January 21, 2015 — Conservation biology and restoration ecology have been roiled by a bandwagon termed “novel ecosystems,” heralded as the “new ecological world order” in a manifesto published in 2006 by several ecologists headed by Richard Hobbs, then editor in chief of the journal Restoration Ecology. The claim is that human influences — especially introduced invasive species, land use changes and global climate change — are altering a large proportion of Earth’s ecosystems at unprecedented rates in a way that could cause assemblages of organisms to “tip” towards new steady states, which should be considered as emerging or, to use the catchier phrase, “novel” ecosystems.
Hobbs and colleagues argued that attempting to restore such ecosystems to some semblance of a pristine or pre-disturbance condition is a futile waste of resources. Rather, in their view, restoration ecologists should strive to manage the resulting “novel ecosystems” to maximize services they provide to human populations, such as flood control, carbon sequestration and pollination. This message was taken further in 2010, when journalist Emma Marris proclaimed novel ecosystems the “new normal” and urged scientists and the public to embrace them and rejoice in the things they can do for us. Marris and Hobbs alike suggested that anyone who doesn’t jump on this bandwagon and instead persists in “classical” restoration or conservation is struggling to work through the first stage of grief (shock and denial) after a major loss — in this case, the irreversible loss of biodiversity.
Though recently both have softened their positions somewhat, the damage has been done. Several scientific papers in some of the most influential journals jumped on the bandwagon, and people started to swallow the whole notion without the benefit of evidence or at least proof of concept and use it without further consideration of what it really means. So we think it is important to ask a few fundamental questions to make sure we are not going astray.
First, though, we must define just what a novel ecosystem is, because definitions have been vague and variable. In 2013 Hobbs and co-authors defined a novel ecosystem as “a system of abiotic, biotic, and social components (and their interactions) that, by virtue of human influence, differ from those that prevailed historically, having a tendency to self-organize and manifest novel qualities without intensive human management.” This is basically a definition of an ecosystem (a self-organizing system with biotic and abiotic components) but with a twist: The combination of elements that compose it must be new and caused by humans, and that novelty needs to persist without further human intervention. The problem is, manmade ecosystems that differ from anything historically and provide ecosystem services, such as farms, are not self-organizing, typically depend on many subsidies and do not persist without them.
Are restoration ecologists hopelessly mired in an attempt to re-create an unattainable prelapsarian Eden? Hardly.
In fact, not a single novel ecosystem by this definition has yet been identified. The graphs in the scientific literature all lack numbers on their axes, so it is unclear at what point in terms of anthropogenic disturbance and biotic novelty an ecosystem might qualify as novel. Also, no evidence has been presented that any candidate system tends to self-organize and would persist without humans. Worse, even this definition’s authors do not see a way to make it operational. In a 2009 paper they write, “the distinction between [novel and historic] is somewhat arbitrary, and the exact point at which an ecosystem is considered novel cannot necessarily be universally applied” and “all ecosystems can be considered ‘novel’ when placed in the appropriate temporal context.”
So, are restoration ecologists hopelessly mired in an attempt to re-create an unattainable prelapsarian Eden? Hardly. Restoration ecologists long ago abandoned the idea that nature is static and that any ecosystem would remain unchanged even if humans were not part of the picture. Nowadays, the goal of ecological restoration is to re-establish as closely as possible the historical trajectories of ecosystems before human actions drastically changed them, so that the restored ecosystems can continue to respond to environmental changes as these arise.
Have restoration ecologists somehow been fooled into thinking that ecological restoration is actually worthwhile and necessary to achieve their goals of reversing land degradation? Three decades of results show that, although sometimes expensive, ecological restoration is possible. But can novel ecosystems do better? Can we get novel ecosystems to perform the services we need? And, if they do, is that good enough for conservation purposes? Importantly, even if we could identify novel ecosystems and they provided services for human populations, that would not mean they would also maintain many of the rare and threatened species we are struggling to save. The ecosystem services that humans want are not necessarily those required by a vast swath of biodiversity.
The argument that attempting to restore an ecosystem is futile — despite the fact that it is demonstrably often wrong — and that novel ecosystems can serve our purposes better can only lead policy-makers to be more willing to allow environmentally damaging projects.
Deficiencies in definition and loose verbiage about stable, service-providing novel ecosystems and the futility of “traditional” restoration can serve as a Trojan horse to biodiversity conservation. Without evidence of self-organization and persistence, not to mention of provision of ecosystem services, the novel-ecosystem label can serve as a Get Out of Jail Free card for companies or individuals trying to avoid investing in research, mitigation or restoration by claiming they are producing novel ecosystems that will provide ecosystem services. In Colombia, for instance, a sugarcane grower who had clear-cut forest right to the edge of rivers, thus violating a law, defended the practice on the grounds that the scientists developing the novel-ecosystem concept advocate seeking a new ecosystem, even one with introduced species, rather than restoring the damaged system, so long as the new ecosystem provides a service. This statement, in turn, led other landowners to boycott a government-driven project to restore riparian forest along the Cauca River. The arguments that attempting to restore an ecosystem is futile — despite the fact that it is demonstrably often wrong — and that novel ecosystems can serve our purposes better can only lead policy-makers to be more willing to allow environmentally damaging projects and the public to exert less pressure to prevent habitat destruction.
This rhetoric is quite damaging, considering that various national and international agencies and treaties, including the European Commission and the United Nations’ Convention on Biological Diversity and Convention to Combat Desertification, have called for increasing restoration efforts, and major non-governmental organizations — such as the International Union for Conservation of Nature, The Nature Conservancy, World Resources Institute and World Wide Fund for Nature — have advocated large-scale restoration as part of their global programs to redress the loss of biodiversity and decline of natural ecosystems. More specifically, in 2011 the German government and IUCN challenged the world’s nations to restore 150 million hectares of deforested and degraded lands by 2020. Brazil intends to restore 15 million hectares, and seven Latin American countries have pledged to restore 20 million more. Are all these countries and international institutions out of touch with reality or misguided by sentimental scientists?
Again, hardly. In fact, at the end of 2014 Hobbs and colleagues in a scientific article, and Marris and a conservation NGO leader in an op-ed, took a starkly more ecumenical line, saying that traditional restoration can play a role alongside novel ecosystems in the new ecological world order they claim is upon us.
It remains to be seen how this new attitude will play out in terms of preserving or recovering the nonanthropogenic ecosystems upon which so much of biodiversity, including many of the most imperiled species, critically depends. One can only hope that it will shift the balance in favor of respecting — and, as appropriate, restoring — these ecosystems before it’s too late.