Restoring our precious wetlands
Awareness of wetlands continues to grow throughout New Zealand and around the world.
Given their importance that’s hardly surprising but it’s also somewhat ironic that we’re only now beginning to understand their value and undo decades of abuse and exploitation.
More than 90% of pre-settlement wetlands have been lost and remaining wetlands are steadily degrading through fragmentation, decreased water supply, eutrophication and weed invasion. All this despite the fact that they sustain indigenous species, maintain water quality, sequester carbon and therefore provide large economic, social and cultural benefits.
However, Landcare Research staff, led by Beverley Clarkson, have worked with partners NIWA, DOC and the University of Waikato to deliver scientifically based guidelines, techniques and tools to improve management and guide restoration of wetlands. This isn’t always easy because wetlands are complex and driven by many interacting physical, chemical and biological processes. This complexity helps to explain the gaps in scientific knowledge that have constrained their management and restoration.
Publication of our wetland restoration handbook (available free online as downloadable chapters) represents the culmination of several years of research. This involved development of best practice techniques from restoration experiments, case studies, and collaboration from wetland partners and the wider community over the course of the programme.
Restoration techniques were developed through field experiments in wetlands that have been drained, burned, mined, invaded by weeds, or otherwise modified. These include restoration of a rare and threatened Sporadanthus bog type at a site that is being mined for horticultural peat.
When the bogs are restored using our patch restoration approach, nutrient balances are improved, leading to better growth rates, better decomposition patterns and increased storage of carbon. Under our technical guidance, end-users have introduced populations of Sporadanthus and rare invertebrates to three new private wetland projects at sites where the bog type once occurred.
Wetland restoration practitioners including DOC, regional and district councils, iwi, landowners, and community groups use the handbook at all stages of their restoration as it provides a comprehensive compilation of current knowledge on major aspects of wetland restoration.