Many times, a tree can become so familiar it is hard to imagine what a place would look like without it. They are beautiful; they create shade and attract wildlife. It is often a difficult decision to let a tree go, but it is important to look at the big picture and the long-term health of individual plants. Tree removal decisions are based on three primary areas: existing tree health and species, potential construction impacts, and careful planning and design.
Existing Tree Health and Species Diversity
In 2014, the City of Johnston consulted with Foth Infrastructure and Environment to conduct a tree survey of the Gateway District property. They surveyed 3,441 individual trees on the site. The species assessment determined nearly 75 percent of the trees were undesirable or invasive plant species. These species included Silver Maple, Siberian Elm, Chinese Elm, Cottonwood, Boxelder, and Mulberry. An additional 10 percent were identified as various Ash species. Ash trees are at high risk of infestation from Emerald Ash Borer.
The City of Johnston's arborist conducted an updated review of the site during the winter of 2021-22 and the findings were consistent with the 2014 survey. The arborist noted many of the Ash trees were either dead or declining. Unfortunately, the storm in the 90s along with recent wind events have taken a toll on a number of the larger trees in the area. Both reviews indicate that many of these trees need to be removed because their specific species are undesirable or invasive. The health concerns of these species mean the trees will eventually become public safety and welfare issues.
Potential Construction Impacts
Even with tree protection in place, construction activities take a heavy toll on trees. This is through cutting roots, soil compaction and grade alteration. The most obvious types of construction-related injuries seen are damage to trunks and branches; however, the most lethal is root damage. Due to development activities, such as grading for the structures and driving range, roads, sidewalks and infrastructure, protecting sufficient root space cannot be achieved for large areas of the site. Tree protection for remaining preserved trees will be provided as part of the Bomber's Golf and Hotel development. This protection limits how close contractors can conduct work near a tree.
Planning & Design
Planning and design are both important in tree preservation. Tree health, species, and construction considerations are only part of the planning process. The next part is locating the physical elements and infrastructure in locations that avoid healthy, desirable tree species. This project accomplishes protection by limiting construction activity near the more sensitive natural areas of the site. These areas include one identified wetland, areas along the Beaver Creek stream bank, and a large area of forest coverage.
The developer has committed to spending $50,000 to $125,000 for the prairie, savannah, and forest restoration through the planning and design process at the City Council's discretion. The restoration process will improve the health of the areas of the site remaining preserved and the restoration of disturbed areas into healthy open spaces for the community's enjoyment. The site's restoration would be in addition to the normal landscaping requirement for new development. The City worked with the Iowa DNR Urban Forest division to restore suggestions during this process. They will provide assistance in the planning process and restoration of the area.
Trees are not forgotten about in Bomber's Golf and Hotel project. The plan will include the installation of a diverse selection of shade and ornamental type trees. A landscaping plan has yet to be prepared for the site, but the trees selected will thrive in urban environments and have resistance to disease and heat/drought tolerance. Diversity for the new trees is also important to ensure health and longevity. The City of Johnston will work closely with the development team to enhance this site into a new destination for entertainment and a place where residents can interact with healthy, restored natural areas.