Editing Carrying capacity (section)

==Origins==
In terms of [[population dynamics]], the term 'carrying capacity' was not explicitly used in 1838 by the [[Belgians|Belgian]] [[mathematician]] [[Pierre François Verhulst]] when he first published his equations based on research on modelling population growth.<ref name="Verhulst1838">{{cite journal |first=Pierre-François |last=Verhulst |author-link=Pierre François Verhulst |year= 1838 |title=Notice sur la loi que la population poursuit dans son accroissement |journal = Correspondance Mathématique et Physique |volume = 10 |pages = 113–121 |url = https://books.google.com/books?id=8GsEAAAAYAAJ |format = PDF |access-date = 3 December 2014}}</ref>

The origins of the term "carrying capacity" are uncertain, with sources variously stating that it was originally used "in the context of international [[shipping]]" in the 1840s,<ref name="Berkshire-2012">{{Cite book|title=Berkshire encyclopedia of sustainability.|date=2010–2012|publisher=Berkshire Publishing Group|isbn=978-1-933782-01-0|location=Great Barrington, MA|oclc=436221172}}</ref><ref name="informaworld.com">{{cite journal |last1=Sayre |first1=N. F. |year=2008 |title=The Genesis, History, and Limits of Carrying Capacity |journal=Annals of the Association of American Geographers |volume=98 |issue=1 |pages=120–134 |doi=10.1080/00045600701734356|s2cid=16994905 |jstor=25515102}}</ref> or that it was first used during 19th-century laboratory experiments with micro-organisms.<ref>{{Cite journal |url=http://dusk.geo.orst.edu/prosem/PDFs/human_geog.pdf |archive-url=https://web.archive.org/web/20110719152701/http://dusk.geo.orst.edu/prosem/PDFs/human_geog.pdf |archive-date=2011-07-19 |url-status=live |doi=10.1111/j.1467-8306.1994.tb01731.x|title=Human Geography and the "New Ecology": The Prospect and Promise of Integration|journal=Annals of the Association of American Geographers|volume=84|pages=108–125|year=1994|last1=Zimmerer|first1=Karl S.}}</ref> A 2008 review finds the first use of the term in English was an 1845 report by the [[US Secretary of State]] to the [[US Senate]]. It then became a term used generally in biology in the 1870s, being most developed in wildlife and [[livestock]] management in the early 1900s.<ref name="informaworld.com"/> It had become a staple term in ecology used to define the biological limits of a natural system related to population size in the 1950s.<ref name="Berkshire-2012" /><ref name="informaworld.com"/>

[[Neo-Malthusians]] and [[eugenicist]]s popularised the use of the words to describe the number of people the Earth can support in the 1950s,<ref name="informaworld.com"/> although American [[Biostatistics|biostatisticians]] [[Raymond Pearl]] and [[Lowell Reed]] had already applied it in these terms to human populations in the 1920s.<ref>{{Cite journal |last=Pearl |first=Raymond |last2=Reed |first2=Lowell J. |date=June 1920 |title=On the Rate of Growth of the Population of the United States since 1790 and Its Mathematical Representation1 |url=https://www.pnas.org/doi/10.1073/pnas.6.6.275 |journal=Proceedings of the National Academy of Sciences |volume=6 |issue=6 |pages=275–288 |doi=10.1073/pnas.6.6.275 |pmc=1084522 |pmid=16576496}}</ref>

Hadwen and Palmer (1923) defined carrying capacity as the density of stock that could be [[Grazing|grazed]] for a definite period without damage to the range.<ref name=Dhondt1988>{{cite journal |last1=Dhondt |first1=André A. |date=January 1988 |title=Carrying capacity - a confusing concept |url=https://www.researchgate.net/publication/229192031 |journal=Acta Oecologica |volume=9 |issue=4 |pages=337–346 |doi= |access-date=19 March 2021}}</ref><ref name=McLeod1997>{{cite journal |last1=McLeod |first1=Steven R. |date=September 1997 |title=Is the Concept of Carrying Capacity Useful in Variable Environments? |journal=Oikos |volume=79 |issue=3 |pages=529–542 |doi=10.2307/3546897 |jstor=3546897|bibcode=1997Oikos..79..529M }}</ref>

It was first used in the context of [[wildlife management]] by the American [[Aldo Leopold]] in 1933, and a year later by the American [[Paul Lester Errington]], a [[wetlands]] specialist. They used the term in different ways, Leopold largely in the sense of grazing animals (differentiating between a 'saturation level', an intrinsic level of density a species would live in, and carrying capacity, the most animals which could be in the field) and Errington defining 'carrying capacity' as the number of animals above which [[predation]] would become 'heavy' (this definition has largely been rejected, including by Errington himself).<ref name=Dhondt1988/><ref>{{cite book |last=Leopold |first=Aldo |author-link=Aldo Leopold |date=1933 |title=Game Management |location=New York |publisher=Charles Sccribener's Sons |page=51 |isbn=}}</ref> The important and popular 1953 [[textbook]] on ecology by [[Eugene Odum]], ''Fundamentals of Ecology'', popularised the term in its modern meaning as the equilibrium value of the logistic model of population growth.<ref name=Dhondt1988/><ref name="Odum1959">{{cite book |last=Odum | first =Eugene P. | author-link =Eugene Odum | title =Fundamentals of Ecology | url =https://archive.org/details/fundamentalsofec0000odum | url-access =registration | edition =2nd | publisher =W. B. Saunders Co. | year =1959 | location =Philadelphia and London | isbn =9780721669410 | oclc =554879 | pages =[https://archive.org/details/fundamentalsofec0000odum/page/183 183]-188}}</ref>