New Paltz shade tree commissioners have been upping their game in recent years in the way they expend their budget for street trees. For a while, there was an emphasis on fruit trees and food justice, but now the hunt is on for an oak that’s adapted to the stresses of village life. Majestic as the oak might be, they can suffer roadside, with the first symptom usually being chlorosis: yellowing leaves. They’ve tapped into a program offering experimental hybrids to help answer that question, and five were planted around the village this spring — including one in memory of Vietnam veteran Hank Schulte.
The trees stem, as it were, from a joint program of Cornell University and Landscape Plant Development Center. Much praise is given to oaks in the supporting literature: “It is difficult to overstate their ecological, economic and cultural value. Oaks provide an essential source of timber for furniture, flooring, interior finishing, and veneer. Cork is sourced from oak and the impervious heartwood of oak is used for shipbuilding and wine and whiskey casks. Oaks are prominent in many forest ecosystems and their acorns are a vital food source for wildlife, high in fat and nutrients. In addition, oaks have an important role to play in urban and suburban landscapes as they are durable, long-lived and majestic trees. They can be an outstanding feature in any park with a large and spreading growth habit. The grand size, longevity, and sturdiness of oaks have made them a familiar symbol in many cultures around the world.”
Urban environments — and New Paltz qualifies — are stressful for trees. Soil gets compacted under vehicles and construction, driving out the nutrients while adding plenty of road salt. It may be that breeding a tree to tolerate salt is easier than weaning a road crew off using it. High pH, limited soil volume and drought stress are also among common stressors of urban street trees. Each of the five trees has different parentage and each will be closely monitored to see how well they do over time. The parents were selected from the Quercus species minima, bicolor, warei, x. comptoniae, mysinifolia, libani, and polymorpha; tags on the trees indicate the mommy and daddy tree. These trees are also larger than the ones planted on village streets in the past, as older trees apparently survive transplanting in greater numbers. With larger root balls, Masseo Landscaping was brought in to care for and plant the trees when they were delivered. The five trees were planted in Hasbrouck Park, in front of the courthouse parking lot entrance, at the Mohonk Avenue intersection with South Chestnut Street, in front of the Awareness Shop at 180 Main Street, and Hank Schulte’s memorial tree was planted at 39-41 Church Street. They are recognizable by the large watering bags attached, which will remain this year.
Breeding oaks intentionally takes time and vigilance. Trees produce tiny female flowers first, which are soon overshadowed by “long, draping catkins of the male flowers,” spilling pollen everywhere. Breeders must pollinate the female flowers — piling on the pollen collected from a male flower on another tree — before the boy flowers open up. Acorns take a season to mature, and breeders must compete with squirrels to collect them. The research project, begun in 2003, has yielded a handful of promising hybrids out of thousands of seedlings. Those are then propagated by cloning. Learning how to replicate full trees, rather than grafting hybrids onto possibly inferior roots, is itself continuing. Oaks are particularly hard to reproduce asexually, and that’s actually a characteristic for which these trees have been bred. Researchers hope to be able to expand the scale of the hybrid testing as the cloning regimen is perfected.
Dr. Nina Bassuk, head of the research program, did not respond to questions about the program’s funding by press time. However Neil Bettez, one of the shade tree commissioners, said that these trees were slightly less expensive than similarly-sized trees purchased locally, even considering shipping. That they will be involved in ongoing research is simply an added benefit.