Kauri ( Agathis australis ), which is one of the world's largest and longest‐living conifer species, is under threat from a root and collar dieback disease caused by the oomycete pathogen Phytophthora agathidicida . The noted incidence of kauri dieback has increased in the past decade, and even trees >1000 years old are not immune. This disease has profound effects on both forest ecosystems and human society, particularly indigenous Māori, for whom kauri is a taonga or treasure of immense significance. This review brings together existing scientific knowledge about the pathogen and the devastating disease it causes, as well as highlighting important knowledge gaps and potential approaches for disease management. The life cycle of P. agathidicida is similar to those of other soilborne Phytophthora pathogens, with roles for vegetative hyphae, zoospores and oospores in the disease. However, there is comparatively little known about many aspects of the biology of P. agathidicida , such as its host range and disease latency, or about the impact on the disease of abiotic and biotic factors such as soil health and co‐occurring Phytophthora species. This review discusses current and emerging tools and strategies for surveillance, diagnostics and management, including a consideration of genomic resources, and the role these play in understanding the pathogen and how it causes this deadly disease. Key aspects of indigenous Māori knowledge, which include rich ecological and historical knowledge of kauri forests and a holistic approach to forest health, are highlighted.

The emergent conifer Araucaria araucana (Mol.) K. Koch and the small deciduous broadleaved tree Nothofagus antarctica (Forst). Oerst. occur as mixed post-fire s...

Naturally thermotolerant vegetation in New Zealand is concentrated in approximately 39 geothermally heated areas totalling only 580 ha scattered along the 300 km length of the Taupo Volcanic Zone. Relationships between composition and structure of vegetation and environment were analysed at the comparatively large (95 ha) and unmodified Te Kopia geothermal steamfield. Vascular vegetation was mostly influenced by a strong gradient in soil temperature, ranging at 15 cm depth from 15°C to 90°C across the steamfield. Dominant species changed from evergreen, broadleaved forest at the cool end of this gradient to dominance on increasingly hot soils by myrtaceous and epacrid (southern heath) shrubs with small needle‐like leaves and shallow roots. While differences in cryptogam composition were mostly associated with spatial variation in soil temperature, they were also significantly influenced by soil acidity and Al concentration. All soils sampled along the gradient had low fertility, high acidity, and high levels of Al, SO ₄ , and Fe. This suggests that vegetation considered to be geothermally influenced should include relatively tall forest and scrub further from fumarole centres than has previously been recognised. Plants of geothermal areas tolerate acid soils with levels of Al that normally would be toxic. Mycorrhizal relationships may play important roles in plant survivorship in this environment by assisting nutrient acquisition. In common with the changes in community characteristics typical of other steep gradients of increasing stress, as soil temperatures increase so canopy height, plant stature, species richness, leaf size, and rooting depth decrease. These distinctive ecosystems provide excellent opportunities for research on plant community response to natural stress.

We define an ecosanctuary in a New Zealand context as ‘a project larger than 25 ha implementing multi‐species, pest mammal control for ecosystem recovery objectives, and with substantial community involvement’. We present attributes of 84 projects meeting this definition, including three lacustrine islands, 16 marine islands, seven ring‐fenced ecosanctuaries, seven peninsula‐fenced ecosanctuaries and 51 unfenced mainland ecosanctuaries. Ecosanctuaries have biological and social objectives, and some have returned threatened, previously extirpated taxa to the New Zealand mainland. Increasingly, these intensively managed sites are being embedded in human‐altered landscapes with low levels of pest control – a ‘core and buffer’ system. Most community groups that establish ecosanctuaries lack the technical expertise, resources and mandate to undertake regional or national prioritisation. There is a strong need for agency leadership of this, and to develop best practice pest control, pest monitoring and biodiversity outcome monitoring tools, as goals for national restoration of biodiversity rapidly expand.