“Maintenance” is a term that gets thrown around our shop a lot during the summer months. You might think we are talking about equipment or vehicles or upkeep, but we’re actually referring to habitat management. In restoration projects, ‘maintenance’ is a period of time after the initial restoration where we try to give the newly restored vegetation community the best chance possible while it establishes. A newly seeded prairie restoration, for example, can quickly become overrun with invasive species during its first years of growth. So while the initial restoration might be complete, we continue to revisit the site every year to help encourage it along in the right direction. The months of July and August are filled with maintenance visits, so this month, we will be discussing the ‘why’ and ‘how’ of ecological restoration maintenance.

Why Do We Perform Maintenance?

Ecological restoration almost always includes changing the vegetation community of a site. Whether we are thinning trees for an oak savanna restoration, or seeding in native species for a prairie restoration, or removing buckthorn for a woodland restoration–the plant community changes. Oftentimes, these changes are intentional, and aim to create a healthier, more resilient habitat overall. However, there is always a transition period as the site adapts to the new changes. For example, a newly seeded prairie may take 2-5 years for the seeds to fully grow to maturity. Alternatively, removing trees or shrubs creates new growing conditions with increased light and nutrients. During this transition period, the habitat is fragile. In natural cycles, this transition period would take a long time, and the ecosystem would eventually sort itself out. However, many of our projects have limited time frames due to resource or funding constraints. Also, some of our sites are subject to significant detriments such as weed pressure, nutrient limits, or human disturbance. These can prevent a habitat from successfully remaining in a restored state, even after the initial restoration. Therefore, we often conduct multiple years of follow up maintenance designed to help the habitat through this transition period until it is stable enough to maintain itself.

How Do We Perform Maintenance?

Almost every kind of habitat can benefit from maintenance visits post-restoration, and every habitat will have different follow-up needs. Prairies and woodlands are our most common sites for follow-up maintenance, and while each site is unique, they do share some similarities. Here are just a few of the most common types of maintenance for prairies and woodlands:

1. Invasive species treatment - In most cases, this is the most important goal of maintenance. Invasive species can be extremely detrimental to rebuilding native plant communities. During maintenance, we mow, spray, or pull invasive species to keep them from outcompeting the native plants. Each species is treated a little differently, depending on the time of year and the plant’s growth cycle. 

2. Woody species treatment - This treatment is very similar to invasive species treatment, however it may target different species for different reasons. For instance, a prairie restoration might target trees like ash, cottonwood, or aspen during maintenance. Even though they are native, they are fast growing trees that could create woodland conditions to the detriment of the new prairie. In woodland restorations, woody species treatment often targets fast growing species like sumac or grapevine to promote greater overall diversity. We will cut and stump treat, or spray species to keep them contained.

3. Aggressive native treatment - Sometimes, even a native species can be detrimental to a site’s restoration goals. In areas where a high level of diversity is desired, a single fast growing or aggressive species can be negative, even if that species is native. This kind of treatment typically isn't as intensive as invasive species treatment. It aims to set back the growth of the dominant plant without completely eradicating it. Treatments often just involve cutting, though selective spraying is occasionally used as well.

4. Introduced disturbance - Intentionally creating disturbance to a habitat may seem counterproductive. Isn’t restoration meant to repair the effects of disturbance? While this is true, many habitats actually do better with occasional disturbance. Natural disturbances such as windthrow or wildfire remove old materials, return nutrients to the soils, and increase light conditions and space for new plants to grow. Without natural disturbances, restoration sites sometimes need introduced disturbances to mimic these natural processes. For example, prairies have a long history of natural disturbance from wildfire and bison grazing. Now, we use prescribed fire and mowing to mimic these disturbances, which encourage healthier prairies. These activities are often included in follow up maintenance plans.

In summary, there is a lot more to a habitat restoration than just the initial work. Ecosystems move much slower than we do, and they need time to transition and adapt, even to restored conditions. We utilize follow-up maintenance to help habitats transition and grow resilient enough to maintain themselves naturally. While this maintenance work might not be as glamorous as the initial restoration, it is a key element to long-term success for habitat restoration.