Monday, September 30, 2024

Council Addresses Challenge of Rebuilding The Desert: Overcoming Bermuda Grass and Restoring Natural Balance (Part 1)

It Takes No Time to Blade the Desert
It Takes Forever to Bring It Back.
Restoring a desert landscape, particularly one previously used as a golf course, presents numerous challenges. In the case of the Vistoso Trails Nature Preserve, the primary obstacles include managing invasive grasses, selecting appropriate native plants, and dealing with the long timelines required for desert ecosystems to recover. These and other issues were discussed by the town council last week as they considered the next steps for the restoration project.

Bermuda Grass: A Persistent Obstacle
One of the most significant challenges in revegetating the desert is controlling Bermuda grass. Commonly used on golf courses for its durability and fast growth, Bermuda grass is incredibly difficult to eliminate once established. It spreads rapidly through underground rhizomes, which makes mechanical removal highly labor-intensive and often ineffective.

As consultant Rebecca Field from Kimley-Horn noted in her remarks to the town council on September 17, "The expectation of completely eradicating Bermuda grass from the site is something that we should just be aware of as a nearly impossible task." Bermuda grass competes with native desert species for water and nutrients, making it a major barrier to successful restoration. Even when treated with herbicides, it often resurfaces, necessitating a long-term management strategy rather than a one-time fix.

Challenges in Selecting the Right Plants
Revegetating a desert is not as simple as planting seeds and waiting for them to grow. The Sonoran Desert's native plants, such as saguaros, mesquite, and palo verde, are adapted to harsh, arid conditions but are slow-growing. Restoring these species to their natural habitats takes considerable time and effort, often requiring decades before the landscape begins to resemble its original state.

Selecting the right mix of plants is essential for establishing a resilient ecosystem. Desert plants need to be able to thrive without irrigation, relying solely on natural rainfall, which is unpredictable. Many species, like creosote, provide benefits beyond their growth; creosote's root system, for example, releases natural toxins that help suppress invasive species like Bermuda grass. However, slow-growing native plants are often outcompeted by fast-spreading invasive species during the early stages of restoration.

Special Challenges at the Vistoso Nature Preserve
The Vistoso Nature Preserve restoration faces additional challenges beyond the usual difficulties of desert revegetation. A key concern is limited funding—although the town is investing $2 million this year and seeking grants to support the restoration, the real cost and timeframe for getting the job done is not known. There are concerns about preserving their mountain views, as trees planted too close to homes could block the scenic vistas of the Catalina Mountains.

Additionally, the use of desert broom, a native but aggressive plant, has been a point of contention. Although desert broom is highly effective in establishing natural vegetation and supports pollinators, residents and the council have expressed concerns about its aesthetic impact. This plant grows quickly and can become invasive, making it unpopular among homeowners.

Time and Patience: The Long Road to Desert Restoration
Restoring a desert to its natural state can take decades. Research shows that fully functional desert ecosystems often require 30 to 50 years to reestablish. During this time, early restoration efforts may seem slow or insignificant, as desert plants take years to grow to maturity. This slow progress can be frustrating, but it is a necessary part of the process.

In addition, the success of desert revegetation is highly dependent on factors like rainfall, soil quality, and ongoing management of invasive species. Without consistent attention, invasive plants like Bermuda grass can easily regain a foothold, undoing years of effort.

Tomorrow—The Latest Plan to Revegetate the Preserve
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