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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]

This review summarises the biology and ecology of the distinctive North Island New Zealand endemic treeIxerba brexioides(A.Cunn.). The genusIxerbais monotypic and belongs to the family Strasburgeriaceae found only in New Zealand and New Caledonia.Ixerba brexioides(tāwari) is a New Zealand tree restricted to rain forests north of 39°S latitude in areas of mature soil in mild, moist climates. With conspicuous white flowers displayed en masse between November and January each year and dark green, long and toothed leaves arranged in whorls, it has earned recognition as one of New Zealand’s most attractive trees. Inflorescences are predominantly insect pollinated, with occasional bird visitation. Capsular fruit are produced in early autumn and dehisce to reveal dark black-purple seeds with an orange fleshy aril that are bird dispersed. Seeds germinate quickly, without a dormancy period, most commonly on soil, logs and mounds, but grow slowly (1.6–2.4 mm year diameter growth rate) in shade conditions until canopy gaps open. Chemicals associated with its leaves include ursolic acid and proanthocyanidins, but their significance is unknown. Agglomerative hierarchical cluster analysis defined four main forest types dominated byI. brexioidescentred on Northland, Waikato, Coromandel and Urewera, the floristically richest occurring in Northland. The genus first appeared in the fossil record in New Zealand in the late Eocene. Flowers ofI. brexioides(whākou) were historically used by Māori in garlands and necklaces, while peak flowering was a signal to harvest certain crops.Ixerba brexioideshoney is popular and honey crops are sought after in areas where the trees are abundant and accessible to beekeepers. Though not currently threatened, the distinctive and geographically limitedI. brexioidesis one of the many New Zealand trees requiring additional research. Priorities include potential threats of climate change, susceptibility to inbreeding depression and the role of birds as dispersers. [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]

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]