Wetlands
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| Awarua Bog, Southland. Photo: B. Clarkson |
New Zealand wetlands have declined significantly since European settlement and those that remain are under severe threat from human activities (see map showing losses in Waikato 1840-1995). Our research aims to assist landowners and managers in the protection and restoration of wetlands by providing scientifically based guidelines to underpin management and restoration strategies. The research will benefit New Zealand by helping prevent further loss and degradation of wetlands. Specifically, by 2009, we aim for a 10% increase in the success rate of wetlands being restored as measured by the biodiversity condition index (using wetland monitoring handbook listed below).
Who is involved?
The project involves researchers mainly from Landcare Research, NIWA, and The University of Waikato, and is linked to The University of Waikato’s Freshwater Restoration OBI (www.lernz.co.nz). Key collaborators include DOC, Regional Councils, National Wetland Trust, Te Whare Wananga o Awanuiarangi and Landcare Trust, who will provide ongoing guidance and uptake of results through membership of an Advisory Group.
What is being investigated?
The influence of water regimes and nutrients on wetland structure and function are being investigated through integrated studies of plant ecology and physiology, biogeochemistry, hydrology, and invertebrate ecology. Guidelines and techniques for restoration are being developed through field trials in wetlands that have been drained, burnt, mined, or otherwise modified.
Some areas of current or recent research:
- Characterising and understanding biotic patterns in lowland wetlands (vegetation, nutrients, invertebrates) for species-environment models (‘intact’ wetlands throughout New Zealand, e.g., Stewart Island, Fiordland, Northland)
- Field fertilisation experiments: testing the applicability of N:P ratio as an indicator of N or P limitation across a wetland successional gradient.
- Experiments on rates of litter decomposition across a wetland successional gradient for comparison with Northern Hemisphere wetland decomposition rates. In collaboration with Professor Tim Moore, McGill University, Montreal, Canada. www.geog.mcgill.ca/faculty/moore/
Recent News:
- Corinne Watts achieved 3rd place in the ‘Understanding Planet Earth’ section of the MacDiarmid Young Scientists of the Year Awards. Her PhD studies on invertebrate restoration in threatened wetlands showed that the simple low-cost technique developed for peat miners to restore vegetation is also equally effective in restoring invertebrate communities.
- Planning is underway for the 3rd biennial wetlands symposium “Wai Wetlands?” to be held in Christchurch 14–16 February 2008. Information is available at : http://www.wetlandtrust.org.nz/symposia.html
Field restoration experiments:
- Restoring vegetation and invertebrates at a mined peat bog, Torehape, Hauraki Plains. In collaboration with Gamman Mining and New Zealand Peat.
- Recreating rare Sporadanthus restiad bog ecosystem at two sites in the Hamilton basin. Project (SMF) led by Landcare Trust.
- Best practice restoration techniques will be summarized and a web-based wetland restoration handbook to be produced in 2009.
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Lake Taharoa, West Coast, North Island |
Whangamarino Wetland, Waikato. |
Tools and services
- Wetland monitoring tools using science-based and Māori-based indicators of wetland condition:
Clarkson B.R., Sorrell B.K., Reeves P.N., Champion P.D., Partridge T.R., Clarkson B.D. 2004: Handbook for monitoring wetland condition. Coordinated Monitoring of New Zealand Wetlands
revised edition. A Ministry for the Environment Sustainable Management Fund Project 5105. 74 p. - Harmsworth, G. 2002. Maori environmental performance indicators for wetland condition and trend. Coordinated Monitoring of New Zealand Wetlands: A Ministry for the Environment SMF Project 5105. Landcare Research contract report LC 0102/099. 65 p.
Recent publications:
Wetland functioning
Clarkson, B.R., Clarkson B.D. 2006: Restiad bogs in New Zealand. In: Rydin, H and Jeglum, JK The biology of peatlands. The Biology of Habitat Series Oxford University Press UK pp 228-233.
Clarkson, B.R., Schipper, L.A., Lehmann, A. 2004: Vegetation and peat characteristics in the development of lowland restiad peat bogs, North Island, New Zealand. Wetlands 24: 133-151.
Clarkson, B.R., Schipper, L.A., Moyersoen, B., Silvester, W.B. 2005: Foliar 15N natural abundance indicates phosphorus limitation of bog species. Oecologia 144: 550–557.
Moore, T.R., Clarkson, B.R. 2007: Dissolved organic carbon in New Zealand peatlands. New Zealand Journal of Marine and Freshwater Research 41:137–141.
Suren, A.M.; Lambert, P.M.; Image, K.; Sorrell, B.K. In press. Variation in wetland invertebrate communities in lowland acidic fens and swamps. Wetlands Ecology and Management.
Wetland restoration
Sorrell B.K., Partridge T.R., Clarkson B.R. Jackson R.J., Chagué-Goff C., Ekanayake J., Payne J., Gerbeaux P., Grainger N.P.J. In press. Soil and vegetation responses to hydrological manipulation in a partially drained polje fen in New Zealand. Wetlands Ecology & Management.
van Bodegom P.M., Grootjans A.P., Sorrell B.K., Bekker R.M., Bakker C. & Ozinga W.A. 2006: Plant traits in response to raising groundwater levels in wetland restoration: evidence from three case studies. Applied Vegetation Science 9: 251–260.
Watts, C.H.; Didham, R.K. 2006: Rapid recovery of an insect-plant interaction following habitat loss and experimental wetland restoration. Oecologia 148: 61–69.
Watts, C.H.; Didham, R.K. 2006: Influences of habitat isolation on invertebrate colonisation of Sporadanthus ferrugineus in a mined peat bog. Restoration Ecology 14: 412–419.
Useful wetland links:
The National Wetland Trust of New Zealand: www.wetlandtrust.org.nz
Lake Ecosystem Restoration New Zealand: www.lernz.co.nz
Freshwater NIWA Science: www.niwascience.co.nz/rc/freshwater/
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Torehape mine restoration, Hauraki Plains. |
Olearia semidentata, Lake Rotokawau bog, Chatham Islands |
Primary contacts:
 | Bev Clarkson Email  |
Landcare Research | |
Phone: +64 7 859 3700 |
Comments and feedback
on these pages are welcomed and should be directed to:
Bev Clarkson
Email