Novel ecosystems: adapting to rapid change

Conservation science is being forced to adapt in the face of increasingly rapid anthropogenic change. In conjunction with this, the novel ecosystems concept provides a refreshingly optimistic discussion point. By accepting the inevitability of planetary changes, advocates are looking at to how conservations’ limited resources can be most effectively utilised.

Socio-wilderness

Human induced environmental changes are tearing apart the fabric of our natural systems, and conservation is increasingly facing an uphill struggle.¹ Consequently, events such a ‘Ocean Optimism’ are organised in an attempt to keep hope alive amongst the conservation community. It seems that the pervasiveness of humanity’s influence knows no bounds, and wilderness is increasingly scarce. However, the novel ecosystems concept poses the notion that it is this attitude that is part of the problem. Although it is true that there are very few areas of the planet untouched by humans, this is not a new phenomenon. Indeed, the widely held conception of wilderness as a place independent of humanity is delusional.² Instead of perpetuating the dichotomy of nature and humanity, the novel ecosystems concept appreciates the complexity, and inevitability of human influenced ecological systems.

Novel ecosystem definitions

Due to the relatively recent emergence of the concept and its ambiguities, definitions of novel ecosystems vary. However, their main advocate amongst the scientific community, Richard Hobbs, defines a novel ecosystem as: “a physical system of abiotic and biotic components (and their interactions) that, by virtue of human influence, differs from those that prevailed historically, having a tendency to self-organize and retain its novelty without future human involvement”.³ In other words, novel ecosystems have been influenced by people to such an extent, that they reach a stage where positive feedbacks reinforce the successions of a new state.

Thresholds and resilience

There is a link to resilience theory, which states that ecosystem stability ensures changes are linear, meaning changes to the environment are proportional to changes in species composition. But when a trigger, for example eutrophication, pushes changes past a threshold, changes are non-linear and dramatic. Communities are shifted into new states, which can be difficult to reverse due to hysteresis, which is where the pathway of degradation differs from the necessary pathway to recovery. This makes life very difficult for conservation.⁴

Examples from Australia and Puerto Rico

As shown in the photograph, one example is in southern Australia, where secondary salinization has led to the replacement of diverse native vegetation with a small number of alien salt tolerant species.

Whilst novel ecosystems are generally characterised by a reduction of wildife, they need not always look this bleak. In the second photograph we can see Puerto Rico’s emerging forests, regenerating on degraded lands, composed largely of non-native species.⁶

The gradient of degradation

Novel ecosystems sit on a gradient of degradation preceded by historic and hybrid ecosystems. Historic ecosystems being landscapes mostly influenced by people, such as areas of the Amazon, and hybrid, areas with some novel features. But distinctions are vague so rather than try to identify the boundaries between states, it is simpler to see ecosystems as existing on a gradient of alteration.⁷

Resource prioritisation and management

Novel ecosystems pose questions as to how environmental management should progress. Advocates of combining the novel ecosystems concept within contemporary conservation science argue that we should minimise spending on degraded ecosystems and instead focus efforts on less impacted areas. Thus, management should account for an ecosystem’s current value and trajectory, and assessments should be made on a case-by-case basis by:

• managing against a historic ecosystem degrading through employing traditional conservation techniques;
• tolerating, through inaction, an ecosystem where management is not essential or there are not the resources to deal with it, relating to a hybrid ecosystem; and
• managing for a novel ecosystem when it is the best alternative. For example, pragmatism may be required when managing non-native species. Their actual or possible damaging impacts (if they have them) should be recognised, but they may be capable of providing the same ecosystem functions as natives, or provide habitat for rare species.⁸

Novel benefits

Managing for novel ecosystems recognises that they can provide novel benefits. A silver lining is in their ability to provide social and cultural ecosystem services for people in urban areas. Most people’s experience of nature is likely to involve novel, or hybrid ecosystems. So, accepting these contrived habitats as legitimate, instead of ‘second class nature’ could help encourage a greater sense of environmental responsibility. The link between physical and mental health and nature has also been known for a long time, so we could capitalise on novel ecosystems’ proximity to residential areas to improve people’s quality of life.⁹

Finding optimism

Whilst the novel ecosystems concept needs to be successfully tested as a management strategy, before it can be incorporated in policy, it provides exciting opportunities for nature conservation when many practitioners struggle to find optimism.

The concept has faced criticism from traditional members of the conservation community because it  challenges existing paradigms and encourages innovation beyond traditional conservation practices and outlooks. However, perhaps we must embrace more dynamic and pragmatic approaches to helping nature and on our fast-changing planet?

Critics of novel ecosystems hope that restoration can tackle the challenges we face, but it may be more realistic to consider that compromises will increasingly be necessary. If novel ecosystems can be managed successfully with minimal intervention, freeing up resources to prevent the degradation of more ‘pristine’ areas of the planet, then I believe they have a place in contemporary conservation science and practice.

References

1. Wiens, John A., and Richard J. Hobbs (2015). Integrating conservation and restoration in a changing world. BioScience3: 302-312 https://academic.oup.com/bioscience/article/65/3/302/237580

2. Marris, Emma (2009). Ecology: ragamuffin earth. Nature News7254: 450-453 http://izt.ciens.ucv.ve/ecologia/Archivos/ECO_POB%202010/ECOPO7_2010/Marris%202010_II.pdf

3. Hobbs, Richard J., Eric S. Higgs, and Carol Hall (2013). Novel ecosystems: intervening in the new ecological world order. John Wiley & Sons.

4. Suding, Katharine N., and Richard J. Hobbs. “Threshold models in restoration and conservation: a developing framework.” Trends in ecology & evolution5 (2009): 271-279 http://www.zoology.ubc.ca/courses/bio416/Suding&Hobbs_TREE.pdf

5. Briske, David D., Samuel D. Fuhlendorf, and F. E. Smeins (2006). A unified framework for assessment and application of ecological thresholds. Rangeland Ecology & Management3: 225-236 http://jornada-dev.nmsu.edu/files/Briske_thresholds_REM_2006.pdf

6. Hobbs, Richard J., Salvatore Arico, James Aronson, Jill S. Baron, Peter Bridgewater, Viki A. Cramer, Paul R. Epstein et al (2006). Novel ecosystems: theoretical and management aspects of the new ecological world order. Global ecology and biogeography15, no. 1: 1-7 http://www.reginozamora.es/wp-content/uploads/2010/04/GEB2006_15_1-71.pdf

7. Miller, James R., and Brandon T. Bestelmeyer (2016). What’s wrong with novel ecosystems, really? Restoration Ecology5: 577-582 https://www.researchgate.net/profile/Brandon_Bestelmeyer/publication/303296088_What%27s_wrong_with_novel_ecosystems_really_What%27s_wrong_with_novel_ecosystems/links/5834b82808ae102f07395fe3/Whats-wrong-with-novel-ecosystems-really-Whats-wrong-with-novel-ecosystems.pdf

8. Truitt, Amy M., Elise F. Granek, Matthew J. Duveneck, Kaitlin A. Goldsmith, Meredith P. Jordan, and Kimberly C. Yazzie (2015). What is novel about novel ecosystems: managing change in an ever-changing world. Environmental management55, no. 6: 1217-1226 https://www.researchgate.net/profile/Kim_Yazzie/publication/274316903_What_is_Novel_About_Novel_Ecosystems_Managing_Change_in_an_Ever-Changing_World/links/55f32c4608ae7a10cf88b718.pdf

9. Hobbs, Richard J., Eric Higgs, Carol M. Hall, Peter Bridgewater, F. Stuart Chapin, Erle C. Ellis, John J. Ewel et al (2014). Managing the whole landscape: historical, hybrid, and novel ecosystems. Frontiers in Ecology and the Environment12, no. 10: 557-564 https://biblio.ugent.be/publication/7057353/file/7057792.pdf

Jack Farge

The author is studying for an MSc in Conservation Science and Policy at the University of Exeter.
Contact the author