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{{short description|Amount of land area covered by forest}}
'''Forest cover''' is the amount of [[land area]] that is covered by [[forest]]. It may be measured as relative (in [[percent]]) or absolute (in [[square kilometre]]s/[[square mile]]s). Around a third of the world's surface is covered with forest, with closed-canopy forest accounting for 4 - 5 billion hectares of land.<ref>{{Cite web|title=Forest Cover - an overview {{!}} ScienceDirect Topics|url=https://www.sciencedirect.com/topics/earth-and-planetary-sciences/forest-cover|access-date=2021-11-12|website=www.sciencedirect.com}}</ref>

== Definition ==

According to the [[UN Food and Agriculture Organization]] (FAO), a forest is defined as land spanning more than {{convert|0.5|ha|acre}} with trees higher than {{convert|5|m|ft}} and a canopy cover of more than 10%, or trees able to reach these thresholds ''in situ''. It does not include land that is predominantly under agricultural or urban land use.<ref>{{Cite book|url=http://www.fao.org/3/I8661EN/i8661en.pdf|title=Global Forest Resources Assessment 2020 – Terms and definitions|publisher=FAO|year=2018|location=Rome}}</ref>

{{quote|Forest cover is one category of terrestrial [[land cover]]. ... [it] is defined as 25% or greater canopy closure at the [[Landsat]] pixel scale (30-m × 30-m spatial resolution) for trees >5 m in height|Hansen et al., 2010<ref>{{cite journal | last1=Hansen | first1=M. C. | last2=Stehman | first2=S. V. | last3=Potapov | first3=P. V. | title=Quantification of global gross forest cover loss | journal=Proceedings of the National Academy of Sciences | volume=107 | issue=19 | date=2010-04-26 | issn=0027-8424 | doi=10.1073/pnas.0912668107 | pmid=20421467 | pages=8650–8655 | pmc=2889354 | doi-access=free }}</ref>}}

== Ecological impact ==

Global forest cover, however crucial for [[soil health]], the [[water cycle]], [[climate]] and [[air quality]] it is, is severely threatened by [[deforestation]], as a direct consequence of [[agriculture]], [[grazing]],<ref>{{Cite book|url=http://www.fao.org/documents/card/en/c/ffed061b-82e0-4c74-af43-1a999a443fbf|title=State of the World's Forests 2016|publisher=FAO|year=2016|isbn=978-92-5-109208-8|location=Rome}}</ref> and [[mining]].<ref name="World Resources Institute 2017">{{cite web | title=Global Tree Cover Loss Rose 51 Percent in 2016 | website=World Resources Institute | date=2017-10-23 | url=http://www.wri.org/blog/2017/10/global-tree-cover-loss-rose-51-percent-2016 | access-date=2018-02-16}}</ref>
Forest cover can be increased by [[reforestation]] and [[afforestation]] efforts, but it is virtually impossible to restore the full range of [[ecological service]]s once natural forests are converted to other land uses.

== Extent ==

Since the onset of agriculture (about 12,000 years ago), the number of trees worldwide has dropped by 46%, according to one research published in 2018.<ref>{{cite journal |last1=Ehrenberg |first1=Rachel |title=Global forest survey finds trillions of trees |url=https://www.nature.com/news/global-count-reaches-3-trillion-trees-1.18287 |journal=Nature |language=en |doi=10.1038/nature.2015.18287 |date=2 September 2015|s2cid=189415504 }}</ref>

Global forest cover now has been estimated to be just 31% or {{convert|40 |e6sqkm|e6sqmi|abbr=unit}} in 2006<ref name="unep">{{cite web | url = http://www.unep.org/vitalforest/Report/VFG-01-Forest-definition-and-extent.pdf | archive-url = https://web.archive.org/web/20100726140947/http://www.unep.org/vitalforest/Report/VFG-01-Forest-definition-and-extent.pdf | url-status = dead | archive-date = 2010-07-26 | title = Forest definition and extent | date = 2010-01-27 | publisher = United Nations Environment Programme | access-date = 2014-11-16 }}</ref> with 12-yearly losses (2000-2012) amounting to {{convert|2.3|e6sqkm|e6sqmi|abbr=unit}} and reforestation gains about {{convert|0.8|e6sqkm|e6sqmi|abbr=unit}}.<ref name="Hansen Potapov Moore Hancher 2013 pp. 850–853">{{cite journal | last1=Hansen | first1=M. C. | last2=Potapov | first2=P. V. | last3=Moore | first3=R. | last4=Hancher | first4=M. | last5=Turubanova | first5=S. A. | last6=Tyukavina | first6=A. | last7=Thau | first7=D. | last8=Stehman | first8=S. V. | last9=Goetz | first9=S. J. | last10=Loveland | first10=T. R. | last11=Kommareddy | first11=A. | last12=Egorov | first12=A. | last13=Chini | first13=L. | last14=Justice | first14=C. O. | last15=Townshend | first15=J. R. G. | title=High-Resolution Global Maps of 21st-Century Forest Cover Change | journal=Science | volume=342 | issue=6160 | date=2013-11-15 | issn=0036-8075 | pmid=24233722 | doi=10.1126/science.1244693 | pages=850–853 | s2cid=23541992 }}</ref> According to the FAO's ''Global Forest Resources Assessment 2020'', the world has a total [[forest area]] of {{convert|4.06|e9ha|e9acre|abbr=none}}, which is 31% of the total land area.<ref name=":0">{{Cite book|title=Global Forest Resources Assessment 2020 – Key findings|publisher=FAO|year=2020|isbn=978-92-5-132581-0|location=Rome|doi=10.4060/ca8753en}}</ref>

More than half (54%) of the world’s forests are found in only five countries ([[Brazil]], [[Canada]], [[China]], [[Russia]] and the [[USA]]).<ref>{{Cite book|url=https://doi.org/10.4060/ca8985en|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|pages=7|doi=10.4060/ca8985en}}</ref><ref name=":0" />

The largest part of the forest (45%) is found in the tropical domain, followed by the boreal, temperate and subtropical domains. These domains are further divided into terrestrial global ecological zones, 20 of which contain some forest cover. Almost half the forest area (49%) is relatively intact, while 9% is found in fragments with little or no connectivity. [[Tropical rainforests]] and boreal [[coniferous forests]] are the least fragmented, whereas [[subtropical dry forest]] and temperate oceanic forests are among the most fragmented. Roughly 80% of the world’s forest area is found in patches larger than {{convert|1|e6ha|e6acre|abbr=none}}. The remaining 20% is located in more than 34 million patches across the world – the vast majority less than {{convert|1000|ha|acre}} in size.<ref>{{Cite book|url=https://doi.org/10.4060/ca8985en|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|pages=7–9|doi=10.4060/ca8985en}}</ref>

The world’s total growing stock of trees decreased slightly, from {{convert|560|e9m3|abbr=unit}} in 1990 to {{convert|557|e9m3|abbr=unit}} in 2020, due to a net decrease in forest area. On the other hand, growing stock is increasing per unit area globally and in all regions; it rose from 132 m3 per ha in 1990 to 137 m3 per ha in 2020. Growing stock per unit area is highest in the tropical forests of South and Central America and West and Central Africa.<ref name=":0" />

==See also==
* By country:
**[[Forest cover by state in the United States]]
**[[Forest cover by state or territory in Australia]]
**[[Forest cover by province or territory in Canada]]
**[[Forest cover by state in India]]
**[[Forest cover by federal subject in Russia]]
*[[List of countries by forest area]]
*[[:Category:Forests by country]]
*[[Deforestation by region]]
*[[Cover crop]]
*[[Plant cover]]
*[[Continuous cover forestry]]
*[[Sustainable forestry]]

== Sources ==
{{Free-content attribution
| title = Global Forest Resources Assessment 2020 Key findings
| author = FAO
| publisher = FAO
| page numbers =
| source =
| documentURL = http://www.fao.org/3/CA8753EN/CA8753EN.pdf
| license statement URL = https://commons.wikimedia.org/wiki/File:Global_Forest_Resources_Assessment_2020_%E2%80%93_Key_findings.pdf
| license = CC BY-SA 3.0
}}

{{Free-content attribution
| title = The State of the World’s Forests 2020. In brief – Forests, biodiversity and people
| author = FAO & UNEP
| publisher = FAO & UNEP
| page numbers =
| source =
| documentURL = https://doi.org/10.4060/ca8985en
| license statement URL = https://commons.wikimedia.org/wiki/File:The_State_of_the_World%E2%80%99s_Forests_2020._In_brief.pdf
| license = CC BY-SA 3.0
}}

==References==
{{reflist}}

==External links==

* {{cite web | title=Interactive Map | website=Global Forest Watch | date=2014-07-28 | url=http://www.globalforestwatch.org/map/ | access-date=2018-02-16}}

{{Deforestation}}
{{Forestry by country}}

[[Category:Deforestation]]
[[Category:Forests]]

Forest cover - Revision history

ImportMaster at 07:14, 12 November 2021