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Summary: The mid-Cretaceous is an important time for the diversification of forests globally, including the rise to dominance of the angiosperms and the beginning of the isolation of Zealandia. In New Zealand, little information is available on the mid-Cretaceous xyloflora. New specimens of fossil wood from the mid-Cretaceous Tupuangi Formation were collected from Waihere Bay, Pitt Island, Chatham Islands, of which 16 well-preserved samples were identified, representing Araucariaceae (Agathoxylon , 5 samples), Cupressaceae (Taxodioxylon and Cupressinoxylon , one sample each), Podocarpaceae (Protophyllocladoxylon , one sample), and the 'Group B' and 'Group C' Mesozoic conifers (four samples each) defined in Bamford & Philippe (2008). Of these, only Taxodioxylon had been identified previously from the Tupuangi Formation. Two new species are erected, Cupressoxylon dianneae sp. nov. and Protophyllocladoxylon jacobusii sp. nov. These records are important for understanding the mid-Cretaceous flora of New Zealand and the history of the unique modern flora of New Zealand. [ABSTRACT FROM AUTHOR]

Abstract< Understanding the interactive effects of fragmentation and invasive species on forest dynamics requires a long-term perspective because they are difficult to assess in the medium- to long-term using observational or experimental data alone. In such settings ecological models have an important role to play. Here we describe the implementation of a spatially explicit individual-based model (SEIBM) representing the dynamics of small forest fragments in northern New Zealand based on empirical data collected in the region. In addition, we performed a baseline analysis to determine how well the model captured podocarp-tawa forest dynamics, and compared its performance with stand structure data obtained from an unfragmented forest in northern New Zealand. We used sensitivity analysis to determine how sensitive the model was to changes in the input parameters. In addition, we simulated different scenarios under diverse management conditions to explore the model’s potential as a management tool. The model captures the stand structural characteristics of the fragments reasonably well but under-predicts stand basal area, suggesting that it does not represent the long-term suppression of some canopy tree species adequately. Although some refinement is needed to improve its performance, we believe that the model presented here is a useful tool for management purposes and for the assessment of the long term viability of forest fragments. The model can help inform managers and decision-makers regarding the long-term persistence of podocarp-tawa forest patches. [ABSTRACT FROM AUTHOR]

The temperate rainforests of southern hemisphere continents share Gondwanan antecedents, but subsequent trajectories exhibit divergent patterns. We review the Cenozoic history of major forest elements (c. 30 genera/families) of the temperate rainforests of New Zealand and compare these with South America and southeast Australia. From macro- and microfossil evidence, the major structural components of temperate rainforests in New Zealand have lineages dating back almost continuously to the Eocene or earlier. These include the tree ferns (CyatheaandDicksonia),Agathis, all but one of the podocarps, Nothofagaceae and other broadleaved genera such as Lauraceae and Cunoniaceae. Collectively these taxa contribute approximately 50% of current biomass in New Zealand temperate forests. However, several previously important groups in the Cenozoic such asAraucaria, theBrassospora-type beeches, and Casuarinaceae became extinct in New Zealand in the Miocene to Pleistocene. Patterns of extinction are broadly similar in New Zealand and South America (mostly late Miocene to Pleistocene) in response to climate cooling along steepened environmental gradients whereas in southern Australia taxa became extinct later (Pleistocene) reflecting limited suitable habitat during glacials. The deep-time continuity evident in the composition of New Zealand temperate rainforests was not influenced by the decrease in land area during the maximum marine transgression in the late Oligocene (c. 25–24 million years ago). Forest canopy dominants and emergents appear to have remained remarkably stable, perhaps reflecting community resilience. However, new subcanopy and open habitat lineages arrived as forest taxa were extirpated and climates cooled, reducing potential forest habitats. [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]

Stable isotope ratios of various proxies are widely used for palaeoclimate reconstruction, and it is often assumed that isotope ratios reflect vegetation abundance or type. However, very little research exists on the isotopic equilibration of extant biomes under variable environmental conditions. In this study, carbon and oxygen isotope ratios from leaves of various Podocarpaceae genera, endemic to New Zealand, are linked to environmental parameters from the Land Environments New Zealand model. The dominant influence on stable isotope ratios within the majority of Podocarpaceae studied here is vapour pressure deficit (VPD). A simple latitudinal trend does not exist, and neither temperature nor rainfall (decoupled from VPD) controls the stable isotope ratios. The results suggest that modern spatial heterogeneity in VPD affects the stable isotope values of vegetation, and that historic VPD variability would change the stable isotope ratios of Podocarpaceae without necessitating a change in vegetation type, density, or productivity. This represents an alternative model for temporal isotope change within geochemical proxies and reinforces the need for increased stable isotopic research in modern plant ecosystems to better understand modern, and eventually palaeoclimatic processes affecting the terrestrial biosphere. [ABSTRACT FROM AUTHOR]

Chromosome numbers have been determined for plants of five species and one unnamed entity of Hydrocotyle, mostly from the Chatham Islands. The chromosome number of H. bowlesioides is reported for the first time, the numbers for H. heteromeria, H. microphylla and H. moschata agree with previously published counts from plants from the New Zealand mainland. Four chromosome races were found in H. robusta, this adds to the list of New Zealand endemic species that show intraspecific chromosome number variation. [ABSTRACT FROM PUBLISHER]

Soil chronosequences provide an opportunity to examine the influence of long-term pedogenesis on the biomass and composition of associated tree communities. We assessed variation in the species composition of trees, saplings, and seedlings, and the basal area of adult trees, in lowland temperate rain forest along the Haast chronosequence on the west coast of the South Island of New Zealand. The sequence consists of Holocene dune ridges formed following periodic earthquake disturbance and is characterized by rapid podzol development, including a marked decline in phosphorus concentrations, accumulation of a thick organic horizon, and formation of a cemented iron pan. Tree basal area increased for the first few hundred years and then declined in parallel with the decline in total soil phosphorus, consistent with the concept of forest retrogression. There were also marked changes in the composition of the tree community, from dominance by conifers on young soils to a mixed conifer-angiosperm forest on old soils. Although a variety of factors could account for these changes, partial Mantel tests revealed strong correlations between tree community composition and soil nutrients. The relationships differed among life history stages, however, because the adult tree community composition was correlated strongly with nutrients in the mineral soil, whereas the seedling community composition was correlated with nutrients in the organic horizon, presumably reflecting differences in rooting depth. The changes in the tree community at Haast are consistent with disturbance-related succession in conifer-angiosperm forests in the region, but the opposite of patterns along the nearby Franz Josef post-glacial chronosequence, where conifers are most abundant on old soils. The Haast chronosequence is therefore an important additional example of forest retrogression linked to long-term soil phosphorus depletion, and provides evidence for the role of soil nutrients in determining the distribution of tree species during long-term succession in lowland temperate rain forests in New Zealand. [ABSTRACT FROM AUTHOR]

Abstract: The development of protocols for the conservation of fungi requires knowledge of the factors controlling their distribution, diversity, and community composition. Here we compare patterns of variation in fungal communities across New Zealand''s Nothofagus forests, reportedly the most myco-diverse in New Zealand and hence potentially key to effective conservation of fungi in New Zealand. Diversity of leaf endophytic fungi, as assessed by culturing on agar plates, is assessed for three Nothofagus sp. growing in mixed stands from four sites. Host species was found to have a greater influence on fungal community assemblage than site. The leaf endophyte communities associated with Nothofagus solandri and Nothofagus fusca (both Nothofagus subgenus Fuscopora), were more similar to each other than either were to the community associated with Nothofagus menziesii (Nothofagus subgenus Lophozonia). The broad taxonomic groups isolated, identified on the basis of internal transcribed spacer (ITS) sequences, were similar to those found in similar studies from other parts of the world, and from an earlier study on the endophyte diversity in four podocarp species from New Zealand, but there were few matches at species level. Average levels of endophyte species diversity associated with single Nothofagus species and single podocarp species were similar, despite historical literature and collection data recording more than twice as many fungal species on average from the Nothofagus species. The significance of these findings to fungal conservation is discussed. [Copyright &y& Elsevier]

Eight species of Podocarpaceae foliage are recognised from the late Oligocene or early Miocene Newvale site, South Island, New Zealand, and the following five new species are described: two of Dacrydium Lamb. and one each of Dacrycarpus (Endl.) de Laub., Phyllocladus Rich. ex Mirb. and Halocarpus Quinn. The latter is the first macrofossil record of this New Zealand endemic genus. All these conifers, plus Agathis Salisb., Microcachrys Hook.f. and Podocarpus Pers., co-occurred in the local vegetation at Newvale. In conjunction with prior records of macrofossils and pollen, these fossils indicate that the late Paleogene to early Neogene conifer flora of New Zealand was very diverse, with all but one of the extant genera present, together with several regionally or globally extinct genera, and multiple species of many of these genera. This fossil diversity is similar to the Paleogene fossil conifer diversity observed in south-eastern Australia (and particularly Tasmania) and in parts of North America. [ABSTRACT FROM AUTHOR]

Abstract: The diversity and distribution of fungal endophytes in the leaves of four podocarps (Dacrydium cupressinum, Prumnopitys ferruginea, Dacrycarpus dacrydioides, and Podocarpus totara, all Podocarpaceae) and an angiosperm (Kunzea ericoides, Myrtaceae) occurring in close stands were studied. The effects of host species, locality, and season on endophyte assemblages were investigated. Host species was the major factor shaping endophyte assemblages. The spatial separation of sites and seasonal differences played significant but lesser roles. The mycobiota of each host species included both generalist and largely host-specialised fungi. The host-specialists were often observed at low frequencies on some of the other hosts. There was no clear evidence for family-level specialisation across the Podocarpaceae. Of the 17 species found at similar frequencies on several of the podocarp species, 15 were found also on Kunzea. Many of the endophytes isolated appear to represent species of fungi not previously recognised from New Zealand. [Copyright &y& Elsevier]

Marine nitrogen (N) has been traced into terrestrial and freshwater food chains at petrel (Aves: Procellariiformes) colonies on the South Island of New Zealand, but the effects of N or other marine-derived nutrients on the productivity of mainland forests are unknown. Mean ring widths in matai (Prumnopitys taxifolia; n = 3) and rimu (Dacrydium cupressinum; n = 2) trees growing in a Westland petrel (Procellaria westlandica) colony were 0.9-1.4 mm yr-1, similar to ring widths reported elsewhere. However, series of much wider rings in cores showed that trees in a petrel colony can experience periods of accelerated growth. δ15N values of whole wood were, at 3.2-11.1‰, significantly enriched in comparison to other temperate forest trees. The highest δ15N values were at the cambial and pith ends of different cores, so isotopic fractionation during N remobilisation is unlikely to have been significant. The radial extent of 15N enrichment suggests that petrels have bred at the site since at least the mid 18th century. [ABSTRACT FROM AUTHOR]

Seven methods, including measurements of photosynthesis ( A) and stomatal conductance ( gs), carbon isotope discrimination, ecosystem CO2 and water vapour exchange using eddy covariance and the use of a multilayer canopy model and ecosystem Keeling plots, were employed to derive estimates of intercellular CO2 concentration ( Ci) across a range of spatial and temporal scales in a low productivity rain forest ecosystem dominated by the conifer Dacrydium cupressinum Lamb. in New Zealand. Estimates of shoot and canopy Ci across temporal scales ranging from minutes to years were remarkably similar (range of 274–294 µmol mol−1). The gradual increase in shoot Ci with depth in the canopy was more likely attributable to decreases in A resulting from lower irradiance ( Q) than to increases in gs due to changes in air saturation deficit ( D). The lack of marked vertical gradients in A and gs at saturating Q through the canopy and the low seasonal variability in environmental conditions contributed to the efficacy of scaling Ci. However, the canopy Ci estimate calculated from the carbon isotope composition of respired ecosystem CO2 ( δ 13CR; 236 µmol mol−1) was much lower than other estimates of canopy Ci. Partitioning δ 13CR into four components (soil, roots, litter and foliage) indicated root respiration as the dominant (> 50%) contributor to δ 13CR. Variable time lags and differences in isotopic composition during photosynthesis and respiration make the direct estimation of canopy Ci from δ 13CR problematic. [ABSTRACT FROM AUTHOR]

1 Angiosperm trees often dominate forests growing in resource-rich habitats, whereas conifers are generally restricted to less productive habitats. It has been suggested that conifers may be displaced by angiosperms except where competition is less intense, because conifer seedlings are inherently slow growing, and are outpaced by faster-growing angiosperm species. Here we investigate whether competition with ferns and deeply shading trees also contributes to a failure of conifers to regenerate in resource-rich habitats. 2 We examined how changes in soil nutrient availability and drainage affected vegetation along the retrogressive stages of a soil chronosequence in southern New Zealand. Vegetation composition shifted from angiosperm-tree dominance on ‘recent’ alluvial terraces (< 24 ky), via coniferous-tree dominance on older marine terraces (79–121 ky), to coniferous-shrub dominance on the oldest marine terraces (291 ky). Soil drainage deteriorated along the sequence, and N : Pleaves and N : Psoil indicate increasing P-limitation. Conifer species appear to be adapted to persistence on infertile and poorly drained soils. 3 The floor of the relatively fertile alluvial forests was deeply shaded (∼1% light transmission) by dense groves of tree-ferns and ground-ferns, and by large-leaved subcanopy trees. Few seedlings of any type were found on the forest floor, even in tree-fall gaps, and establishment was restricted to rotting logs and tree-fern trunks. Angiosperms were particularly successful at colonizing these raised surfaces. 4 Less shade was cast by the conifer-dominated forests on infertile marine terraces (∼5% light transmission), which lacked tall ferns. There were many opportunities for conifer establishment, with high seedling densities recorded on the forest floor and on logs. By contrast, angiosperm seedlings were mainly restricted to logs. 5 Our results suggest that several mechanisms act in concert to reduce regeneration opportunities for conifers in productive habitats. In particular, we suggest that tall ferns and deep shade are responsible for a restriction of regeneration opportunities in relatively productive forests in New Zealand, diminishing the opportunities for conifers to escape the competitive effects of fast-growing angiosperms. Thus ‘crocodiles’ may alter the outcome of the race between ‘hares’ and ‘tortoises’. [ABSTRACT FROM AUTHOR]

Cool temperate rain forests on Stewart Island, southern New Zealand, have had little direct human modification, but introduced white-tailed deer (Odocoileus virginianus) have influenced forest understoreys. Changes in life stages (seedlings, saplings and adult trees) of common tree and shrub species were recorded over at least 18 years in permanent plots in these forests. Faecal pellet indices of deer frequency in the forests were slightly greater in the most recent survey. However, during this period overall seedling and sapling densities increased, including species browsed preferentially by deer. In deer exclosures maintained over 21 years, densities of woody seedlings and saplings increased, but not of highly palatable species. While deer frequency was a significant predictor of increased seedling densities of unpalatable species and decreases of palatable species at a plot scale, so also were measures of local seed availability and competition from other seedlings and ferns. Seedling density increases were not uniform across species in response to stand structural attributes, and there were interactions between effects of browsing by deer and stand structural attributes. Therefore, relationships between deer frequency and seedling regeneration need to be set in the context of other biotic influences in these forests. [Copyright &y& Elsevier]

Investigates the dynamics of competition that affects the growth and survival of Dacrycarpus dacrydioides and Dacrydium cupressinum trees in a mixed podocarp stand in New Zealand. Correlation between mean radial growth rate and number of conspecific neighbors among D. dacrydioides; Low rate of mortality for D. cupressinum; Degree of intraspecific intensity for both types of trees.

Abstract: Ehrendorferiana and its two included new species, E. austrocedri (the type species) and E. fitzroyae, are diagnosed. The new genus is a member of the predominantly temperate Neotropical subfamily Aphalaroidinae (Psyllidae). Based on the absence of metabasitarsal spurs it forms a likely monophyletic group with Baccharopelma, Panisopelma and Russelliana. The absence or paucity of long dorsal or marginal setae on the wing pads and caudal plate suggests a probable sister-taxon relationship with Russelliana. Apart from two species of Triozidae from New Zealand on Podocarpaceae, Ehrendorferiana is unique within Psylloidea in its host association with conifers, viz. Austrocedrus and Fitzroya (both Cupressaceae). See also Electronic Supplement at: http://www.senckenberg.de/odes/05-12.htm [Copyright &y& Elsevier]