229 results for Journal article, 1980

  • A dendrometer band study of the seasonal pattern of radial increment in kauri (Agathis australis) ( New Zealand).

    Palmer, J.; Ogden, J. (1983)

    Journal article
    The University of Auckland Library

    Simple dendrometer bands were used to measure the radial increment of kauri (Agathis australis Salisb.) at 3 sites to the south and east of Auckland during the 1980-81 growing season. Diameter increment cores taken from some of the trees at the beginning and end of the study showed that the radial expansion measured by the bands correlated significantly (P<0.001) with the width of the annual ring formed over the same period. A reduction in tree growth rate during summer drought was recorded at 2 mid-altitude sites, but not near the altitudinal limit of kauri. These growth patterns were attributed to the different soil moisture conditions at the different sites.

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  • An introduction to plant demography with special reference to New Zealand trees.

    Ogden, J. (1985)

    Journal article
    The University of Auckland Library

    An outline of the scope and origins of plant demography emphasises the link between numerical and evolutionary approaches. The rules governing thinning in monocultures and some general features of plant competition in mixtures are described. Plant demography can be applied at several levels ó that of the genetic individuals or that of the modular components of which plants are usually composed. This dual population structure puts a new emphasis on the morphological changes occurring in competing mixtures. Various approaches to the definition of strategies are discussed. Plants with short life cycles and abundant production of small seeds are contrasted with long-lived species producing fewer larger seeds. This 'r-K' continuum is used as a broad frame- work, although Grime's (1979) two dimensional strategy model may be more realistic. The concept of the 'regeneration gap' has been a persistent theme in forest ecology in New Zealand, and its explanation has generally been presumed to lie in past climatic change. However, population age and size frequency distributions reflect demographic processes, which must be properly explored before extrinsic causes can be ascribed to particular structures. The steady state climax theory is an inappropriate concept on which to build an understanding of the demography of canopy trees in New Zealand. A kinetic model, in which disturbance is accepted as a selective force to which different tree species have become differentially adapted, accepts regeneration gaps localised in space and time as demographic phenomena. A model of cohort structure in kauri is used to illustrate the dangers inherent in drawing conclusions about population 'status' from a small sample of diameters and approximate ages. The difficulties of applying transition matrix models emphasises our lack of basic demographic information for most New Zealand trees. The errors inherent in determining tree population age structures are addressed. The regeneration strategies of the beeches {Nothofagus spp.) and the podocarps (Podocarpaceae) are outlined primarily in relation to seed size and seed production periodicity. The beeches conform well to the predator satiation theory of mast seeding, but the podocarps (and other bird-dispersed trees) present additional problems. More information on the interactions between tree fruiting behaviour and the avifauna is needed for satisfactory evolutionary accounts. The existence of'advance growth' seedling populations in New Zealand forests is well known, but there is little information on dormant buried seed banks. Some information about the sizes of seed banks in New Zealand forests is provided, and it is concluded that they are probably of similar magnitude to those in other temperate forests, and warrant more rigorous study.

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  • The soil seed bank of a kauri (Agathis australis) forest remnant near Auckland, New Zealand

    Enright, N.J.; Cameron, E.K. (1988)

    Journal article
    The University of Auckland Library

    The "transient' and "persistent' components of the soil seed bank beneath a kauri forest remnant are described, recent seed rain (collected in trays over a two year period being distinguished from dormant viable seed with longevity >2 years (soil beneath trays). A total of 46 vascular plant species was recorded. Trays are dominated by 4 woody, native species, Kunzea ericoides, Coprosma arborea, Myrsine australis and Carpodetus serratus. Sub-tray samples show an accumulation of seeds from light-demanding weedy species, including many adventives, eg Solanum mauritianum, Phytolacca octandra and Cirsium vulgare. In addition, seeds of 2 woody, native species, Cordyline australis and Geniostoma rupestre, are abundant. Detrended correspondence analysis shows clear differences between floristic composition of trays and sub-trays, and between on-site vegetation and components of the soil seed bank. differences explained in terms of seed longevity, seed accumulation rates, suitability of site conditions for growth of individual species, and the role of seed dispersal agents, especially birds.

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  • Reproductive biology of Phormium tenax: a honeyeater-pollinated species

    Craig, J.L.; Stewart, A.M. (1988)

    Journal article
    The University of Auckland Library

    Phormium tenax, studied on Tiritiri Matangi Island and in Auckland, reproduces asexually by offsets and sexually by large inflorescences. Flowers are protandrous hermaphrodites that exhibit partial dichogamy and herkogamy. The pollen or the stigma are presented sequentially for initial contact with floral visitors. Nectar rewards are greatest during the male phase of flowering. Shape and configuration of flowers ensures that large birds are the most likely pollinators. Two honeyeaters (Meliphagidae), tui Prosthemadera novaeseelandiae and bellbird Anthornis melanura were the most frequent visitors and pollinators although some introduced bird species also commonly visited, especially in Auckland City. Many flowers appear to function solely as pollen donors.

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  • A differential response to self pollination: seed size in Phormium

    Craig, J.L. (1989)

    Journal article
    The University of Auckland Library

    An open access copy of this article is available from the publishers website. Phormium tenax self pollination from the same inflorescence produced many small seeds and the fewest large seeds. These had the least endosperm. Self-pollination between inflorescences of the same plant produced more large seeds with intermediate amounts of endosperm. Naturally outcrossed flowers produced mainly large seeds and these had the most endosperm.

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  • Tributyl tin levels for sea water, sediment, and selected marine species in coastal Northland and Auckland, New Zealand

    King, N.; Miller, M.; De, Mora, S. (1989)

    Journal article
    The University of Auckland Library

    Water and sediment samples were collected from the Waitemata Harbour, Opua Inlet, and Tutukaka Harbour. Provides evidence for the toxic influence of TBT on non-target organisms in New Zealand.

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  • Picophytoplankton in the Hauraki Gulf, New Zealand

    Booth, W.E.; Sondergaard, M. (1989)

    Journal article
    The University of Auckland Library

    Picophytoplankton represented a mean value of >30% of the total chlorophyll a in winter and c20% in other seasons. In terms of total carbon fixation, values of 23% and 13% contribution were obtained. The picophytoplankton were composed of chroococcoid cyanobacterial cells at densities between 103 and 104 ml-1 together with larger eukaryote cells at densities up to 103 ml-1. Winter counts were lower than those for summer. Cyanobacteria displayed subsurface peak densities higher in the water column than the eukaryotes.

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  • Confirmation of Parma polylepis, a pomacentrid teleost, in New Zealand waters

    Francis, M.P. (1988)

    Journal article
    The University of Auckland Library

    Juvenile and subadult specimens of Parma polylepis (Pomacentridae) were photographed at North Cape and the Poor Knights Islands respectively. -

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  • A preliminary survey for crassulacean acid metabolism (CAM) in submerged aquatic macrophytes in New Zealand

    Webb, D.R.; Rattray, M.R.; Brown, J.M.A. (1988)

    Journal article
    The University of Auckland Library

    This preliminary survey covered 13 aquatic macrophytes present at 2 sites in Lake Taupo and 2 sites in the Auckland region. Three species previously unrecorded as CAM plants, Isoetes kirkii, Lilaeopsis lacustris and Vallisneria spiralis, exhibited diurnal fluctuations in titratable acidity and malic acid content.

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  • Ecology of molluscan grazers and their interactions with marine algae in north-eastern New Zealand: a review

    Creese, R.G. (1988)

    Journal article
    The University of Auckland Library

    A considerable amount of unpublished material exists for intertidal and shallow subtidal rocky reefs in NE New Zealand. Much of the information is from unpublished theses. This review summarises this material and discusses it in the light of published accounts from the NE coast (especially the areas around Leigh, Northland), and studies from elsewhere within and outside New Zealand. While some reasonably well-supported models for subtidal grazers can now be formulated, the intertidal material is still too diffuse to allow meaningful models to be proposed. -

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  • Distribution of barnacle larvae in Mahurangi Harbour, North Auckland.

    Martin, A.T.; Foster, B.A. (1986)

    Journal article
    The University of Auckland Library

    Adult Balanus variegatus occur in the upper harbour reaches, Elminius modestus throughout the harbour, and other coastal species of barnacles at the harbour entrance and outside. Maximum numbers of the larvae of B. variegatus and E. modestus occurred in the middle harbour, with apparent accumulation of late stage nauplii an cyprids of the more numerous E. modestus. Maximum numbers of the nauplii of the coastal species B. trigonus, Chamaesipho columna, Epopella plicata and C. brunnea occurred at the harbour entrance, their pattern of distribution was similar to those of coastal cladocerans Penilia avirostris and Evadne tergestina. The only plankter with a restricted up harbour distribution was the estuarine copepod Sulcanus conflictus. The maxima of occurrence of larvae of B. variegatus down harbour from the position of the adult population are interpreted as a result of current flows and tidal oscillations, retaining the larvae within the harbour system. Such larval retention may explain why Mahurangi Harbour is a good place for oyster settlement.

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  • Copper, chromium, and lead in Manukau Harbour sediments.

    Aggett, J.; Simpson, J.D. (1986)

    Journal article
    The University of Auckland Library

    The concentrations of copper and chromium were of the same order of magnitude as those reported for other New Zealand harbours. However, lead concentrations were higher than those found for the other harbours. This may be a consequence of higher traffic densities in the surrounding area.

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  • The demersal eggs and planktonic larvae of Chromis dispilus (Teleostei: Pomacentridae) in north-eastern New Zealand coastal waters.

    Kingsford, M.J. (1985)

    Journal article
    The University of Auckland Library

    Recognition of egg stages can be used to study the spawning and egg hatching times of C. dispilus. Larvae captured in a demersal plankton trap showed that eggs hatch after dark and usually on the outgoing tide. Immediately after hatching, larvae swim to the surface where they can be captured in large numbers using ichthyoplankton hauls. Since C. dispilus spawning is synchronous, large pulses of larvae can be expected to enter the plankton at intervals over the summer breeding season.-

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  • Reproductive periodicity in Evechinus chloroticus in the Hauraki Gulf.

    Walker, M.M. (1982)

    Journal article
    The University of Auckland Library

    Gametogenesis began in the spring, and major spawning occurring in mid to late summer. The proportion of the gonads taken up by nutritive phagocyte cells increased from autumn to spring. During proliferation and growth of gametes and nutritive phagocytes declined in abundance and globulation, suggesting that reserves stored in these cells were transferred to developing gametes. Although synchronous gametogenesis occurred in the 3 populations studied, spawning occurred at different times, which suggests that spawning was induced by factors acting either within sea urchin populations or over distances of a few km or less.-

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  • Relativistic pseudopotential calculations for HBr+, HBr, HBr-, HI+, HI, and HI-

    Schwerdtfeger, P.; Szentpaly, L.V.; Stoll, H.; Preuss, H. (1987)

    Journal article
    The University of Auckland Library

    An open access copy of this article is available and complies with the copyright holder/publisher conditions. Valence SCF/CI calculations using nonrelativistic, relativistic, and semiempirical pseudopotentials have been carried out for the ground states of HBri and HIi(i = + 1,0, - 1). Autoionization of HBr - and HI- is characterized by the crossing points between the Born-Oppenheimer potential energy curves of the negative and neutral molecules. Relativistic and correlation effects are discussed for several molecular properties. Using semiempirical pseudopotentials + valence-CI, our calculated values for HX and HX+ (X = Br, I) are in good agreement with experiment. The crossing between the 1?+ (HX) and 2?+ (HX-) curves is calculated to occur at 1.70 A for HBr/HBr- and 1.84 A for HI/HI -. Dissociative attachment energies for HX/HX- are compared with results from low-energy electron scattering experiments.

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  • Relativistic effects in molecules: Pseudopotential calculations for PbH+, PbH, PbH2, and PbH4

    Schwerdtfeger, P.; Silberbach, H.; Miehlich, B. (1989)

    Journal article
    The University of Auckland Library

    Nonrelativistic, relativistic, and semiempirical pseudopotentials for the Pb atom have been generated to replace the chemically inert core electrons for investigating the effects of relativity and correlation on molecular properties of PbH+, PbH, PbH2, and PbH4. Spin-orbit effects are taken into account by using a quasirelativistic two-spinor pseudopotential. The relativistic bond contraction is found to be dependent on the Pb(6s) orbital participation in the Pb-H bond (?relr e: 0.04 A for PbH+, PbH, and PbH2 and 0.07 A for PbH4). The calculated and measured values agree excellently [e.g., re (PbH) = 1.839 A expt. 1.839 A]. The inert pair effect for the lead hydrides will be discussed.

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  • Antigone and Orestes in the works of Athol Fugard

    Mackay, Elizabeth (1989-10)

    Journal article
    The University of Auckland Library

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  • Alienation of the Right to Rental Income: Booth v FCT

    Cassidy, Julie (1987)

    Journal article
    The University of Auckland Library

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  • The Taxation of Compensation Payments for Personal Injury – Are the Complexities All Getting a Bit Much?

    Cassidy, Julie (1988)

    Journal article
    The University of Auckland Library

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  • Attributing Significance to Unobvious Musical Relationships

    Davies, Stephen (1983)

    Journal article
    The University of Auckland Library

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