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.
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:
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.
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.
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.
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.