Threats to native plants and animals

Since 1840, three quarters of the native vegetation in the Waikato Region has been cleared. Just over half of what is left is legally protected. Many natural areas require fencing to keep stock out, and regular pest and weed control. Environment Waikato is working with the community to protect and enhance our remaining natural habitat.

• Habitat loss
• Pests
• Grazing
• Protecting the remaining habitat

Habitat loss

Since 1840, people have drained wetlands and cleared native vegetation in the Waikato Region for pasture, horticulture, pine plantation or urban areas.

Today, much of the land suitable for pastoral farming has been cleared. Most of the remaining vegetation covers steep hill country, which is prone to erosion and uneconomic to farm.

Change in vegetation type by area since 1840¹

Almost half of the remaining areas of native vegetation are not legally protected. Native timber milling is restricted to sustainable harvest under the Forest Amendment Act 1993. However, these unprotected areas may still be at risk of being cleared for pasture or pine plantation.

Drainage in nearby areas can affect wetlands even if the vegetation in the wetland is not cleared. Find out more about the effects of draining wetlands and of drainage on peatland areas.

Check out our indicators on the extent of native vegetation and wetland vegetation in our Region. You can also compare the changes in our native vegetation and wetlands between 1840 and today.

Pests

Introduced pests have become established in all of our mainland forests and wetlands and threaten many of our native plants and animals. Almost all of the Region’s native forests are at risk from possum damage. Rats, wild pigs, deer, rabbits, hedgehogs, and domestic pets or stock can also cause significant damage.

Often a range of animal and plant pests is found in the same area, with their combined effects causing a lot of damage:

• Plant pests, such as wild ginger and old man’s beard, strangle trees or smother seedlings.
  
• Animal pests such as rats, possums, wild cats and stoats eat native animals or kill them indirectly by eating their food.
  
• Some animal pests kill trees by eating leaves and bark, or by compacting soils with their hooves.
  
• Animal pests also interfere with plant breeding by killing the animals that pollinate flowers and spread seeds, or by eating and trampling the flowers and seeds themselves.
  
• In wetlands introduced plants like willow and sweetgrass can choke out the native plants.

Find out more about specific plant and animal pests.

Grazing

Unlike most countries, New Zealand’s plants and animals evolved without any large grazing mammals around. Our soils and plants cannot cope with the trampling, grazing and waste from stock. When stock get into natural areas they can cause:

• soil compaction and erosion
  
• reduced seedling survival
  
• damage to bark and shrubs
  
• changes in the microclimate (by creating gaps and opening the understorey)
  
• excess nutrient deposits.

Find out more about the effects of stock in forest fragments and wetlands.

Protecting the remaining habitat

Around 270,000 ha of native vegetation in the Waikato Region (45 percent of the total) is protected as public conservation estate under the Conservation Act, Reserves Act or National Parks Act. The Department of Conservation purchases natural areas most in need of legal protection through the Forest Heritage Fund, or protects them on Maori land through Nga Whenua Rahui funding.

Many landowners have protected individual areas of native vegetation through Queen Elizabeth II National Trust covenants.

The Royal Forest and Bird Protection Society and the New Zealand Native Forests Restoration Trust own and protect areas of native forest.

District and city councils control land use activities and also protect some natural areas as reserves. Some district plans contain:

• schedules of significant areas of vegetation or habitat of native animals
  
• criteria to determine and protect such sites with regulations, incentives or purchase.

Hundreds of individuals and groups are working voluntarily to protect native plants and animals. About 120 community groups are actively working in wetlands, forest, dunes, lakes and riversides in the Waikato Region. Activities range from small projects like planting stream banks to major undertakings, such as the plan to eliminate all introduced pest animals from Maungatautari Mountain and return native species that have been extinct on the New Zealand mainland for over 100 years.

Contact the Waikato Biodiversity Forum on 0800 BIODIV (0800 246 348) to find out about community biodiversity projects near you.

Find out more about protecting private land on the Department of Conservation website.

What Environment Waikato is doing

• In the Waikato Region, resource consents are currently required to clear any type of vegetation greater than one hectare within the West Coast or Waikato River catchments. When Environment Waikato’s Regional Plan becomes operative this rule will be withdrawn and replaced with rules regarding vegetation clearance in ‘High Risk Erosion areas’, and adjacent to ‘Natural State Water bodies’. A consent is also required by Environment Waikato to drain wetlands.
  
• Environment Waikato provides information and assistance to landowners, who are legally obliged to control environmental plant pests on their property. Find out which plant pests landowners are required to treat in the Regional Pest Management Strategy.
  
• The Department of Conservation and Environment Waikato undertake possum control operations to combat Bovine Tb and protect our native plants and animals. Environment Waikato also supports community-initiated possum control schemes, carrying out the initial possum control in large or inaccessible areas. Landowners control possums in the easier areas and carry out maintenance control to keep possum numbers low.
  
• Environment Waikato is also working with owners of key ecological sites (areas of Regionally significant native habitat) to form partnerships to protect their bush or wetlands. This protection will include control of plant and animal pests and fencing to exclude stock.
  
• Environment Waikato works with care groups in the Region to enhance natural areas including:
  
  • planting native trees along river edges or catchments
    
  • fencing off riparian vegetation
    
  • protecting areas of native forest.

Footnotes

1. Native vegetation data from Leathwick, J. Clarkson, B. and Whaley, P. 1995: Vegetation of the Waikato Region: Current and Historic Perspectives, Landcare Research, Hamilton; Plantation forest data from Terralink New Zealand (Landcover Database, 1996) and Agriculture/horticulture (including cropping) data from AgriQuality New Zealand (Agribase, 1998).