Environmental Impacts

The environmental impacts associated with plantation forestry, both good and bad, are often measured in terms of changes to soil, water and aquatic habitats. Protecting soil and water resources is the key to sustainable forest management, because soil and water resources underpin forest ecosystems.

Impacts of plantation forestry

Forest management activities can significantly alter forest soils, water quality and associated aquatic habitats. Good management of forests and riparian land protects and enhances the chemical, biological and physical properties of soil and water resources and aquatic habitats.  

Poor management of forests and riparian land can cause environmental damage including:

  • soil compaction
  • loss of the soil A horizon
  • loss of riparian buffering capacity
  • increased sediment loads in streams
  • debris flows of wood and soil material
  • degradation and destruction of aquatic habitats
  • altered flow regimes, which may increase the risk of flooding or the complete desiccation of streams.

Soil erosion and water quality

Approximately 1.2 million hectares of planted forest are classified from slight-to-moderate erosion risk and 60,000 hectares of planted forest are classified severe-to-extreme erosion risk.

The quality of water flowing from forest catchments is generally considered to be high. Increased suspended sediment is the main risk to water quality associated with planted forestry.

Protection of soil and water

Legislative mechanisms  

New Zealand has two key legislative mechanisms to address the environmental impacts of forestry. All commercial forest management must meet the requirements of these Acts.

  • Resource Management Act 1991
  • Forests Act 1949.

Standards and Guidelines

A number of standards and guidelines exist to assist planted forest managers to safeguard soil and water resources. These documents are supported by, and widely promoted by, the industry.

  • The New Zealand Forest Road Engineering Manual
  • New Zealand Standard NZS AS 4708:2014 Sustainable Forest Management.
  • New Zealand Environmental Code of Practice for Plantation Forestry
  • Standards and Guidelines for the Sustainable Management of Indigenous Forests
  • National Policy Statement for Freshwater Management.

Forest certification

Forest certification schemes recognise good forest management, including safeguarding soil and water resources. Most large-scale forest owners in New Zealand have international Forest Stewardship Council (FSC) certification. This provides a third-party guarantee that the products come from forests that have been managed in accordance with FSC principles and criteria.

  • 1.499 million hectares:  gross forest area under FSC certification
  • 1.054 million hectares:  productive forest area under FSC certification (61 percent of  the planted forest estate)
  • 12 000 hectares: area of indigenous forests included and managed under Part 3A of the Forests Act 1949.

Length of rivers within forested areas...

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