Untangling the causes of vegetation change in a 5,300 year pollen record at Tiniroto Lakes,Gisborne, New Zealand

To address potential causes of disturbances in recent New Zealand vegetation a sediment core from Tiniroto Lakes near Gisborne was used to reconstruct the local history of ecological disturbance and vegetation dynamics. Our approach was to examine the pattern and rate of vegetation change, against known disturbances, in order to identify different causes of disturbance. Despite intermittent disturbances, a steady transformation of vegetation dominates the period from c. 4,900 to c. 2,300 cal. yrs b.p. This is a time of climatic amelioration, with increasing precipitation suggested by the decline of light-adapted taxa, together with the establishment of forest. After c. 2,300 cal. yrs b.p., vegetation change becomes much more irregular, and apparently driven by disturbances, including unusual ones, such as earthquakes. In contrast to earlier disturbances, later vegetation responses are typified by a reduction of forest species and the establishment of semi-open vegetation, which persists for decades. This dichotomy suggests that a change in disturbance regime, especially in terms of fire, characterises the period after c. 2,300 cal. yrs b.p. The rises of fire frequency and of intensity at that time could be a result of severe droughts under climate extremes associated with intensified ENSO frequencies.     

Growth of opossums (Trichosurus vulpecula) in the Orongorongo Valley,Wellington, New Zealand, 1953–61

The growth of pouch young and juvenile Trichosurus vulpecula to maturity is described, based on animals gin‐trapped in 800 ha of indigenous forest in the Orongorongo Valley, near Wellington. Commencing in March 1953 opossums were trapped continuously for 1 year, and then intermittently until 1961. Four ageing criteria were considered: ossification of limb epiphyses and development of cranial ridges were unreliable; tooth wear and closure of the spheno‐occipital skull sutures were more satisfactory, and were adopted. For the first 180 days the mean growth followed a rectilinear regression when size, expressed as cube root of weight, was plotted against age. Thereafter growth accelerated greatly, but steadied towards the end of the first year; its rate increased after several months, and ceased at 2 to 21/2 years. Though adult males (2.65 kg) and females (2.41 kg) differed significantly in weight, there was no detectable difference during the growth phase. Births occurred throughout the year, but were markedly seasonal, 86% occurring between mid March and the end of May. A secondary birth peak in spring, recorded in other areas, was barely apparent. Most young consequently grew fastest in their first spring and summer. The growth pattern appeared to be mainly dependent on age rather than season_^ since all young reared in captivity conformed, irrespective of the season of birth.     

Population viability analysis of New Zealand sea lions, Auckland Islands, New Zealand’s sub-Antarctics: assessing relative impacts and uncertainty

A common issue faced in wildlife management is how to assess the uncertainty of potential impacts on the viability of a species or population. The pup production of New Zealand (NZ) sea lions (Phocarctos hookeri) has declined 50% in the last 12?years at their main breeding area, the Auckland Islands. The two major known atypical impacts on NZ sea lions are as follows: (1) the direct mortality as bycatch of trawling and (2) bacterial epizootics, which can affect reproduction and mortality. Both of these impacts include high levels of uncertainty, with fisheries data being variable due to percentage observer coverage and the effect of sea lion exclusion devises, while the timing and severity of bacterial epizootics are not predictable. In this paper, an age-structured model of the NZ sea lion population at the Auckland Islands was built to examine the predicted effects of fisheries mortality and catastrophes (bacterial epizootics), both separately and then combined, on population viability over a 100-year period using the VORTEX population viability analysis programme. These models are then compared against 15?years of empirical field data to determine the actual level of impacts being observed. Model results indicate that although naturally occurring epizootics reduce the growth rate of the population, it does not cause a decline in the Auckland Island population. However, sustained fisheries bycatch at current estimated levels, particularly considering its potential impact on adult female survival, could result in a population decline and possible functional extinction over the modelled time period.     

14 What RNA world ?? Ancestral polypeptides likely participated in the origins of translation

A widespread consensus holds that protein synthesis according to a genetic code was launched entirely by sophisticated RNA molecules that played both coding and functional roles. This belief persists, unsupported by phylogenetic evidence for ancestral ribozymes that catalyzed either amino acid activation or tRNA aminoacylation. By contrast, we have adduced strong experimental evidence that the most highly conserved portions of contemporary aminoacyl-tRNA synthetases (aaRS) accelerate both reactions well in excess of rates achieved by RNA aptomers derived from combinatorial libraries and of rates required for primordial protein synthesis. Such ancestral enzymes, or “Urzymes”, characterized for Class I (TrpRS (Pham et al., 2010, 2007) and LeuRS (Collier et al., 2013); 130 residues) and Class II (HisRS; 120–140 residues; (Li et al., 2011)) synthetases generally have promiscuous amino acid specificities, whereas ATP and cognate tRNA affinities are within an order of magnitude of those for contemporary enzymes. These characteristics match or exceed expectations for the primordial catalysts necessary to launch protein synthesis. Structural hierarchies in Class I and II aaRS also exhibit plateaus of increasing enzymatic activity, suggesting that catalysis by peptides similar to the Aleph motif identified by Trifonov (Sobolevsky et al.) may have been both necessary and sufficient to launch protein synthesis. Sense/antisense alignments of TrpRS and HisRS Urzyme coding sequences reveal unexpectedly high middle-base complementarity that increases in reconstructed ancestral nodes (Chandrasekaran et al.), consistent with the proposal of Rodin and Ohno (Rodin & Ohno, 1995). Thus, these ancestors were likely coded by opposite strands of the same gene, favoring simultaneous expression of aaRS activating both hydrophobic (core) and hydrophilic (surface) amino acids. Our results support the view that aaRS coevolved with cognate tRNAs from a much earlier stage than that envisioned under the RNA World hypothesis, and that their descendants make up appreciable portions of the proteome.     

LCA and LCC of the world’s longest pier: a case study on nickel-containing stainless steel rebar

Purpose

Built in 1941, the Progreso Pier was the first concrete structure in the world built with nickel-containing stainless steel reinforcement. The Pier has been in service for over 70 years without any significant repair or maintenance activities. The aim of this study was to understand the environmental and economic implications of selecting nickel-containing stainless steel reinforcement using the Progreso Pier as the case study.

Methods

A combined environmental life cycle assessment (LCA) and life cycle costing (LCC) study was conducted. The analysis considered the potential environmental impacts and the net present cost of the stainless steel reinforced structure from cradle to grave and compared it to the same structure using conventional carbon steel.

Results and discussion

The results indicated that while using stainless steel reinforcement resulted in a marginally higher environmental impact after initial construction, this is offset by the increased service life and, hence, less frequent maintenance and reconstruction activities. Relative to the as-built stainless steel reinforcement design, the environmental impacts of the carbon steel reinforced design are between 69 and 79 % higher over the analysis period. Similar observations were made for the other investigated impact categories. The cost implications of using stainless steel reinforcement show economic benefits that are complementary to the environmental benefits. Similar to the LCA, the service life benefits outweigh the higher unit costs for stainless steel, assuming a discount rate of 0.01 % as the baseline scenario. The carbon steel reinforced design has a net present cost that is 44 % higher than the as-built stainless steel reinforcement design. The crossover point for the two designs occurs at year 50, which corresponds to the reconstruction activity. A sensitivity analysis shows that the results and conclusions are sensitive to the choice in discount rate: Rates 3 % and lower produce net present costs that are lower for the as-built design; rates 4 % and higher produce net present costs that are lower for the alternative design.

Conclusions

The study demonstrates how LCA and LCC are complementary tools that can be used in decision-making for sustainable construction. The Progreso Pier exemplifies the importance of considering the entire life cycle with service life and recycling as well as long-term life cycle impacts of infrastructure projects from an environmental and economic perspective.

     

Diet of the opossum Trichosuvus vulpecula (Kerr) in the Orongorongo Valley,Wellington, New Zealand,in relation to food‐plant availability

The food preferences of a population of opossums in 4.4 ha of lowland broadleaf/podocarp forest were studied for 4 years by faecal analysis. A survey and phenological records were made of the vegetation to compare foods eaten with foods available. Metrosideros robusta and Weinmannia racemosa contributed 60% to the leaf diet, and were being defoliated and killed by opossums. Metrosideros fulgens and Ripogonum scandens, both lianes, together contributed 15 % to the leaf diet but were eaten seasonally. About 10 other species contributed small amounts. Flowers, flower buds, fruit, seeds, bark, and petiole made up about 35 % of the total diet. Compared with their status in the same area 30 years ago, Fuchsia excorticata, Alectryon excelsus, Pseudopanax arboreum, Myrsine salicina, and Coriaria arborea are now rare or localised and of much less consequence in the diet.     

Skink predation by hedgehogs at Macraes Flat, Otago, New?Zealand

The stomach contents of 158 hedgehogs captured at Macraes Flat, Otago, New Zealand, over two summers in 2000 and 2001 were examined for the occurrence of lizards. The remains of at least 43 skinks (both Oligosoma nigriplantare polychroma and O.?maccanni) and one gecko (Hoplodactylus sp.) were found. Twenty-one percent (n?=?33; 8 males and 25 females) of the examined hedgehogs had fed on skinks. Female hedgehogs ate significantly more skinks than did males. Our results suggest that the presence of large numbers of hedgehogs can have a high impact on native reptile populations in New Zealand and therefore they should be targeted in future trapping programmes.     

Population monitoring of the endangered New?Zealand spider,

The endangered New?Zealand widow spider, Latrodectus katipo, is believed to have undergone marked population decline over the last 30 years, but as monitoring methods are time- and labour-intensive, and require observers to have a high level of experience, the current status of many populations is unknown. We investigated the use of artificial cover objects (ACOs) as an alternative monitoring tool for L. katipo at three sites at Himatangi Beach, Manawatu, New?Zealand, from late 2004 through to mid-2005. Occupancy rates of the ACOs were compared with population densities obtained from habitat searches, to assess their efficacy as a monitoring tool. Numbers of the introduced spider, Steatoda capensis, which may be a competitor of L.?katipo, were also recorded during habitat searches. ACOs were reliable monitoring tools, with occupancy rates higher at the site with the highest L.?katipo population density. Latrodectus katipo populations were found to have highly female biased sex-ratios, with a longer breeding season at Himatangi than reported previously at other sites. Steatoda capensis exists at much higher population densities than L.?katipo at Himatangi. However, fluctuations in the populations of the two species appear to be unrelated. ACOs could be used as a non-destructive monitoring tool for many other arachnid species.     

The ancient DNA revolution: the latest era in unearthing New Zealand’s faunal history

In the 25 years since the first DNA sequences were obtained from the extinct moa, ancient DNA analyses have significantly advanced our understanding of New Zealand's unique fauna. Here, we review how DNA extracted from ancient faunal remains has provided new insights into the evolutionary histories and phylogenetic relationships of New Zealand animals, and the impacts of human activities upon their populations. Moreover, we review how ancient DNA has played a key role in improving our ability to taxonomically identify fragmentary animal remains, determine biological function within extinct species, reconstruct past faunas and communities based on DNA preserved in sediments, resolve aspects of the ecology of extinct animals and characterising prehistoric parasite faunas. As ancient DNA analyses continue to become increasingly applied, and sequencing technologies continue to improve, the next 25 years promises to provide many more exciting new insights and discoveries about New Zealand's unique fauna.     

Abstracts of papers presented at the 12th Biennial Conference of the Society for Research on Amphibians and Reptiles in New Zealand,University of Otago,Dunedin, New Zealand, 9–11 February 2007

Abstract

This study of customary harvests of sooty shearwater Puffinus griseus chicks by Rakiura Maori compares the utility of Traditional Ecological Knowledge (TEK) and ecological science for understanding patterns in prey availability. We recorded TEK of 28 muttonbirders about emergence patterns and variation in chick size at different aspects of 14 breeding islands and in their coastal fringe compared to inland areas. Spatial and temporal variation of chick availability were measured using the methods of ecological science in the 2001 harvest season across Putauhinu Island, south west of Rakiura, New Zealand. As predicted by TEK, titi emerged earlier from west than east coast locations on Putauhinu. Scientific measures were also consistent with an earlier emergence in coastal compared to inland areas as asserted by TEK, but conclusive inference is potentially confounded by movement of chicks between burrows just before fledging. A TEK construct predicting heavier chicks on the west coast was not supported by scientific measurements. We also measured the characteristics of areas preferred for harvesting so that we could gauge representativeness of the areas “sampled” by the muttonbirders to accumulate their TEK. Within forested habitat, areas harvested by muttonbirders had 62–65% higher chick density than unharvested areas. The muttonbirders concentrated harvesting where there was less ground cover and taller canopy cover and only hunted on nights and times of the season when harvesting was most profitable. Therefore, TEK may be less able to detect wider‐scale variation and harvest impacts on prey in particular. Short runs of scientific information from spatially and temporally stratified sampling will complement and assist inference from longer term TEK. As shown in this case study, TEK and science often agree on pattern, but are likely to disagree on why a pattern exists.     

Historical and ecological context, pattern and process, in the derivation of New Zealand?s freshwater fish fauna

This paper explores distribution patterns exhibited by New Zealand?s freshwater fish fauna, both fossil and extant, and seeks to clarify processes that have generated these patterns. Knowledge of a Miocene New Zealand terrestrial/freshwater fossil fauna is based substantially on lacustrine deposits in Central Otago. It reflects an ecologically very different fauna from that known today. Nothing is known of the Miocene fluvial fauna. Present-day patterns of distribution and diversity reflect a deep ecological dichotomy. About half the fauna is diadromous, and the habit of these species, of moving to and from the sea, provides them with great resilience in the face of major known landscape perturbations resulting from orogeny and land submergence, glaciation and volcanism. The diadromous species tend to be widespread throughout New Zealand. In contrast, non-diadromous species are more strictly confined to freshwater habitats, and a major means of spread relates to changes in directions and connections of stream flows. As a result, species are much less resilient, they exhibit complex patterns of sympatry, and their ranges are much more localised. Despite all elements in the fauna living across the same landscape in space and time, distribution patterns of the varying species groups display great differences in pattern.     

Proposed Changes to New Zealand’s Medicines Legislation in the Medicines Amendment Bill 2011

This article evaluates New Zealand’s Medicines Amendment Bill 2011. This Bill is currently before Parliament and will amend the Medicines Act 1981. On June 20, 2011, the Australian and New Zealand governments announced their decision to proceed with a joint scheme for the regulation of therapeutic products such as medicines, medical devices, and new medical interventions. Eventually, the joint arrangements will be administered by a single regulatory agency: the Australia New Zealand Therapeutic Products Agency. The medicines regulations in Australia and New Zealand will be updated as part of this process. The Medicines Amendment Bill addresses some of the well-recognised deficiencies in the Medicines Act 1981. However, a comprehensive overhaul of the Act is not being undertaken. I argue that repealing and replacing the Medicines Act 1981 would be preferable and advisable, given the number of legal difficulties with the Act and, in particular, where it does not align with equivalent current international law.     

A Megafauna’s Microfauna: Gastrointestinal Parasites of New Zealand’s Extinct Moa (Aves: Dinornithiformes)

We perform the first multidisciplinary study of parasites from an extinct megafaunal clade using coprolites from the New Zealand moa (Aves: Dinornithiformes). Ancient DNA and microscopic analyses of 84 coprolites deposited by four moa species (South Island giant moa, Dinornis robustus; little bush moa, Anomalopteryx didiformis; heavy-footed moa, Pachyornis elephantopus; and upland moa, Megalapteryx didinus) reveal an array of gastrointestinal parasites including coccidians (Cryptosporidium and members of the suborder Eimeriorina), nematodes (Heterakoidea, Trichostrongylidae, Trichinellidae) and a trematode (Echinostomida). Parasite eggs were most prevalent and diverse in coprolites from lowland sites, where multiple sympatric moa species occurred and host density was therefore probably higher. Morphological and phylogenetic evidence supports a possible vicariant Gondwanan origin for some of the moa parasites. The discovery of apparently host-specific parasite taxa suggests paleoparasitological studies of megafauna coprolites may provide useful case-studies of coextinction.     

Ground Beetles (Coleoptera, Carabidae) in Forest Fragments of the Manawatu, New Zealand: Collapsed Assemblages?

Botanically diverse and well-maintained, protected forest fragments in the Manawatu area of the North Island of New Zealand contained very species-poor carabid assemblages. In a nearby large forest tract, the potential source area, nine species were caught in pitfall traps, while the largest forest remnant had two species, and a well-managed suburban forest patch had three species but only one with a potentially reproducing population. Lack of grazing and high botanical diversity was insufficient to maintain the potential carabid assemblage in these fragments. Predation risk and a low dispersal power in endemic New Zealand ground beetles, combined with fragment size and degree of isolation could contribute to this collapse. Active management of ground-active invertebrate species seems necessary to protect them in isolated forest fragments in New Zealand.     

Are predator-proof fences the answer to New?Zealand?s terrestrial faunal biodiversity crisis?

A review of pest-exclusion fences throughout New?Zealand shows that the goals of fence projects are frequently not achieved and cost-benefit analyses often do not adequately quantify ongoing costs. The creation of these sanctuaries enclosed by predator-proof fences often creates small expensive zoos surrounded by degraded habitat that will never be able to sustain the animal and plant species contained within the fence. We examine what fence proponents and conservation trusts believe they are achieving and ask whether the evidence available demonstrates that fenced areas are capable of fulfilling these objectives.