Struggling deciduous trees along West Winnie Lane on June 9.
Photo by Scott Neuffer.
At the end of May, Carson City officials announced they were investigating tree decline in different areas of the city.
“The city is committed to maintaining its urban canopy and ensuring a healthy ecosystem for residents and understands the importance of trees for providing shade, improving air quality, and enhancing the overall aesthetic of the community, and is taking decisive action,” said a news release.
The Appeal contacted Jennifer Budge, director of parks and recreation, and David Navarro, parks operation superintendent, for details. According to the department, the city has been monitoring some trees since last year, but “others started showing signs of decline earlier this year and well into spring.”
These are primarily deciduous trees, the department said, and the city has identified insect infestation and disease in some trees, though a more thorough investigation is underway.
The complete Q&A:
Where are people seeing tree decline on city land, specific locations, and are these mostly citizen reports?
City staff have observed tree decline on city land in various areas around town, including Silver Oak, Northridge, North Carson Street, and some small segments of our park system. Many residents from a wide variety of neighborhoods have contacted the department, expressing concern about tree decline on private property and seeking guidance.
Treesaregood.org/treeowner is a great resource for residents to learn about proper tree care, maintenance, planting, tree health, and finding an ISA certified arborist in the area.
How long has the problem been observed, and what are the signs?
While some trees were “on watch” since last year, others started showing signs of decline earlier this year and well into spring.
Trees require sufficient light, balanced nutrients in the soil, and access to oxygen for a healthy root system. When trees are stressed or don’t have balanced nutrition, they are more susceptible to disease. Stress makes the trees more susceptible to certain insects and diseases. While most insects are beneficial, some can be destructive.
Signs of stress include:
• Twisted or curled leaves (infection/insects).
• Not flowering in spring or leafing out later than normal.
• Brown roots (dry soil/environmental impact).
• Black roots (over-watering or root-rotting organisms).
• Trunk and branch wounds (weather, animals, disease).
• Leaf discoloration, drooping, wilting, spots, or sap or honeydew secretions (pests, disease).
Also, areas that are overplanted can cause competition from root systems for water and nutrients.
What species of trees are being affected?
Primarily flowering pears, plums, and some oaks.
What invasive species and/or diseases do you think are causing this?
The city has consulted with two independent ISA-certified arborists to inspect the trees, as well as a representative from the Nevada Department of Agriculture. Scale (hard or soft), an insect infestation that can target flowering trees, has been identified in some areas. Also, fire blight, a destructive bacterial disease, and sunscald, a form of winter injury caused by rapid temperature fluctuations, were also observed.
Does this involve an irrigation issue?
Irrigation season begins in April and lasts through November, and irrigation systems have been inspected and are functioning correctly. However, some of the trees appear to be competing for water and nutrients in the soil in some areas. Tree crowding, resulting from overplanting, overgrowth, or the incorrect selection of species for the space, can cause competition over time, which contributes to stress.
Who will be involved in the assessment, how long will it take, and when will the results be available?
So far, the city has consulted with two independent ISA-certified arborists and the Nevada Department of Agriculture. Staff has also been in contact with a municipal urban forester from Northern Nevada and UNR Cooperative Extension. Photo documentation and monitoring, specimen clippings, and mapping are in progress. The next steps include soil sampling and disease treatment where possible. Once soil testing results are available, a prescription and plan of action will be implemented. Soil testing may take two to four weeks once the sample is collected.
After assessment, what are the next steps?
Carson City is a proud Tree City USA and will work through these challenges while consulting with technical experts. Should there be tree loss, we are committed to replenishing the city’s urban forest, as it is vital to the health and quality of life in our community. Some trees that were monitored since last fall are being removed now and will be evaluated for replacement with new trees in the fall. However, none of the trees being removed now are in the Silver Oak and Northridge area.
For information, contact Navarro at dnavarro@carson.org or 775-283-7346.