By Elton Rogers, Milwaukee Area Technical College and Dan Buckler, DNR Urban Forest Assessment Specialist, Milwaukee, Daniel.Buckler@wisconsin.gov or 608-445-4578

An urban forest is not an island. Trees and maintenance practices in one community inevitably affect the environment in another, while pests, pathogens and other damage agents don’t respect political boundaries. Because of these shared experiences, researchers have partnered with the Wisconsin DNR to assess the current state of publicly managed trees across the Milwaukee Metropolitan Area. Inventories from 40 organizations (mostly municipalities) totaling almost 440,000 trees point to worrying diversity issues and vulnerability to climate change, but also positive planting trends.

An article in the September issue of Arboriculture & Urban Forestry, the research publication of the International Society of Arboriculture, reviews the Milwaukee area’s species diversity, resilience to climate projections, availability of planting sites and more. A high-level summary of those results is below.

Continue reading “The Good, The Bad And The Ugly: The Current State Of Public Trees In Southeastern Wisconsin” →

Dan Buckler, Urban Forestry Assessment Specialist, Daniel.Buckler@wisconsin.gov

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” →

By Dan Buckler, DNR Urban Forest Assessment Specialist, Madison, daniel.buckler@wisconsin.gov or 608-445-4578

Successfully planting a tree in an urban space is hard. There are so many factors to consider to ensure that the tree survives and thrives in its new home. Climate change may not be at the top of that list, but it should be one of the factors taken into consideration.

To help think through the topic, the Wisconsin Department of Natural Resources (DNR) has released a new story map that explores urban trees and climate change in Wisconsin.

The new resource is organized into three main sections. The first provides a brief overview of projected changes in Wisconsin’s climate over the past century, specifically highlighting shifts in cold hardiness zones and heat zones. Precipitation patterns and intensities have and are projected to continue changing, though precipitation is not featured in the story map’s overview. For more information on that, scroll down to the precipitation section on the DNR climate science page.

Continue reading “DNR Releases New Climate Change And Urban Trees Story Map” →