Fifteen years ago, the Asian Longhorned Beetle (ALB) made a dramatic and devastating entrance into Worcester, boring through the maple, birch, and poplar trees that for generations had provided a leafy and cooling canopy across the northern part of the city. The infestation led to the removal of some 19,000 trees, temporarily denuding entire neighborhoods.

The Massachusetts Department of Conservation and Recreation, and the Worcester Tree Initiative, in collaboration with the U.S. Department of Agriculture, restored much of the greenery, planting thousands of young trees. But years later, how have they fared? Are city residents again enjoying the shade and natural beauty that they lost to the beetle invasion?

Those were the questions that compelled the undergraduate students in the Human Environment Research Observatory (HERO) program to spend the early part of this summer assessing the health of thousands of trees in Worcester’s Burncoat, Greendale, North Lincoln Street, and Great Brook Valley neighborhoods — designated as part of the Longhorned Beetle Regulation Zone. The students also interviewed 52 residents to gain their perspectives on the perceived successes and drawbacks of the planting program and the benefits and challenges of maintaining trees on their property.

Why study geography at Clark?

In 2012, Clark received a National Science Foundation grant to examine the effects of the ALB invasion on Worcester. The results of the three-year study were presented by the 2014 class of HERO fellows at a community stakeholder summit.

At a July 20 presentation attended by DCR representatives, members of local environmental groups, Worcester residents, and Clark faculty, the students described their study, which included examinations of the neighborhoods’ biophysical and socioeconomic characteristics, the types and condition of the trees, and the locations of plantings.

Of the 2,794 trees studied, students found that trees planted along city streets had a better rate of survival (88.6%) than trees planted on private property (66.9%). The students determined that property owners more readily removed private trees for a variety of reasons — to change the appearance of the landscaping or to make room for a pool or shed, for instance. Public trees were also watered more regularly than trees on private property in the first two years after their planting, they found.

In a Worcester Telegram & Gazette story about the HERO presentation, John Rogan, who co-directs the program with fellow professor of geography Deb Martin, noted that more tree surveys will be conducted in the future, which will help clarify the data surrounding survival rates. HERO participants will expand the analysis to include the full Longhorned Beetle Regulation Zone and address questions like “What can be done to reduce the likelihood of healthy tree removals in the future?” and “What is the impact of shifts in home ownership on tree survival rates and overall health?”

Until then, as Rogan told the T&G, the story told by the data is clear: “Watering and maintenance result in success.”