Novel ecosystems: concept or inconvenient reality? A response to Murcia et al.

We are concerned by mischaracterizations, misrepresentations, and selective uses of evidence in a recent critical opinion of ‘the novel ecosystems concept’ [1]. Murcia et al. contend that the concept is poorly developed, has no evidence base, and has little management application and potential negative policy impacts. However, it is more accurate to observe that conceptual development is ongoing (as would be expected in a relatively new area of endeavor), empirical evidence is mounting, many managers find the ideas useful for framing what they observe on the ground, and negative policy impacts are feared rather than observed, despite the growing attention that novel ecosystems are receiving. Murcia et al.’s mischaracterizations risk entrenching objections that fail to address urgent conservation and restoration needs in an era of rapid environmental, ecological, and cultural change. The concept of novel ecosystems, in its various formulations, is based on the fact of novel ecosystems: there is indisputable evidence that some ecosystems have departed entirely and irreversibly from their historical analogs (e.g., the recent examples in [2–4]). This (unfortunate) reality has led us, and other researchers and practitioners, to consider how traditional practices in conservation and restoration might adapt and whether new practices are required [5]. In particular, attention needs to be focused on intransigent ecosystems that are unresponsive to restorative measures because of directional changes in environmental conditions or have persistent assemblages of alien species for which removal is practically impossible. Some of these new ecosystems clearly have ecological and cultural value (e.g., [6]). These constitute increasingly difficult conservation and restoration conundrums for which new thinking is required. As noted elsewhere, recognizing the need to address these conundrums does not constitute a willingness to give up entirely on conventional methods [7,8]. Examples of hybrid and novel ecosystems are mounting rapidly in the ecological literature, and there are ongoing discussions regarding how to modify current management and policy to deal with the rapid changes being observed on the ground. The concept of novel ecosystems is finding traction with practitioners who wrestle with altered ecosystems on a daily basis. Decisions are almost always made