Editing Biodiversity (section)

== Distribution ==
[[File:Map latitudinal gradient of biodiversity mannion 2014.png|thumb|upright=1.5|Distribution of living terrestrial vertebrate species, highest concentration of diversity shown in red in equatorial regions, declining polewards (towards the blue end of the spectrum)]]
Biodiversity is not evenly distributed, rather it varies greatly across the globe as well as within regions and seasons. Among other factors, the diversity of all living things ([[biota (ecology)|biota]]) depends on [[temperature]], [[precipitation]], [[altitude]], [[soil]]s, [[geography]] and the interactions between other species.<ref>{{cite journal |last1=Clay |first1=Keith |last2=Holah |first2=Jenny |title=Fungal Endophyte Symbiosis and Plant Diversity in Successional Fields |journal=Science |date=10 September 1999 |volume=285 |issue=5434 |pages=1742–1744 |doi=10.1126/science.285.5434.1742 |pmid=10481011 }}</ref> The study of the spatial distribution of [[organism]]s, species and [[ecosystem]]s, is the science of [[biogeography]].<ref name="MorandKrasnov2010" /><ref name="the-functional-role-of-producer-diversity" />

Diversity consistently measures higher in the [[tropics]] and in other localized regions such as the [[Cape Floristic Region]] and lower in polar regions generally. [[Rain forests]] that have had wet climates for a long time, such as [[Yasuni National Park|Yasuní National Park]] in [[Ecuador]], have particularly high biodiversity.<ref name="dotearth">{{cite news | url=http://dotearth.blogs.nytimes.com/2010/01/20/a-durable-yet-vulnerable-eden-in-amazonia/ | title=A Durable Yet Vulnerable Eden in Amazonia | work=Dot Earth blog, New York Times| date=20 January 2010 | access-date=2 February 2013 }}</ref><ref name="journal.pone.0008767">{{cite journal |title=Global Conservation Significance of Ecuador's Yasuní National Park |author1=Margot S. Bass |author2=Matt Finer |author3=Clinton N. Jenkins |author4=Holger Kreft |author5=Diego F. Cisneros-Heredia |author6=Shawn F. McCracken |author7=Nigel C. A. Pitman |author8=Peter H. English |author9=Kelly Swing |author10=Gorky Villa |author11=Anthony Di Fiore |author12=Christian C. Voigt |author13=Thomas H. Kunz |journal= PLOS ONE|year=2010 |volume=5 |issue=1 |doi=10.1371/journal.pone.0008767 |bibcode = 2010PLoSO...5.8767B |pages=e8767 |pmid=20098736 |pmc=2808245|doi-access=free }}</ref>

There is local biodiversity, which directly impacts daily life, affecting the availability of fresh water, food choices, and fuel sources for humans. Regional biodiversity includes habitats and ecosystems that synergizes and either overlaps or differs on a regional scale. National biodiversity within a country determines the ability for a country to thrive according to its habitats and ecosystems on a national scale. Also, within a country, [[endangered species]] are initially supported on a national level then internationally. [[Ecotourism]] may be utilized to support the economy and encourages tourists to continue to visit and support species and ecosystems they visit, while they enjoy the available amenities provided. International biodiversity impacts global livelihood, food systems, and health. Problematic pollution, over consumption, and climate change can devastate international biodiversity. Nature-based solutions are a critical tool for a global resolution. Many species are in danger of becoming extinct and need world leaders to be proactive with the [[Kunming-Montreal Global Biodiversity Framework]]. 

Terrestrial biodiversity is thought to be up to 25 times greater than ocean biodiversity.<ref>{{cite journal | author = Benton M. J. | year = 2001 | title = Biodiversity on land and in the sea | journal = Geological Journal | volume = 36 | issue = 3–4| pages = 211–230 | doi = 10.1002/gj.877 | bibcode = 2001GeolJ..36..211B }}</ref><!-- true for microorganisms as well?--> Forests harbour most of Earth's terrestrial biodiversity<!-- This is not true for microorganisms. -->. The conservation of the world's biodiversity is thus utterly dependent on the way in which we interact with and use the world's forests.<ref name="FAO & UNEP-2020">{{Cite book |title=The State of the World's Forests 2020. In brief – Forests, biodiversity and people |publisher=FAO & UNEP |year=2020 |isbn=978-92-5-132707-4 |location=Rome, Italy |doi=10.4060/ca8985en |s2cid=241416114}}{{pn|date=November 2024}} Text was added from this source which has a Wikipedia-specific [[c:File:The_State_of_the_World’s_Forests_2020._In_brief.pdf|licence statement]]</ref> A new method used in 2011, put the total number of species on Earth at 8.7&nbsp;million, of which 2.1&nbsp;million were estimated to live in the ocean.<ref name="Moraplos">{{cite journal |last1=Mora |first1=Camilo |last2=Tittensor |first2=Derek P. |last3=Adl |first3=Sina |last4=Simpson |first4=Alastair G. B. |last5=Worm |first5=Boris |title=How Many Species Are There on Earth and in the Ocean? |journal=PLOS Biology |date=23 August 2011 |volume=9 |issue=8 |pages=e1001127 |doi=10.1371/journal.pbio.1001127 |doi-access=free |pmid=21886479 |pmc=3160336 }}</ref> However, this estimate seems to under-represent the diversity of microorganisms.<ref name="Microorganisms Editorial Office-2019">{{Cite journal|date=2019-01-09|title=Acknowledgement to Reviewers of Microorganisms in 2018|journal=Microorganisms|volume=7|issue=1|pages=13|doi=10.3390/microorganisms7010013| pmc=6352028 |doi-access=free|author1=Microorganisms Editorial Office}}</ref> Forests provide habitats for 80 percent of amphibian [[species]], 75 percent of bird species and 68 percent of mammal species. About 60 percent of all vascular plants are found in tropical forests. Mangroves provide breeding grounds and nurseries for numerous species of fish and shellfish and help trap sediments that might otherwise adversely affect seagrass beds and coral reefs, which are habitats for many more marine species.<ref name="FAO & UNEP-2020" /> Forests span around 4 billion acres (nearly a third of the Earth's land mass) and are home to approximately 80% of the world's biodiversity. About 1 billion hectares are covered by primary forests. Over 700 million hectares of the world's woods are officially protected.<ref>{{Cite web |title=Global Forest Resource Assessment 2020 |url=http://www.fao.org/forest-resources-assessment/2020 |access-date=2023-01-30 |website=Food and Agriculture Organization |language=en}}</ref><ref>{{Cite web |title=The State of the World's Forests 2020: Forests, biodiversity and people [EN/AR/RU] – World {{!}} ReliefWeb |url=https://reliefweb.int/report/world/state-world-s-forests-2020-forests-biodiversity-and-people-enarru |access-date=2023-01-30 |website=reliefweb.int |date=September 2020 |language=en}}</ref>

The biodiversity of forests varies considerably according to factors such as forest type, geography, climate and soils – in addition to human use.<ref name="FAO & UNEP-2020" /> Most forest habitats in temperate regions support relatively few animal and plant species and species that tend to have large geographical distributions, while the montane forests of Africa, South America and Southeast Asia and lowland forests of Australia, coastal Brazil, the Caribbean islands, Central America and insular Southeast Asia have many species with small geographical distributions.<ref name="FAO & UNEP-2020" /> Areas with dense human populations and intense agricultural land use, such as [[Europe]], parts of Bangladesh, China, India and North America, are less intact in terms of their biodiversity. Northern Africa, southern Australia, coastal Brazil, Madagascar and South Africa, are also identified as areas with striking losses in biodiversity intactness.<ref name="FAO & UNEP-2020" /> European forests in EU and non-EU nations comprise more than 30% of Europe's land mass (around 227 million hectares), representing an almost 10% growth since 1990.<ref>{{Cite web |title=39% of the EU is covered with forests |url=https://ec.europa.eu/eurostat/web/products-eurostat-news/-/edn-20210321-1 |access-date=2023-01-30 |website=ec.europa.eu |language=en-GB}}</ref><ref>{{Cite web |last=Cavallito |first=Matteo |date=2021-04-08 |title=European forests are expanding. But their future is unwritten |url=https://resoilfoundation.org/en/environment/eu-forests-growth/ |access-date=2023-01-30 |website=Re Soil Foundation |language=en-US}}</ref>

===Latitudinal gradients===
{{Main|Latitudinal gradients in species diversity}}

Generally, there is an increase in biodiversity from the [[Geographical pole|poles]] to the [[tropics]]. Thus localities at lower [[latitudes]] have more species than localities at higher [[latitude]]s. This is often referred to as the latitudinal gradient in species diversity. Several ecological factors may contribute to the gradient, but the ultimate factor behind many of them is the greater mean temperature at the equator compared to that at the poles.<ref name="MoraRobertson2003">{{cite journal |last1=Mora |first1=Camilo |last2=Robertson |first2=D. Ross |title=Causes of Latitudinal Gradients in Species Richness: A Test with Fishes of the Tropical Eastern Pacific |journal=Ecology |date=July 2005 |volume=86 |issue=7 |pages=1771–1782 |doi=10.1890/04-0883 |bibcode=2005Ecol...86.1771M }}</ref>

Even though terrestrial biodiversity declines from the equator to the poles,<ref name="auto"/> some studies claim that this characteristic is unverified in [[aquatic ecosystems]], especially in [[marine ecosystems]].<ref>{{cite journal|title= How diverse is aquatic biodiversity research? | doi=10.1007/s10452-005-6041-y|volume=39|issue= 3 |journal=Aquatic Ecology|pages=367–375|date= September 2005 |last1= Karakassis |first1= Ioannis |last2= Moustakas |first2= Aristides | bibcode=2005AqEco..39..367M }}</ref> The latitudinal distribution of parasites does not appear to follow this rule.<ref name="MorandKrasnov2010">{{cite book|first1=Serge |last1=Morand|first2=Boris R. |last2=Krasnov|title=The Biogeography of Host-Parasite Interactions|url={{google books |plainurl=y |id=08keK5vc888C|page=93}}|access-date=28 June 2011|date=1 September 2010|publisher=Oxford University Press|isbn=978-0-19-956135-3|pages=93–94}}</ref> Also, in terrestrial ecosystems the soil bacterial diversity has been shown to be highest in temperate climatic zones,<ref>{{Cite journal |last1=Bahram |first1=Mohammad |last2=Hildebrand |first2=Falk |last3=Forslund |first3=Sofia K. |last4=Anderson |first4=Jennifer L. |last5=Soudzilovskaia |first5=Nadejda A. |last6=Bodegom |first6=Peter M. |last7=Bengtsson-Palme |first7=Johan |last8=Anslan |first8=Sten |last9=Coelho |first9=Luis Pedro |last10=Harend |first10=Helery |last11=Huerta-Cepas |first11=Jaime |last12=Medema |first12=Marnix H. |last13=Maltz |first13=Mia R. |last14=Mundra |first14=Sunil |last15=Olsson |first15=Pål Axel |date=August 2018 |title=Structure and function of the global topsoil microbiome |journal=Nature |volume=560 |issue=7717 |pages=233–237 |doi=10.1038/s41586-018-0386-6 |pmid=30069051 |bibcode=2018Natur.560..233B |hdl=1887/73861 |hdl-access=free }}</ref> and has been attributed to carbon inputs and habitat connectivity.<ref>{{Cite journal |last1=Bickel |first1=Samuel |last2=Or |first2=Dani |date=2020-01-08 |title=Soil bacterial diversity mediated by microscale aqueous-phase processes across biomes |journal=Nature Communications |volume=11 |issue=1 |pages=116 |doi=10.1038/s41467-019-13966-w |pmc=6949233 |pmid=31913270|bibcode=2020NatCo..11..116B }}</ref>

In 2016, an alternative hypothesis ("the [[fractal]] biodiversity") was proposed to explain the biodiversity latitudinal gradient.<ref>{{cite journal | last1 = Cazzolla Gatti | first1 = R | year = 2016 | title = The fractal nature of the latitudinal biodiversity gradient | journal = Biologia | volume = 71 | issue = 6| pages = 669–672 | doi = 10.1515/biolog-2016-0077 | bibcode = 2016Biolg..71..669C }}</ref> In this study, the [[species]] pool size and the fractal nature of ecosystems were combined to clarify some general patterns of this gradient. This hypothesis considers [[temperature]], [[moisture]], and [[net primary production]] (NPP) as the main variables of an ecosystem niche and as the axis of the ecological [[hypervolume]]. In this way, it is possible to build fractal hyper volumes, whose [[fractal dimension]] rises to three moving towards the [[equator]].<ref>{{Citation|last=Cogitore, Clément (1983–....).|title=Hypothesis|date=January 1988|publisher=National Academy Press |isbn=9780309037396|oclc=968249007}}</ref>

===Biodiversity Hotspots===
A [[biodiversity hotspot]] is a region with a high level of [[Endemism|endemic]] species that have experienced great [[Habitat destruction|habitat loss]].<ref>{{cite web|url= http://www.biodiversitya-z.org/content/biodiversity-hotspots | author = Biodiversity A–Z | title = Biodiversity Hotspots}}</ref> The term hotspot was introduced in 1988 by [[Norman Myers]].<ref>{{cite journal | doi = 10.1007/BF02240252 | author = Myers N | year = 1988 | title = Threatened biotas: 'hot spots' in tropical forests | journal = Environmentalist | volume = 8 | issue = 3| pages = 187–208 | pmid = 12322582 | bibcode = 1988ThEnv...8..187M }}</ref><ref>{{cite journal |last1=Myers |first1=Norman |title=The biodiversity challenge: Expanded hot-spots analysis |journal=The Environmentalist |date=December 1990 |volume=10 |issue=4 |pages=243–256 |doi=10.1007/BF02239720 |pmid=12322583 |bibcode=1990ThEnv..10..243M }}</ref><ref>{{cite journal |last1=Tittensor |first1=Derek P. |last2=Mora |first2=Camilo |last3=Jetz |first3=Walter |last4=Lotze |first4=Heike K. |last5=Ricard |first5=Daniel |last6=Berghe |first6=Edward Vanden |last7=Worm |first7=Boris |title=Global patterns and predictors of marine biodiversity across taxa |journal=Nature |date=August 2010 |volume=466 |issue=7310 |pages=1098–1101 |doi=10.1038/nature09329 |pmid=20668450 |bibcode=2010Natur.466.1098T }}</ref><ref name="McKee2004">{{cite book|first=Jeffrey K. |last=McKee|title=Sparing Nature: The Conflict Between Human Population Growth and Earth's Biodiversity|url={{google books |plainurl=y |id=omgIyInG8qEC|page=108}}|access-date=28 June 2011|date=December 2004|publisher=Rutgers University Press|isbn=978-0-8135-3558-6|page=108}}</ref> While hotspots are spread all over the world, the majority are forest areas and most are located in the [[tropics]].<ref>{{Cite web |title=Explore the Biodiversity Hotspots {{!}} CEPF |url=https://www.cepf.net/our-work/biodiversity-hotspots |access-date=2024-03-10 |website=www.cepf.net |language=en}}</ref>

[[Brazil]]'s [[Atlantic Forest]] is considered one such hotspot, containing roughly 20,000 plant species, 1,350 vertebrates and millions of insects, about half of which occur nowhere else.<ref>{{Cite book|title=The Atlantic Forest of South America: Biodiversity Status, Threats, and Outlook|last=Galindo-Leal|first=Carlos|publisher=Island Press|year=2003|isbn=978-1-55963-988-0|location=Washington|pages=35}}</ref><ref name="MyersMittermeierMittermeier2000">{{cite journal |last1=Myers |first1=Norman |last2=Mittermeier |first2=Russell A. |last3=Mittermeier |first3=Cristina G. |last4=da Fonseca |first4=Gustavo A. B. |last5=Kent |first5=Jennifer |title=Biodiversity hotspots for conservation priorities |journal=Nature |date=February 2000 |volume=403 |issue=6772 |pages=853–858 |doi=10.1038/35002501 |pmid=10706275 |bibcode=2000Natur.403..853M }}</ref> The island of [[Madagascar]] and [[India]] are also particularly notable. [[Colombia]] is characterized by high biodiversity, with the highest rate of species by area unit worldwide and it has the largest number of endemics (species that are not found naturally anywhere else) of any country. About 10% of the species of the Earth can be found in Colombia, including over 1,900 species of bird, more than in Europe and North America combined, Colombia has 10% of the world's mammals species, 14% of the amphibian species and 18% of the bird species of the world.<ref>{{cite web
 |url=http://www.humboldt.org.co/iavh_en/index.php/component/k2/item/129-colombia-in-the-world.html
 |title=Colombia in the World
 |publisher=Alexander von Humboldt Institute for Research on Biological Resources
 |access-date=30 December 2013
 |url-status=dead
 |archive-url=https://web.archive.org/web/20131029194602/http://www.humboldt.org.co/iavh_en/index.php/component/k2/item/129-colombia-in-the-world.html
 |archive-date=29 October 2013
}}</ref> [[Madagascar dry deciduous forests]] and lowland rainforests possess a high ratio of [[endemism]].<ref>{{cite web|last1=godfrey|first1=laurie|title=isolation and biodiversity|url=http://www.pbs.org/edens/madagascar/eden.htm|website=pbs.org|access-date=22 October 2017}}</ref><ref name="Harrison-2013">{{Citation|last=Harrison|first=Susan P.|title=Plant Endemism in California|date=2013-05-15|work=Plant and Animal Endemism in California|pages=43–76|publisher=University of California Press|doi=10.1525/california/9780520275546.003.0004|isbn=978-0-520-27554-6}}</ref> Since the island separated from mainland [[Africa]] 66&nbsp;million years ago, many species and ecosystems have evolved independently.<ref>{{Cite web|url=https://www.pbs.org/edens/madagascar/eden.htm|title=Madagascar – A World Apart: Eden Evolution|website=www.pbs.org|access-date=6 June 2019}}</ref> [[Indonesia]]'s 17,000 islands cover {{convert|735355|sqmi}} and contain 10% of the world's [[flowering plant]]s, 12% of mammals and 17% of [[reptile]]s, [[amphibian]]s and [[bird]]s—along with nearly 240&nbsp;million people.<ref>{{cite journal |last1=Normile |first1=Dennis |title=Saving Forests to Save Biodiversity |journal=Science |date=10 September 2010 |volume=329 |issue=5997 |pages=1278–1280 |doi=10.1126/science.329.5997.1278 |pmid=20829464 |bibcode=2010Sci...329.1278N |doi-access=free }}</ref><!--This source is only about Indonesia--> Many regions of high biodiversity and/or endemism arise from specialized [[habitat]]s which require unusual adaptations, for example, [[alpine climate|alpine]] environments in high [[mountain]]s, or [[Northern Europe]]an peat [[bog]]s.<ref name="Harrison-2013" />

Accurately measuring differences in biodiversity can be difficult. [[Selection bias]] amongst researchers may contribute to biased empirical research for modern estimates of biodiversity. In 1768, Rev. [[Gilbert White]] succinctly observed of his [[Selborne|Selborne, Hampshire]] ''"all nature is so full, that that<!--"that" is correct--> district produces the most variety which is the most examined."''<ref name="White1887">{{cite book|first=Gilbert |last=White|title=The Natural History of Selborne: With A Naturalist's Calendar & Additional Observations|chapter-url={{google books |plainurl=y |id=q7UOQQAACAAJ}}|year=1887|chapter=letter xx|publisher=Scott}}</ref>