Trees: Worth our Time and Resources

Richard Leon, Forester for City of Lakeway
LMUD Open House presentation, October 18, 2023

Planting a quality tree in the right spot is the key to having a healthy urban forest, but there is no replacement for an established tree. My job as a city forester is to look at our public infrastructure and see where our trees fit in with the goals of conservation, preservation, and the wise use of resources. 

Urban forestry is the combination of forestry with urban planning. Trees are not just an aesthetic commodity, but an important addition to our community that help support our infrastructure:

  • Electricity: trees provide shade
  • Water treatment: trees help filter water to our groundwater aquifers
  • Sewer and Stormwater management: trees help with water retention and erosion control

As such, trees require our care and attention, the same way our infrastructure deserves, with ongoing maintenance and protection. I currently see Lakeway as a tale of two cities: the west has a lot of new development and the east is the established Old Lakeway. Looking at an aerial view of the community, it’s obvious to see where the majority of our tree canopy is consolidated.  Often times, when development and infrastructure come through they do what they have to do, trees be darned. But trees are a complex system; you typically don’t see the effects of the work until three or four years later.

It’s important to find creative ways to preserve mature, non-invasive trees because the benefits that they provide are exponentially greater than that of new trees.

In fact, small trees require more energy to go into them than they give out.

I think people value trees more than they realize subconsciously. An example would in parking lots: people seek out spots under a tree for shade so their car is more comfortable when they get back. This is especially apparent in urban areas where the “heat island effect” is a real problem: temperatures are higher due to the asphalt and concrete absorbing heat all day long and then slowly emitting it throughout the evening hours. 

In addition to providing shade, there are so many benefits of mature trees:

  • Air pollution removal: particulates gets trapped into the canopy/leaves then when it rains, it gets washed down into the soil.
  • Stormwater Runoff and Erosion Control: Water has cohesive and adhesive properties: the molecules attach to each other as well as to the surface of things. At the beginning of a rain event, the leaves and bark of the trees, hold the water until they get saturated. This helps with runoff and erosion by capturing the water and slowly dispersing it it.
  • Wildlife habitat: trees provide an opportunity for food and shelter for local wildlife which helps support a healthy ecosystem.
  • Increased Property Value: studies have shown that there is a 3 to 15 percent increase in value for properties with trees over those without.
  • Reduction in Home Cooling Costs: a study showed that with 50 percent canopy cover, cooling costs were reduced by 15 to 20 percent.
  • Lower Crime Rates: studies have shown that well-manicured streets with trees have lower crime rates
  • Replacement Value: large, mature trees are irreplaceable because you can’t buy them and trees take a long time to grow.
  • Community economics: In shopping districts with tree-lined streets, a study showed that there were 7 percent higher rental rates and shoppers spend 9 to 12 percent more time there.

In an effort to preserve and maintain our mature trees, the City of Lakeway recently updated our Tree Ordinance:

  • Public Tree Protection: includes trees in parks, right of ways, and public buildings.
  • Protected versus Unprotected Trees: we don’t protect invasive species; in fact, we encourage their removal.
  • Trees during Construction: When developers clear land they have three options: they can preserve trees, plant new trees, or pay into a tree mitigation plan. To be in compliance, they sometimes plant trees “nilly willy” and then they don’t survive because there is no management plan for them so we want to avoid this through replanting spacing requirements or paying into a tree fund so the required planting can be done by the city in public spaces. Credits are given for following certain standards for protecting trees during construction.

To care for your own trees:

  • Planting: The U.S. plant nursery industry is a multi-billion dollar industry because this is where quality trees begin. Consider buying bare-root trees, rather than those grown in containers, since they are usually already adapted to local soil so can take off quicker.
  • Maintenance: Use arborists certified by International Society of Arboriculture (ISA) and insured.