Coda
National and international policies have embraced the principle of
conserving 30% of land and water by 2030. To protect biodiversity, this
so-called ‘30×30’ must be achieved in each ecoregion. This can be
achieved through conservation of the large habitat areas that resemble
wilderness, combined with protection and restoration of many small
habitat patches in ecoregions severely affected by human activities. In
fact, in heavily populated and highly human-modified regions, reaching
area targets will be possible only through protection of small patches
and habitat restoration. In such regions, new conservation of many small
areas is essential to get to 30×30, and such areas may represent the
greatest net gains for conservation going forward.
More broadly, realizing 30×30 and other ambitious, collective,
area-based plans will be possible only if we recognize that common
ground far exceeds disagreement among researchers working on area-based
biodiversity conservation. All sides agree that reversing biodiversity
declines cannot be accomplished without conservation and restoration of
native habitat, especially in regions where most native habitat is
already gone. The disagreements are secondary to the general principles
we outline in this letter, and we are confident that they will be
resolved as data accumulate and science progresses. In the meantime, to
address a global biodiversity emergency, proactive implementation of the
unequivocal principles that we all agree upon will bolster our chances
of preserving the Earth’s biodiversity heritage.
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Acknowledgments:
Author contributions:Conceptualization: FR, NH, LF, CBL
Visualization: FR, NH, LF, CBL
Writing – original draft: FR, CBL
Writing – review & editing: FR, NH, LF, CBLCompeting interests:Authors declare that they have no
competing interests.Data and materials availability:No data analysis presented in this
Policy Forum
Supplementary Materials
No supplementary material
Fig. 1. Three principles for area-based biodiversity
conservation. (1) To protect Earth’s biodiversity, we must protect and
restore native habitat in all biomes and ecoregions. Shown are Earth’s
14 biomes. (2) Protecting as much native habitat as possible is our best
way to safeguard biodiversity, and requires protecting both smaller and
larger patches. For instance, while in some tropical biomes forest may
exist in large, continuous patches, other biomes have been reduced to
highly fragmented habitat. Green circles represent habitat patches
separated by anthropogenic land use in two adjacent biomes (green and
blue background); the fading, green area on the bottom-left corner of
the inset represents a large expanse of wilderness. (3) Habitat patches
must be functionally connected. Habitat connectivity can increase with
stepping stone habitat (a), corridors (b), or by reducing distances
between patches (i.e., increasing patch density in the landscape) (c).