Географиялық кеңістіктегі түрлер мен экожүйелердің таралуы

Study of the distribution of species and ecosystems in geographic space and through geological time

Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area. Phytogeography is the branch of biogeography that studies the distribution of plants. Zoogeography is the branch that studies distribution of animals. Mycogeography is the branch that studies distribution of fungi, such as mushrooms. Knowledge of spatial variation in the numbers and types of organisms is as vital to us today as it was to our early human ancestors, as we adapt to heterogeneous but geographically predictable environments. Biogeography is an integrative field of inquiry that unites concepts and information from ecology, evolutionary biology, taxonomy, geology, physical geography, palaeontology, and climatology. Modern biogeographic research combines information and ideas from many fields, from the physiological and ecological constraints on organismal dispersal to geological and climatological phenomena operating at global spatial scales and evolutionary time frames. The short term interactions within a habitat and species of organisms describe the ecological application of biogeography. Historical biogeography describes the long term, evolutionary periods of time for broader classifications of organisms. Early scientists, beginning with Carl Linnaeus, contributed to the development of biogeography as a science. The scientific theory of biogeography grows out of the work of Alexander von Humboldt (1769–1859), Francisco Jose de Caldas (1768–1816), Hewett Cottrell Watson (1804–1881), Alphonse de Candolle (1806–1893), Alfred Russel Wallace (1823–1913), Philip Lutley Sclater (1829–1913) and other biologists and explorers.

The patterns of species distribution across geographical areas can usually be explained through a combination of historical factors such as: speciation, extinction, continental drift, and glaciation. Through observing the geographic distribution of species, we can see associated variations in sea level, river routes, habitat, and river capture. Additionally, this science considers the geographic constraints of landmass areas and isolation, as well as the available ecosystem energy supplies. Over periods of ecological changes, biogeography includes the study of plant and animal species in: their past and/or present living refugium habitat; their interim living sites; and/or their survival locales. As writer David Quammen put it, " biogeography does more than ask Which species? and Where. It also asks Why? and, what is sometimes more crucial, Why not?." Modern biogeography often employs the use of Geographic Information Systems (GIS), to understand the factors affecting organism distribution, and to predict future trends in organism distribution. Often mathematical models and GIS are employed to solve ecological problems that have a spatial aspect to them. Biogeography is most keenly observed on the world's islands. These habitats are often much more manageable areas of study because they are more condensed than larger ecosystems on the mainland. Islands are also ideal locations because they allow scientists to look at habitats that new invasive species have only recently colonized and can observe how they disperse throughout the island and change it. They can then apply their understanding to similar but more complex mainland habitats. Islands are very diverse in their biomes, ranging from the tropical to arctic climates. This diversity in habitat allows for a wide range of species study in different parts of the world. One scientist who recognized the importance of these geographic locations was Charles Darwin, who remarked in his journal "The Zoology of Archipelagoes will be well worth examination". He discussed plant distribution and his theories eventually had a great impact on Charles Darwin, who was inspired to consider species adaptations and evolution after learning about botanical geography. De Candolle was the first to describe the differences between the small scale and large scale distribution patterns of organisms around the globe. Uniformitarianism also introduced the idea that the Earth was actually significantly older than was previously accepted. Using this knowledge, Lyell concluded that it was possible for species to go extinct. Since he noted that Earth's climate changes, he realized that species distribution must also change accordingly. Lyell argued that climate changes complemented vegetation changes, thus connecting the environmental surroundings to varying species. This largely influenced Charles Darwin in his development of the theory of evolution. In 1958 paleontologist Paul S. Martin published A Biogeography of Reptiles and Amphibians in the Gómez Farias Region, Tamaulipas, Mexico, which has been described as "ground breaking" and "a classic treatise in historical biogeography". Martin applied several disciplines including ecology, botany, climatology, geology, and Pleistocene dispersal routes to examine the herpetofauna of a relatively small and largely undisturbed area, but ecologically complex, situated on the threshold of temperate – tropical (nearctic and neotropical) regions, including semiarid lowlands at 70 meters elevation and the northernmost cloud forest in the western hemisphere at over 2200 meters. The publication of The Theory of Island Biogeography by Robert MacArthur and E. O. Wilson in 1967 showed that the species richness of an area could be predicted in terms of such factors as habitat area, immigration rate and extinction rate. This added to the long standing interest in island biogeography. The application of island biogeography theory to habitat fragments spurred the development of the fields of conservation biology and landscape ecology. Classic biogeography has been expanded by the development of molecular systematics, creating a new discipline known as phylogeography. This development allowed scientists to test theories about the origin and dispersal of populations, such as island endemics. For example, while classic biogeographers were able to speculate about the origins of species in the Hawaiian Islands, phylogeography allows them to test theories of relatedness between these populations and putative source populations on various continents, notably in Asia and North America. See also Oceanic dispersal.

Biogeography now incorporates many different fields including but not limited to physical geography, geology, botany and plant biology, zoology, general biology, and modelling. A biogeographer's main focus is on how the environment and humans affect the distribution of species as well as other manifestations of Life such as species or genetic diversity. Biogeography is being applied to biodiversity conservation and planning, projecting global environmental changes on species and biomes, projecting the spread of infectious diseases, invasive species, and for supporting planning for the establishment of crops. Technological evolving and advances have allowed for generating a whole suite of predictor variables for biogeographic analysis, including satellite imaging and processing of the Earth. Two main types of satellite imaging that are important within modern biogeography are Global Production Efficiency Model (GLO PEM) and Geographic Information Systems (GIS). GLO PEM uses satellite imaging gives "repetitive, spatially contiguous, and time specific observations of vegetation". These observations are on a global scale. GIS can show certain processes on the earth's surface like whale locations, sea surface temperatures, and bathymetry. Current scientists also use coral reefs to delve into the history of biogeography through the fossilized reefs. Two global information systems are either dedicated to, or have strong focus on, biogeography (in the form of the spatial location of observations of organisms), namely the Global Biodiversity Information Facility (GBIF: 2.57 billion species occurrence records reported as at August 2023) and, for marine species only, the Ocean Biodiversity Information System (OBIS, originally the Ocean Biogeographic Information System: 116 million species occurrence records reported as at August 2023), while at a national scale, similar compilations of species occurrence records also exist such as the U. K. National Biodiversity Network, the Atlas of Living Australia, and many others. In the case of the oceans, in 2017 Costello et al. analyzed the distribution of 65,000 species of marine animals and plants as then documented in OBIS, and used the results to distinguish 30 distinct marine realms, split between continental shelf and offshore deep sea areas. Since it is self evident that compilations of species occurrence records cannot cover with any completeness, areas that have received either limited or no sampling, a number of methods have been developed to produce arguably more complete "predictive" or "modelled" distributions for species based on their associated environmental or other preferences (such as availability of food or other habitat requirements); this approach is known as either Environmental niche modelling (ENM) or Species distribution modelling (SDM). Depending on the reliability of the source data and the nature of the models employed (including the scales for which data are available), maps generated from such models may then provide better representations of the "real" biogeographic distributions of either individual species, groups of species, or biodiversity as a whole, however it should also be borne in mind that historic or recent human activities (such as hunting of great whales, or other human induced exterminations) may have altered present day species distributions from their potential "full" ecological footprint. Examples of predictive maps produced by niche modelling methods based on either GBIF (terrestrial) or OBIS (marine, plus some freshwater) data are the former Lifemapper project at the University of Kansas (now continued as a part of BiotaPhy) and AquaMaps, which as at 2023 contain modelled distributions for around 200,000 terrestrial, and 33,000 species of teleosts, marine mammals and invertebrates, respectively. One advantage of ENM/SDM is that in addition to showing current (or even past) modelled distributions, insertion of changed parameters such as the anticipated effects of climate change can also be used to show potential changes in species distributions that may occur in the future based on such scenarios.

There are many types of biogeographic units used in biogeographic regionalisation schemes, as there are many criteria (species composition, physiognomy, ecological aspects) and hierarchization schemes: biogeographic realms (ecozones), bioregions (sensu stricto), ecoregions, zoogeographical regions, floristic regions, vegetation types, biomes, etc. The terms biogeographic unit, biogeographic area can be used for these categories, regardless of rank. In 2008, an International Code of Area Nomenclature was proposed for biogeography. It achieved limited success; some studies commented favorably on it, but others were much more critical, and it "has not yet gained a significant following". Similarly, a set of rules for paleobiogeography has achieved limited success. In 2000, Westermann suggested that the difficulties in getting formal nomenclatural rules established in this field might be related to "the curious fact that neither paleo nor neobiogeographers are organized in any formal groupings or societies, nationally (so far as I know) or internationally — an exception among active disciplines."