll, Isaak S. Zonneveld, Zev Naveh, Richard T. T. Forman/Michel Godron and others that landscapes are arenas in which humans interact with their environments on a kilometre-wide scale; instead, he defines 'landscape'—regardless of scale—as ""the template on which spatial patterns influence ecological processes"". Some define 'landscape' as an area containing two or more ecosystems in close proximity. A main concept in landscape ecology is ""scale"". Scale represents the real world as translated onto a map, relating distance on a map image and the corresponding distance on earth. Scale is also the spatial or temporal measure of an object"
"Q-analysis Q-analysis is a mathematical framework to describe and analyze set systems, or equivalently simplicial complexes. This idea was first introduced by Ronald Atkin in the early 1970s. Atkin was a British mathematician teaching at the University of Essex. Crediting the inspiration of his idea to Clifford Dowker’s paper (Homology Groups of Relations, Annals of Mathematics, 1952), he became interested in the algebra of relations in social structures. He tried to explain his idea in both mathematical and also accessible forms to both technical and general audience. His main ideas are reflected in ""The Mathematical Structure of Human Affairs"" (1974)."
"influence the population structure and gene flow of plant and animal populations across space and time and on how the quality of intervening landscape, known as ""matrix,"" influences spatial variation. After the term was coined in 2003, the field of landscape genetics had expanded to over 655 studies by 2010, and continues to grow today. As genetic data has become more readily accessible, it is increasingly being used by ecologists to answer novel evolutionary and ecological questions, many with regard to how landscapes effect evolutionary processes, especially in human-modified landscapes, which are experiencing biodiversity loss. Landscape ecology Landscape ecology is"
"area (particularly with varying latitude), or those that are """"equal area"""", that have cell sizes that are constant in distance on the ground (e.g. 100 km, 10 km) but not in degrees of longitude, in particular. A commonly used triangular grid is the ""Quaternary Triangular Mesh"" (QTM), which was developed by Geoffrey Dutton in the early 1980s. It eventually resulted in a thesis entitled ""A Hierarchical Coordinate System for Geoprocessing and Cartography"" that was published in 1999. This grid was also employed as the basis of the rotatable globe that forms part of the Microsoft Encarta product. Hexagonal grids may"
"leaving the q's fixed. The vector field ""R"", defined by the equalities is called the Reeb vector field, and it generates the geodesic flow of the Riemannian metric. More precisely, using the Riemannian metric, one can identify each point of the cotangent bundle of ""N"" with a point of the tangent bundle of ""N"", and then the value of ""R"" at that point of the (unit) cotangent bundle is the corresponding (unit) vector parallel to ""N"". On the other hand, one can build a contact manifold ""M"" of dimension 2""n"" + 1 by considering the first jet bundle of the"
"provide a rich summary of (literally) multi-faceted relationships between entities. Q-analysis Q-analysis is a mathematical framework to describe and analyze set systems, or equivalently simplicial complexes. This idea was first introduced by Ronald Atkin in the early 1970s. Atkin was a British mathematician teaching at the University of Essex. Crediting the inspiration of his idea to Clifford Dowker’s paper (Homology Groups of Relations, Annals of Mathematics, 1952), he became interested in the algebra of relations in social structures. He tried to explain his idea in both mathematical and also accessible forms to both technical and general audience. His main ideas"
"Further, the isometry groups of ""Q"" and −""Q"" are the same (, but the associated Clifford algebras (and hence pin groups) are different. An quadratic form over a field ""K"" is a map formula_12 from a finite dimensional ""K"" vector space to ""K"" such that formula_13 for all formula_14 and the function formula_15 is bilinear. More concretely, an ""n""-ary quadratic form over a field ""K"" is a homogeneous polynomial of degree 2 in ""n"" variables with coefficients in ""K"": This formula may be rewritten using matrices: let ""x"" be the column vector with components ""x"", ..., ""x"" and be the"
"study of the biotic and abiotic components of ecosystems and the Earth in ecology and other fields. In ecology: In biogeography: In zoogeography: In phytogeography: For the physiognomic approach, see Vegetation#Classifications. For the association (phytosociological) approach, see Phytosociology#Classificatory traditions. In physiography: In Geology: In pedology (soil study): Ecological land classification Ecological land classification is a cartographical delineation or regionalisation of distinct ecological areas, identified by their geology, topography, soils, vegetation, climate conditions, living species, habitats, water resources, and sometimes also anthropic factors. These factors control and influence biotic composition and ecological processes. The expression ""ecological land classification"" as understood in"
"careful planning to be representative and as noninvasive as possible. For grasslands and other low growing habitats the use of a quadrat – a 1-metre square frame – is often used with the numbers and types of organisms growing within each quadrat area counted Sediments and soils require specialist sampling tools to ensure that the material recovered is representative. Such samplers are frequently designed to recover a specified volume of material and may also be designed to recover the sediment or soil living biota as well such as the Ekman grab sampler. The interpretation of environmental data produced from a"
"format is also known as a digital orthophoto quarter quadrangle (DOQQ) because each covers one quarter of a quadrangle (four 1:12,000-scale DOQQs display the same area as one 1:24,000-scale DOQ). Digital orthophoto quadrangle A digital orthophoto quadrangle (DOQ) is aerial photography or satellite imagery that has been corrected so that its pixels are aligned with longitude and latitude lines, and have a narrowly defined region of coverage. This is a widely used format introduced by United States Geological Survey (USGS). The correction technique is called image rectification and is a large part of photogrammetry. DOQs produced by the USGS cover"
"reflected in dictionaries conveys both a particular and a general meaning, the particular referring to an area of the Earth's surface and the general being that which can be seen by an observer. An example of this second usage can be found as early as 1662 in the Book of Common Prayer: There are several words that are frequently associated with the word landscape: Geomorphology is the scientific study of the origin and evolution of topographic and bathymetric features created by physical or chemical processes operating at or near Earth's surface. Geomorphologists seek to understand why landscapes look the way"
"consideration is the flow of air along its surface. A ""(topological) surface"" is a topological space in which every point has an open neighbourhood homeomorphic to some open subset of the Euclidean plane E. Such a neighborhood, together with the corresponding homeomorphism, is known as a ""(coordinate) chart"". It is through this chart that the neighborhood inherits the standard coordinates on the Euclidean plane. These coordinates are known as ""local coordinates"" and these homeomorphisms lead us to describe surfaces as being ""locally Euclidean"". In most writings on the subject, it is often assumed, explicitly or implicitly, that as a topological"
"Quadrangle (geography) In geology or geography, the word ""quadrangle"" usually refers to a United States Geological Survey (USGS) 7.5-minute quadrangle map, which are usually named after a local physiographic feature. The shorthand ""quad"" is also used, especially with the name of the map; for example, ""the Ranger Creek, Texas quad map"". These maps are one-quarter of the older 15-minute series. On a quadrangle map, the north and south limits of the quadrangle are not straight lines, but are actually curved to match Earth's lines of latitude on the standard projection. The east and west limits are usually not parallel as"
"assumed to be everywhere constant with respect to position, and perpendicular to the surface. Second, flux as a scalar field defined along a surface, i.e. a function of points on the surface: As before, the surface is assumed to be flat, and the flow is assumed to be everywhere perpendicular to it. However the flow need not be constant. ""q"" is now a function of p, a point on the surface, and ""A"", an area. Rather than measure the total flow through the surface, q measures the flow through the disk with area ""A"" centered at ""p"" along the surface."
"P'Q' and the projection of the meridian is the bearing formula_4. In general formula_5. Comment: this precise distinction between azimuth (on the Earth's surface) and bearing (on the map) is not universally observed, many writers using the terms almost interchangeably. Definition: the point scale at P is the ratio of the two distances P'Q' and PQ in the limit that Q approaches P. We write this as where the notation indicates that the point scale is a function of the position of P and also the direction of the element PQ. Definition: if P and Q lie on the same"
"(listed in alphabetical order): Geomorphometry Geomorphometry, or geomorphometrics, is the science of quantitative land surface analysis. It gathers various mathematical, statistical and image processing techniques that can be used to quantify morphological, hydrological, ecological and other aspects of a land surface. Common synonyms for geomorphometry are geomorphological analysis, terrain morphometry or terrain analysis and land surface analysis. Geomorphometrics is the discipline based on the computational measures of the geometry, topography and shape of the Earth's horizons, and their temporal change. In simple terms, geomorphometry aims at extracting (land) surface parameters (morphometric, hydrological, climatic etc.) and objects (watersheds, stream networks, landforms"
"space it can be regarded as the position of q relative to p. It may also be called a displacement vector if p and q represent two positions of some moving point. The Euclidean distance between p and q is just the Euclidean length of this displacement vector: which is equivalent to equation 1, and also to: In the context of Euclidean geometry, a metric is established in one dimension by fixing two points on a line, and choosing one to be the origin. The length of the line segment between these points defines the unit of distance and the"
"Water, Land and Ecosystems Water, Land and Ecosystems is one of several new research programmes approved by the CGIAR during 2011 after an extensive period of consultation that began in 2009. This research programme will draw on the resources of 14 CGIAR and numerous external partners to provide a more integrated approach to research into managing natural resources. The aim of the research programme is to increase agricultural productivity while protecting the environment, so food security is ensured for most of humanity and that poverty becomes history. The five main strands to the programme are: River basins; Irrigation systems; Information"
"Land lab A land lab is an area of land that has been set aside for use in biological studies. Thus, it is literally an outdoor laboratory based on an area of land. Studies may be elementary or advanced. For instance, students may simply be given the task of identifying all the tree species in a land lab, or an advanced student may be doing an intensive survey of the microbial life forms found in a soil sample. Land labs are often marked out in plots or transects for studies. A plot may be any size, usually marked out in"
"Quadrilateralized spherical cube In mapmaking, a quadrilateralized spherical cube, or quad sphere for short, is an equal-area mapping and binning scheme for data collected on a spherical surface (either that of the Earth or the celestial sphere). It was first proposed in 1975 by Chan and O'Neill for the Naval Environmental Prediction Research Facility. This scheme is also often called the COBE sky cube, because it was designed to hold data from the Cosmic Background Explorer (COBE) project. The quad sphere has two principal characteristic features. The first is that the mapping consists of projecting the sphere onto the faces"
"Quadratic field In algebraic number theory, a quadratic field is an algebraic number field ""K"" of degree two over Q, the rational numbers. The map ""d"" ↦ Q() is a bijection from the set of all square-free integers ""d"" ≠ 0, 1 to the set of all quadratic fields. If ""d"" > 0 the corresponding quadratic field is called a real quadratic field, and for ""d"" < 0 an imaginary quadratic field or complex quadratic field, corresponding to whether it is or not a subfield of the field of the real numbers. Quadratic fields have been studied in great depth,"
"went through four major phases: environmental determinism, regional geography, the quantitative revolution, and critical geography. The strong interdisciplinary links between geography and the sciences of geology and botany, as well as economics, sociology and demographics have also grown greatly, especially as a result of earth system science that seeks to understand the world in a holistic view. Geography Geography (from Greek: , ""geographia"", literally ""earth description"") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of the Earth and planets. The first person to use the word γεωγραφία was Eratosthenes (276–194 BC). Geography"
"metric geometry of ""Q"". If one only considers the Euclidean topology of the plane and the topology inherited by ""Q"", then the lines bounding ""Q"" seem close to ""Q"". Insight from the metric space ""HP"" shows that the open set ""Q"" has only the origin as boundary when viewed through the correspondence. Indeed, consider rays from the origin in ""Q"", and their images, vertical rays from the boundary ""R"" of ""HP"". Any point in ""HP"" is an infinite distance from the point ""p"" at the foot of the perpendicular to ""R"", but a sequence of points on this perpendicular may"
"Stratum In geology and related fields, a stratum (plural: strata) is a layer of sedimentary rock or soil, or igneous rock that were formed at the Earth's surface, with internally consistent characteristics that distinguish it from other layers. The ""stratum"" is the fundamental unit in a stratigraphic column and forms the basis of the study of stratigraphy. Each layer is generally one of a number of parallel layers that lie one upon another, laid down by natural processes. They may extend over hundreds of thousands of square kilometers of the Earth's surface. Strata are typically seen as bands of different"
"may be darker in colour than deeper layers and contain more organic matter, or they may be lighter but contain less clay or pedogenic oxides. The A is a surface horizon, and as such is also known as the zone in which most biological activity occurs. Soil organisms such as earthworms, potworms (enchytraeids), arthropods, nematodes, fungi, and many species of bacteria and archaea are concentrated here, often in close association with plant roots. Thus, the A horizon may be referred to as the biomantle. However, since biological activity extends far deeper into the soil, it cannot be used as a"
"Q-system (geotechnical engineering) The Q-system for rock mass classification is developed by Barton, Lien, and Lunde. It expresses the quality of the rock mass in the so-called ""Q-value"", on which are based design and support recommendations for underground excavations. The Q-value is determined with The first term ""RQD"" ""(Rock Quality Designation)"" divided by ""J (joint set number)"" is related to the size of the intact rock blocks in the rock mass. The second term ""J (joint roughness number)"" divided by ""J (joint alteration number)"" is related to the shear strength along the discontinuity planes and the third term ""J (joint"
"a specific area to represent specific qualities of the area covered. However, differences in area between 'squares' enlarge along with longitudinal distance and this can violate assumptions of many statistical analyses requiring truly equal-area grids. For instance species range modelling or estimates of ecological niche could be substantilly affected if data were not appriopriatelly transformed, e.g. projected onto a plane using a special projection. Around the equator we have 360 longitudinal lines, and from the north to the south pole we have 180 latitudinal lines. Together this gives us 64800 segments or tiles covering earth. The form of the squares"
"Geomorphology Geomorphology (from Ancient Greek: γῆ, ""gê"", ""earth""; μορφή, ""morphḗ"", ""form""; and λόγος, ""lógos"", ""study"") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or near the Earth's surface. Geomorphologists seek to understand why landscapes look the way they do, to understand landform history and dynamics and to predict changes through a combination of field observations, physical experiments and numerical modeling. Geomorphologists work within disciplines such as physical geography, geology, geodesy, engineering geology, archaeology, climatology and geotechnical engineering. This broad base of interests contributes to many"