Disturbance regimes are short-term changes to the landscape that can have significant impacts on ecosystems. They can be natural, such as fires and floods. They can be man-made like logging and mining. Conservation activities can disrupt disturbance regimes, potentially impacting ecosystems in both positive and negative ways. The Conservation Foundation has overseen well-thought-out activities that maintain the positive aspects of disturbance regimes, minimize their negative effects, and help prevent some from occurring. Let’s delve into all of this.
Disturbances
A disturbance is an ecosystem perturbation that causes a pronounced ecosystem change. Disturbances can be natural or man-made. Natural disturbances are fires, droughts, floods, windstorms, landslides, avalanches, insect and pest outbreaks, volcanic eruptions, disease epidemics, ocean temperature changes, and introduction of invasive species. Man-made disturbances include logging, mining, farming, pollution, and urbanization.
A disturbance is not always bad. Floods and fires can be quite good, where some ecosystems have adapted to these natural disturbances to maintain their balance. Fires are a natural phenomenon. Some species benefit from its effects, while others can be remarkably resilient in the face of flames. For example, longleaf pine forests depend on fire to control undergrowth. Natural floods can provide nutrients and water to help animals and plants to survive and even thrive. In many parts of the world, floods are essential for agriculture.
Disturbance Regimes and Disruptions
A disturbance regime is the cumulative effect of short-term disturbance events over space and time. Disturbance regimes are defined by their timing, frequency, predictability, and severity.
For example, floods are often seasonal, predictable, and have a severity that can be managed. That is why they can be beneficial for agriculture.
Fires may not be very predictable, but they do occur often enough and with appropriate severity to maintain a certain environmental equilibrium and help biodiversity. Native Americans understood this and often set fires intentionally to help keep the landscape healthy for their survival.
Because disturbance regimes involving natural disturbances are typically beneficial, ecosystem managers often make efforts to facilitate these regimes.
Changes in disturbance regimes can trigger rapid reorganization into new ecosystem states, alter forest structure and composition, and maintain ecosystems in a new or transitional state. The impacts of changing disturbance regimes can be further complicated by climate change and interactions between disturbances.
There are many causes for disruptions. Climate change is partly to blame. Man-made activities such as mining, logging, and farming also disrupt as well. Disruption by mega-fires can be caused by the expansion of flammable invasive species and fire suppression that leaves some forests thick with trees, giving flames more fuel and resulting in more intense and damaging wildfires.
How Conservation Helps
All of this begs two questions. What can conservation do to prevent, or at least, mitigate the effects of man-made disturbance regimes? What can conservation do to promote, or at least, maintain natural disturbance regimes?
Certainly, conservation efforts help mitigate the effects of climate change. Conservation can help with the prevention and management of man-made disruptions related to land use by focusing on healthy development that addresses ecological concerns.
When it comes to disruption of natural disruption regimes, the efforts of conservation can be controversial.
Conservation activities can disrupt disturbance regimes, potentially impacting ecosystems in various ways. This disruption can have both positive and negative consequences, depending on the context. One positive consequence is the maintenance of disturbance regimes that can sustain rare and declining species and ecosystem types. And yet, there are other factors to consider:
- Reduction of Natural Disturbances: Some conservation activities, like fire suppression or invasive species control, can reduce natural disturbances, such as wildfires. This may disrupt the ecosystem’s natural cycle and affect species adapted to these disturbances.
- Altered Interactions: Conservation efforts might inadvertently change the interactions between disturbances. For example, when wildfires are suppressed, it can lead to more severe megafires later when they do occur.
- Climate Change Interaction: Climate change can further complicate disturbance regimes, making it challenging to predict how conservation activities will interact with these changing patterns.
- Management Specificity: Ecosystem management based on natural disturbances emphasizes the need for specificity in understanding the relationships between disturbance types and specific ecosystem characteristics. In other words, one size does not fit all.
And there are events like avalanches and volcanic eruptions, where conservation cannot do a lot to prevent them or mitigate their effects.
In summary, while conservation activities are essential for protecting disruption regimes, they should be carefully planned to consider the potential disruptions to disturbance regimes and their consequences for ecosystems. Balancing conservation goals with the maintenance of natural processes is a complex challenge.
What The Conservation Foundation Does
And this is where The Conservation Foundation comes into play. They work on the disturbances common to the Illinois area. Natural disturbance is fundamental to how ecosystems function. Fire is the most common form used by The Conservation Foundation and others who manage natural areas. Thinning small trees from dense forests and removing non-native invasive species are other forms of positive ecological disturbance.
Over its 50+ years, The Conservation Foundation has addressed many aspects of disturbance regimes:
- Fires – fighting fire with prescribed fire in prairies and woodlands to remove non-native invasive species.
- Droughts – planting drought resistant plants, promoting water conservation, and advocating for improved cropland practices that lower water usage.
- Floods – preservation and protection of floodplains (let them flood), stormwater management, easements, and watersheds. In addition, promoting protection and creation of green stormwater infrastructure as best management practices.
- Windstorms – planting native plants with better and deeper roots (see The Conservation Foundation’s Conservation@Home program).
- Insect and pest outbreaks and introduction of invasive species – ensuring threatened and endangered species and habitat are included in designated uses and developing criteria to protect them. Removal of invasive species, such as buckthorn, honeysuckle, and garlic mustard.
- Land-use conversion – preservation and protection of forests, prairies, wetlands, streams, and lakes.
Ready to support land conservation and positive disturbances for nature? Well, land conservation is what The Conservation Foundation does every day. We can all do more together than we can alone. Join our collective momentum – become a member today!
Feel free to comment on this blog with additional ideas you have on disturbance regimes.
By Steve Stawarz, Oak Brook
DuPage County Advisory Council Member
Bacchanal with Kid Goat and Onlooker, 1959 Linocut on Arches paper
P.S. Since we are discussing disturbance regimes in nature and their disruptions, I suggest you see Picasso: Fifty Years Later at the Elmhurst Art Museum running through January 7, 2024. That exhibit includes a nature piece by Picasso, the ultimate disrupter.
P.S.S. Editor’s Note – this is Steve’s 25th blog! Thank you, Steve for helping to inform our members on important conservation issues!
