James A. Estes Michael E. Soule 2005 <p class="chapter-para">The letter from Kimberly Heiman points out the applicability of our framework to nonnative invasive species. Indeed, many alien species are changing the sign and increasing the amplitude of strong interactions in contemporary ecosystems, in some cases catastrophically. Invasive exotic species require much more attention at the policy and administrative levels.</p> application/pdf 10.1641/0006-3568(2005)055[0549:RFSAE]2.0.CO;2 en Oxford Academic Press Response from Soulé and Estes article