Local residents have probably noticed several other trees in town with similar markings.

This is not an outbreak of vandalism. The markings were placed by city employees who were marking the trees to be removed.

The city has committed to cutting down 182 more trees this year as part of a plan to remove all ash trees and a number of silver maples, as well as other damaged and dying trees, from city property and roadsides.

“Our main goal for the next five years is to remove all ash trees from street trees,” said Gene Maffit, city parks director.

South Sioux City has received a $1 million federal grant and a $145,000 grant from the Nebraska State Arboretum to cut down an average of 130 trees per year over the next five years. Maffit said the city will soon solicit bids for the removal of the first 182 trees, and he hopes to have them cut down by late fall or early winter.

“We will also replace removed trees with a diverse tree population,” said Maffit.

The new trees will be financed through subsidies.

Removing and replanting the trees will increase the diversity of the city’s tree population, nearly half of which currently consists of two species whose future is in jeopardy. Maffit said surveys from 2006 and 2014 found that 24% of the trees on city property and rights-of-way are ash and 23% are silver maples. South Sioux City’s percentage of ash trees was the highest of any city in Nebraska.

Since those surveys, the invasive Asian ash beetle has swept the country, killing millions of ash trees. Its presence in South Sioux City has not been confirmed, but based on the condition of some of the city’s ash trees, Maffit suspects that the insects and their tree-killing larvae, which eat away at the water- and nutrient-conducting tissue beneath the trees’ bark, are here.

Silver maples struggle with iron chlorosis, a yellowing of the leaves due to iron deficiency that occurs for unknown reasons when the trees stop absorbing iron from the soil.

Of the trees scheduled for felling this year, 147 are ash and 22 are silver maples. The rest are trees damaged by storms and other natural causes. All are dead, dying or diseased.

The felled trees are not wasted. Some are used as firewood in the Scenic Park. Smaller trees and branches are put through the chipper and turned into mulch. The logs are saved and a Nebraska Forest Service mobile sawmill is brought in to cut them into boards for use in high school shop classes.

The city will also continue an ongoing program in which it shares the cost of removing ash trees on private property 50-50 with city property owners.

Maffit’s goal is to reduce the tree population to a level where no more than 10% of each species remains, so that the next disease or pest infestation does not destroy such large parts of the city’s tree population.

“The more diverse a tree population is, the less susceptible it is to disease,” said Maffit.

To achieve this goal, he wants to plant many more trees. For every tree cut down, he wants to plant three new ones. This way, streets will be lined with healthy trees that will provide shade for sidewalks and houses and fill parks.

City residents can help achieve this goal. Using grant funds, the city is sponsoring a tree drive where residents can request trees from Maffit’s office. He will fill the orders based on availability with his regular tree suppliers. When the trees are picked up in the fall, the city will provide instructions on planting and care. The trees must be planted on city rights-of-way along streets in front of homes or businesses.

“If enough people want them, we will continue to give them away,” said Maffit.

Maffit’s budget includes the removal of 50 to 60 damaged or dying trees in the city each year and the planting of 250 to 350 new trees. Thanks to the funding, Maffit can significantly increase these efforts in the coming years.

“We are taking care of an urban forest,” he said.