Column: Let’s talk about the wonder of trees

Mayor-MarvinThis past fall, the village planted more than 20 street trees—including red maples, lindens and pears—but, given that we lost more than 100 during the past two years of storms, we are clearly playing catch-up.

Unfortunately, this number does not even take into account the many lost on private property due to storms or disease or, sadly, healthy ones removed for expansion or remodeling.

The village does not have a tree ordinance as we have historically relied on the foresight and stewardship of our residents to value this intrinsic asset. With few glaring exceptions, this has been the case.

“Street” trees serve archite­ctural and engineering functions beyond the aesthetic value. They enhance building design, reduce glare and reflection, screen unsightly areas, muffle urban noise and reduce the “heat island effect” caused by pavement and commercial buildings.

As an added plus, urban trees grow in value as they age while most other municipal assets, including roads and sewers, decline in value.

Trees on private property produce even greater monetary value. Studies have demonstrated 10 to 23 percent of the value of a residence is based on its tree stock. A municipality also captures some of this monetary value as enhanced property values increase assessed values and the resulting tax base.

Trees also provide important symbolic links with the past and are important often simply because they have lived through eras with which we have few other connections left.

They also positively alter our environment by moderating climate, improving air quality, harboring wildlife, preserving soil and conserving water.

As example: Tree roots hold soil in place, slow runoff and combat erosion.

Leafy trees catch precipita­tion before it reaches the gro­und, allowing some to drip and evaporate, thereby reducing runoff and erosion.

Leaf litter creates an environment for earthworms and other organisms that helps maintain soil quality.

Trees reduce the heat intensity of the greenhouse effect by maintaining low levels of carbon dioxide.

Trees also remove gaseous pollutants from the air by absorption of particulates such as ozone sulphur dioxide and PAN, the chemical component of smog.

Trees also shield people from ultraviolet rays, reducing UV-B exposure by about 50 percent. Trees are especially important on playgrounds where children spend hours outdoors.

Not only do the trees themselves represent economic value, the ancillary benefits also translate into long-term economic savings.

The net cooling effect of just one young healthy tree is equivalent to 10 room-size air conditioners operating 20 hours a day. Well-placed trees on a property can cut air conditioning costs by 10 percent to 15 percent as well as indirectly cut the carbon dioxide emissions from cooling units.

Rows of trees, even small co­nifers, reduce wind speed up to 85 percent and a good windbreak can save up to 25 percent of winter heating costs.

Selecting a tree that will thrive in a given set of site conditions is the key to long-term tree survival. Before selecting a tree for planting, many factors should be considered: the soil conditions, exposure to sun and wind, human activity near the tree site, drainage, space constraints and hardiness zone. The tree must also have adequate space to grow to maturity, both above and below ground. Of particular importance in Bronxville is a tree’s proximity to power lines. Con Edison has the absolute right to trim trees into the infamous V shape to expose their wires.

The Bronxville Historical Conservancy has embarked on a project to delineate native plant and tree species best suited for the various topographical differences in village neighborhoods. The end product will be a very useful, long-term guide for successful planting in the village.

If you spot a distressed or dead tree, or notice a public location that merits a tree, please email us at Village Hall at and we will put the location on our list for remediation.