Introduction to special section on New Zealand restoration

Despite only 800 years of human occupation, New Zealand has suffered from a rate and scale of ecosystem transformation and species extinction rarely matched elsewhere. However, New Zealand's biodiversity is on the cusp of a major recovery because of the variety of restoration initiatives currently underway and of groups implementing them, and because of new cutting-edge national scale projects that have just been announced. In this introduction, we briefly discuss what makes restoration in New Zealand distinctive, review the contributions to this Ecological Management & Restoration special section and highlight other aspects of restoration in New Zealand. New Zealand has one of the highest proportions of land managed solely for nature conservation of any country (8.6 million ha or 33% of the land area), with this land managed by one government agency, the Department of Conservation. While the area of conservation land is large, it is not representative of the original diversity because the majority is concentrated in the mountains and uplands. Furthermore, New Zealand's biota has been decimated by the impacts of invasive species. New Zealand was the last major land mass to be settled by humans (ca. 1280 A.D.), and apart from some smaller islands (e.g. Hawai'i), nowhere else has the rate of invasions and their impacts been so high. Our endemic birds best characterise this decimation: nearly one quarter (21%) of all bird species (263 species including terrestrial, freshwater and marine) resident at the time of human settlement are extinct, while 81% of the remaining species are directly threatened with or at risk of extinction. Primary production is the main land use across the remaining two thirds of New Zealand, with sheep and beef farms, plantation forests and dairy farms covering three-quarters of this. Within landscapes favoured for agriculture, the scale of ecological decline has been dramatic. For example, of the three million ha of the Canterbury plains and downs, less than 0.1% still contains remnants of the original vegetation. A unique feature of New Zealand is the central role that indigenous Māori have in both society and land management. Notwithstanding signing the Treaty of Waitangi with the British Crown in 1840 guaranteeing them the undisputed chieftainship of their lands and resources, Māori were marginalised and had most of their lands and resources wrongfully taken. Although not perfect, a process to rectify Treaty violations has been in place since 1975 and has led to substantial settlements with individual iwi (tribes) that have gone someway towards redressing past injustices, including the return of land, legal recognition of mana (authority, prestige) over land, access to resources, co-management and financial settlements amongst other things. This process has led to Māori today having substantial ownership and say in natural resource management, especially biodiversity conservation. In addition, many legal statutes now specifically recognise the principles of the Treaty of Waitangi and require those implementing them (especially government agencies) to take these into account. In New Zealand, almost all conservation work is restorative and encompasses a continuum of activities including restoration of degraded ecosystems such as abandoned farmland, removal of pests and reintroduction of locally extinct fauna. In New Zealand, the words conservation and restoration are used interchangeably and both are as much about inclusion of people as they are about the biophysical. This is well articulated in the Māori proverb: Toitū te marae a Tāne, Toitū te marae a Tangaroa, Toitū te Iwi (which in effect means ‘When the land and water are sustained, the people will prosper’). Central to the interdependency between people and the environment has been the concept of adaptive management. The magnitude of the biodiversity crisis in New Zealand is such that management is often implemented before the hard science is undertaken. This adaptive management approach is not unique to New Zealand, but has been essential and highly successful here and has led to some outstanding conservation successes (e.g. the recovery of the Black Robin, Petroica traversi, from the brink of extinction with all birds today descended from one female). This special section has been assembled to celebrate the first joint meeting between the Australasian chapter of the Society for Ecological Restoration and the New Zealand Ecological Society. These six articles are by no means exhaustive, and a wide range of other exciting restoration initiatives also exist. Nevertheless, we provide a summary of the current position of restoration in New Zealand across a range of ecosystems and approaches. In the opening paper Norton et al. emphasise that if we are to make meaningful progress in restoring New Zealand's biological heritage by 2050, a range of fundamental issues need to be addressed. These relate not just to restoration science but also to building resilience in the wider socio-economic and cultural context within which restoration occurs. With nearly 90% of the population living in urban centres, urban restoration has been expanding rapidly in New Zealand; Clarkson and Kirby review the history and current state of urban restoration and highlight some constraints and opportunities for the future. Many lowland lakes have become degraded as a result of agricultural intensification and invasive species. Hamilton et al. emphasise the role of catchment restoration and in-lake interventions to improve lake condition touching on the challenges posed by climate change and invasive species. Reducing the abundance of introduced predators to allow native fauna to flourish has been a central theme in New Zealand conservation management. However, the occurrence of unusually large-scale tree seeding events causing predator irruptions has posed exceptionally difficult challenges. Elliott and Kemp review the government's 2014 Battle for our Birds programme, which applied poison over 10% of New Zealand's native forests to reduce predators. Sullivan and Molles consider the role of community monitoring in restoration and emphasise that collaboration is essential to develop simple, accessible and informative monitoring systems that capitalise on modern technology. Riparian restoration is a critical issue because of the adverse effects of intensive farming on waterways. McKergow et al. assess the progress that has been made with riparian restoration and highlight some future challenges and solutions. One aspect of restoration that the articles presented here only cover in part is the rapid upsurge of restoration initiatives across private land, especially farmland. More than half of the New Zealand land area is used for primary production (meat, wool, milk, timber), which is vital to our economy. While farmers and foresters are primarily focused on running economically viable businesses, there has been a massive increase in the interest shown in restoration and biodiversity conservation more generally. There are now over 4000 legally binding conservation covenants with the Queen Elizabeth II National Trust covering nearly 200,000 ha of rural New Zealand whose primary purpose is to ensure that native remnants (forest, shrubland, wetland, grassland) are protected in perpetuity. Tens of thousands of kilometres of waterways and lake margins have been fenced, and many of them have been planted with native vegetation. The plantation forestry sector has signed an accord where NGOs recognise the importance of plantation forestry for the New Zealand economy while the forestry industry agrees not to clear native vegetation when establishing new plantations and protect existing native vegetation associated with plantations. Many farmers appreciate the value of native vegetation for their farming operations, not only aesthetic values but also the benefits it can provide for farming (shade, shelter, timber, pollinator habitat). The amount of native woody vegetation across rural New Zealand is higher today than it was half a century ago, helped in part by the 1980s removal of government subsidies for developing ‘rough country’. As a result, native woody vegetation is regenerating vigorously in many areas initiating a succession back to mature forest. Many ‘uneconomic’ farms are being bought by individuals and organisations whose primary goal is to restore natural values (Fig. 1). Several projects have recently been initiated that aim to integrate biodiversity conservation and farming across landscape scales, for example on Banks Peninsula (100,000 ha) and in Northland (1.4 million ha). An exciting new national initiative ‘Trees That Count’ has just been announced (July 2016) that aims to plant millions of native trees across rural New Zealand allowing for even greater reconnection and integration of native biodiversity. While New Zealand's native biodiversity has declined dramatically over the 800 years since the first Polynesian voyagers stepped ashore, the amount of restorative work that is now underway suggests that the outlook is not as bleak as it is often thought to be. Optimists focus on practical solutions, and the powerful nexus of restoration science and practice gives hope for the future; the examples discussed in this special section along with many others suggest that there are plenty of reasons to be optimistic for our biodiversity. At the time of writing this introduction (July 2016), the government has just announced a bold and aspirational vision for New Zealand to be completely predator free by 2050. If we are to be successful with this and other inspirational restoration initiatives, from local to national, then it is essential we ensure that restoration is about the inclusion and enthusiasm of people as much as it is about biodiversity, science and technology. David Norton is a Professor, School of Forestry, University of Canterbury (Private Bag 4800, Christchurch 8140, New Zealand) Laura Young is a Post-Doctoral Researcher, School of Forestry, University of Canterbury (Private Bag 4800, Christchurch 8140, New Zealand) Bruce Clarkson is Deputy Vice Chancellor Research, University of Waikato (Private Bag 3105, Hamilton 3240, New Zealand).