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Although New Zealand's 2020 biodiversity strategy, Te Mana o Te Taiao, places a high priority on protecting indigenous ecosystems, it provides minimal detail on how this will be accomplished. Using spatial data and a conservation prioritisation tool we demonstrate the implementation of a comprehensive framework for the systematic conservation of New Zealand's terrestrial ecosystems, as proposed in a pioneering paper by Kelly (1980). Working within the Horizons Region (Manawatū-Whanganui, lower North Island), we analyse the extent of losses of 65 terrestrial ecosystems since human settlement by combining maps of their potential distribution and current land cover. Two-thirds of the original indigenous cover has been lost, with lowland ecosystems suffering greatest losses; much surviving cover is substantially modified. Our prioritisation analyses identify various options for siting conservation management to maintain the integrity of a full range of indigenous ecosystems in a highly modified landscape, given varying degrees of constraint on the availability of land for conservation. Restricting management to DOC-administered land would severely constrain ecosystem representation, but dramatic improvements in ecosystem representation would result from protecting and managing a relatively small number of sites on land of other tenures, mostly at lower elevations. Results such as these could play a crucial role in supporting achievement of New Zealand's high-level goals for ecosystem conservation and meeting international conservation obligations. They could be used to (1) assess the conservation status of individual terrestrial ecosystems, (2) develop national and regional policies specifically targeting protection of at-risk ecosystems, (3) design and implement strategies that explicitly target management across a full range of ecosystems, (4) support processes designed to coordinate management among different conservation actors, and (5) inform individual landowners of the conservation value of indigenous ecosystems on their land. Obstacles to implementing such an approach include a range of technical, institutional, and social factors. [ABSTRACT FROM AUTHOR]

River water temperature is known to be important for water quality and ecosystem processes. We quantified the degree to which lower river flows are associated with warmer river water, after accounting for seasonality and meteorological variability. We applied a systematic methodology to analyse observed mean daily river water temperature and mean daily river flow from 47 sites draining mountain, hill, and lowland catchments across the Canterbury region of Aotearoa New Zealand. We fitted regression models to remove seasonal patterns from all variables, then removed correlations between water temperature and each of three meteorological variables (solar radiation, air temperature, and earth temperature) before quantifying water temperature‐river flow relationships. Strong seasonal patterns were present in water temperature and each meteorological variable across all sites. Many sites also showed strong seasonal patterns in river flows. We demonstrated that seasonal patterns must be accounted for before day‐to‐day associations between water temperature and meteorological variables or river flow can be characterised. Higher water temperatures were associated with lower flows for 46 of 47 sites, even after having accounted for seasonality and associations with each meteorological variable. Increases in water temperature associated with a hypothetical reduction in river flow from the median to the fifth percentile varied with the site but were 0.5°C on average. This finding has important implications for river flow management because it indicates that increased river water temperatures would accompany reduced river flows regardless of site or catchment characteristics. [ABSTRACT FROM AUTHOR]

1080 toxin (sodium fluoroacetate) is used in New Zealand for possum (Trichosurus vulpecula) and ship rat (Rattus rattus) control but can result in unintentional by-kill of native (e.g. kea Nestor notabilis) and non-native (e.g. deer) fauna. A newly developed deer repellent (Prodeer) in 1080 bait has proved highly effective in reducing deer by-kill while not impacting target pest efficacy. The ingredients in Prodeer bait are undisclosed due to commercial sensitivity, thus it is unknown whether this bait type increases acceptability and palatability to kea and increases risk over and above that posed by the standard (RS5) bait type normally used in aerial poisoning operations. During choice trials comparing kea responses to, and consumption of, non-toxic Prodeer and RS5 baits at alpine sites around Arthur’s Pass National Park and central Westland we found kea Prodeer and RS5 consumption (per interaction and total) were not significantly different. Most individuals consumed substantially less of both bait types than the estimated lower 1080 LD50 threshold for kea, and vastly less than captive kea consume. We conclude that 1080 operations using Prodeer are unlikely to pose a risk significantly over and above that already presented to kea in standard RS5 1080 operations. [ABSTRACT FROM AUTHOR]

The freshwater diatom Lindavia intermedia is believed to have been recently introduced to New Zealand lakes. Mucilage ("lake snow") produced by L. intermedia can block water intakes and/or degrade recreational values. Because nuisance L. intermedia proliferations and lake snow occur rarely in lakes overseas, the species was not initially recognised as invasive and knowledge of its ecology and threat to New Zealand lakes remains sparse. We combined distribution data from several sources with an existing dataset of environmental variables linked to ~ 3800 New Zealand lakes (area > 1 ha) and used a boosted regression trees modelling approach to: (a) describe the environmental niche occupied by L. intermedia; and (b) predict its potential distribution. The effect of human-mediated spread was incorporated using a binary predictor (road200) indicating the presence or absence of vehicle access. "Niche" models were developed using absences (non-detections based on a sensitive molecular method) only in lakes with road access, and "spread" models using all absences and including road200 as a predictor. Lindavia intermedia was observed in 38 lakes, from central North Island to southern South Island, in oligotrophic conditions (total phosphorus < 0.011 mg L-1, total nitrogen < 0.3 mg L-1) with cool temperatures (mean annual temperature < 11 °C). All 38 lakes had road access. Likelihood of presence predicted from the combined niche models was lower in North Island lakes (< 1% assessed as vulnerable) than in the South Island (~ 12.5% vulnerable), highlighting that many additional South Island lakes may be environmentally suitable for L. intermedia. However, using the spread models, only 46 lakes were assessed as vulnerable nationwide reflecting a lack of road access to most lakes. Lindavia intermedia was already present in 22 (48%) of the most environmentally suitable lakes with road access. The dataset and models thus implicated humans as important (but not the only) vectors of this diatom within New Zealand, emphasising the critical role of current New Zealand biosecurity policy for reducing the spread of freshwater pests. [ABSTRACT FROM AUTHOR]

Scientific research is often targeted towards predicting broad-scale patterns in biophysical variables, with spatial data traditionally communicated using static figures and written descriptions in scientific journals and reports. However, inaccessibility and lack of flexibility mean that these communication methods have often hindered research uptake by resource managers and decision-makers. We used R shiny to develop an interactive webtool that maps estimates of 109 biophysical variables, including hydrology, ecology and water quality metrics across the New Zealand digital river network. NZ River Maps is freely available online and can be used to visualise regional patterns, identify site-specific characteristics and overlay regional planning layers. Interactive webtools improve on traditional communication methods by allowing inspection of predictions for selected sites and plotting of spatial patterns. The ability to quickly visualise and quantify relevant spatial data has enabled better communication of research outputs to provide robust and transparent inputs into environmental management. [ABSTRACT FROM AUTHOR]

Biodiversity impact assessments under threatened species legislation often focus on individual development proposals at a single location, usually for a single species, leading to inadequate assessments of multiple impacts that accumulate over large spatial scales for multiple species. Regulations requiring ad-hoc assessments can lead to 'death by a thousand cuts,' where biodiversity is degraded by many small impacts that individually do not appear to threaten species' persistence. Spatial prioritization methods can improve the efficiency of decision-making by explicitly considering cumulative impacts of multiple proposed developments on multiple species over large spatial scales. We present an assessment approach and a unique case study in which spatial prioritization tools were used to support strategic assessment of a large development plan in Western Australia. The application of the approach helped identify relatively minor alterations to development plans that resulted in reductions in biodiversity impacts and informed expansion of the protected area network. Using these tools to assess trade-offs between conservation and development will help identify planning footprints that minimize biodiversity losses. [ABSTRACT FROM AUTHOR]

Australia's northern savannas are one of the few remaining large and mostly intact natural areas on Earth. However, their biodiversity and ecosystem values could be threatened if proposed agricultural development proceeds. Through land-use change scenarios, we explored trade-offs and synergies among biodiversity conservation, carbon farming and agriculture production in northern Australia. We found that if all suitable soils were converted to agriculture, habitat at unique recorded locations of three species would disappear and 40 species and vegetation communities could lose more than 50% of their current distributions. Yet, strategically considering agriculture and biodiversity outcomes leads to zoning options that could yield >56,000 km2 of agricultural development with a significantly lower impact on biodiversity values and carbon farming. Our analysis provides a template for policy-makers and planners to identify areas of conflict between competing land-uses, places to protect in advance of impacts, and planning options that balance agricultural and conservation needs. [ABSTRACT FROM AUTHOR]

Sample size justification is an important consideration when planning a clinical trial, not only for the main trial but also for any preliminary pilot trial. When the outcome is a continuous variable, the sample size calculation requires an accurate estimate of the standard deviation of the outcome measure. A pilot trial can be used to get an estimate of the standard deviation, which could then be used to anticipate what may be observed in the main trial. However, an important consideration is that pilot trials often estimate the standard deviation parameter imprecisely. This paper looks at how we can choose an external pilot trial sample size in order to minimise the sample size of the overall clinical trial programme, that is, the pilot and the main trial together. We produce a method of calculating the optimal solution to the required pilot trial sample size when the standardised effect size for the main trial is known. However, as it may not be possible to know the standardised effect size to be used prior to the pilot trial, approximate rules are also presented. For a main trial designed with 90% power and two-sided 5% significance, we recommend pilot trial sample sizes per treatment arm of 75, 25, 15 and 10 for standardised effect sizes that are extra small (≤0.1), small (0.2), medium (0.5) or large (0.8), respectively. [ABSTRACT FROM AUTHOR]