Invasives: classify with care.

A statement made by Davis and Coauthors ([ 1 ][1]) last month urged “conservationists and land managers to organize priorities around whether species are producing benefits or harm to biodiversity, human health, ecological services and economies.” In the ensuing tumult, their ideas have become obfuscated by semantics. In the Letter “Invasives: A major conservation threat” (22 July, p. [404][2]), M. Lambertini et al. accuse Davis et al. of “propos[ing] downsizing the struggle against invasives.” This description is misleading. There are many terms to describe non-native species, the degree to which they thrive in their new environment, and their impacts on ecosystems. The word “invasive” is explicitly defined in mainstream textbooks and the invasion literature as “exotic species that have successfully invaded (or are likely to invade) an ecosystem, causing significant ecological, economic, or human health problems” ([ 2 ][3]). In fact, Davis et al. never used the word “invasive.” In the midst of this debate [e.g., ([ 3 ][4]–[ 5 ][5])], it is important to keep the arguments clear. Davis et al. are not suggesting a way forward to deal with invasive species, as Lambertini et al. claim. Rather, they are reflecting an idea shared by most managers and decision-makers: Species management decisions should be based on goals for the area in question, not solely on the native or nonnative classification of the species. 1. [↵][6]1. M. A. Davis 2. et al ., Nature 474, 153 (2011). [OpenUrl][7][CrossRef][8][PubMed][9][Web of Science][10] 2. [↵][11]1. M. L. Hunter Jr., 2. J. P. Gibbs , Fundamentals of Conservation Biology (Blackwell Publishing, Malden, MA, 2007). 3. [↵][12]1. D. Simberloff , Nature 475, 36 (2011). [OpenUrl][13][PubMed][14] 4. 1. A. Alyokhin , Nature 475, 36 (2011). [OpenUrl][13][PubMed][14] 5. [↵][15]1. J. L. Lockwood, 2. M. F. Hoopes, 3. M. P. Marchetti , Nature 475, 36 (2011). [OpenUrl][13][PubMed][14] [1]: #ref-1 [2]: http://www.sciencemag.org/content/333/6041/404.2.full [3]: #ref-2 [4]: #ref-3 [5]: #ref-5 [6]: #xref-ref-1-1 "View reference 1 in text" [7]: {openurl}?query=rft.jtitle%253DNature%26rft.stitle%253DNature%26rft.aulast%253DDavis%26rft.auinit1%253DM.%2BA.%26rft.volume%253D474%26rft.issue%253D7350%26rft.spage%253D153%26rft.epage%253D154%26rft.atitle%253DDon%2527t%2Bjudge%2Bspecies%2Bon%2Btheir%2Borigins.%26rft_id%253Dinfo%253Adoi%252F10.1038%252F474153a%26rft_id%253Dinfo%253Apmid%252F21654782%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [8]: /lookup/external-ref?access_num=10.1038/474153a&link_type=DOI [9]: /lookup/external-ref?access_num=21654782&link_type=MED&atom=%2Fsci%2F333%2F6045%2F936.2.atom [10]: /lookup/external-ref?access_num=000291397800026&link_type=ISI [11]: #xref-ref-2-1 "View reference 2 in text" [12]: #xref-ref-3-1 "View reference 3 in text" [13]: {openurl}?query=rft.jtitle%253DNature%26rft.stitle%253DNature%26rft.aulast%253DAlyokhin%26rft.auinit1%253DA.%26rft.volume%253D475%26rft.issue%253D7354%26rft.spage%253D36%26rft.epage%253D36%26rft.atitle%253DNon-natives%253A%2Bplusses%2Bof%2Binvasion%2Becology.%26rft_id%253Dinfo%253Apmid%252F21734691%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [14]: /lookup/external-ref?access_num=21734691&link_type=MED&atom=%2Fsci%2F333%2F6045%2F936.2.atom [15]: #xref-ref-5-1 "View reference 5 in text"