Editing Test:SRCCL/Chapter-1 (section)

== 1.1.2.2 Current patterns of land use and land cover ==

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Around three-quarters of the global ice-free land, and most of the highly productive land area, are by now under some form of land use (Erb et al. 2016a <sup>[[#fn:r112|112]]</sup> ; Luyssaert et al. 2014 <sup>[[#fn:r113|113]]</sup> ; Venter et al. 2016 <sup>[[#fn:r114|114]]</sup> ) (Table 1.1). One-third of used land is associated with changed land cover. Grazing land is the single largest land-use category, followed by used forestland and cropland. The total land area used to raise livestock is notable: it includes all grazing land and an estimated additional one-fifth of cropland for feed production (Foley et al. 2011 <sup>[[#fn:r115|115]]</sup> ). Globally, 60–85% of the total forested area is used, at different levels of intensity, but information on management practices globally is scarce (Erb et al. 2016a). Large areas of unused (primary) forests remain only in the tropics and northern boreal zones (Luyssaert et al. 2014 <sup>[[#fn:r116|116]]</sup> ; Birdsey and Pan 2015 <sup>[[#fn:r117|117]]</sup> ; Morales-Hidalgo et al. 2015 <sup>[[#fn:r118|118]]</sup> ; Potapov et al. 2017 <sup>[[#fn:r119|119]]</sup> ; Erb et al. 2017 <sup>[[#fn:r120|120]]</sup> ), while 73–89% of other, non-forested natural ecosystems (natural grasslands, savannahs, etc.) are used. Large uncertainties relate to the extent of forest (32.0–42.5 million km <sup>2</sup> ) and grazing land (39–62 million km <sup>2</sup> ), due to discrepancies in definitions and observation methods (Luyssaert et al. 2014 <sup>[[#fn:r121|121]]</sup> ; Erb et al. 2017; Putz and Redford 2010 <sup>[[#fn:r122|122]]</sup> ; Schepaschenko et al. 2015 <sup>[[#fn:r123|123]]</sup> ; Birdsey and Pan 2015 <sup>[[#fn:r124|124]]</sup> ; FAO 2015a <sup>[[#fn:r125|125]]</sup> ; Chazdon et al. 2016a <sup>[[#fn:r126|126]]</sup> ; FAO 2018a <sup>[[#fn:r127|127]]</sup> ). Infrastructure areas (including settlements, transportation and mining), while being almost negligible in terms of extent, represent particularly pervasive land-use activities, with far-reaching ecological, social and economic implications (Cherlet et al. 2018 <sup>[[#fn:r128|128]]</sup> ; Laurance et al. 2014 <sup>[[#fn:r129|129]]</sup> ).

The large imprint of humans on the land surface has led to the definition of anthromes, i.e. large-scale ecological patterns created by the sustained interactions between social and ecological drivers. The dynamics of these ‘anthropogenic biomes’ are key for land-use impacts as well as for the design of integrated response options (Ellis and Ramankutty 2008 <sup>[[#fn:r130|130]]</sup> ; Ellis et al. 2010 <sup>[[#fn:r131|131]]</sup> ; Cherlet et al. 2018 <sup>[[#fn:r132|132]]</sup> ; Ellis et al. 2010 <sup>[[#fn:r133|133]]</sup> ) (Chapter 6).

The intensity of land use varies hugely within and among different land-use types and regions. Averaged globally, around 10% of the ice-free land surface was estimated to be intensively managed (such as tree plantations, high livestock density grazing, large agricultural inputs), two-thirds moderately and the remainder at low intensities (Erb et al. 2016a <sup>[[#fn:r134|134]]</sup> ). Practically all cropland is fertilised, with large regional variations. Irrigation is responsible for 70% of ground- or surface-water withdrawals by humans (Wisser et al. 2008 <sup>[[#fn:r135|135]]</sup> ; Chaturvedi et al. 2015 <sup>[[#fn:r136|136]]</sup> ; Siebert et al. 2015 <sup>[[#fn:r137|137]]</sup> ; FAOSTAT 2018 <sup>[[#fn:r138|138]]</sup> ). Humans appropriate one-quarter to one-third of the total potential net primary production (NPP), i.e. the NPP that would prevail in the absence of land use (estimated at about 60 GtC yr <sup>–1</sup> ; Bajželj et al. 2014 <sup>[[#fn:r139|139]]</sup> ; Haberl et al. 2014 <sup>[[#fn:r140|140]]</sup> ), about equally through biomass harvest and changes in NPP due to land management. The current total of agricultural (cropland and grazing) biomass harvest is estimated at about 6 GtC yr <sup>–1</sup> , around 50–60% of this is consumed by livestock. Forestry harvest for timber and wood fuel amounts to about 1 GtC yr <sup>–1</sup> (Alexander et al. 2017 <sup>[[#fn:r141|141]]</sup> ; Bodirsky and Müller 2014 <sup>[[#fn:r142|142]]</sup> ; Lassaletta et al. 2014 <sup>[[#fn:r143|143]]</sup> , 2016; Mottet et al. 2017 <sup>[[#fn:r144|144]]</sup> ; Haberl et al. 2014 <sup>[[#fn:r145|145]]</sup> ; Smith et al. 2014 <sup>[[#fn:r146|146]]</sup> ; Bais et al. 2015 <sup>[[#fn:r147|147]]</sup> ; Bajželj et al. 2014 <sup>[[#fn:r148|148]]</sup> ) (Cross-Chapter Box 7 in Chapter 6).

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====== Table 1.1 ======

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==== Extent of global land use and management around the year 2015. ====

[[File:e3d41fd1998d4fdcd307deb1ab7a72f4 table-1.1a.png|thumb|400x300px]] [[File:79f4c97e80bcbf7bab026e72f3ea760c table-1.1b.png|thumb|400x300px]]

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