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, 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 highly
human-modified regions, reaching area targets will be possible only
through protection of small patches and habitat restoration. In such
regions, conservation and restoration of many small areas is essential
to get to 30×30, and such areas may represent
the greatest net gains for
area-based habitat conservation
going forward.
More broadly, realizing 30×30 and other ambitious, collective,
area-based plans will be possible only through coordination (Eckertet al. 2023) and if we promptly recognize common ground among
researchers working on biodiversity conservation. Ongoing disagreements
such as the fragmentation debate 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
shared principles will bolster our chances of preserving the Earth’s
biodiversity heritage.
References
Albert, J.S., Carnaval, A.C., Flantua, S.G.A., Lohmann, L.G., Ribas,
C.C., Riff, D., et al. (2023). Human impacts outpace natural
processes in the Amazon. Science , 379, eabo5003.
Arroyo-Rodríguez, V., Fahrig, L., Tabarelli, M., Watling, J.I.,
Tischendorf, L., Benchimol, M., et al. (2020). Designing optimal
human-modified landscapes for forest biodiversity conservation.Ecol. Lett. , 23, 1404–1420.
Balmford, A. (2021). Concentrating vs. spreading our footprint: how to
meet humanity’s needs at least cost to nature. J. Zool. (1987) ,
315, 79–109.
Banks-Leite, C., Betts, M.G., Ewers, R.M., Orme, C.D.L. & Pigot, A.L.
(2022). The macroecology of landscape ecology. Trends Ecol. Evol.
Basso, B. & Antle, J. (2020). Digital agriculture to design sustainable
agricultural systems. Nat. Sustain. , 3, 254–256.
Bateman, I. & Balmford, A. (2023). Current conservation policies risk
accelerating biodiversity loss. Nature , 618, 671–674.
Bellotto-Trigo, F.C., Uezu, A., Hatfield, J.H., Morante-Filho, J.C., dos
Anjos, L., Develey, P.F., et al. (2023). Intraspecific variation
in sensitivity to habitat fragmentation is influenced by forest cover
and distance to the range edge. Biol. Conserv. , 284, 110167.
Betts, M.G., Wolf, C., Pfeifer, M., Banks-Leite, C., Arroyo-Rodríguez,
V., Ribeiro, D.B., et al. (2019). Extinction filters mediate the
global effects of habitat fragmentation on animals. Science , 366,
1236–1239.
Betts, M.G., Yang, Z., Hadley, A.S., Smith, A.C., Rousseau, J.S.,
Northrup, J.M., et al. (2022). Forest degradation drives
widespread avian habitat and population declines. Nat Ecol Evol ,
6, 709–719.
Diamond, J.M. (1975). The island dilemma: Lessons of modern
biogeographic studies for the design of natural reserves. Biol.
Conserv. , 7, 129–146.
Eckert, I., Brown, A., Caron, D., Riva, F. & Pollock, L.J. (2023).
30×30 biodiversity gains rely on national coordination. Nat.
Commun. , 14, 7113.
Fahrig, L. (2017). Ecological Responses to Habitat Fragmentation Per Se.
Fahrig, L. (2023). Patch‐scale edge effects do not indicate
landscape‐scale fragmentation effects. Conserv. Lett.
Fahrig, L., Arroyo-Rodríguez, V., Bennett, J.R., Boucher-Lalonde, V.,
Cazetta, E., Currie, D.J., et al. (2019). Is habitat
fragmentation bad for biodiversity? Biol. Conserv. , 230,
179–186.
Fletcher, R.J., Jr, Didham, R.K., Banks-Leite, C., Barlow, J., Ewers,
R.M., Rosindell, J., et al. (2018). Is habitat fragmentation good
for biodiversity? Biol. Conserv. , 226, 9–15.
Haddad, N.M., Brudvig, L.A., Clobert, J., Davies, K.F., Gonzalez, A.,
Holt, R.D., et al. (2015). Habitat fragmentation and its lasting
impact on Earth’s ecosystems. Sci. Adv. , 1, e1500052.
Hortal, J., de Bello, F., Diniz-Filho, J.A.F., Lewinsohn, T.M., Lobo,
J.M. & Ladle, R.J. (2015). Seven shortfalls that beset large-scale
knowledge of biodiversity. Annu. Rev. Ecol. Evol. Syst. , 46,
523–549.
Olson, D.M., Dinerstein, E., Wikramanayake, E.D., Burgess, N.D., Powell,
G.V.N., Underwood, E.C., et al. (2001). Terrestrial ecoregions of
the world: A new map of life on earth. Bioscience , 51, 933.
Plumptre, A.J., Fuller, R.A., Rwetsiba, A., Wanyama, F., Kujirakwinja,
D., Driciru, M., et al. (2014). Efficiently targeting resources
to deter illegal activities in protected areas. J. Appl. Ecol. ,
51, 714–725.
Richardson, K., Steffen, W., Lucht, W., Bendtsen, J., Cornell, S.E.,
Donges, J.F., et al. (2023). Earth beyond six of nine planetary
boundaries. Sci. Adv. , 9, eadh2458.
Riva, F. & Fahrig, L. (2022). The disproportionately high value of
small patches for biodiversity conservation. Conservation
Letters .
Riva, F. & Fahrig, L. (2023a). Landscape-scale habitat fragmentation is
positively related to biodiversity, despite patch-scale ecosystem decay.Ecol. Lett. , 26, 268–277.
Riva, F. & Fahrig, L. (2023b). Obstruction of biodiversity conservation
by minimum patch size criteria. Conserv. Biol.
Riva, F., Martin, C.J., Millard, K. & Fahrig, L. (2022). Loss of the
world’s smallest forests. Glob. Chang. Biol. , 28, 7164–7166.
Scholtz, R. & Twidwell, D. (2022). The last continuous grasslands on
Earth: Identification and conservation importance. Conserv. Sci.
Pract. , 4.
Schwartz, M.W. (1999). Choosing the appropriate scale of reserves for
conservation. Annu. Rev. Ecol. Syst. , 30, 83–108.
Shafer, C.L. (1995). Values and shortcomings of small reserves.Bioscience , 45, 80–88.
Simberloff, D.S. & Abele, L.G. (1976). Island biogeography theory and
conservation practice. Science , 191, 285–286.
Terborgh, J. (1974). Preservation of natural diversity: The problem of
extinction prone species. Bioscience , 24, 715–722.
Tilman, D., Isbell, F. & Cowles, J.M. (2014). Biodiversity and
ecosystem functioning. Annu. Rev. Ecol. Evol. Syst. , 45,
471–493.
Zemp, D.C., Guerrero-Ramirez, N., Brambach, F., Darras, K., Grass, I.,
Potapov, A., et al. (2023). Tree islands enhance biodiversity and
functioning in oil palm landscapes. Nature , 618, 316–321.