Urban Forest Master Plans (UFMPs) often include goals for planting trees and expanding urban tree canopy. While trees bring innumerable benefits to a community, considering the larger landscape where they’re planted can help urban foresters and project managers support successful tree establishment and long-term tree health. Follow this link to view our recorded webinar Growing Green: Expert Strategies for Successful Sustainable Tree Planting Initiatives.
The ecosystem of trees, soil, water, and other plant life is a delicate balance in which each component interacts with and depends on one another. Trees need healthy soil and the right amount of water to thrive and provide the shade, wildlife habitat, visual appeal, and carbon sequestration communities need.
Incorporating soil care and water management into a UFMP helps ensure trees are not only planted, but also thrive for generations to come.
Digging Into Soil Health
The importance of soil can’t be overstated. Soil is a complex working system that regulates water, buffers contaminants and pollutants, holds roots in place, and fuels the ecosystem above ground. It acts as a reservoir, soaking up water and storing it so plant roots can access it for longer. Microorganisms within soil break down organic matter, releasing nutrients like nitrogen, phosphorus, and potassium to support healthy trees.
Soil health is the foundation for healthy tree growth, health, and aesthetics. If soil can’t do its job properly, a tree runs the risk of not getting the water and nutrients it needs to establish. Factors like soil type, structure, pH, compaction, and organic matter content all interact to either support or hinder healthy tree root function.
Soil Type – Soil profiles vary by region. The clay-heavy soils of the Midwest face very different drainage and compaction challenges than the sandy soils of the Southeast or alkaline soils in the Southwest. Knowing a community's soil type is key to understanding what the trees in the area actually need.
Structure and Compaction – Well-aggregated soil has balanced pore sizes and types to allow better air and water exchange, as well as root penetration. As compaction, salt exposure, or other disturbances break down the structure, crusting and runoff increase.
Soil pH – pH affects nutrient availability, with overly acidic or alkaline soils making key minerals less soluble.
Organic Matter Content – High levels of organic matter, like leaves, organisms, and compost, improve water retention, aggregation, and prevent soil degradation.
By incorporating soil health management into a UFMP, project managers can ensure newly planted and existing trees are receiving the nutrients and water they need for a longer lifespan.
Keeping Your Head Above Water
Mature trees have extensive root systems that tap into water stored deeply in the soil. Too much water can cause root rot, disease, and shallow root growth, while too little can cause drought stress. Generally, a slow watering method that delivers water directly to the tree’s root system is an effective way to keep trees hydrated.
When water is too quickly delivered to the ground’s surface, much of it evaporates or runs off before reaching the roots. Slow watering uses less water and delivers it more efficiently to tree roots, helping develop a deeper root system.
To incorporate water management into a UFMP, consider regional climate differences, assess and test the soil in the area the UFMP focuses on to determine best practices, then design a water management plan that provides the right amount of water when it’s needed.
In the design phase, consider existing infrastructure, capacity needs, and tree needs to create a system that supports tree health and sustainability.
For UFMPs, applying water management best practices avoids overwatering trees, which can seriously damage an urban forest and a project’s budget.
A UFMP For The Long Run
Incorporating soil health and water management best practices into a UFMP is an investment in long-term tree health. Highlighting the importance of these practices in the plan can help support the funding needed for implementation.
Davey’s experts are backed by the scientists and researchers at the Davey Institute to provide holistic urban forest care, including soil health and proper water management practices. Contact your local Davey office to learn more.
FAQs For Urban Foresters
Soil health and water management should be included in an Urban Forest Master Plan (UFMP) because both directly influence tree establishment, long-term health, and canopy sustainability. Healthy soil provides the structure, nutrients, oxygen, and water storage that tree roots need, while effective water management helps prevent drought stress and excessive moisture. Incorporating these factors into urban forest planning shifts the focus from the number of trees planted to whether those trees can establish and mature successfully.
Urban forest planning should evaluate soil type, structure, compaction, pH, and organic matter because these conditions affect root development, nutrient availability, drainage, and water retention. Soil conditions can vary considerably by region and even between planting sites within the same community. Soil assessment and testing can help urban foresters and project managers identify these constraints before planting and establish appropriate soil health management practices for both newly planted and existing trees.
Water management should be incorporated into an Urban Forest Master Plan by assessing regional climate, existing regulations, soil conditions, tree water requirements, maintenance practices, resources, budget allocations, and existing infrastructure before establishing irrigation practices. Both insufficient and excessive water can affect urban tree health, causing problems such as drought stress, root rot, disease, or shallow root development. Slow watering methods that deliver water directly to the root zone can reduce runoff and evaporation while encouraging deeper root systems.
Soil health and water management work together by determining how effectively water, oxygen, and nutrients reach and remain available to tree roots. By coordinating soil health management with appropriate irrigation and water management strategies, urban foresters can create better growing conditions that support root development, tree establishment, and the long-term resilience of the urban tree canopy iInfiltration.
Integrating soil and water planning into an Urban Forest Master Plan can improve sustainability by addressing the conditions trees need to survive beyond initial planting. These practices can help project managers prioritize long-term tree establishment and maintenance when planning budgets, infrastructure, and urban forestry programs. A holistic approach also helps communities connect tree-planting investments to broader goals for a resilient tree canopy, resource conservation, and sustainable urban forest management.
Article Contributors:
Nathan Davila, Senior Associate Consultant, Davey Resource Group, Southern California
Paul Kovacik, Senior Managing Consultant, Davey Institute, Water Management
