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Sea urchin overgrazing is a leading cause of kelp forest loss and in such cases their removal is increasingly advocated for kelp forest restoration. However, refining removal approaches is needed to improve the efficiency and success of restoration, as most previous removal studies have been small scale and require ongoing removals to maintain low densities and allow kelp recovery. We investigated the effectiveness of one‐off urchin removal from large, semi‐discrete areas of urchin barrens as a tool to promote kelp recovery. We removed sea urchins (Evechinus chloroticus) from four areas (1.6–2 ha) of urchin barrens in northeastern New Zealand. Exposed urchins were reduced to approximately 7% of initial densities and remained low, yet cryptic urchin densities increased after 2 years. Kelp (Ecklonia radiata) and fucoid (Sargassum sinclairii, Carpophyllum spp.) densities increased rapidly in removal areas, but remained constant or declined in adjacent control urchin barren areas. Macroalgal canopy recovery varied among and within removal areas, but increased on average from approximately 5 to 43% in 2 years. Densities of large sea urchin predators did not increase with kelp recovery, likely due to ongoing fishing within removal areas. Our results demonstrate that a single urchin removal from large, semi‐discrete areas of urchin barrens can effectively and efficiently promote rapid multi‐species macroalgal recovery without additional actions (e.g. repeated urchin removals or macroalgae enhancement) for at least 2 years. However, this approach does not restore whole ecosystems and consequently restoration benefits through kelp recovery will be temporary without longer‐term urchin management and/or rebuilding of predator populations. [ABSTRACT FROM AUTHOR]

Kahikatea (Dacrycarpus dacrydioides) is a tall, wetland‐tolerant native podocarp tree that has potential for restoration of New Zealand wetlands currently dominated by invasive Grey willow (Salix cinerea). We investigated methods to jump‐start establishment of Kahikatea saplings in the Ramsar‐listed Whangamarino Wetland. Treatments involved planting saplings after full herbicide clearance of the willow canopy (FULL), partial herbicide clearance of the canopy (PARTIAL), and manual cutting of light wells (MANUAL). Saplings were planted as individuals or clusters of seven. Treatment plots were established in 2015 and monitored until 2020. Despite Kahikatea being considered a "light‐demanding" species, saplings grew best in the PARTIAL treatment which had the lowest ambient light levels (x̄=32% of non‐intercepted sunlight). PARTIAL treatment saplings were estimated to require 24–36 years to reach the height of the surrounding willow canopy if they maintained similar growth rates. Preconditioning saplings by soaking roots before planting provided a growth advantage in the PARTIAL treatment plots, whereas nonconditioned plants grew better in the higher‐light MANUAL and FULL plots. No benefit was found for cluster planting. Restoration toward a native Kahikatea‐dominated forest will be contingent on saplings reaching willow canopy height before the faster‐growing willows reestablish, or periodic management of willows to maintain light levels above the compensation point for continued growth. Ultimately, the utility of this approach depends on what on‐going facilitation is required and whether seedlings subsequently produced by these emergent podocarp "islands" are able to jump‐start a long‐term change in the successional trajectory of the surrounding willow‐dominated wetland. [ABSTRACT FROM AUTHOR]

Wildlife sanctuaries in Aotearoa/New Zealand involve community groups that often prefer using non-lethal monitoring methods for invertebrates. We examined one method for monitoring tree wētā with the aim of improving monitoring design. Pest management at our study site did not vary for 10 years before our study and remained unchanged between sampling, so we assumed that abundance of tree wētā would not vary significantly over the four years of the study. We recorded occupancy and marked every tree wētā (Hemideina spp.) using the same set of 38 artificial tree-hole refuges (galleries) every 1–2 weeks. We tested the prediction that non-lethal monitoring of tree wētā is a suitable proxy for relative wētā abundance by comparing the number of tree wētā using the same galleries four years apart. As expected, no change in numbers of wētā was detected. However, the level of site/gallery fidelity, seasonal fluctuations and movement between artificial galleries suggest that monitoring design needs to incorporate the life history and behaviour of these insects. We recommend comparison of wētā occupancy be restricted to the same season, galleries be placed more than 50 m apart and checked only once or twice a year. [ABSTRACT FROM AUTHOR]

Sea urchin overgrazing has caused widespread phase shifts from kelp forests to "urchin barrens" on many temperate reefs, reducing habitat complexity, productivity, and biodiversity. Sea urchin removal is increasingly used for kelp restoration; however, few studies have quantified the efficiency and effectiveness of different removal methods, resulting in limited understanding of their practicality. In this study, the efficiency (removal rate) and effectiveness (proportion removed) of four removal methods were evaluated in northeastern New Zealand. We compared culling or collecting sea urchins by either SCUBA or freediving in 128 small‐scale plots (25 m2). We also evaluated the efficiency and effectiveness of culling in four large (1.6–2 ha) barren areas, scales relevant for restoration. On average, culling sea urchins was 1.9–4.4 times faster than collecting, and SCUBA was 1.5–3.3 times faster than freediving. Removal rates increased with sea urchin density, especially for culling on SCUBA, while freediving removal rates increased with experience. Effectiveness was lower in large‐scale removals (86–93% of sea urchins ≥40 mm removed) compared to small‐scale removals (98–99%), but sufficient for restoration objectives. Estimated time per area (using SCUBA culling) was similar across large‐scale removals (49–57 hours/ha), despite an almost 2‐fold variation in initial sea urchin densities (approximately 4–8 urchins/m2), suggesting area may better predict total removal time than simply number of sea urchins across low‐density ranges. While sea urchin removal provides a rapid, feasible, and effective approach to restoring kelp in urchin barrens, restoration plans need to also address the causes of sea urchin overpopulation to ensure long‐term benefits. [ABSTRACT FROM AUTHOR]

New forests can bring many benefits; however, public concern over wildfires can create a dilemma for restoration ecologists, managers, and policy makers advocating for forestation. In southern montane New Zealand, destocking following pastoral tenure review and forestation incentives have resulted in an increase in woody vegetation, raising concerns over fire risk. We used abundance‐weighted community flammability metrics to investigate changes in the flammability of montane grassland within Mahu Whenua Ecosanctuary following destocking, and the relative flammability of woody communities likely to establish naturally in this area. While woody species cover increased following destocking, a decrease in highly combustible graminoids and shrubs, and increased abundance of non‐flammable herbaceous species meant community flammability metrics reduced or showed no change. Woody communities that could potentially develop in the area varied substantially in structure and composition. Open, species‐rich, shrublands showed lower flammability metrics for both understorey and canopy than mixed dense shrubland/forests or species‐poor beech (Nothofagaceae) forests. For active forestation projects where fire is undesirable, a low‐flammability herbaceous understorey can reduce fire risk. Where desirable forest species are highly combustible but fire‐intolerant, e.g. New Zealand beech, fire risk could be reduced by maintaining buffer zones of low‐flammability vegetation or applying planting strategies such as nucleation that accelerate the development of closed canopy forest patches more likely to have moisture‐retentive ground layers. However, in historically burnt landscapes, additional information will be needed to define the wider pool of low‐flammability species appropriate for forestation programs. [ABSTRACT FROM AUTHOR]

Nature-based solutions (NbS) are actions to address societal problems. They are similar to soil and water bioengineering (SWB), where trees and forests are used to mitigate natural hazards. However, NbS can have unintended consequences. Forest-based NbS may involve the enhancement, rehabilitation or restoration of natural forests or planting of trees and forests to provide a range of services including the production of timber and wood. In New Zealand, planted steepland forests have been widely used as NbS for erosion control. While intact, these forests provide various beneficial ecosystem services. However, if these forests are harvested, there is a period of up to 6–‍8 years following clear-fell harvesting, known as the 'window of vulnerability' (WoV) when the landscape is susceptible to rainfall-induced landslides. During this time, the combination of declining root strength and changes in soil hydrology can lead to shallow landslides, especially during heavy storms. This study focuses on three questions: determining whether there is a time within the WoV when susceptibility to rainfall-induced landslides, expressed as landslide density, reaches a maximum; are such landslides related to forestry infrastructure; and are those landslides connected to the stream network. We examined three areas in New Zealand (Tolaga Bay, Marlborough, and Tasman) where exceptional rain events triggered thousands of landslides on forest land harvested in the years immediately preceding those events. Using a range of high-resolution satellite imagery, we manually mapped rainfall-induced landslides and identified those due to the rain events. The maximum landslide number and density occurred on land harvested 1–4 years (and on average 2–3 years) before the event and varied slightly for each study area. Landslides also occurred in areas with trees up to harvest age of about 30 years and on areas with different vegetation covers, i.e., mature indigenous forests, pasture, scrub, etc. There were fewer landslides associated with forest infrastructure such as roads and landings than triggered on clearcut slopes. On average across the three study regions, about half the landslides were connected to streamlines, and so were able to deliver sediment and woody debris. Better information on susceptibility to rainfall-induced landslides following forest removal may help forest managers and regulators understand this hazard and what can (and cannot) be done to mitigate events which often result in 'disastrous' off-forest impacts as observed in New Zealand in recent years. • Maximum landslide density occurred on forest land harvested 1–4 years before a rainfall triggering event • Fewer landslides were associated with forest infrastructure such as roads and landings • On average, half the triggered landslides reached a streamline and so were able to deliver sediment and woody debris • Results were consistent across three regional study areas • In the context of NbS, consideration needs to be given to potential unintended consequences before implementation. [ABSTRACT FROM AUTHOR]

Australia and New Zealand share many historical and contemporary commonalities. These define five contemporary forest environmental frontiers—for First Nations peoples, between agriculture and forestry, in forest management, in urban and peri-urban environments, and in relation to climate change. In both countries, the First Nations frontier is expanding in scale and significance with those peoples' rights to land and forests. Frontiers with agriculture and in forest management are longstanding but dynamic and as yet little realised in relation to the need for forest and landscape restoration. Both countries are highly urbanised, elevating the significance of the urban and peri-urban frontier, particularly in the context of climate change. In both countries, forests will be profoundly impacted by climate change and are central to mitigation and adaptation strategies. Experience within and intersections between the frontiers offer encouraging prospects for synergies and for learning between the two countries and more widely. [ABSTRACT FROM AUTHOR]

Ectomycorrhizal fungi (EMF) are critical to the establishment of many plant species and an important consideration in ecological restoration of southern beech (Nothofagaceae) forest. However, information on spore viability and storage is lacking for EMF taxa associated with southern beech. This study tested the viability and germination of spores from fruiting bodies collected during autumn and spring from mountain beech forest, Otago, New Zealand. Nuclear ribosomal ITS sequences matched autumn collections to the EMF genera Cortinarius, Inocybe and Russula, but all spring collections were an undescribed hypogeous taxon resembling the native EMF genus Hysterangium, referred to here as Hysterangiaceae 'Motatapu'. We investigated propidium iodide as a spore viability test, and compared spore germination in water vs glucose, in different temperature and light regimes, and between freshly collected spores and spores from fruiting bodies dried at 30°C or frozen at −20°C. Propidium iodide did not stain all devitalised spores, so may be unreliable for quantifying viability of fresh spores. Spore germination in water was <6% for all genera and <2% for most taxon × treatment combinations. Fresh spores of Hysterangiaceae 'Motatapu' suspended in 4°C water showed higher germination than at 20°C; excluding light had no significant effect. Spores of the same taxon suspended in 10% and 20% glucose showed lower germination in comparison to water and showed deformations. Germination percentages of all taxa decreased with storage, but spores of some taxa retained viability for 120 days in 4°C water suspensions. Spores of Hysterangiaceae 'Motatapu' showed the least loss of viability with storage of all taxa investigated. For the purposes of storing EMF material for use as inoculum, we recommend drying fruiting bodies at 30°C for storage, then preparing fresh spore suspensions in water when inoculum is required. [ABSTRACT FROM AUTHOR]

Summary: Gap creation in recovering rainforests may reduce the intensity of competition and provide opportunities for later successional species to co‐occur with predominant earlier successional species. This study examined the potential of artificial gaps to facilitate the natural regeneration and establishment of woody species in dense regenerating stands of Kānuka (Kunzea robusta) that have developed following the removal of degrading factors especially clearing and grazing in many parts of New Zealand. Artificial gaps were created through selective felling of Kānuka canopy trees and the species composition, density, growth and survival of native woody species regenerating in the canopy gaps and under paired intact Kānuka canopies were monitored for 28 months. Gap creation resulted in a significant increase in the number of species and density of woody regeneration including a wider range of woody species, although no mature phase species (including podocarps) were found, potentially due to seed limitations. There was no significant effect detected with respect to the interaction of time and gap creation on species recruitment. Survival and growth of woody regeneration were significantly greater in canopy gaps than beneath the intact canopy despite the higher proportions of herbaceous ground vegetation and browsing incidence in gap treatments. The tendency of woody seedlings to grow taller in canopy gaps may have permitted them more rapid recovery from browsing. The duration of the study was too short to fully capture the potential of canopy intervention, but woody regeneration within the artificial gaps is likely to accelerate as the regeneration proceeds, especially if browsing is controlled, and the results presented here provide useful insight into the early stages of this process. [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]

Anthropogenic CO 2 emissions are one of the principal driving forces of climate change. Climate change leads to systematic changes of ecosystems that cause significant impacts on species interactions, ecosystem processes, and result in profound socio-economic consequences. While carbon offsetting of terrestrial forests and their monetary value are well accepted, the carbon offsetting potential and value of coastal and marine ecosystems (Blue Carbon, BC) remains excluded from the international carbon accounting framework. In this study, we estimated the carbon offsetting value of kelp forests (Ecklonia radiata) against urchin barrens (dominated by crustose coralline algae) using the standing stock biomass as a metric. We propose that standing stock biomass is a crucial next step in introducing BC to the general carbon offsetting framework. Our approach is informed by long-term ecological research conducted in a marine reserve, which highlights the potential of utilizing trophic cascades to limit the dominance of urchin barrens in shallow coastal habitats. We found that the value of carbon standing stock in current kelp forests with reforestation in the Hauraki Gulf Marine Park (HGMP) is worth up to $NZ 7.9 million, based on 2021 carbon market pricing in New Zealand. This simple step towards realizing the value of marine conservation and its multiple benefits to society highlights the missed opportunities when policy and plans do not align with ecology and economics. Including the ocean's contributions to carbon storage is a critical step in using monetization techniques to overcome climate change challenges. Monetizing the carbon offsetting value of kelp forests contributes to establishing funding mechanisms to attract diverse investments in marine ecosystem restoration while providing ecological benefits in ocean governance. • This paper draws attention to the missed opportunity of including kelp forest in the current carbon offsetting framework. • The CO 2 stored in kelp standing stock biomass could be worth up to NZD 7.9 million (2021, with reforestration) in the Hauraki Gulf Marine Park. • Monetizing the carbon storage value of kelp contributes to the establishment of funding mechanisms to attract investments as a nature-based solution to climate change. [ABSTRACT FROM AUTHOR]

Globally, lowland forests have been depleted, fragmented, and degraded by land clearance and conversion by humans. Many remnants are also invaded by non-native plants and mammals, which can exacerbate biodiversity loss and impede ecosystem recovery. We examined the effects of non-native ground cover weeds and mammals on the seedling recruitment of native woody plants in lowland forests in northern New Zealand by following establishment over 2 years at sites experiencing different levels of weed cover, with or without supplemental seed addition, and with or without mammal exclusion. In general, native seedling recruitment was highest where seeds had been added and mammals excluded. Native seedling recruitment was negatively correlated with weed cover at sites invaded by Asparagus scandens or Tradescantia fluminensis, but only where seeds had been added. These results suggest that attempts to facilitate native seedling recruitment by sowing native seeds will be most successful where ground cover weeds and introduced mammals are low in abundance. Seedling recruitment was highest for Piper excelsum, Myrsine australis and Melicytus ramiflorus, so these species could be good options for lowland-forest restoration projects where ground cover weeds are present. [ABSTRACT FROM AUTHOR]

Fencing forest fragments to limit the effects of herbivores is a common method for restoration, but recent studies have suggested that fencing alone is insufficient for fragment recovery. The endemic New Zealand canopy tree tawa ( Beilschmiedia tawa (A.Cunn.) Kirk) is suffering recruitment failure in forest fragments throughout its northern range. We sought to determine the role of fragmentation and fencing on B. tawa seedling survival and to identify the factors driving recruitment failure in this species. The main factors that affected B. tawa seedling survivorship were desiccation and herbivory. Fragmentation had a negative effect on the survivorship and growth of potted B. tawa seedlings. Fencing neither influenced survivorship nor diminished mortality by desiccation. However, small roofed enclosures positively affected seedling survivorship, potentially by diminishing desiccation. Our results are consistent with other studies where desiccation has been deemed a key factor of tree mortality in fragmented forests. As a single management strategy, fencing appears to be insufficient to positively affect B. tawa regeneration and other complementary activities are suggested. [ABSTRACT FROM AUTHOR]

Tree ferns are a ubiquitous and often locally dominant element of wet southern temperate rainforests across Australasia, southern Africa and in regions adjacent to the tropics in South America. Published data on the ecology of tree ferns throughout these forest ecosystems is piecemeal, with the most comprehensive literature describing the ecology of tree ferns coming from New Zealand. Therefore using New Zealand forests as a model system, we review the ecology and importance of tree ferns for forest structure and composition. Most studies of the ecology and function of forest species in New Zealand have focussed on spermatophytes. Even though tree ferns (Cyatheaceae, Dicksoniaceae) can represent more than 50% of basal area and more than 20% of forest biomass they have been largely overlooked and quantitative information on their contribution to forest structure and function is relatively scarce. Here for the first time we synthesise information on NZ’s indigenous tree ferns published over the last 100 years and present new data on their ecology and potential ecosystem influences. Irradiance and nutrient (N, P) levels constrain development of tree fern gametophytes, with P limitation potentially influencing sporophyte production. Tree ferns establish during temporary removal of forest canopies across various spatio-temporal scales including after local disturbances, wind-throw openings of the canopy, and landslides. Members of the Cyatheaceae exhibit spatial differentiation along temperature and solar radiation gradients; the Dicksoniaceae species differentiate most strongly on their frost tolerance. Frequency/abundance of all nine understory tree fern species indigenous to New Zealand increases with total soil phosphorus, with some niche differentiation among species along a broader nutrient gradient. Tree ferns are prominent in early and mid-successional forest communities where they may persist for more than 250 years. Individually, and as a group, tree-ferns impact nutrient cycling, organic matter accumulation and ground-level irradiance, often shading out tree seedlings. Tree ferns also have long-term physical impacts on the regeneration niche of associated species, with epiphytism on tree fern trunks providing alternative establishment surfaces for many species. Domination of nutrient resources by tree ferns early in succession is likely a key factor influencing community establishment. We conclude with key recommendations for future research on fundamental unknown elements of the ecology and synecology of tree ferns including greater determination of their ecophysiology and influence on forest community assemblages. [ABSTRACT FROM AUTHOR]

Tree ferns are recognized as “keystone” species for their role in casting deep shade on forest floor environments, acting as a differential ecological filter on forest regeneration processes. Tree fern dominance is a feature of New Zealand’s central North Island exotic Pinus radiata (Pinaceae) plantations, particularly beyond 20 years following plantation establishment. In circumstances where plantation forests are managed for restoration of indigenous forest species, rather than timber harvest, an understanding of the competitive role of dense tree fern stands on forest regeneration processes in these “non-harvest” plantations is necessary. We investigated the competitive effect of tree fern (Cyatheaceae and Dicksoniaceae) cover on seedling growth rates of two mature forest tree species, Podocarpus totara (Podocarpaceae) and Pittosporum eugenioides (Pittosporaceae), over two austral summers in five 36–92-year P. radiata plantations. We experimentally manipulated tree fern canopies in order to contrast heavy versus light shading. Tree fern removal significantly increased the growth rate of both P. totara and P. eugenioides , and the growth rate of the shorter-lived, faster-growing, light demanding P. eugenioides was greater than that of P. totara with tree fern removal. Damage to the seedlings by mammalian animal browsers when tree ferns were removed was greater than that occurring under tree fern cover. This damage diminished the effect of tree fern removal on seedling growth rates for P. totara , but not for the faster growing P. eugenioides . The physical clearance of tree fern stands and then the establishment of fast growing, locally representative, indigenous canopy tree species of low palatability, along with protection from animal browse, are suggested restoration strategies. Our results are consistent with existing literature in showing that where tree ferns are a dominant feature of plantation understories, deep shade is likely to reduce canopy species seedling growth rates, reducing the potential for forest regeneration. [ABSTRACT FROM AUTHOR]

• New Zealand's nurseries have high species richness, growing 863 tree species. • More than 20 % of tree species grown in nurseries are native to New Zealand. • Differences in beta diversity among nurseries are scale dependent. Nurseries play an important role providing trees for a variety of managed environments including urban forests. The diversity of urban forests and forest restoration projects are influenced by nursery species availability, and as such, there is a need to better understand tree species diversity at nurseries. We collected tree species lists from 75 nurseries throughout New Zealand, which were used to describe species richness (alpha diversity) and to examine similarity in the composition of native and non-native species assemblages among nurseries (beta diversity) at three spatial scales: island, region, city. Together, the nurseries grew 863 species, 174 of which were native to New Zealand, from 312 genera and 130 families. Nurseries grew significantly more non-native species (μ = 63.5, σ = 60.6) than native species on average (μ = 31.7, σ = 22.7) (t = 2.99, df = 48.45, p = 0.004). Beta diversity for native and non-native tree species were only significantly different at the scale of cities or regions, not at the larger scale of islands. Few species were grown in all cities or all regions and the majority of those that were common were native species. In contrast, non-native species dominated the unique species at all spatial scales, (i.e., species uniquely grown in one city, region, or island). By quantifying tree species diversity in New Zealand's nurseries, this research provides a basis to better understand the influence that nurseries have on urban and peri-urban tree diversity, and ultimately how that diversity impacts resilience and the provision of ecosystem services. [ABSTRACT FROM AUTHOR]

Restoration of postmining substrates to native forest is a standard requirement of resource consents for mine sites located within areas of native forest in New Zealand. Unweathered waste rock presents significant challenges for plant growth, and past research highlights the importance of replacing soil as part of restoration. However, replacing soil with its horizon structure intact or even obtaining sufficient soil for restoration can be a challenge in some situations. In this paper, we describe the results of two trials undertaken at the OceanaGold Ltd. open‐cast gold mine in Reefton to explore the influence of substrate conditions on the growth of native forest seedlings. We show that beech (Nothofagus) seedlings grown on A‐horizon soil grew significantly better than those grown on soil mixed with waste rock, and both grew significantly better than plants grown just on waste rock. In the second trial, we show that bark chips are not a good substitute for soil. These results confirm the importance of having the correct substrate for successful native forest restoration. [ABSTRACT FROM AUTHOR]

A personal narrative is presented which explores the author's experience regarding the restoration project for Mount Karioi in New Zealand, Karioi Maunga.

There is growing interest in the use of arbuscular mycorrhizal fungi (AMF) for ecological restoration. Numerous commercial AMF products are now available and are often used in preference to collecting indigenous AMF in treating restoration plants. Commercial AMF products are typically based on AMF strains exotic to the plant species and locations where they are used. We treated rooted cuttings of an endemic New Zealand tree species ( Podocarpus cunninghamii) and an exotic and invasive grass ( Agrostis capillaris) with an indigenous, pot-cultured AMF ( Acaulospora laevis) and an exotic commercial AMF product ( Glomus spp.). P. cunninghamii was grown in monoculture and together with A. capillaris, the latter to simulate field competition that often occurs in restoration plantings. In monoculture, the indigenous AMF resulted in significant increases in P. cunninghamii growth rates and tissue concentrations of both nitrogen and phosphorus. The commercial AMF had either no effect or a negative effect on P. cunninghamii growth and nutrient levels. A. capillaris growth and nutrient status were unaffected by the different AMF treatments. Competition eliminated any AMF benefit for P. cunninghamii. The results show that, for our chosen indigenous woody plant species, the commercially available AMF did not improve its early growth and nutrient acquisition in monoculture while, over the same period, the indigenous AMF induced positive growth and nutrient responses. These results have potential implications for forest restoration, particularly for nursery production of indigenous woody species. [ABSTRACT FROM AUTHOR]

There is increasing interest in the use of arbuscular mycorrhizal fungi (AMF) for ecological restoration, as AMF can improve plant nutrition and growth. However, some AMF can have negative effects on plant growth. It is therefore critical that restoration strategies incorporate appropriate AMF. This research investigated differences in growth and survival of Podocarpus cunninghamii (mountain tōtara) cuttings with six different AMF inoculums, with the aim of choosing the most appropriate mycorrhizal species for restoration success. Cuttings of P. cunninghamii were inoculated with AMF ranging from indigenous to exotic, including commercially available AMF and AMF isolated from remnant P. cunninghamii forest and ex-agricultural grassland. Plant growth and survival was compared after two seasons at a high country restoration site in the Mackenzie Basin. Plants treated with forest and indigenous AMF had significantly greater survival than those treated with commercial AMF. Forest AMF also resulted in significantly greater P. cunninghamii growth than all the other treatments. This has potentially important implications for restoration, as improved growth and survival of native woody species can improve restoration success by increasing establishment success and reducing management costs. [ABSTRACT FROM PUBLISHER]

Abstract: The composition of arbuscular mycorrhizal fungi (AMF) communities found in agricultural systems has been found to be very different to that of forest. The implications of this, if any, for the restoration of indigenous forest on ex-agricultural land is poorly understood. This study investigated the effect that AMF communities isolated from ex-agricultural and forest soils have on the growth of an indigenous New Zealand tree species (Podocarpus cunninghamii). The forest AMF community was isolated from a remnant stand of P. cunninghamii forest and the ex-agricultural AMF from a retired grazing grassland. In addition, the study examined how the two AMF communities affected the competitiveness of P. cunninghamii when grown in competition with an invasive grass species (Agrostis capillaris), which is frequently dominant on ex-agricultural land in New Zealand. P. cunninghamii growth was significantly decreased by inoculation with ex-agricultural AMF compared to forest AMF. Furthermore, the forest AMF community was able to significantly increase P. cunninghamii root production when in competition with A. capillaris. The findings suggest that when attempting to restore indigenous forest on ex-agricultural land, inoculation of tree seedlings with appropriate forest AMF may improve their growth and survival. [ABSTRACT FROM AUTHOR]

1. Ungulates have reached such high densities in some natural ecosystems that culling is frequently used to reduce their impacts on vegetation. However, much is still unknown about the outcomes of landscape-level control, in part because monitoring vegetation recovery requires decades. 2. We report long-term vegetation changes in permanent plots located in forest, shrubland and grassland communities across a mountain range in southern New Zealand. We test whether c. 92% reduction in the population of invasive non-indigenous red deer Cervus elaphus since 1964 has led to the recovery of deer-preferred species. 3. Tree seedlings, saplings and the number of seedlings per adult tree increased over time. There was lower recruitment, however, of highly palatable forest species compared with less palatable species, and the recruitment of saplings was lower in browsed forest plots compared with deer exclosures. 4. The total number of occurrences and absolute number of palatable species per plot increased over time in shrublands and grasslands respectively. The height of both shrublands and palatable grassland snow tussocks Chionochloa spp. increased, although the occurrences of most individual species remained unchanged over time. 5. Vegetation recovery at our site in response to long-term and significant herbivore reductions may be limited by several factors, including the slow growth rates of New Zealand species, density-dependent diet switching by deer, altered successional trajectories and below-ground processes. 6. Synthesis and applications. Our results suggest that after nearly four decades, even low densities of introduced herbivores may restrict ecosystem recovery, and therefore, restoring herbivore-disturbed ecosystems by solely manipulating herbivore population numbers may require a long-term perspective. Management strategies can accelerate recovery by protecting existing palatable plants within deer-exclosures, and planting or seeding palatable species within these refugia. However, in addition to increasing seed sources, restoration may only become apparent following large-scale disturbance events and canopy turnover. [ABSTRACT FROM AUTHOR]

Tawa ( Beilschmiedia tawa)-dominated forest fragments on farms within the Rotorua Basin were surveyed to quantify the likely recovery processes following exclusion of domestic livestock grazing, using a space-for-time substitution approach. Vegetation structure, plant diversity and soil fertility were measured at 24 sites within 15 forest fragments on six farms, covering a range in time since exclusion from grazing of 1–53 years. The forest fragments were compared with a large area of ungrazed forest in the nearby Lake Okataina Scenic Reserve. As time since exclusion from grazing increased, indigenous plant species diversity increased (up to 30–35 years); ground fern and epiphyte abundance increased (up to 30–35 years); tree seedling and sapling numbers, and litter cover also increased (up to 10–15 years); and overall tree numbers increased, while average tree diameter at breast height and overall tree basal area did not differ significantly. The soil fertility status was highly variable, obscuring clear patterns, although Olsen P status decreased with time since grazing exclusion. Once grazing of forest fragments ceases, significant changes in their diversity, structure and soil characteristics can be expected, which indicate recovery of these plant communities towards the conditions observed in ungrazed forest. [ABSTRACT FROM AUTHOR]

This paper uses the concept of 'governance' and the related notion of 'multi-layered' forest management decision making as an overarching framework for analysis of conflict between different stakeholder groups with contrasting perceptions about 'appropriate' use of indigenous forests in a New Zealand case study. In New Zealand, recent institutional reforms inspired by neo-liberal policy agendas have led to substantial conflicts between segments of society over the 'appropriate' governance of remnant indigenous forests. This study focuses on the West Coast Forest Accord (WCFA) as an illustration of the attempt to change governance structures of indigenous forest management by re-regulating the indigenous forest industry. It is argued that by seeking to accommodate multiple stakeholder interests, in particular industry, community and environmental groups, the WCFA was doomed to fail, as multiple, and often conflicting, stakeholder agendas focused on the goal of 'sustainable management' of indigenous forests could no longer be reconciled. Notwithstanding the shift in emphasis from government towards governance in the recent literature, the study findings confirm a continuing strong role by the state as an actor in the forestry sector in New Zealand. [ABSTRACT FROM AUTHOR]

Efforts to re-establish indigenous forests in pastoral New Zealand have increased as the value of native biodiversity has been realized. Direct seeding of woody species is preferable to transplanting, as labour and material costs are less. However, the success rate of direct seeding in pasture has been variable due to intense competition from adventive species. We initiated an experiment in pasture plots adjacent to a forest fragment where seed bed treatments (increasing in degree of disturbance from herbicide application to turf removal and topsoil removal) in combination with mulch treatments (wood chip shavings with and without forest floor organic material) were seeded with a mixture of New Zealand lowland forest species. The objective of the study was to determine if early successional plant communities, and ultimately seedling establishment, differed as a result of seed bed preparation after 1 year. Coprosma robusta (Karamu) and Kunzea ericoides (Kanuka) seedlings established on plots in significant numbers: both species were most abundant on topsoil-removed plots where bare substrate was greatest and plant cover least. Both seed bed treatments and mulching treatments led to measurable differences in overall composition of early successional plant communities. However, absence of plant cover and low soil fertility (both associated with the topsoil-removed treatment) were the most important factors in seedling success. [ABSTRACT FROM AUTHOR]

Summary1.Tradescantia fluminensis is an invasive weed of New Zealand, eastern Australia and Florida, where it carpets the ground in canopy-depleted native forest remnants and prevents regeneration. The aim of our study was to determine the Tradescantia biomass levels at which this occurs. 2.At two podocarp/broad-leaved forest remnants in New Zealand, we showed that Tradescantia biomass increased logistically with available light, to a maximum at 10–15% full light. The maximum Tradescantia biomass was greater at the wetter site (819 g m-2 ) than at the comparatively dry site (695 g m-2 ). 3.Native forest seedling species richness and abundance decreased exponentially with increasing Tradescantia biomass, for example from 3·4 and 81·5 m-2 , respectively, in the absence of the weed, to 0·37 and 6·28 m-2 at maximum Tradescantia biomass. We attributed this to decreasing light levels beneath Tradescantia . Under approximately 500 g m-2 of Tradescantia (c. 100% weed cover), available light was reduced to < 1% full light. 4.The compositions of the extant vegetation, seed rain and seed bank were consistent with our interpretation that light availability drives the differences in seedling species richness and abundance between Tradescantia and non-Tradescantia habitats. 5.We estimated the response of seedlings of six commonly occurring native woody species to Tradescantia biomass. Macropiper excelsum appeared to be the least tolerant, its LD50 (the biomass of Tradescantia at which its abundance is reduced to 50% of the maximum) being approximately 12 g m-2 , whereas Dysoxylum spectabile was the most tolerant, with an LD50 of 40 g m-2 . 6.Dysoxylum spectabile germination and early seedling establishment could occur in dense Tradescantia , but the probability of survival over 20 months decreased logistically with increasing Tradescantia biomass. The probability of survival at 100% weed cover was 6% compared with 84% for seedlings in non-Tradescantia habitat. We estimated that emergence above the weed occurs only where cover of Tradescantia is < 200 g m-2 (70–90% cover). 7.We predicted that increases in native species richness and abundance will accumulate with increasing suppression of the weed. Imposing shade by planting trees to improve the canopy cover is a potentially useful tool for restoration of Tradescantia -affected forest remnants. [ABSTRACT FROM AUTHOR]

• Indigenous people developing leading restoration techniques. • Site factors predicted regeneration potential of exotic conifer clear-fells. • Predicted regeneration potential modelled across 583-ha restoration area. • Method quantifies areas requiring active vs passive restoration. • Method assists restoration planning at landscape-scales. The decline in forest area from local to global scales has been partly attributed to land-use changes. There is an increasing demand to reverse this land use change by the restoration of former forests. In Aotearoa/New Zealand, there is a desire to re-establish indigenous forests when some exotic conifer plantations are clear-felled. Ngāti Whare, a Māori tribe in the central North Island, wish to use plantings and natural regeneration to restore indigenous conifer-angiosperm forest on an area currently covered by such plantations. Large-scale indigenous forest restoration by planting is potentially costly and logistically demanding and there is therefore a need to find an optimal balance between active and passive restoration. We collected field data across 206 ha of exotic conifer plantation clear-fells to model the spatial distribution of indigenous tree species regeneration and weed cover importance values (IV) as measures of ecosystem resilience. Strong relationships were found between site factors (i.e., elevation, slope, slope aspect, distance from seed source, and clear-fell age) and our measures of resilience in clear-fells. We therefore used these modelled relationships, along with GIS layer generated site factors, to map potential indigenous regeneration and weed cover IV on the nearby 583-ha Ngāti Whare restoration area. These maps show the balance between active and passive restoration that will be required when the restoration area is clear-felled. Active restoration would require that seedlings are planted across 48% of the restoration area, along with appropriate weed control, while passive restoration, with just weed control, would be required on 52% of the area. A sensitivity analysis showed that these proportions were sensitive to assumptions around required seedling densities and weed cover so that we suggest further work to clarify these assumptions. To our knowledge, this approach has not been applied elsewhere to indigenous forest restoration and this study provides a template for guiding future landscape scale restoration projects. [ABSTRACT FROM AUTHOR]

The article presents abstracts on topics related to urban restoration such as the influence of seed rain and soil seed banks on native regeneration in urban forest restoration in Hamilton City, New Zealand and ecological restoration planning based on urban connectivity.