Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Highlights: Sustainable business

Magnetic South

Magnetic South

Impact 1 Approaches to resolving complex environmental issues are understood, and opportunities recognised for adapting to global change and reducing vulnerability to resource scarcity.

Review praises the ICM programme´s approach

In late 2010, a panel (comprising academic, international, regional council and Māori representatives) completed an end–of–programme review of the Motueka River Integrated Catchment Management (ICM) research. Landcare Research partnered with the Cawthron Institute and Tasman District Council to lead the research, which also involved NIWA, GNS, Scion, NZ Landcare Trust, Te Tau Ihu iwi and the community. The ICM programme scored 5/5 for Science Quality & Productivity, 4/5 for Impact on Catchment Management & Policy Development, and 5/5 for Knowledge Transfer, with the panel recommending similar approaches be used across the country to manage competing expectations for limited land, water and coastal resources.

Councils, government, Māori and sector groups from across New Zealand were similarly positive. They revealed a widespread desire to move from the adversarial effects–based approach of the Resource Management Act, to a collaborative approach built on community trust, as documented at and in a 2011 special issue of the New Zealand Journal of Marine & Freshwater Research.

Magnetic South – for Christchurch’s recovery

Magnetic South was an online discussion about the long–term future opportunities for Christchurch following the highly damaging earthquakes of 2010/11. It used the Foresight Engine, courtesy of the Californian Institute for the Future, to generate a fast flow of almost 9000 ideas from 850 people. Popular broadcaster Kim Hill featured Magnetic South on her Saturday morning radio show. This led to an overwhelming surge in public participation, swamping the US–based servers and forcing an earlier than expected end after 27 hours – called ‘epic–win–for–onlineparticipation–silicon–valley–server–munted’ in the final blog.

Magnetic South revealed a genuine community desire for an environmentally sustainable city that attracts talent and investment.

We released the data under a Creative Commons Attribution 3.0 New Zealand Licence. The information complements the Christchurch City Council ‘Share an Idea’ initiative. Magnetic South collaborated with StratEDGY, and was supported by Christchurch City Council and the Mayor Bob Parker. Plans for future events include more boutique crowd–sourcing events (perhaps no more than 500 people) on quite specific issues in more focused environments.

Economic modelling for global change and trade

Policymakers increasingly want economic models to guide how primary production and international trade should respond to climate change. However, technologies for large–scale modelling of production, emissions and responses in the primary sector are still in their infancy because they require particularly complex integration of economic and biophysical data and processes.

In partnership with the University of Chicago and Argonne National Laboratory’s Computation Institute, we are investing in developing a new, dynamic, spatially detailed model. The complementary and multidisciplinary skills will contribute significantly to the innovative and ambitious research project.

Wildlife diseases – individuals to ecosystems

While infectious diseases and parasites obviously affect individual wildlife hosts, they also have an impact at the ecosystem scale. An important challenge is to determine the key transmission mechanisms maintaining the persistence of different types of diseases in the wild. Good evidence now shows that both direct and indirect effects of parasites frequently mediate the success of invasive species and their impacts on recipient communities. Such interactions may offer key insights into when and how different regulatory factors are important, when disease can cause species extinctions, and what characteristics are indicative of functionally resilient ecosystems.

Impact 2 Integrated economic, social, cultural and environmental initiatives for business and industry are effective in maintaining or enhancing their international competitiveness, market access and social licence to operate.

Water footprinting green kiwifruit

The Ministry of Agriculture and Forestry (MAF) and ZESPRI International commissioned Landcare Research to assess the water footprint of green kiwifruit supplied to the UK — the environmental impact of water used, directly and indirectly, throughout all stages from growing the fruit through to it reaching the consumer. The project, a partnership with Plant & Food Research and AgriLink, was the first–ever comprehensive water footprinting exercise to be carried out in the New Zealand horticulture sector.

At the orchard gate, green kiwifruit have an average water footprint of 417 litres per kilogram of fruit. Using this national average, 85% is water available for fruit growth from rainwater or soil moisture, 5% is from irrigation, and 10% is used to dilute orchard inputs, e.g. nitrogen fertiliser entering the environment. However, several regions made a relatively low contribution to national production yet had relatively high environmental impacts. Hypothetically converting irrigated orchards into rain–fed orchards had a significant impact on water footprints for only the low–rainfall areas (Hawke’s Bay, Gisborne and Nelson), but significantly reduced orchard gate returns for Hawke’s Bay and Nelson. In the Te Puke region, neither the application of fast–release nitrogen fertiliser nor halving of the amount of nitrogen fertiliser typically applied had a significant influence on the water footprint.

The research has been of considerable value to ZESPRI, as major global retailers, such as Walmart and Sainsbury’s, are paying increasing attention to water footprints across suppliers worldwide. MAF will use the results in formulating New Zealand’s responses to development of the ISO water footprinting standard.

Beech forest production systems

New Zealand has a wealth–creation opportunity through building an industry based upon the sustainable management of a portion of its 1.5 million hectares of privately owned indigenous forests, including 300,000 ha owned by Māori. Sustainable management of privately owned indigenous forests for high–value timber products requires management systems that have limited impact on the environment. In the last year, our research improved the confidence of forest owners and managers to adopt the management systems we have researched.

Beech (Nothofagus spp.) is the main indigenous forest managed for timber production in New Zealand. Perceived difficulties around stand stability and regeneration following harvesting have long limited the development of a beech timber industry. We reviewed management systems prescribed in the 1993 amendments to the Forests Act 1949 for beech forests, and concluded that in most places beech regenerates following harvest and that residual beech stands are usually stable.

Beech trees grow slowly, and stands regenerating from past felling develop into dense even–aged thickets of saplings and pole–sized trees where individual growth rates are in the order of 2 mm in stem diameter per year, with expected rotations of more than 120 years. However, beech saplings respond well when freed from neighbouring competition.

We remeasured two thinning trials set up in the 1970s. Stem diameter of 58–year–old beech trees in thinned areas was about double that of trees in the unthinned stands; potential sawtimber yields were up to 7 or 21 times higher compared with unthinned stands. An initial discounted cashflow analysis (undertaken with the University of Canterbury) for silver beech stands indicated that, while thinning operations are currently unprofitable for timber production, revenue from trading carbon credits could offset thinning costs.

Sustainable possum harvesting

Possum harvesting in accessible areas of native forest is a balancing act. Sufficient animals need to be trapped for commercial viability and to protect the forest, but if too many animals are killed the operation will not be sustainable. Working with full–time possum harvesters and using our extensive information about possum behaviour and control, we are developing an economic model that considers variations in trapping effort, possum density and economic variables. Together with Tūhoe Tuawhenua Trust, we are determining the optimal trapping frequency and trap–line spacing for sustainable harvests. We are also investigating the links between post–harvest possum densities and benefits for forest biodiversity. This work is likely to lead to further research of benefit to Māori land owners and the possum fibre industry.

Strategies for reducing bovine TB spread

In New Zealand, four wild mammal species are frequently infected with bovine tuberculosis (TB), but possums are the only true ‘maintenance’ host. Red deer, ferrets and pigs are generally ‘spillover’ hosts that become infected from possums. Spillover hosts may occasionally transmit infection back to possums (‘spillback’). Spillback transmission is potentially far more epidemiologically important than its low frequency of occurrence might suggest, as deer, ferrets and pigs can spread TB far more widely than possums; and persistence of TB in long–lived deer extends the risk of spillback far into the future. Reducing the number of deer to very low levels would be controversial and expensive. Although the risk of spillback is undoubtedly low, it may nonetheless determine the minimum scale and duration of possum management required. The current strategy for eradication of TB aims to keep possum numbers low for 5–10 years longer than would be necessary if possums were the only TB host involved, thus eliminating spillback risk.

Biocontrol of weeds of pastoral weeds

Over 2010/11, 115 releases of eight control agents were made against broom, gorse, tradescantia, woolly nightshade and thistles. ERMA (now the Environmental Protection Authority) also approved the release of an ultra–specific control agent for Chilean needle grass (Nassella neesiana), which is harmful to stock. The debilitating rust is so specific that Chilean needle grass from the North Island of New Zealand was not affected, and not a single spore formed on the 43 non–target grasses (including nassella tussock, oats, barley, rye grass, wheat, rice, bamboo and sweet corn) that were inoculated during safety–testing. The rust will hopefully prove to be a useful tool for the most serious Chilean needle grass infestations in Marlborough as well as North Canterbury. An additional isolate of the rust that can attack North Island plants is still being sought.

Living roofs – reducing stormwater runoff

Although living green roofs are increasingly common overseas, adoption in New Zealand has been impeded by lack of local data on suitable materials and performance in New Zealand conditions. For the last four years, we have worked with University of Auckland’s School of Engineering and Auckland Council to develop a resilient light–weight substrate based on locally available materials and which conforms to international standards. We tested over 45 native and non–native plants, and quantified the performance and maintenance needs of the roofs. Trial living roofs in Auckland retained a median of 82% of rainfall per rainfall event, and reduced peak flow by a median of 93%. Living roofs had a moderating affect on external roof and internal building temperatures, making them cooler in summer. Other benefits include increased biodiversity and pollination services.

Considerable effort has gone into disseminating findings to planners, stormwater engineers, architects, landscape architects, contractors, industry suppliers and home owners with the support of Auckland Council and Auckland Botanic Gardens. Increasing the number of installations across domestic, commercial, private and public applications is key to making green roofs the norm in New Zealand, and it is pleasing to see such widespread community support advocating their extensive use in the rebuild of Christchurch.