Looking After our Roots

In Western Australia, our trees work hard. From the scorching heat of Perth summers to wet winter storms, trees are essential assets in our urban and regional landscapes. They provide shade, reduce heat, support biodiversity and enhance livability — but their long-term health depends on what lies below ground.

While canopy health is often the most visible indicator of a tree’s condition, the real story frequently begins underground.

Why Roots Matter

Root damage can cause tree decline and failure. In new developments, roots are commonly impacted by trenching, excavation and paving.

When roots are severed, crushed or compacted, the consequences can be significant:

• Reduced nutrient and water uptake.

• Canopy thinning and branches dying.

• Increased susceptibility to drought.

• Structural instability and increased risk of tree falling.

In sandy WA soils, root anchorage is particularly important. Mature eucalyptus  trees and other large species rely on extensive root systems for stability. Root damage can compromise both the tree’s biological health and its structural integrity.

Often, symptoms begin subtly, with minor canopy decline, leaf discolouration or reduced vigour — before progressing to more serious issues such as soil heave at the base or fungal bodies indicating decay.

A Safer Way to Excavate

Where excavation near trees is unavoidable, traditional mechanical digging methods can pose significant risks.

According to Vermeer Equipment of WA & NT, vacuum excavation provides a far safer alternative.

Sales Manager Sam Hayes explains:

“Vacuum excavation operates through two key components that work together to provide a safe, non‑destructive digging method. Part one is the water system, where water pressure can be adjusted to suit the application. This controlled water stream is used to break up and loosen the soil. Part two is the high‑velocity vacuum system, which then extracts the loosened material and deposits it into a sealed spoil tank for easy removal.

For arborists, this method is particularly valuable when excavation is required around or beneath tree roots. Because the process relies on water and suction rather than mechanical digging, it significantly reduces the risk of damaging the root system or compromising the health and stability of the tree. Vacuum excavation provides a precise, low‑impact solution that helps protect mature trees during critical underground work.

In WA’s increasingly dense urban environments, where retaining established canopy is a priority, this non-destructive approach is becoming an important tool for arborists, contractors and local governments alike.”

Sam Hayes, Vermeer Equipment of WA & NT

Tree Work Requires the Right Equipment

Looking after roots is only part of the picture. Safe and efficient above-ground management is equally important, particularly as we transition from bushfire season into winter storm preparation.

Sam highlights that having fit-for-purpose equipment can dramatically improve both productivity and safety on site.

“A wood chipper is an essential asset for arborists, and Vermeer Equipment of WA and NT are proud to support the industry with a broad range of machines tailored to real‑world needs,” he said.

“We recognise that one size does not fit all - whether a client requires hydraulic features such as landing legs, chutes, deflectors and a remote control, or prefers the simplicity of manual configurations, we can supply a machine that matches their needs and workflow. With advanced safety and productivity features—including smart feed, winch interlock systems and vertical feed rollers - feeding material into the chipper has never been easier or safer.”

In WA conditions where large removals, such as storm-damaged trees and high-volume green waste are common, efficient processing equipment reduces manual handling and reduces the risk of injury.

Understanding the Critical Root Zone

Photo: Vermeer Equipment of WA & NT

When assessing potential root damage, arborists consider the critical root zone — the area around the trunk where the most important structural and absorbing roots are located.

If roots within this zone are severed or decayed, the risk of significant tree damage increases markedly. A tree may remain biologically alive — still producing leaves and appearing superficially healthy — yet be structurally compromised below ground.

As a general guide, trees can sometimes tolerate up to around 40 per cent root loss from a biological perspective before severe decline occurs. However, structural stability may be compromised well before visible canopy symptoms appear.

This is particularly relevant in Western Australia, where:

• Sandy soils offer less resistance to root movement.

• Prolonged summer drought stresses trees already coping with reduced root mass.

• Winter storms can expose weaknesses created months or years earlier.

What Should Property Owners Do?

Root problems are often subtle and easily overlooked by the untrained eye. Warning signs may include:

• Thinning canopy, particularly at the top.

• Tree leaning or soil lifting at the base.

• Dead or broken surface roots.

• Fungal growth around the trunk.

If you suspect root damage, engaging a qualified arborist is essential. Professional assessment may include root investigation, soil testing, structural analysis and risk evaluation.

As Sam Hayes said, the goal is not simply to remove trees at the first sign of trouble — but to manage and protect them wherever possible.

“Protecting root systems during excavation is one of the most effective ways to preserve mature trees. Once significant root damage has occurred, options become limited. Using the right method from the start makes all the difference,” he said.

Protecting WA’s Urban Forest

In Western Australia, retaining mature canopy is increasingly important for trees to survive.

Whether it’s through non-destructive excavation methods, careful construction planning, or using fit-for-purpose equipment, proactive management below ground supports safer, longer-lived trees above ground.

When we get the roots right, everything else has a stronger foundation.

To find a qualified arborist near you, please have a look on the ArbWest website: https://www.arbwest.com.au/statewide