Key Threats

Of the environmental trends that affect biodiversity, climate change may be the most influential. By mid-century, climate change is projected to become a major driver of land cover change 5106 resulting from changes in the suitability of land to different types of production. For example climate-related crop failure may affect prices, which in turn influences land use decisions. Projections show that in New Zealand, drought events are likely to increase in both frequency and severity in the eastern lowlands and this would also likely lead to increased damming and abstraction for irrigation, which modifies freshwater habitats. 5107 Climate induced droughts and severe winters in some regions may lead to a change in traditional land-uses or increased irrigation. Management responses to climate change also affect biodiversity. Climate change mitigation policies influence land-use decisions, which could have negative impacts on habitat/species. 5108

In New Zealand, a potential example could be the carbon credit schemes (designed to manage emissions) incentivise conversion to exotic forestry which in turn, can compete with ecosystems such as indigenous grasslands, while being beneficial to some species. Rising sea level is also an issue where maladaptation can cause loss of valuable intertidal and wetland areas. The forecasted effects on New Zealand’s biodiversity are varied but include: 

  • degradation of the rich biota of the alpine zone through increasing shrubby growth and loss of herbs, especially if combined with increased establishment of invasive species
  • death of cold water-adapted freshwater fish and invertebrates which are vulnerable to warming
  • increased spring flooding may increase egg/chick mortality for braided-river birds
  • Tuatara populations are at risk as warming increases the ratio of males to females 

There is little doubt that the consequences of a changing climate will have an impact at all levels of the biodiversity spectrum, including genes, species and ecosystems.

Snells Beach Earthworks (Credit: Raewyn Peart)

  1. IPCC, 2014, Climate Change 2014: Impacts, Adaptation, and Vulnerability. Summaries, Frequently Asked Questions, and Cross-Chapter Boxes. A Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Field C, Barros V, Dokken D, Mach K, Mastrandrea M, Bilir T Chatterjee M, Ebi K, Estrada Y, Genova R, Girma B, Kissel E, Levy A, MacCracken S, Mastrandrea P and White L (Eds). World Meteorological Organization, Geneva, Switzerland.

  2. Young R, Smart G and Harding J, 2004. Impacts of hydro-dams, irrigation schemes and river control works. In Harding J, Mosley P, Pearson C and Sorrell B (Eds) Freshwaters of New Zealand, Caxton Press, Christchurch, New Zealand

  3. Jantz S, Barker B, Brooks T, Chini L, Huang Q, Moore R, Noel J & Hurtt G, 2015. Future habitat loss and extinctions driven by land-use change in biodiversity hotspots under four scenarios of climatechange mitigation. Conservation Biology, 29: 1122–1131

  4. Green W and B Clarkson, 2005, Turning the tide? A review of the first five years of the New Zealand Biodiversity Strategy, The Synthesis Report submitted to the Biodiversity 

Last updated at 8:36AM on May 3, 2018