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RESEARCH ◥ benign ecosystem shifts that will cause no sub- REVIEW SUMMARY stantial loss of ecosystem function or services. Conservation success will also increasingly hinge on choosing among different, sometimes CONSERVATION mutually exclusive approaches to best achieve ◥ three conceptually distinct Merging paleobiology with ON OUR WEBSITE goals: maximizing biodi- Read the full article versity, maximizing ecosys- at http://dx.doi. tem services, and preserving conservation biology to guide the org/10.1126/ wilderness. These goals vary science.aah4787 in applicability depending .................................................. future of terrestrial ecosystems on whether historical or novel ecosystems are the conservation target. — Anthony D. Barnosky,* Elizabeth A. Hadly, Patrick Gonzalez, Jason Head, Tradeoffs already occur for example, man- P. David Polly, A. Michelle Lawing, Jussi T. Eronen, David D. Ackerly,† Ken Alex, aging to maximize certain ecosystem services Eric Biber, Jessica Blois, Justin Brashares, Gerardo Ceballos, Edward Davis, upon which people depend (such as food Gregory P. Dietl, Rodolfo Dirzo, Holly Doremus, Mikael Fortelius, Harry W. Greene, production on farm or rangelands) versus main- Jessica Hellmann, Thomas Hickler, Stephen T. Jackson, Melissa Kemp, Paul L. Koch, taining healthy populations of vulnerable species Claire Kremen, Emily L. Lindsey, Cindy Looy, Charles R. Marshall, Chase Mendenhall, (such as wolves, lions, or elephants). In the fu- Andreas Mulch, Alexis M. Mychajliw, Carsten Nowak, Uma Ramakrishnan, ture, the choices will be starker, likely involving Jan Schnitzler, Kashish Das Shrestha, Katherine Solari, Lynn Stegner, decisions such as which species are candidates M. Allison Stegner, Nils Chr. Stenseth, Marvalee H. Wake, Zhibin Zhang for managed relocation and to which areas, and whether certain areas should be off limits for intensive management, even if it means losing BACKGROUND: The pace and magnitude of exhibited over their long histories. Such infor- some species that now live there. Developing the human-caused global change has accelerated mation is necessary for recognizing which cur- capacity to make those choices will require con- on February 9, 2017 dramatically over the past 50 years, overwhelm- rent changes foretell transitions to less robust servation in both historical and novel ecosystems ing the capacity of many ecosystems and spe- ecological states and which changes may signal and effective collaboration of scientists, govern- cies to maintain themselves as they have under mental officials, nongovernmental organizations, the more stable conditions that prevailed for at the legal community, and other stakeholders. least 11,000 years. The next few decades threat- en even more rapid transformations because OUTLOOK: Conservation efforts are currently by 2050, the human population is projected to in a state of transition, with active debate about grow by 3 billion while simultaneously increas- therelativeimportanceofpreservinghistorical ing per capita consumption. Thus, to avoid landscapes with minimal human impact on one losing many species and the crucial aspects of end of the ideological spectrum versus ma- ecosystems that we need—for both our physical nipulating novel ecosystems that result from and emotional well-being—new conservation human activities on the other. Although the http://science.sciencemag.org/ paradigms and integration of information from two approaches are often presented as dichot- conservation biology, paleobiology, and the omous, in fact they are connected by a con- Earth sciences are required. tinuum of practices, and both are needed. In most landscapes, maximizing conservation suc- ADVANCES: Rather than attempting to hold cess will require more integration of paleo- ecosystems to an idealized conception of the biology and conservation biology because in past, as has been the prevailing conservation a rapidly changing world, a long-term perspec- Downloaded from paradigm until recently, maintaining vibrant tive (encompassing at least millennia) is necessary ecosystems for the future now requires new to specify and select appropriate conservation approaches that use both historical and novel targets and plans. Although adding this long- conservation landscapes, enhance adaptive ca- term perspective will be essential to sustain bio- pacity for ecosystems and organisms, facilitate diversity and all of the facets of nature that connectedness, and manage ecosystems for humans need as we continue to rapidly change functional integrity rather than focusing en- the world over the next few decades, maximizing tirely on particular species. Scientific break- the chances of success will also require dealing throughs needed to underpin such a paradigm Fewer than 900 mountain gorillas are left with the root causes of the conservation crisis: shift are emerging at the intersection of ecol- in the world, and their continued existence rapid growth of the human population, increasing ogy and paleobiology, revealing (i) which species depends upon the choices humans make, per capita consumption especially in developed and ecosystems will need human intervention exemplifying the state of many species and countries, and anthropogenic climate change to persist; (ii) how to foster population connec- ecosystems. Can conservation biology save bio- that is rapidly pushing habitats outside the ’ tivity that anticipates rapidly changing climate diversity and all the aspects of nature that bounds experienced by today s species.▪ and land use; (iii) functional attributes that people need and value as 3 billion more of us characterize ecosystems through thousands to are added to the planet by 2050, while climate The list of author affiliations is available in the full article online. millions of years, irrespective of the species that continues to change to states outside the bounds *Corresponding author. Email: [email protected] † ’ Authors after the first seven are listed alphabetically. are involved; and (iv) the range of compositional that most of today s ecosystems have ever Cite this article as A. D. Barnosky et al., Science 355, and functional variation that ecosystems have experienced? eaah4787 (2017). DOI: 10.1126/science.aah4787 PHOTO: E. A. HADLY, AT VOLCANOES NATIONAL PARK, RWANDA Barnosky et al., Science 355, 594 (2017) 10 February 2017 1of1 RESEARCH ◥ ecosystems to adapt to current and impending REVIEW changes (4–11). Recent work highlights that achieving such goals will require understanding how ecological CONSERVATION dynamics play out over time scales much longer than a human lifetime (12). Such information has long been known to be available from historical, Merging paleobiology with paleobiological, and geological records (10, 13). However, scientists and land managers are still grappling with how to more fully integrate paleo- conservation biology to guide the biological information into conservation theory future of terrestrial ecosystems and decisions (Fig. 1). The current conservation landscape Anthony D. Barnosky,1,2* Elizabeth A. Hadly,3 Patrick Gonzalez,4,5 Jason Head,6 More than half of Earth’s ice-free land has been P. David Polly,7 A. Michelle Lawing,8 Jussi T. Eronen,9,10 David D. Ackerly,11† converted for human use (14), tens of thousands Ken Alex,12 Eric Biber,13 Jessica Blois,14 Justin Brashares,15 Gerardo Ceballos,16 of species have been transported around the globe Edward Davis,17 Gregory P. Dietl,18,19 Rodolfo Dirzo,20 Holly Doremus,21 (15), and species and populations are going ex- Mikael Fortelius,22,23 Harry W. Greene,24 Jessica Hellmann,25 Thomas Hickler,26 tinct at highly elevated rates (16). As a result, Stephen T. Jackson,27 Melissa Kemp,28 Paul L. Koch,29 Claire Kremen,30 much if not most of the planet is now covered 6 — Emily L. Lindsey,31‡ Cindy Looy,32 Charles R. Marshall,33 Chase Mendenhall,34,35 by novel ecosystems (Fig. 1D) ( ) that is, those Andreas Mulch,36,37 Alexis M. Mychajliw,38 Carsten Nowak,39 Uma Ramakrishnan,40 with assemblages of species or other character- Jan Schnitzler,41,42 Kashish Das Shrestha,43 Katherine Solari,44 Lynn Stegner,45 istics that did not exist before preindustrial times, which human activities have created, either in- M. Allison Stegner,46§ Nils Chr. Stenseth,47 Marvalee H. Wake,48 Zhibin Zhang49 tentionally or inadvertently. Here, we include as novel ecosystems cropland, pastureland, timber Conservation of species and ecosystems is increasingly difficult because anthropogenic plantations, and land modified by logging and on February 9, 2017 impacts are pervasive and accelerating. Under this rapid global change, maximizing human-caused erosion and sedimentation, in total conservation success requires a paradigm shift from maintaining ecosystems in idealized covering ~47% of ice-free land (14). Urban and past states toward facilitating their adaptive and functional capacities, even as species ruralcommunities,roads,reservoirs,railways,and ebb and flow individually. Developing effective strategies under this new paradigm will mining areas account for an additional ~7% (14). require deeper understanding of the long-term dynamics that govern ecosystem Historical ecosystems are defined loosely as persistence and reconciliation of conflicts among approaches to conserving historical thosepresumedtobeoperatingastheyhavefor versus novel ecosystems. Integrating emerging information from conservation biology, at least centuries (Fig. 1B) (6). They include some paleobiology, and the Earth sciences is