Biodiversity is the variety of life forms – the different plants, animals and microorganisms, the genes they contain and the ecosystems of which they form part of. Biodiversity provides people with the fundamental processes and products needed to survive.
Biodiversity loss is a global issue and provides one of the greatest challenges currently faced by the world community, including New Zealand. The decline of New Zealand’s indigenous biodiversity is described in the State of New Zealand’s Environment report 1 as our 'most pervasive environmental issue'. This issue still exists with continual loss of indigenous vegetation, the decline of ecosystems such as sand dunes and wetlands, and the threat of extinction of many of our endemic species 2 (Aotearoa, 2015).
Roads are a significant threat to biodiversity, affecting ecological features both through road construction, and through their operation and maintenance. Ecological effects of roads may include:
- Direct and indirect mortality
- Habitat loss and degradation
- Loss of connectivity in the landscape
- Alteration of animal behaviour (eg disturbance, avoidance)
- Facilitating weed establishment and providing a corridor by which weeds disperse.
The New Zealand Transport Agency is committed to acting in an environmentally and socially responsible manner, as set out in our Environmental and Social Responsibility Policy. We aim to minimise the negative effects of roads on ecological features, and to protect and, where possible, enhance biodiversity on Transport Agency land. There are opportunities for roads to support native biodiversity with road verges potentially playing an important role either because of the species and/or habitat they support or the environmental function they perform.
[1] The State of New Zealand’s Environment 1997, Publication reference number: ME 612, Ministry for the Environment.
For further information contact environment@nzta.govt.nz .