6.0 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Anthropogenic biome | 2/3 | https://en.wikipedia.org/wiki/Anthropogenic_biome | reference | science, encyclopedia | 2026-05-05T16:00:46.809220+00:00 | kb-cron |
=== Human population === Following the industrial revolution, the human population experienced a rapid increase. The human population density in certain anthromes began to change, shifting away from rural environments to urban settlements, where the population density was much higher. These changes in population density between areas shifted global patterns of anthrome emergence, and also had wide-spread effects on various ecosystems. Half of the Earth's population now lives in cities, and most people reside in urban anthromes, with some populations dwelling in smaller cities and towns. Currently, human populations are expected to grow until at least midcentury, and the transformation of the Earth's anthromes are expected to follow this growth.
=== Current state of the anthropogenic biosphere === The present state of the terrestrial biosphere is predominantly anthropogenic. More than half of the terrestrial biosphere remains unused directly for agriculture or urban settlements, and of these unused lands still remaining, less than half are wildlands. Most of Earth's unused lands are now within the agricultural and settled landscapes of semi-natural, rangeland, cropland and village anthromes.
=== Major anthromes === Anthromes include dense settlements (urban and mixed settlements), villages, croplands, rangelands and semi-natural lands and have been mapped globally using two different classification systems, viewable on Google Maps and Google Earth. There are currently 18 anthropogenic biomes, the most prominent of which are listed below.
==== Dense settlements ==== Dense settlements are the second most densely populated regions in the world. They are defined as areas with a high population density, though the density can be variable. The population density, however, never falls below 100 persons/km, even in the non-urban parts of the dense settlements, and it has been suggested that these areas consist of both the edges of major cities in underdeveloped nations, and the long standing small towns throughout western Europe and Asia. Most often we think of dense settlements as cities, but dense settlements can also be suburbs, towns and rural settlements with high but fragmented populations.
==== Villages ==== Villages are densely populated agricultural landscapes, many of which have been inhabited and intensively used for centuries to millennia.
==== Croplands ==== Croplands are another major anthrome throughout the world. Croplands include most of the cultivated lands of the world, and also about a quarter of global tree cover. Croplands which are locally irrigated have the highest human population density, likely due to the fact that it provides crops with a constant supply on water. This makes harvest time and crop survival more predictable. Croplands that are sustained mainly from the local rainfall are the most extensive of the populated anthromes, with annual precipitation near 1000 mm in certain areas of the globe. In these areas, there is sufficient water supplied by the climate to support all aspects of life without hardly any irrigation. However, in dryer areas, this method of agriculture would not be as productive.
==== Rangelands ==== Rangelands are a very broad anthropogenic biome group that has been described according to three levels of population density: residential, populated and remote. The Residential rangeland anthrome has two key features: its population density is never below 10 persons per square kilometre, and a substantial portion of its area is used for pasture. Pastures in rangelands are the most dominant land cover. Bare earth is significant in this anthrome, covering nearly one third of the land for every one square kilometer. Rangeland anthromes are less altered than croplands, but their alteration tends to increase with population. Domesticated grazing livestock are typically adapted to grasslands and savannas, so the alteration of these biomes tends to be less noticeable.
==== Cultured lands ==== Cultured anthromes are landscapes shaped by low levels of intensive land use and substantial to very low density populations. The Cultured anthrome classification was introduced in 2021 to replace analogous classifications, "Seminatural" (2010 classification) and "Forested" (original 2008 classification). Cultured woodland anthromes are woodland biomes shaped by land use and human inhabitation, and their population densities are usually less than 3 persons/km2. Many cultured woodlands are secondary forests that act as carbon sinks as a result of ongoing regrowth of woody vegetation. Some cultured woodlands are partially cleared for agriculture, including domestic livestock, and to utilize timber. Cultured dryland anthromes are dryland biomes shaped by land use and human inhabitation.
==== Indoor ==== Very few biologists have studied the evolutionary processes at work in indoor environments. Estimates of the extent of residential and commercial buildings range between 1.3% and 6% of global ice-free land area. This area is as extensive as other small biomes such as flooded grass-lands and tropical coniferous forests. The indoor biome is rapidly expanding. The indoor biome of Manhattan is almost three times as large, in terms of its floor space, as is the geographical area of the island itself, due to the buildings rising up instead of spreading out. Thousands of species live in the indoor biome, many of them preferentially or even obligatorily. The only action that humans take to alter the evolution of the indoor biome is with cleaning practices. The field of indoor biomes will continue to change as long as our culture will change.
==== Aquatic ==== Managed aquatic biomes or aquatic anthromes have rarely been studied as such. They range from fish ponds, marine shrimp and benthic farming sites to large tracts of land such as parts of the Guadalquivir Marshes in Andalusia, Spain.