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Identifying appropriate restoration strategies is vital for successful urban remnant restoration, but projects often lack consistent methods that distinguish them. In New Zealand, there are unique opportunities to restore depleted Dacrycarpus dacrydioides (A.Rich.) de Laub. (kahikatea, white pine) semi-swamp forest remnants in numerous urban centres. To assess potential restoration strategies for three kahikatea remnants in Hamilton City, we compared their physical features, native vascular species composition, age structures, life forms and epiphytes with a notional reference site (Te Papanui). Numerous native vascular species gaps are revealed among Te Papanui (66 species), Totara Park (40 species), Hillcrest Park (15 species) and Grove Park (nine species). Age structure analyses suggest that Hillcrest Park comprises the oldest kahikatea population, with an average age of 82 years, followed by Grove Park (70 years), Te Papanui (60 years) and Totara Park (32 years). A native floristic analysis of thirteen life forms found that Te Papanui contains the most (11), followed by Totara Park (eight), Grove Park (six) and Hillcrest Park (five). Despite the abundance of invasive plants at Totara Park, its high-water table and favourable humid, sheltered conditions support more epiphytes (nine) than Te Papanui (six), Hillcrest Park (one; Pyrrosia eleagnifolia), and Grove Park (none). Epiphytes absent from Te Papanui found at Totara Park may be due to the loss of the once abundant tree fern and host, Dicksonia squarrosa (whekī). Totara Park requires careful manipulation of troublesome weeds, whereas Hillcrest Park and Grove Park necessitate buffer extensions and native understory plantings. This study provides a simple framework that uses biophysical differences among urban remnants and a reference site to reveal suitable restoration strategies that could guide other urban restoration projects regionally and nationally. [ABSTRACT FROM AUTHOR]

The majority of the world's population now lives in cities, where reduced levels of native biodiversity, coupled with fewer opportunities for people to experience nature, are expected to result in an urban public increasingly disconnected from the natural environment. Residential gardens have great potential to both support native species and allow people daily contact with nature. Embracing the epistemological assumption that urban residents' interactions with nature in their gardens and parks may be complex, unpredictable, contradictory, and context-dependent, we used an interpretative phenomenological analysis approach to explore the human relationship with urban nature in a New Zealand city. We conducted 21 semi-structured "go-along" interviews to facilitate a deeper understanding of participants' personal experiences of nature in parks and gardens. Interviews revealed a tension between stated values and concrete actions affecting urban biodiversity in private gardens. This value-action gap stemmed from the multiple purposes and values that people hold for their gardens, which do not necessarily align with conservation of native nature. By recognizing that urban residents hold multiple values and want their gardens to fulfill multiple purposes, local authorities aiming to promote nature conservation in cities can design wildlife gardening programs that meet these multiple needs and reconcile conflicting priorities. [ABSTRACT FROM AUTHOR]

This review summarises the ecology and biology of the North Island New Zealand endemic evergreen epiphytic shrub Pittosporum kirkii Hook.f. ex Kirk (Pittosporaceae). While mainly found as an epiphyte associated with other nest epiphytes such as Astelia spp., it also exhibits rupestral and terrestrial lifestyles. Pittosporum kirkii is distinguished from other members of New Zealand Pittosporum by distinctive thick, fleshy, coriaceous leaves, which may assist survival in water-stressed habitats. Water availability is speculated to be the most limiting factor across all of the habitats that P. kirkii occupies and when under water stress, the species utilises a desiccation postponement strategy. Pittosporum kirkii has a restricted distribution with strong habitat preferences restricting it to upper lowland and lower montane mainly old-growth forest ecosystems of the upper North Island. The highest probabilities of P. kirkii occurrence lie within mean annual temperature between 7.8°C and 15.6°C, mean annual rainfall between 1172 and 4432 mm, mean minimum solar radiation in the coldest month between 4.8 and 6.6 MJ/m2/day, and vapour pressure deficits between 0.15 and 0.39 kPa. Pittosporum kirkii is currently listed as at risk–declining and qualified as data-poor and partial decline because of a lack of autecological information. Palatability to introduced brushtail possums and forest clearance have been suggested as the main agents of decline. Due to significant morphological differences between mainland New Zealand and Great Barrier Island/Aotea populations, further study is warranted to determine distinctness. Including P. kirkii in restoration plans and conservation monitoring is recommended in areas where it naturally occurs as this species is recognised as an indicator of overall forest health. Further detailed research on P. kirkii would be invaluable to fill the current gap in knowledge on its ongoing threats, sexual expression, pollination and seed dispersal. [ABSTRACT FROM AUTHOR]

New Zealand's formerly extensive lowland native forests have been comprehensively cleared or modified, and large areas of secondary-growth vegetation have subsequently established. These areas are comprised of native, exotic, and mixed tree and shrub species assemblages. The mature-phase canopy and emergent tree species representative of pre-human New Zealand forests are often rare or locally extinct in these forests, indicating negative ramifications for long-term biodiversity conservation and ecosystem service provision, especially such as carbon sequestration. The successful recruitment of mature-phase canopy and emergent tree species may be prevented by biotic and abiotic filters related to dispersal (e.g. lack of seed sources or lack of dispersal agents), environmental variation (e.g. unsuitable germination microclimate or light availability), and competition (e.g. exotic weed competition). Failure of mature-phase tree species to cross through these filters may halt forest succession and cause arrested development of the ecosystem. There are also social and cultural imperatives for restoring mature-phase tree species, such as reassembling desired forest habitat and landscapes and providing lost natural heritage and cultural resources. Therefore, to restore secondary forests, depauperate remnant forests and create new forests that have complex structure, high biomass, and natural canopy tree diversity, mature-phase canopy and emergent species should be reintroduced through human interventions (i.e. enrichment planting). Experiments demonstrate that mature-phase tree species establishment can be optimised through canopy manipulation to address competition for light. Such targeted management can determine successful recruitment of mature-phase tree species, as can weed maintenance post-enrichment planting and landscape-level pest animal control. Currently political focus is emphasising planting of new early-successional native forests. However, support from scientific research and policy development is essential to actively recruit mature-phase tree species where they are now poorly represented and hence forest succession may be arrested. Afforestation and emissions trading policies need to support the reinstatement of mature-phase tree species within existing regenerating and degraded forests and newly created forests to facilitate the substantial ecological and ecosystem service benefits they provide over the long-term. [ABSTRACT FROM AUTHOR]

Restoration of urban forest improves quality of life for city residents and is important for boosting native biodiversity. However, the scientific knowledge required to inform successful restoration is largely lacking for urban forest ecosystems, which differ from rural forests. Here we review two decades of urban forest restoration research in Hamilton, New Zealand and summarise key findings across seven major ecological topics: i. species traits, filters and thresholds, ii. species richness and target ecosystems, iii. tree regeneration, iv. seed banks and seed rain, v. seed predation, vi. enrichment planting and vii. restored forest function. We then discuss general urban restoration principles that increase the efficacy of urban restoration efforts including restore to a minimum of 10% indigenous cover in cities, develop a step-wise restoration plan and prioritise partner engagement. The purpose of this review is to aid urban forest restoration across New Zealand and globally. [ABSTRACT FROM AUTHOR]

Information relevant to the ecology and morphology of Eleocharis sphacelata (Cyperaceae) available through published and unpublished sources is assembled and reviewed. Eleocharis sphacelata is a freshwater wetland sedge found growing at the edge of lake margins, swamps, lagoons, and bogs within New Zealand, Australia, and Papua New Guinea. It is a perennial rhizomatous herb, with tall green cylindrical culms rising from submerged rhizomes generally buried under water in aerobic soils. A tendency to dominate the deepwater margins makes E. sphacelata crucial to the ecology of this habitat as a source of food, shelter, and protection for invertebrates, birds, and fish. Eleocharis sphacelata is commonly named giant spike-rush, kuta, or paopao. Maori have traditionally used the plant for clothing and warm coverings within whare (houses). Recent interest comes from its use in restoration plantings and constructed wetlands. [ABSTRACT FROM AUTHOR]

We review the biosystematics, chemistry, phenology, ecology, and cultural and economic uses of Phormium tenax, a widespread iconic New Zealand monocotyledon. Phormium tenax is endemic to New Zealand, Norfolk Island, and the Chatham Islands, and is distinguished from the sole other member of the genus, P. cookianum, by its erect trigonous seed capsules and red flowers, despite incomplete barriers to hybridisation. Flowers produce abundant nectar and are bird pollinated. Seed is orthodox and tolerates drying, while chilling overcomes dormancy. Rich, well-drained alluvial and organic soils encourage abundant growth in P. tenax but prolonged flooding and drought reduce growth and survival. Lack of tolerance to both frost and low mean annual temperatures distinguish its environmental niche from that of P. cookianum, but further research is required to characterise these differences more accurately. Phormium tenax is a significant component of vegetation on coastal cliffs, slopes, and dunelands; in estuarine shrublands; and lake margin and freshwater communities. Wide morphological variation in Phormium has led to cultivar development by Maori for weaving and by horticulturalists for ornamental garden use. Phormium tenax is important in many ecological communities as a food source, and is often used in restoration and revegetation plantings. [ABSTRACT FROM AUTHOR]

High levels of endemism, the sensitivity of species that have evolved without humans, and the invasion of exotic species have all contributed to severe depletion of indigenous biodiversity in New Zealand. We considered the contribution that urban restoration can make to maximising biodiversity by analysing landcover patterns from two national databases along an urban-rural gradient. Thirteen of 20 land environments in New Zealand are represented in cities, and nearly three-quarters of all acutely threatened land environments are represented within 20 km of city cores nationally. Despite this, remaining indigenous landcover is low within urban cores, with less than 2% on average, but increasing to more than 10% on average in the periurban zone. Threatened lowland environments are most commonly represented within cities, and least represented within protected natural areas. Restoration of existing urban habitat is insufficient to halt biodiversity loss. Ecosystem reconstruction is required to achieve a target of 10% indigenous cover within cities. A co-ordinated national urban biodiversity plan to address issues beyond a local and regional focus is needed. Analysis of national patterns of urban land environments, indigenous cover and remnant ecosystems will support action at a regional and local level while enhancing national and global biodiversity goals. [ABSTRACT FROM AUTHOR]

Whether nitrogen-fixing plants facilitate or inhibit species change in primary succession is best resolved by examining their impacts throughout the plant's entire life cycle from arrival to senescence. We experimentally examined two aspects of the successional impacts of a nitrogen-fixing shrub, Coriaria arborea, on Mt. Tarawera, a volcano in New Zealand: factors limiting Coriaria colonization and impacts of Coriaria-induced soil changes on a later successional tree, Griselinia littoralis. Coriaria germination was promoted by artificial wind protection and by the presence of heath shrubs. Transplanted Coriaria seedlings survived only if nodulated with Frankia, and the addition of Coriaria-enriched soils slowed Coriaria seedling growth and did not improve seedling survival. This explained why Coriaria seedlings were found mostly in protected habitats away from adult Coriaria, and suggested that Coriaria thickets are not self-replacing. Coriaria increased soil fertility by developing a 4 cm thick organic soil horizon that was richer in nitrogen (tenfold) and phosphorus (threefold) than pre-Coriaria stages. These soil changes resulted in three- to sixfold increases in growth of Griselinia when it was grown in Coriaria-enriched soils in a glasshouse. Coriaria's net effect on primary succession is facilitative, but the establishment of Coriaria is itself facilitated by the amelioration of the physical habitat by earlier colonists, suggesting facilitation is important throughout the life cycle of Coriaria. Sequential facilitative events determine the order of species replacements in this study but inhibition, linked to the developmental stages of Coriaria, may determine... [ABSTRACT FROM AUTHOR]

Restoring forest structure and composition is an important component of urban land management, but we lack clear understanding of the mechanisms driving restoration success. Here we studied two indicators of restoration success in temperate rainforests: native tree regeneration and epiphyte colonization. We hypothesized that ecosystem properties such as forest canopy openness, abundance of exotic herbaceous weeds, and the microclimate directly affect the density and diversity of native tree seedlings and epiphytes. Relationships between environmental conditions and the plant community were investigated in 27 restored urban forests spanning 3-70 years in age and in unrestored and remnant urban forests. We used structural equation modelling to determine the direct and indirect drivers of native tree regeneration and epiphyte colonization in the restored forests. Compared to remnant forest, unrestored forest had fewer native canopy tree species, significantly more light reaching the forest floor annually, and higher exotic weed cover. Additionally, epiphyte density was lower and native tree regeneration density was marginally lower in the unrestored forests. In restored forests, light availability was reduced to levels found in remnant forests within 20 years of restoration planting, followed shortly thereafter by declines in herbaceous exotic weeds and reduced fluctuation of relative humidity and soil temperatures. Contrary to expectations, canopy openness was only an indirect driver of tree regeneration and epiphyte colonization, but it directly regulated weed cover and microclimatic fluctuations, both of which directly drove the density and richness of regeneration and epiphyte colonization. Epiphyte density and diversity were also positively related to forest basal area, as large trees provide physical habitat for colonization. These results imply that ecosystem properties change predictably after initial restoration plantings, and that reaching critical thresholds in some ecosystem properties makes conditions suitable for the regeneration of late successional species, which is vital for restoration success and long-term ecosystem sustainability. Abiotic and biotic conditions that promote tree regeneration and epiphyte colonization will likely be present in forests with a basal area ≥27 m 2 /ha. We recommend that urban forest restoration plantings be designed to promote rapid canopy closure to reduce light availability, suppress herbaceous weeds, and stabilize the microclimate., (© 2017 by the Ecological Society of America.)