Tradeoffs between soil, water, and carbon -- a national scale analysis from New Zealand

The tradeoffs between the regulation of soil erosion, provision of fresh water, and climate regulation associated with new Pinus radiata forests in New Zealand are explored using national models. These three ecosystem services for which there is strong demand are monetised as commodities (avoided soil erosion is NZ $1 per tonne; water is NZ $1 per cubic metre; and sequestered carbon is assumed to be NZ?$73 per tonne). This permits their summation on a spatial basis to produce a national map of the net benefit of these ecosystem services. Net benefit is spatially variable depending primarily on the relative mix of forest growth rates and demand for irrigation water. New P.?radiata forests (once mature) generally reduce mass-movement erosion by an order of magnitude. This provides significant benefits for erosion control where there are high natural rates of erosion. Benefits are especially large in catchments where high sedimentation is increasing flood risk and degrading aquatic ecosystems. The generally high growth rates of P.?radiata in New Zealand (8.5 tonnesCha(-1)yr(-1) on average for existing forest) add significant environmental benefits of carbon sinks to climate regulation. However, the reduction of water yield associated with new forests (between 30% and 50%) can neutralise these benefits in catchments where there is demand for irrigation water, such as the eastern foothills of the Southern Alps and the tussock grasslands in the South Island.     

Soil quality in New Zealand: policy and the science response

Soil depletion and degradation have been increasingly recognized as important environmental issues in many parts of the world. Over the last decade a number of political and legislative measures have been introduced to encourage and enforce sustainable soil management in New Zealand. Application of the new legislation has highlighted gaps in our knowledge of soil quality and a lack of scientific methods to assess and monitor soil quality. This paper describes the legislative measures and outlines the sdentific response to the needs of regulatory agencies responsible for maintaining environmental quality. The research recommended a set of indicators to assess soil quality. Each soil quality attribute has an associated "target range" defining the acceptable value for the attribute. The paper also discusses the communication of results to end-users, including the development of a computerized assessment tool. The legislative measures and scientific response have fostered a closer relationship between the policy and science communities, leading to more well-focused research, but greater collaboration is still required.     

Field dissipation of acetochlor in two New Zealand soils at two application rates

The persistence of pesticides in soils has both economic and environmental significance and is often used as a key parameter in pesticide risk assessment. Persistence of acetochlor [2'-ethyl-6'-methyl-N-(ethoxymethyl)-2-chloroacetylanilide] in two New Zealand field soils was measured over two years and the data were used to identify models that adequately describe acetochlor persistence in the field. Acetochlor was sprayed onto six fallow plots (3 x 9 m each) at each site at the recommended rate (2.5 kg a.i. ha(-1)) and at twice that rate. Acetochlor concentrations were measured in soil cores. Simple first-order kinetics (Model 1) adequately described acetochlor persistence in Hamilton clay loam soil (Humic Hapludull, Illuvial Spadic) at the high application rate, but overestimated it at the low application rate. A quadratic model (Model 2), a first-order double-exponential model (Model 3), a first-order biphasic model (Model 4), or a two-compartment model (Model 5) better described acetochlor persistence at the low application rate. The time for 50% (DT50) and 90% (DT90) of initial acetochlor loss was approximately 9 and 56 d, and 18 and 63 d at low and high application rates, respectively. The more complex Models 2 through 5 also better described the biphasic dissipation of acetochlor in Horotiu sandy loam soil (Typic Orthic Allophanic) than Model 1, with Model 1 significantly underestimating acetochlor concentrations on the day of application at both application rates. The DT50 and DT90 values were 5 and 29 d and 7 and 31 d at low and high application rates, respectively. Overall, application rate significantly affected the DT50 and DT90 values in the Hamilton soil, but not in the Horotiu soil. Faster acetochlor loss in the Horotiu soil possibly resulted from the higher soil organic carbon content that retained more acetochlor near the soil surface where higher temperature and photolysis accelerated the loss.     

Evaluating environmental plan quality: the case of planning for sustainable development in New Zealand

This study examines the quality of local and regional environmental plans produced under New Zealand's Resource Management Act (RMA) of 1991, which sets forth a national sustainable development strategy. Plan quality characteristics are defined and used as criteria for plan evaluation. A key finding is that planning programmes have significantly advanced since passage of the RMA, but that high quality plans are not necessarily produced by simply passing mandate legislation. Implications of study findings for sustainable development initiatives in other countries and for future research are presented.     

Evaluating policy options for managing diffuse source water quality in Lake Taupo,New Zealand

Environmental policy makers are interested in ways to prevent environmental degradation without significantly limiting economic and social development. Increasingly, market-based instruments are being incorporated into the suite of policy tools to accomplish these aims. However, the lack of information on market-based instruments accessible to non-economists limits understanding of how and when a market-based instrument can be integrated into a traditional policy regime. This paper aims to address the lack of accessible information using a generic screening process for policy instruments demonstrated through application to a non-point source pollution problem in Lake Taupo, New Zealand.     

Simulated wetland conservation-restoration effects on water quantity and quality at watershed scale

Wetlands are one of the most important watershed microtopographic features that affect hydrologic processes (e.g., routing) and the fate and transport of constituents (e.g., sediment and nutrients). Efforts to conserve existing wetlands and/or to restore lost wetlands require that watershed-level effects of wetlands on water quantity and water quality be quantified. Because monitoring approaches are usually cost or logistics prohibitive at watershed scale, distributed watershed models such as the Soil and Water Assessment Tool (SWAT), enhanced by the hydrologic equivalent wetland (HEW) concept developed by Wang [Wang, X., Yang, W., Melesse, A.M., 2008. Using hydrologic equivalent wetland concept within SWAT to estimate streamflow in watersheds with numerous wetlands. Trans. ASABE 51 (1), 55–72.], can be a best resort. However, there is a serious lack of information about simulated effects using this kind of integrated modeling approach. The objective of this study was to use the HEW concept in SWAT to assess effects of wetland restoration within the Broughton's Creek watershed located in southwestern Manitoba, and of wetland conservation within the upper portion of the Otter Tail River watershed located in northwestern Minnesota. The results indicated that the HEW concept allows the nonlinear functional relations between watershed processes and wetland characteristics (e.g., size and morphology) to be accurately represented in the models. The loss of the first 10–20% of the wetlands in the Minnesota study area would drastically increase the peak discharge and loadings of sediment, total phosphorus (TP), and total nitrogen (TN). On the other hand, the justifiable reductions of the peak discharge and loadings of sediment, TP, and TN in the Manitoba study area may require that 50–80% of the lost wetlands be restored. Further, the comparison between the predicted restoration and conservation effects revealed that wetland conservation seems to deserve a higher priority while both wetland conservation and restoration may be equally important.     

Risk-based targeting of diffuse contaminant sources at variable spatial scales in a New Zealand high country catchment.

Management of agricultural diffuse pollution requires targeting or prioritising critical source areas at various spatial scales within watersheds. This study develops, evaluates and illustrates a risk-based approach for assessment and targeting of source areas at catchment, subarea and individual farm scales. Catchment water quality data are used in conjunction with information on watershed characteristics from the New Zealand Land Resources Inventory at the subarea scale and land use information at the farm scale to assess risk and target source areas. Total phosphorus in the Lake Hayes Catchment, a high country pastoral catchment in the South Island of New Zealand, is used as a case study. Use, comparison and evaluation of several different methodologies for subareas and individual properties showed that a subarea in the upper catchment and one immediately upstream from the lake were the worst source areas. Targeting of other subareas varied dependent on the method used. The worst individual properties were targeted based on the combination of intensity of cattle and sheep grazing, fertilizer usage, bank erosion and location in the worst subareas. Water quality results are critical to successful targeting, particularly for convincing landowners that streams will benefit from best management practices on their properties. In addition to concentrations, average and extreme loadings are important. Data on catchment characteristics, particularly land use, are needed for targeting, but are not always readily available at small scales. This study demonstrated simple but useful methods for application of assessment information for quantitative targeting of contaminant source areas at different spatial scales.     

Planning under a Co-operative Mandate: New Plans for New Zealand

The Resource Management Act 1991 provides a new mandate for effectsbased planning with its goal of sustainable management. Regional, city and district councils are responsible for administering the Act, including preparation of regional policy statements, regional and district plans. The paper reports on a collaborative research programme,funded by the New Zealand Foundation for Research, Science and Technology. The three-year programme has two objectives: (1) to determine the quality of policy statements and plans; and (2) to identify the extent and means by which councils co-ordinate policy statements and plans. Preliminary findings on implementation of the Act are presented.     

Nitrous oxide dynamics in a braided river system, New Zealand

Recently the Intergovernmental Panel on Climate Change (IPCC) emission factor EF5-r was revised downward to a value of 0.0025 kg N?O-N per kg NO?-N leached. It was not reduced further due to the continued uncertainty surrounding the dynamics of N?O in river systems. There have been few studies where river system N?O yields and fluxes have been measured. In this study, we examined the relationship between NO?-N and N?O-N fluxes at 10 sites along a braided river system (84 km) over a 397-d period. Isotopic analysis of NO?-N river water samples and the potential agricultural nitrogen (N) sources demonstrated that the NO?-N came from agricultural or sewage sources. Percent saturation of N?O varied with site and date (average, 114%) and correlated with river N?O-N concentrations. Modeled N?O fluxes (16-30 μg m(-2) h(-1)) from five sites were strongly related to river NO?-N concentrations ( r2 = 0.86). The modeled N?O-N fluxes ranged from 39 to 81% of the IPCC-derived emissions based on the NO?-N load in the river over 397 d and do not support further lowering of the EF5-r. Further in situ river studies are required to verify the N?O-N fluxes and the calculated gas transfer velocity values for these braided river systems.     

Drivers and barriers to water transfer in a New Zealand irrigation scheme

Policy makers, economists and water researchers have advocated water transfer and trade as a key potential response to worldwide water scarcity and/or efficiency problems. This paper examines aspects of an operational irrigation scheme in New Zealand that enables transfer of water between shareholders, arguing that the set-up and processes involved with the scheme can provide a wider context for analysis and consideration of social and cultural issues involved with resource allocation. Analysis of the key drivers and barriers for water reveal that while there is potential for real benefits from transferring water for farmers and the community, an examination of some of the processes used, and barriers to transfer reveals important lessons for planning and regulatory perspectives, including the importance of looking at the issues from a procedural and distributive justice viewpoint.     

The climate's long-term impact on New Zealand infrastructure (CLINZI) project - a case study of Hamilton City, New Zealand

Infrastructure systems and services (ISS) are vulnerable to changes in climate. This paper reports on a study of the impact of gradual climate changes on ISS in Hamilton City, New Zealand. This study is also the first of its kind to be applied to New Zealand ISS. In the future, the CLINZI project will extend to other areas of New Zealand. Using historical climate data and four climate change scenarios, we modelled the impact of climate change on aspects of water supply and quality, transport, energy demand, public health and air quality. Our analysis reveals that many of Hamilton City's infrastructure systems demonstrated greater responsiveness to population changes than to gradual climate change.     

Water quality modeling of fertilizer management impacts on nitrate losses in tile drains at the field scale

Nitrate losses from subsurface tile drained row cropland in the Upper Midwest U.S. contribute to hypoxia in the Gulf of Mexico. Strategies are needed to reduce nitrate losses to the Mississippi River. This paper evaluates the effect of fertilizer rate and timing on nitrate losses in two (East and West) commercial row crop fields located in south-central Minnesota. The Agricultural Drainage and Pesticide Transport (ADAPT) model was calibrated and validated for monthly subsurface tile drain flow and nitrate losses for a period of 1999-2003. Good agreement was found between observed and predicted tile drain flow and nitrate losses during the calibration period, with Nash-Sutcliffe modeling efficiencies of 0.75 and 0.56, respectively. Better agreements were observed for the validation period. The calibrated model was then used to evaluate the effects of rate and timing of fertilizer application on nitrate losses with a 50-yr climatic record (1954-2003). Significant reductions in nitrate losses were predicted by reducing fertilizer application rates and changing timing. A 13% reduction in nitrate losses was predicted when fall fertilizer application rate was reduced from 180 to 123 kg/ha. A further 9% reduction in nitrate losses can be achieved when switching from fall to spring application. Larger reductions in nitrate losses would require changes in fertilizer rate and timing, as well as other practices such as changing tile drain spacings and/or depths, fall cover cropping, or conversion of crop land to pasture.     

Minimizing Harm in Agricultural Animal Experiments in New Zealand

Intrusive agricultural experimentspublished in New Zealand in the last five yearsare reviewed in terms of the degree of animalsuffering involved, and the necessity for thissuffering in relation to research findings.When measured against animal welfare criteriaof the Ministry of Agriculture, thirty-sixstudies inflicted ``severe' or ``very severe'suffering. Many of these experiments hadquestionable short-term applications, had anapplication restricted to agriculturalproduction or economic growth, or could havebeen modified to prevent or reduce suffering.     

Accumulation of perchlorate in aquatic and terrestrial plants at a field scale

Previous laboratory-scale studies have documented perchlorate ClO(-)(4) uptake by different plant species, but less information is available at field scale, where ClO(-)(4) uptake may be affected by environmental conditions, such as distance to streams or shallow water tables, exposure duration, and species. This study examined uptake of ClO(-)(4) in smartweed (Polygonum spp.) and watercress (Nasturtium spp.) as well as more than forty trees, including ash (Fraxinus greggii A. Gray), chinaberry (Melia azedarach L.), elm (Ulmus parvifolia Jacq.), willow (Salix nigra Marshall), mulberry [Broussonetia papyrifera (L.) Vent.], and hackberry (Celtis laevigata Willd.) from multiple streams surrounding a perchlorate-contaminated site. Results indicate a large potential for ClO(-)(4) accumulation in aquatic and terrestrial plants, with ClO(-)(4) concentration in plant tissues approximately 100 times higher than that in bulk water. Perchlorate accumulation in leaves of terrestrial plants was also dependent on species, with hackberry, willow, and elm having a strong potential to accumulate ClO(-)(4). Generally, trees located closer to the stream had a higher ClO(-)(4) accumulation than trees located farther away from the stream. Seasonal leaf sampling of terrestrial plants indicated that ClO(-)(4) accumulation also was affected by exposure duration, with highest accumulation observed in the late growing cycle, although leaf concentrations for a given tree were highly variable. Perchlorate may be re-released into the environment via leaching and rainfall as indicated by lower perchlorate concentrations in collected leaf litter. Information obtained from this study will be helpful to understand the fate of ClO(-)(4) in macrophytes and natural systems.     

Prioritisation of farm scale remediation efforts for reducing losses of nutrients and faecal indicator organisms to waterways: a case study of New Zealand dairy farming

The international competitiveness of the New Zealand (NZ) dairy industry is built on low cost clover-based systems and a favourable temperate climate that enables cows to graze pastures mostly all year round. Whilst this grazed pasture farming system is very efficient at producing milk, it has also been identified as a significant source of nutrients (N and P) and faecal bacteria which have contributed to water quality degradation in some rivers and lakes. In response to these concerns, a tool-box of mitigation measures that farmers can apply on farm to reduce environmental emissions has been developed. Here we report the potential reduction in nutrient losses and costs to farm businesses arising from the implementation of individual best management practices (BMPs) within this tool-box. Modelling analysis was carried out for a range of BMPs targeting pollutant source reduction on case-study dairy farms, located in four contrasting catchments. Due to the contrasting physical resources and management systems present in the four dairy catchments evaluated, the effectiveness and costs of BMPs varied. Farm managements that optimised soil Olsen P levels or used nitrification inhibitors were observed to result in win-win outcomes whereby nutrient losses were consistently reduced and farm profitability was increased in three of the four case study farming systems. Other BMPs generally reduced nutrient and faecal bacteria losses but at a small cost to the farm business. Our analysis indicates that there are a range of technological measures that can deliver substantial reductions in nutrient losses to waterways from dairy farms, whilst not increasing or even reducing other environmental impacts (e.g. greenhouse gas emissions and energy use). Their implementation will first require clearly defined environmental goals for the catchment/water body that is to be protected. Secondly, given that the major sources of water pollutants often differed between catchments, it is important that BMPs are matched to the physical resources and management systems of the existing farm businesses.     

新西兰猕猴桃科研和产业化状况

通过对新西兰猕猴桃的考察,本文介绍了新西兰猕猴桃的科研、产业化状况及市场情况。     

New Zealand environmental standards and energy policies

This paper describes the primary energy resources of New Zealand and their relative importance. It describes the principal legislation that provides environmental protection and public participation with which State and private agencies are bound to comply. The paper then discusses air pollution in further detail and cites three examples where there is cause for concern. By international standards, air pollution is not a serious problem in New Zealand and so the economic consequences have received little attention Two simple examples are cited. A map showing the main centers and the location of facilities referred to in the text is included     

Issues Associated with Research on Sheep Parasite Control in New Zealand – a Descriptive Ethic

In common with much of theEnglish-speaking world, New Zealandersgenerally oppose the use of animalexperimentation where there is no demonstrableand immediate benefit for human, animal, orenvironmental health. Intrusive experiments onsheep internal and external parasites publishedbetween 1996 and 2000 are reviewed, anddiscussed in relation to these publicsensibilities. A total of 16 publishedexperiments on sheep parasites involvedsurgical manipulations or other intrusiveprocedures. Some of these experiments had noshort-term application, or the only applicationwas in increasing animal production. Otherscould have been modified at some extra expenseso that they were less intrusive. Still otherswere duplications of previous work. All thesemanipulations would be unacceptable accordingto the orthodox morality of the general public.Breeding programs, rotation of grazing,``low-tech' vaccination, and in vitromodels of sheep can provide insights intopreventing parasite infestation withoutintrusive experiments. Such research protocolsshould take priority over existing programs.The results also confirm earlier reports thatanimal ethics committees are not fulfillingtheir mandated objective of acting as watchdogsfor the public. Possible changes in New Zealandanimal welfare legislation and itsinterpretation by Animal Ethics Committees arediscussed.