Which Tree Species Best Withstand Urban Stressors? Ask the Experts

Introduction

Are you a tree lover, passionate about greening urban spaces? Have you ever wondered which tree species can thrive in challenging city environments? Look no further! At Tips Tree Planting, we have gathered insights from urban forestry professionals to discover the tree species that can withstand the stressors of urban life. From air pollution to extreme temperatures, we’ve got you covered!

The Challenges Faced by Urban Trees

Urban trees play a crucial role in enhancing the urban environment, benefiting both humans and nature. They improve air and water quality, reduce stormwater runoff, and lower temperatures, mitigating the urban heat island effect. However, these trees face numerous challenges in city settings.

Air pollution, de-icing salts, soil compaction, and temperature extremes pose significant risks to the health and survival of urban trees. Air pollution damages their photosynthetic systems and stomatal functioning, hindering growth. De-icing salts alter soil structure and increase salinity, making it harder for trees to absorb nutrients and water. Soil compaction limits root growth and nutrient uptake. Additionally, climate change intensifies these challenges, bringing more severe droughts, heatwaves, pests, diseases, and extreme weather events.

Understanding Stressors and Tolerance

To better understand how different tree species cope with these stressors, we sought the expertise of urban forestry professionals. We defined stressors as environmental factors that debilitate trees, such as pollution or extreme temperatures. Tolerance, on the other hand, refers to a species’ ability to maintain normal growth despite these stressors.

Certain stressors, like pest outbreaks or ice storms, have short but intense impacts, while others, like soil compaction or drought, persist over more extended periods. To ensure the survival and growth of urban trees, it is crucial to understand their vulnerability to multiple stressors.

The Importance of Species Diversity

While certain tree species have traditionally been favored by urban forest managers, their suitability for future climates may be questionable. To increase the resilience of urban forests, species diversity is essential. However, planting diverse species can lead to higher mortality if trees are not suited to local conditions.

Despite existing research on tree vulnerability in urban areas, there are still significant gaps in our knowledge. We lack a comprehensive understanding of which species can tolerate specific stressors or multiple stressors acting additively.

Seeking Expert Knowledge

To address these knowledge gaps, we conducted a study in northeastern North America, focusing on common urban tree species. We engaged urban forestry professionals through an iterative process, using the Delphi method, to gather their opinions and reach consensus on species tolerance to various stressors. In the second part of our study, we expanded our reach by circulating a questionnaire among researchers and practitioners in arboriculture and urban forestry.

By combining expert opinions, we aimed to classify tree species based on their tolerance to stressors such as soil compaction, air pollution, pests and diseases, ice storms, snow, de-icing salts, strong winds, drought, and extreme temperatures. Additionally, we sought to identify the characteristics that contribute to a species’ ability to cope with these stressors.

Our approach, which we provide the means to replicate, will serve as a valuable tool for informing the selection of tree species in urban environments and promoting more resilient urban forests.

Remember, if you want to learn more about tree planting, caring for urban forests, or finding the perfect tree for your city, visit us at Tips Tree Planting. Let’s make our cities greener together!