Conservation of New Zealand's tussock grassland moth fauna

New Zealand has a relatively rich moth fauna associated with tussock grasslands, reflecting the historic importance of plant communities containing native grasses in the New Zealand landscape. Extensive grassland communities were most common in the eastern and central regions of New Zealand’s South Island where what now remains of these communities is contained within more than 350 Pastoral Leases managed for pastoral farming. Because these various grassland communities are distributed from coastal areas to the limit of vegetation on mountains there has been an uneven human impact. Grasslands at sea-level (including those on sand dunes and alluvial plains) have almost been eliminated while those in montane valleys have until now escaped intensive development. Alpine grasslands, like those of montane areas are now much less woody as a result of both Polynesian and more recent burning. From the late 1970s, based on public concern that continuing development was eliminating the natural landscapes and conservation values of the distinctive tussock grasslands of the South Island, a concerted programme of identification of the broad conservation values of the remaining grassland dominated regions was initiated. Implementation of the recommendations in the resulting published reports relating to priority areas for conservation and the subsequent full-scale review of Pastoral Leases has resulted in the formation of large grassland Conservation Parks and the reservation of a multitude of smaller areas, based on a suite of recreation, landscape and biological values. This important ongoing Tenure Review process has important implications for the conservation of tussock grassland biota including numerous native moths and their habitats.     

Potential of direct seeding for establishing native plants into pastoral land in New Zealand

Native plants are an important part of New Zealand?s uniqueness, and there is increasing awareness of the need to maintain these species in managed landscapes, particularly pastoral areas, in addition to the country?s conservation lands. The most widely used method of establishing native plants is transplanting nursery-grown seedlings, and for many species, much experience and knowledge has been gained in using this technique. Establishment of native plants in the field by direct seeding is a potentially useful alternative technique-which has been evaluated in the North and South Islands only to a limited extent. This paper reviews the current state of knowledge on the direct seeding of species into pastoral areas. It covers site and species selection, seed availability and quality, site preparation, and post-sowing management. It also compares the economics of native plant establishment by transplanting and by direct seeding. Direct seeding of pastoral areas is a relatively cheap technique, but its general applicability is currently limited because of frequently inadequate supplies of viable seed, lack of knowledge on appropriate sowing times and rates, unreliable field germination and seedling emergence, and frequent intense competition from existing vegetation, particularly exotic grasses.     

The conservation of declining butterfly populations in Britain and Europe: priorities, problems and successes

The status, ecology and conservation of butterflies in Europe and Britain are reviewed, as a background to the National Trust's past and future contribution to British conservation. Britain has a poor butterfly fauna by European standards, the main areas of endemism and species richness being in the Alps and southern Europe. To date, the main declines among European butterfly populations have occurred across central-northern Europe, with slightly higher extinction rates in mainland countries than in Britain. The main causes of decline are biotope destruction, the loss of certain species' habitats within surviving semi-natural biotopes due to changed land management, and a failure by several species to track the patches of their habitat that are still being generated in modern fragmented landscapes. Until recently, most conservation programmes failed to take account of the latter two factors, resulting in many local extinctions of rare butterfly species even in conservation areas. Recent measures have been much more successful; many were first tested on National Trust properties.     

Options for enhancing forest biodiversity across New Zealand's managed landscapes based on ecosystem modelling and spatial design

In most regions of the world removal of environmental stress facilitates regeneration of native plants and habitats. However, in many of New Zealands modified landscapes, exotic species are likely to respond first to any reduction in stress because these fast-growing species are prevalent in local vegetation and dominate seed banks. Given the trend in agriculture towards intensive management on larger units, the indigenous character in New Zealand landscapes is being marginalised and there is the risk that further reduction in visibility of native vegetation may be perpetuated by a growing familiarity and identification with ubiquitous exotic species. Alternative landscapes, based on an understanding of ecosystem processes, need to be explored if biodiversity goals set by international convention and national resource management law are to be achieved. This study provides a set of predictions and pathways, backed by field observations, to underpin a restoration strategy at patch to landscape scales. A forest model, LINKNZ, is employed to simulate species succession under New Zealand conditions. The incorporation of disturbance regimes and species dispersal processes in the model permits a wide range of scenarios to be investigated encompassing indigenous forest development, exotic species interactions with indigenous forest ecosystems, management of mixed introduced-indigenous forests, and landscape dynamics. The results illustrate an approach that identifies potential biosecurity threats and provides additional options for integrating nature and production in New Zealands rural and urban landscapes.     

Assessing the impact of local habitat variables and landscape context on riparian birds in agricultural,urbanized, and native landscapes

Large tracts of natural habitat are being replaced by agriculture and urban sprawl in Mediterranean regions worldwide. We have limited knowledge about the effects of human activities on native species in these landscapes and which, if any, management practices might enhance the conservation of native biodiversity within them. Through a citizen volunteer bird-monitoring project, we compared bird abundance and species richness in northern Californian riparian zones surrounded by vineyards, urban areas, and natural areas. We assessed both local and landscape-level variables that may enhance native bird diversity in each land use type. We also demonstrate a new statistical approach, generalized estimating equations, to analyze highly variable data, such as that collected by volunteers. Avian abundance was highly correlated with both landscape context and local habitat variables, while avian richness was correlated with local habitat variables, specifically shrub richness, and percent of tree cover. In particular, shrub species richness has a strong positive correlation with riparian-preferring bird species. This suggests that active local management of riparian zones in human-dominated landscapes can increase our ability to retain native bird species in these areas.     

Secondary forest succession differs through naturalised gorse and native kānuka near Wellington and Nelson

The dominant native woody species forming early-successional vegetation on formerly forested sites in lowland New Zealand were kānuka (Kunzea ericoides) and mānuka (Leptospermum scoparium) (Myrtaceae). These have been replaced extensively by gorse (Ulex europaeus, Fabaceae), a naturalised species in New Zealand. Because gorse typically gives way to native broadleaved (angiosperm) forest in about 30 years, it is often considered desirable for facilitating native forest restoration. We tested three hypotheses, derived from the New Zealand literature, on gorse and kānuka: (1) kānuka stands have a different species composition and greater species richness than gorse stands at comparable successional stages; (2) differences between gorse and kānuka stands do not lessen over time; and (3) several native plant taxa are absent from or less common in gorse than in kānuka stands. We sampled 48 scrub or low-forest sites in two regions, Wellington and Nelson. Sites were classified into one of four predefined categories – young gorse, young kānuka, old gorse, old kānuka – based on canopy height of the succession and the dominant early-successional woody species. Few characteristics of the sites and surrounding landscapes differed significantly among site categories, and none consistently across regions. The vegetation composition of gorse and kānuka and their immediate successors differed in both regions, mainly in native woody species. Species richness was often lower in gorse and there were fewer smallleaved shrubs and orchids in gorse. Persistent differences at the older sites suggest the successional trajectories will not converge in the immediate future; gorse leads to different forest from that developed through kānuka. Gorse-dominated succession is therefore not a direct substitute for native successions. We suggest areas of early native succession should be preserved, and initiated in landscapes where successions are dominated by gorse or other naturalised shrubs.     

Response of wild bee diversity,abundance, and functional traits to vineyard inter‐row management intensity and landscape diversity across Europe

Agricultural intensification is a major driver of wild bee decline. Vineyards may be inhabited by plant and animal species, especially when the inter‐row space is vegetated with spontaneous vegetation or cover crops. Wild bees depend on floral resources and suitable nesting sites which may be found in vineyard inter‐rows or in viticultural landscapes. Inter‐row vegetation is managed by mulching, tillage, and/or herbicide application and results in habitat degradation when applied intensively. Here, we hypothesize that lower vegetation management intensities, higher floral resources, and landscape diversity affect wild bee diversity and abundance dependent on their functional traits. We sampled wild bees semi‐quantitatively in 63 vineyards representing different vegetation management intensities across Europe in 2016. A proxy for floral resource availability was based on visual flower cover estimations. Management intensity was assessed by vegetation cover (%) twice a year per vineyard. The Shannon Landscape Diversity Index was used as a proxy for landscape diversity within a 750 m radius around each vineyard center point. Wild bee communities were clustered by country. At the country level, between 20 and 64 wild bee species were identified. Increased floral resource availability and extensive vegetation management both affected wild bee diversity and abundance in vineyards strongly positively. Increased landscape diversity had a small positive effect on wild bee diversity but compensated for the negative effect of low floral resource availability by increasing eusocial bee abundance. We conclude that wild bee diversity and abundance in vineyards is efficiently promoted by increasing floral resources and reducing vegetation management frequency. High landscape diversity further compensates for low floral resources in vineyards and increases pollinating insect abundance in viticulture landscapes.     

The forgotten 60%: bird ecology and management in New Zealand?s agricultural landscape

Production lands make up 58% of Aotearoa?New Zealand?s landcover and contribute greatly not only to the national economy but also to patterns and trends in native and introduced avian biodiversity. However, unlike in native forest and other indigenous habitats, birds in agro-ecosystems have received little attention to date. We argue that this is due to (1) a research focus on understanding the causes of the dramatic decline of New Zealand?s critically endangered, endemic species, (2) an adherence to a ?preservation for intrinsic value? over a ?conservation through sustainable use? paradigm for environmental management, and (3) a historical view of production landscapes as being devoid of endemic and native species and thus of no conservation value. In countering these attitudes, we suggest that the agricultural matrix may contain more native species than many people believe, and that many introduced bird species are key contributors to the social and environmental performance and resilience of these systems. We draw attention to the context, composition, ecology, and status of native and introduced birds in production landscapes in New Zealand, particularly in the face of ongoing agricultural intensification. We first identify the potential roles of local habitat, landscape composition, and introduced predators in shaping farmland bird communities. We then highlight the potential threats and opportunities for birds posed by ongoing intensification, particularly the influences of habitat modification and simplification, increased ecological subsidies through farm inputs, increased stocking rates and yields, and altered predator?prey interactions. We suggest the landscape is the appropriate spatial scale for research and management, and call for an integrated approach to the investigation of farmland birds that combines ecology, sociology, and agro-ecosystems management, and includes farmers, researchers, regulators, and the wider New Zealand public.     

Translocation of threatened New Zealand falcons to vineyards increases nest attendance, brooding and feeding rates

Anthropogenic landscapes can be rich in resources, and may in some cases provide potential habitat for species whose natural habitat has declined. We used remote videography to assess whether reintroducing individuals of the threatened New Zealand falcon Falco novaeseelandiae into a highly modified agricultural habitat affected the feeding rates of breeding falcons or related breeding behavior such as nest attendance and brooding rates. Over 2,800 recording hours of footage were used to compare the behavior of falcons living in six natural nests (in unmanaged, hilly terrain between 4 km and 20 km from the nearest vineyard), with that of four breeding falcon pairs that had been transported into vineyards and nested within 500 m of the nearest vineyard. Falcons in vineyard nests had higher feeding rates, higher nest attendance, and higher brooding rates. As chick age increased, parents in vineyard nests fed chicks a greater amount of total prey and larger prey items on average than did parents in hill nests. Parents with larger broods brought in larger prey items and a greater total sum of prey biomass. Nevertheless, chicks in nests containing siblings received less daily biomass per individual than single chicks. Some of these results can be attributed to the supplementary feeding of falcons in vineyards. However, even after removing supplementary food from our analysis, falcons in vineyards still fed larger prey items to chicks than did parents in hill nests, suggesting that the anthropogenic habitat may be a viable source of quality food. Although agricultural regions globally are rarely associated with raptor conservation, these results suggest that translocating New Zealand falcons into vineyards has potential for the conservation of this species.     

Quantifying fine-scale resource selection by introduced European hedgehogs (Erinaceus europaeus) in ecologically sensitive areas

Introduced predators are important drivers of ecosystem change and can threaten native species. The European hedgehog (Erinaceus europaeus) was introduced from Britain into New Zealand where it is currently widespread, including in braided-river environments of the interior cold drylands where it might threaten native species such as riparian ground-nesting birds. The establishment of hedgehogs in braided-river environments may be facilitated by adjacent pastoral landscapes that provide food, primarily invertebrates, and dry shelter. Forays by hedgehogs into native prey habitats, such as riverbed floodplains, increase predation pressure. Understanding the spatial ecology of introduced predators can improve effectiveness of control measures. We assessed spatial resource selection by hedgehogs in a braided-river environment by tracking 27 individuals for 4–8 days in summer and autumn using microGPS-backpacks. We extracted fine-scale landscape variables from a map created using very high resolution satellite imagery to model home range placement within the study area. We also assessed habitat composition and ranking within high-use areas using compositional analysis. Hedgehogs established home ranges in pastoral landscapes containing abundant edges and high vegetation productivity (mainly green pastures and shrubs), and selected pastures and patches of shrubs as high-use areas. Hedgehogs avoided riverbed floodplains, suggesting that reported predation events on ground-nesting birds might be a consequence of secondary predation or individual specialization. We recommend that predation of native species by hedgehogs might be best alleviated if trapping is focused on those areas selected by native fauna of conservation concern (e.g. riverbed floodplains), as well some biologically-determined buffer surrounding these sites.     

Remotely sensed landscape heterogeneity as a rapid tool for assessing local biodiversity value in a highly modified New Zealand landscape

The widespread conversion of natural habitats to agricultural land has created a need to integrate intensively managed landscapes into conservation management priorities. However, there are no clearly defined methods for assessing the conservation value of managed landscapes at the local scale. We used remotely sensed landscape heterogeneity as a rapid practical tool for the assessment of local biodiversity value within a predominantly agricultural landscape in Canterbury, New Zealand. Bird diversity was highly significantly correlated with landscape heterogeneity, distance from rivers and the Christchurch central business district, altitude and average annual household income, indicating that remotely sensed landscape heterogeneity is a good predictor of local biodiversity patterns. We discuss the advantages and limitations of using geographic information systems to determine local areas of high conservation value.     

The vegetation of roadside verges with respect to environmental gradients in southern New Zealand

Abstract. A survey of the vegetation of roadside verges was made across the southern part of the South Island of New Zealand. Samples were taken at 10-km intervals along selected roads providing a climatic range from the suboceanic conditions of the east coast into semi-arid Central Otago, and from Central Otago through the Southern Alps to the hyper-oceanic areas of high rainfall on the west Coast. The variation in the floristic composition is associated mainly with variation in rainfall, continentality, altitude, soil acidity, soil organic matter, and presence of forest. Sites in the arable and pastoral regions on the eastern side of the Southern Alps support a herbaceous vegetation consisting mostly of exotic species of European origin, with a few native grasses scattered through the drier and less fertile sites. A greater proportion of native species is found at higher altitudes. Roadside vegetation in the area of high rainfall to the west is characterized by indigenous ferns and woody species, although vegetation adjacent to cleared areas is more similar to that on roadsides adjacent to farmland on the east coast. The pattern of distribution of both native and exotic species is strongly related to altitudinal and climatic gradients, and the environmental responses of the exotic species are similar to those recorded in Europe. This suggests a colonization of all available sites by the exotic species, despite the relatively short time since their introduction to New Zealand, rather than an incomplete invasion.     

Diversity and composition of fruit-feeding butterflies in tropical <Emphasis Type="Italic">Eucalyptus</Emphasis> plantations

Production landscapes are rarely considered as priority areas for biodiversity conservation in the tropics. Tree plantations have the potential to provide a conservation service in much of the humid tropics since they are rapidly increasing in extent and present less of a structural contrast with native vegetation than many more intensive agricultural land-uses. We used hierarchical partitioning to examine the factors that influence the value of large-scale Eucalyptus plantations for tropical fruit-feeding butterflies (Lepidoptera: Nymphalidae) in the Brazilian Amazon. We focused on evaluating the importance of landscape versus stand-level factors in determining the diversity and composition of butterfly assemblages, and how butterfly-environment relationships vary within and between subfamilies of Nymphalidae. Native understorey vegetation richness had the strongest independent effect on the richness, abundance and composition of all fruit-feeding butterflies, as well as a subset of species that had been recorded in nearby primary forests. However, overall patterns were strongly influenced by the most abundant subfamily (Satyrinae), and vegetation richness was not related to the abundance of any other subfamily, or non-Satyrinae species, highlighting the importance of disaggregating the fruit-feeding Nymphalidae when examining butterfly-environment relationships. Our results suggest that plantations can help conserve a limited number of forest species, and serve to highlight the research that is necessary to understand better the relationship between fruit-feeding butterflies and environmental variables that are amenable to management.     

A comparison of realised niche relations of species in New Zealand and Britain

Summary Many plant species prominent in the native vegetation of the dry shingle banks at Dungeness (Britain) are also prominent as exotics in the dry Upper Clutha catchment (New Zealand). To examine the realised niche relations of these species, vegetation was sampled in the two areas. Inverse classification and ordination were used to determine the relative beta niches of the species in the two areas. There was little agreement; it seems that the exotic species in the Upper Clutha were pre-adapted to different niches from those in their native range.     

Successful restoration of abandoned terraced vineyards and grasslands in Southern Switzerland

Extensively managed semi-natural grasslands represent species-rich habitats and therefore play a key role for the maintenance of biodiversity in agricultural areas. In marginal and poorly accessible areas, the traditional management of grassland is frequently abandoned, which leads to the spread of forest. In Southern Switzerland, terraced vineyards (a special grassland type) and terraced grasslands are part of the cultural heritage and local biodiversity hotspots. Yet, many of them are overgrown by forest. In the past years, several abandoned terraced vineyards and grasslands have been restored by removing the forest, rebuilding the walls and re-introducing the traditional management. We examined restoration success by assessing plant species richness, diversity and species composition in both the aboveground vegetation and soil seed bank in (1) restored, (2) abandoned for 25–50 years, and (3) permanently used areas of six terraced vineyards and six terraced grasslands. Plant species richness and diversity were reduced and species composition altered in the aboveground vegetation of abandoned vineyards and grasslands compared to the permanently used and restored ones. However, species richness, Shannon-diversity and species composition of the aboveground vegetation did not differ between restored and permanently used areas, indicating a successful restoration of the vegetation 10–15 years after restoration. In abandoned vineyards, species richness of plants emerging from the soil seed bank was slightly higher than in permanently used and restored vineyards. No difference in seedling species richness was found between abandoned, permanently used and restored terraced grasslands. Our results showed that the soil seed bank played a minor role for the re-establishment of the above-ground vegetation. We assume that the large species pool in the surroundings and the presence of dispersal vectors are essential for the successful passive restoration of abandoned grassland in this region.     

Restoration of tree lines in an agricultural landscape: their effectiveness as a conservation management tool

As remnant vegetation covers <15% of the Australian sheep‐wheat belt, it is important to identify conservation strategies suitable for use in agricultural landscapes. Tree lines are widespread ecological structures in rural areas, and are now the subject of government subsidy schemes in New South Wales. However, the contribution of tree lines to biodiversity conservation is poorly understood. To identify the conservation value of tree lines, the bird communities in 36 tree lines in Cowra Shire, New South Wales, were surveyed 4 times each. The results demonstrated that tree lines were used by a large number of species, six of which were threatened. Different taxa were associated with different physical tree line attributes, with tree line age an important predictor of species occurrence. While mature tree lines tended to support more species, as was reflected in higher Shannon Diversity Index scores, they also harboured relatively more introduced species and nest predators, while young tree lines provided the best habitat for threatened species. However, these tree lines will mature, and as they do so they will provide increasingly suitable habitat for the hyperaggressive native honeyeater, the Noisy Miner (Manorina melanocephala), and introduced species. Therefore, tree lines in agricultural landscapes may only be serving an important role for conservation on short time scales, and the suite of threatened species young tree lines currently support appear likely to decline further in the future.     

Restoring native ecosystems in urban Auckland: urban soils, isolation, and weeds as impediments to forest establishment

New Zealand urban environments are currently dominated by exotic plant species. Restoring native vegetation and its associated native biodiversity in these landscapes is desirable for both cultural and ecological reasons. We report on the first four years of an ongoing vegetation restoration experiment in Waitakere City, Auckland, that addresses four challenges to urban restoration: weeds, Anthropic Soils, attraction of frugivorous birds, and patch isolation. Nine commonly planted native species, grouped separately into wind- and bird-dispersed species, were planted across four sites increasingly isolated from native bush patches, using two site preparation methods. By year three, woody weeds >50 cm tall had established with an average density of 1.7 plant m^-? across all sites. This was more than 17 times denser than all established wild native woody seedlings of any height. One of our establishment methods, sparse planting with mulch, resulted in higher native plant survival and faster plant growth. However, after 4 years, the more intensive method, dense planting and ripping of the soil, resulted in a denser canopy and a 2.8-fold reduction in woody weed establishment. The typically urban soils of all sites were highly modified, with substantial variation in compaction, ponding risk, and fertility over distances of 5?15?m. Several, but not all, species were detrimentally affected by soil compaction and ponding. Many bird-dispersed species, both native and non-native, colonised the experiment, although this did not differ between plots with planted wind-dispersed and bird-dispersed species, perhaps due to the small size of these plots. Site colonisation by native species was particularly high at sites ≤?100 m from existing native vegetation, suggesting that even small patches of native vegetation in urban landscapes will be valuable as seed sources for accelerating native plant establishment at nearby receptive sites.     

Segregation,nestedness and homogenisation in plant communities dominated by native and alien species

ABSTRACT

Background: Highly modified landscapes offer the opportunity to assess how environmental factors influence the integration of alien plant species into native vegetation communities and determine the vulnerability of different communities to invasion.

Aims: To examine the importance of biotic and abiotic drivers in determining whether alien plant species segregate spatially from native plant communities or become integrated and lead to biotic homogenisation.

Methods: Ordination and classification of a floristic survey of over 1200 systematically located 6 m × 6 m plots were used to examine how plant community segregation, nestedness and homogenisation varied in relation to climate, environmental and human-related factors across Banks Peninsula, New Zealand.

Results: The analyses of community structure indicated that native and alien plant communities were spatially and ecologically segregated due to different responses primarily to an anthropogenic impact gradient and secondly to environmental factors along an elevation gradient. Human-land use appeared most strongly linked to the distribution of alien species and was associated with increased vegetation homogenisation. However, despite spatial segregation of alien and native plant communities, biotic homogenisation not only occurred in highly managed grasslands but also in relatively less managed shrublands and forest.

Conclusions: The role played by anthropogenic factors in shaping alien and native plant species community structure should not be ignored and, even along a marked environmental gradient, if the recipient sites have a long history of human-related disturbance, biotic homogenisation is often strong.     

Some issues and options for the conservation of native biodiversity in rural New Zealand

Summary For the 70% of New Zealand under private ownership, native biodiversity conservation has to occur within a landscape that must also provide a productive return to land owners. Recent New Zealand legislation, especially the Resource Management Act 1991, promotes sustainable management on private land by allowing for the economic and cultural well-being of local communities while providing for the protection of natural resources including native biodiversity. We suggest that, to effectively conserve native biodiversity in rural landscapes, we need to consider four key issues: (i) what might be realistic goals for native biodiversity conservation; (ii) how might we better arrange different land uses to meet both native biodiversity and production goals; (iii) what is the optimum arrangement of native biodiversity; and (iv) how native biodiversity conservation can improve productive returns to land managers. Options to enhance native biodiversity conservation include a variety of incentives (e.g. management agreements, financial incentives and regulatory systems) and onsite management options (e.g. remnant management, restoration plantings, weed and pest control, use of native species for commercial and amenity purposes, use of exotic species to facilitate native biodiversity). The importance of taking a landscape-based rather than a paddock-based approach to management is emphasized.     

Identifying important areas for butterfly conservation in Italy

The current study combines the use of niche modelling with a site prioritization method to identify important areas for butterfly conservation in Italy. A novel machine learning method (bagging predictors) was used to predict the distribution of 232 species of butterflies across the Italian Peninsula. The results of the models were used to identify high-value sites with a multispecies prioritization method called zonation. In order to identify important areas for species of conservation concern, we incorporated a species weighting scheme to zonation analyses. We also used the results of the zonation analyses to identify a series of management landscapes on the basis of the similarity in species composition among sites. The basic zonation showed that most important areas for butterfly conservation are located in the Alps, the Appennine, the Apulia region and in the island of Sardinia. The inclusion of a species weighting scheme in the zonation analyses revealed the importance of two new areas located in Southern Italy and emphasized the importance of the Alps for species of conservation concern. The landscape identification procedure selected a series of landscapes, which provide protection to a full range of species ranging from the Alps to Mediterranean areas. Our study shows that the areas selected in our analyses should be given high priority in future conservation plans and monitoring schemes.