Heat Mapping Results From Milwaukee Published

Dan Buckler, Urban Forestry Assessment Specialist,

Trees are sometimes called the lungs of the Earth. You might also call them and the neighborly Lake Michigan the air conditioners of Milwaukee.

A preview of the Milwaukee Heat Map

The Wisconsin Department of Natural Resources helped coordinate a heat mapping campaign in the City of Milwaukee in 2022. A  resulting map shows where it is relatively hot or cool.

Trees provide shade and conduct evapotranspiration, the process by which water moves from the ground, through their stems, and out their leaves as water vapor. In these ways, trees helped make parks and other green spaces temperature oases, with evening air temperatures up to seven degrees cooler than nearby locations.

Densely developed urban areas tend to be warmer than more open rural spaces due to the concentration of manmade surfaces, such as asphalt and concrete, that absorb and reradiate heat. This phenomenon, known as the urban heat island effect, is further compounded by rising temperature trends due to climate change.

Urban neighborhoods are also affected by this heat island dynamic, particularly in large cities such as Milwaukee, where there is a great variety of land covers and uses. The mapping campaign recorded a 10-degree difference in the evening between the hottest and coolest parts of the city. Continue reading “Heat Mapping Results From Milwaukee Published”

Tips to Acquire Desired Tree Species

By: Abby Krause, Western Region Urban Forestry Coordinator,  

Hoping to avoid the repeated destruction from Dutch elm disease (DED) and emerald ash borer (EAB), a new wave of planting initiatives focuses on species diversity. However, acquiring species to meet these diversity goals is often easier said than done. Below are some tips based on comments and feedback from nurseries and other tree managers to help your tree ordering process go smoother in the future.

  • Know B&B (Balled and Burlapped) seasonality. Some species are harvested from the fields in spring only because they do not tolerate having their roots disturbed later in the season. If these species sell out at the beginning of the year, they will not be available again until the following year. Prioritize B&B spring dug species for spring orders or check the availability of container-grown stock for later in the year. Your nursery supplier will be able to elaborate on which of their offerings are exclusively spring dug.
  • Specify (spec) by caliper and not DBH. Both are measures of tree diameter, so what’s the difference? Caliper is predominantly measured at 6 inches above the soil, while DBH (diameter at breast height) is measured at 4.5 feet. While DBH is used in other parts of urban forestry (think inventories, wood volume, etc.), caliper is the go-to when referring to nursery stock. You may have difficulty finding large enough stock if you’re using DBH by mistake.
  • Don’t specify species included in NR 40 (the invasive species rule). First, you don’t want to use species that can become problematic in the natural areas of your community. Secondly, some nurseries cannot bid on proposals that include invasive species because of their company procedures and will end up rejecting your entire proposal.
  • Be flexible (but firm) on species substitutions. What was the main reason behind your original species selection: Do they handle tough soil conditions, maximize stormwater interception, and provide wildlife habitat? Will another species accomplish the same primary goal? Keep in mind the 5-10-15 Diversity Rule. Your urban tree population should include no more than 5% of any one species, 10% of any one genus, and 15% of any one family. Knowing why a tree was selected will allow you to make an informed decision on potential substitutions and prevent you from planting an unsuitable tree for the site simply because it was the only thing available.
  • Be flexible on stock size. Nurseries noted that people tend to prefer 1.75-2.00” caliper stock. Will a slightly smaller or larger stock size work for your planting site? Smaller trees can be easier to work with and additionally establish and start putting on new growth faster. Larger trees need a longer water maintenance plan, but their size can help deter vandalism in high-traffic areas and add instant aesthetics.

Credit: Alfo Medeiros, Pexels

  • Seedlings in natural areas. Response to storms/pests/disease, stormwater mitigation, and the addition of no-mow areas are a few instances that may spur planting in community natural areas. Using bare root seedlings often makes the most financial and logistical sense in these instances. Natural areas also offer locations to plant trees that may be less desirable along roads and trails but still help increase the community’s overall species diversity. Native seedlings are available each spring from private nurseries and the DNR nursery, with orders typically opening each October for spring delivery.
  • When in doubt, call and ask. Calling nurseries to ask about their species availability for the upcoming season and future years can help plan your planting projects. Trees need time to grow to reach their salable size. When a species you’re interested in is not readily available, inquire if it’s currently being grown and when it will be ready for purchase. If it’s not being grown, let the nursery know it’s a species you’d be interested in acquiring in the future. The 2020 Diverse Urban Tree Species Survey results highlight the availability and success rate of lesser-used species in Wisconsin communities.
  • Let nurseries know if you’re open to trying new species. While chatting with your local nurseries about the species you’d like to see available, make them aware if you’re also open to trying new species. Nurseries are interested in the performance of new species in the landscape before they scale up production. The City of Stevens Point’s Forestry Department tests new species in a local park before using them
  • Contract grows for known upcoming projects. Most municipalities don’t meet the minimum quantity requirements for contract grows with their regular annual plantings. However, it may be viable for projects like a new park or major street redevelopment. Exploring the feasibility of splitting a contract grow with a neighboring community may be another way to meet the minimum thresholds.
  • Don’t wait to order. Lastly, a simple tip but perhaps the most important of them all: For the best-guaranteed selection, plan on having your trees ordered they will be going in the ground. The earlier, the better if there are specific species and sizes needed. With the high demand for trees, some communities even order trees in the fall for their spring planting season.  

Grant Opportunities and Ideas

As we get through a chilly February, here are a few different grant opportunities and ideas to help you think ahead to a (hopefully) warmer spring! 

  1. Knowles-Nelson Stewardship Nonprofit Conservation Organization funding

Grant applications are due Wednesday, March 1, 2023. The DNR will consider all complete applications received by this date. Tentative dates for round two and three funding are August 1 and November 1.

Nonprofit conservation organizations (NCOs) may apply for funding from eight Stewardship grant subprograms to help fund the acquisition of land and conservation easements. Continue reading “Grant Opportunities and Ideas”

Urban Wood Utilization Resources

The highest value of an urban tree is when it’s living; however, if it is killed or damaged, there are many ways to recycle it. Urban wood includes logs, brush and chips generated from urban or community trees.

Urban wood utilization is not a novel notion, but with the introduction of the emerald ash borer, it has become more prevalent. The DNR has a site for Urban Wood Utilization resources to help a community as needed with dead and fallen trees, which have become more prevalent with forest pests such as the emerald ash borer.

Once a community realizes its need to deal with wood efficiently and productively, community leaders can use the links and information listed to help manage this resource. For additional and more specific information pertinent to your area, contact your local DNR Forest Products Specialist.

For tips and resources to facilitate a healthy urban tree canopy, visit our Tree Learning Center for details. Continue reading “Urban Wood Utilization Resources”

Pruning Video Training Opportunities

Below is a list of pruning training videos compiled by our Urban Forestry Regional Coordinators.


Continue reading “Pruning Video Training Opportunities”

Urban Tree Loss And How To Stop It

Trees are struggling to survive in cities, which is not good news for communities across the United States.

One study by the USDA Forest Service has estimated that 36 million urban trees are lost each year in the U.S. Estimated loss of benefits from trees in urban areas is conservatively valued at $96 million per year. These benefits include cooling urban areas, lowering carbon emissions, removing pollution and mental health benefits amongst many others. While trees and their benefits are needed more now than ever, it’s not too late to change the trend. Continue reading “Urban Tree Loss And How To Stop It”

The Many Lives Of Christmas Trees

By: Dan Buckler, Urban Forest Assessment Specialist,

There aren’t any permanent trees in this part of Kevin Naze’s yard, but Christmas trees help blunt the winter winds for cardinals and other visiting birds.

In last month’s newsletter we posted a survey on how readers use their Christmas tree following its initial use as an umbrella for gifts.

Readers came through with pragmatic, delightful and creative ways that they put their stray Christmas trees to work. Continue reading “The Many Lives Of Christmas Trees”

Wheels To Woods Program – Health Benefits Of Educating Kids Outdoors

Some organizations are working to get children outside due to increasing worry over “nature deficit disorder.” Nature deficit disorder, a term popularized by Richard Louv term in his 2005 book “Last Child in the Woods: Saving Our Children from Nature Deficit Disorder,” describes a concern that children are more disconnected from nature than ever due to using technology indoors instead of playing outside. There are very real mental and physical health benefits that come from interacting with nature. Continue reading “Wheels To Woods Program – Health Benefits Of Educating Kids Outdoors”

DNR Foresters Partner with LEAF Program to Update Forester Activity Guide

In 2008, LEAF, Wisconsin’s K-12 Forestry Education Program, created a Forester Activity Guide. The intent of the guide was to help foresters lead age-appropriate, interactive, hands-on classroom programs for students in grades K-8 with a minimum amount of advanced preparation. The guide was promoted to foresters throughout Wisconsin and even included as part of programming during new forester orientation.

Front page of the Forester Activity Guide. Credit: LEAF

In fall 2021, LEAF staff, working with Kirsten Held, determined that an update to the guide was overdue. To be certain a new guide would meet the needs of current foresters, LEAF sought input from professionals around the state who have both field experience and an enthusiasm for working with students.

The following DNR Division of Forestry staff partnered with LEAF to create a new and improved Forester Activity Guide: Brooke Ludwig, Eau Claire; Steven Kaufman, Oconto Falls; Kara Oikarinen, Washburn; Scott Mueller, Medford; Sarah Ward, Montello; and Brian Wahl, Fitchburg.

The new Forester Activity Guide builds upon the goals set for the original K-8 guide by including more opportunities for outdoor learning around themes that foresters are frequently asked about: What Do Foresters Do?; Caring for the Forest; Forest Products & Benefits, Tree Planting and Natural Restoration and Fire.

All activities include tips for modifying lessons to urban settings and suggestions on how to use the lessons with learners from grades K-12. Lessons in the new guide all have slideshow presentations that foresters can use if their visits must take place in an indoor setting and require even less advanced preparation than lessons for the original guide. Continue reading “DNR Foresters Partner with LEAF Program to Update Forester Activity Guide”