Tree Preservation Services in Dunedin

Construction and development is one of the most common causes of tree decline and death in urban environments — and the damage often doesn't become visible until years after the work is complete. Professional tree preservation planning protects trees during building and landscaping projects, keeping valuable trees alive and reducing legal and financial risk for property owners, developers, and builders.

Why Trees Die During Construction

Trees are far more vulnerable to construction activity than most people realise. The most common causes of construction-related tree death include:

Root zone compaction — heavy machinery driving over root zones compacts soil, cutting off oxygen and water to roots
Root severance — trenching for pipes, drainage, or foundations cuts major roots that the tree cannot recover from
Grade changes — raising or lowering soil levels around a tree trunk smothers roots or exposes them to air and drought
Trunk and bark damage — machinery contact with trunks causes wounds that allow disease and decay to enter
Chemical contamination — concrete washout, fuel spills, and paint on root zones kill fine roots

Tree Protection Zones and Fencing

The foundation of tree preservation is establishing a Tree Protection Zone (TPZ) around each tree before any work begins. The TPZ is calculated based on the tree's trunk diameter and species, and is typically fenced with physical barriers before site preparation begins. Within the TPZ, no machinery, materials storage, or ground disturbance should occur without explicit arborist approval.

For development projects in Dunedin requiring resource consent, the Dunedin City Council may require a Tree Protection Plan and arborist supervision as a consent condition.

Construction Methodology for Root Zones

When construction must occur within a TPZ, we specify alternative construction methodologies that minimise root damage — including hand excavation, air spading, bridging foundations, and directional boring for services. These approaches allow development to proceed while giving the tree the best possible chance of survival.

Arborist Monitoring and Reporting

For projects with significant trees or consent conditions, we provide on-site monitoring during critical construction phases and produce written reports documenting tree condition before, during, and after the works. This creates a record of compliance and helps identify any issues early when intervention is still possible.