Pureora Forest Park Research Articles

Recovery of North Island kākā (Nestor meridionalis septentrionalis) within Pureora Forest Park, 2000–2020

To test the long-term efficacy of mammalian pest control, annual distance sampling estimates of the density of North Island kākā (Nestor meridionalis septentrionalis) within the southern Waipapa Ecological Area (WEA), Pureora Forest Park from 2008–2020 are compared to previously published estimates made at the same sites and time of year (October) between 2000–2007. Kākā density increased approximately four-fold from an average of c. 0.5 (95% CI 0.5–0.6) birds ha−1 between 2000 and 2007 to c.

The costs and benefits of conservation versus logging of old-growth native forest: A case history

Pureora Forest Park is one of the largest remaining and most ecologically and culturally significant areas of the native forest that once clothed almost all the North Island of New Zealand. Systematic logging and the establishment of sawmilling villages began in the Pureora area in the late 1940s. Concern about the effects of logging of virgin forest on native fauna accelerated until 1978, when a widely publicised tree-sitting protest led to a forced moratorium. The settlement that followed stopped the logging, closed the sawmills, and caused mass local unemployment and social conflict. The long-term solution required an integrated approach, reconciling the needs of economic resource utilisation with those of social welfare and biodiversity conservation. This paper describes the processes leading up to the unprecedented financial settlement that saved the forest, plus the details of the compensation package paid to timber companies for broken contracts, and the consequent benefits for conservation and tourism.

Developing tree-ring chronologies from New Zealand matai (Prumnopitys taxifolia) and miro (Prumnopitys ferruginea) for archaeological dating: Progress and problems

This paper describes attempts to develop tree-ring chronologies from New Zealand matai (Prumnopitys taxifolia) and miro (Prumnopitys ferruginea). These tree species have been recovered from Māori archaeological contexts, including as objects such as canoes and palisade posts. Dendrochronology offers the potential to establish accurate and precise calendar dates for wooden objects but relies on cultural use of species that are also suitable for tree-ring analysis, and the availability of calendar-dated reference chronologies for crossdating wood of unknown age. We used archived cross-section and core samples from seven sites in central North Island, and nineteen core samples collected in 2019 from matai and miro trees at Pureora Forest Park for our analysis. Some of these samples came from long lived trees, with ring counts indicating ages up to 800 years old. We found that both matai and miro exhibit considerable variability in ring clarity and ring width. They also have ring anomalies affecting the reliability of ring-width series. Miro was very challenging, and no tree sequences were built for this species. Tree-ring sequences were built for several matai samples but no secure inter-tree matches were identified. Further analysis of matai samples is required to establish reliable tree ring patterns for inter-tree and inter-site crossmatching.

Interactions between ship rats and house mice at Pureora Forest Park

ABSTRACTWhen the abundance of ship rats (Rattus rattus) is reduced, sympatric house mice (Mus musculus) are released from constraints of food shortage, intimidation or predation. As a result, mice may become either more abundant or more active and detectable. To distinguish between these effects, we monitored mice at eight sites within Pureora Forest Park during periods of rat removal and non-removal, and supplemented food in mouse-specific feeders to half of the sites. We used live-trapping to estimate mouse relative abundance, and tracking tunnels to detect activity. Mouse relative abundance increased when rats were removed, which correlated with increased mouse activity in tracking tunnels. Analysis of mouse capture probability showed that although rat population levels predominantly influenced mouse relative abundance, mouse detectability was also affected at a subtler level. Fluctuations in mouse relative abundance were driven by immigration, and there was evidence that mice were food-limited in the presence of abundant rats. However, this effect was not offset by supplementing food, so it is unlikely that exploitation competition alone limits mice in the presence of rats. Instead, when ship rats were abundant the danger to mice was likely to have limited their foraging opportunities. Evidence of direct predation of mice by ship rats was observed, but it is unclear what role direct predation plays in determining mouse abundance relative to risk effects.

Successful translocation of the threatened New Zealand root-holoparasite Dactylanthus taylorii (Mystropetalaceae)

The conservation and translocation of threatened holoparasitic flowering plants provide added challenges due to their complete host dependency and often large knowledge gaps of their autecology. Here, we present the first successful, quantified field trial to establish from seed populations of dactylanthus (Dactylanthus taylorii, Mystropetalaceae), a threatened New Zealand endemic root-holoparasitic angiosperm. Establishment was monitored at four sites at Waipapa, Pureora Forest Park. The impact of two different sowing methods (broad- and central-sown), canopy state (as a proxy for soil moisture levels) and three dominant host species were tested. Establishment of dactylanthus was confirmed in 22 out of 24 plots 10 years after sowing, with earliest emergence after 4 years. Average and maximum inflorescence numbers per plot were similar to those of protected wild populations. The only open-canopy site performed worse in comparison with a closed-canopy site sharing the same dominant host species; differences in root availability and survival of the desiccation-sensitive seeds were regarded as the most likely explanations. Host species dominance had a significant impact on inflorescence numbers, indicating host preference in the species despite a wide host range. In contrast to longer-established wild populations, most of which are male-biased, female inflorescences strongly outnumbered males, considered as evidence of environmental sex determination and sex-switching of individuals. Findings from this study have increased our knowledge of the biology of dactylanthus, confirmed translocation as an effective tool in the conservation of the species and should be applicable for the protection of threatened parasitic plants species elsewhere in the world.

Nontarget mortality of New Zealand lesser short-tailed bats (Mystacina tuberculata) caused by diphacinone.

Primary and secondary poisoning of nontarget wildlife with second-generation anticoagulant rodenticides has led to restrictions on their use and to increased use of first-generation anticoagulants, including diphacinone. Although first-generation anticoagulants are less potent and less persistent than second-generation compounds, their use is not without risks to nontarget species. We report the first known mortalities of threatened New Zealand lesser short-tailed bats (Mystacina tuberculata) caused by diphacinone intoxication. The mortalities occurred during a rodent control operation in Pureora Forest Park, New Zealand, during the 2008-09 Austral summer. We observed 115 lesser short-tailed bat deaths between 9 January and 6 February 2009, and it is likely that many deaths were undetected. At necropsy, adult bats showed gross and histologic hemorrhages consistent with coagulopathy, and diphacinone residues were confirmed in 10 of 12 liver samples tested. The cause of mortality of pups was diagnosed as a combination of the effects of diphacinone toxicity, exposure, and starvation. Diphacinone was also detected in two of 11 milk samples extracted from the stomachs of dead pups. Eight adults and 20 pups were moribund when found. Two adults and five pups survived to admission to a veterinary hospital. Three pups responded to treatment and were released at the roost site on 17 March 2009. The route of diphacinone ingestion by adult bats is uncertain. Direct consumption of toxic bait or consumption of poisoned arthropod prey could have occurred. We suggest that the omnivorous diet and terrestrial feeding habits of lesser short-tailed bats make them susceptible to poisoning with the bait matrix and the method of bait delivery used. We recommend the use of alternative vertebrate pesticides, bait matrices, and delivery methods in bat habitat.

Physical damage by litterfall to canopy tree seedlings in two temperate New Zealand forests

Abstract. The importance of litterfall as an agent of physical damage and mortality to canopy tree seedlings was investigated in two New Zealand forests: Huapai Scientific Reserve, a warm temperate forest and Pureora Forest Park, a cool temperate forest. 200 natural seedlings within the 10–30 cm height class and 200 artificial seedlings, made from plastic straws and wire, were monitored at 4–6 week intervals over two years in each forest. Litterfall was the cause of a significant proportion of seedling mortality in each forest (11–18%).Seedling growth rates were measured and used to estimate the mortality that a cohort of seedlings may suffer due to litterfall in the time taken to grow through the 10–30 cm height class. Up to 38% mortality due to litterfall may occur to such a cohort at Huapai and up to 29% at Pureora.Although mortality due to litterfall of natural seedlings was similar in both forests, damage at Huapai (7%/yr) was almost 3 × greater than at Pureora (2.5%/yr) (P < 0.001). Artificial seedlings were damaged due to litterfall at almost five times the rate at Huapai (16%/yr) than at Pureora (3%/yr) (P < 0.0001). The rate of damage to artificial seedlings at Pureora is similar to that reported for a Northern Hemisphere temperate forest, however, the rate of damage to artificial seedlings at Huapai is much greater, and of a similar rate to those reported from tropical forests. The evolutionary and ecological implications of the differences between the rates of damage at Huapai and at Pureora, and the mechanisms promoting litterfall damage to seedlings, are discussed.

Population biology of the ship rat and Norway rat in Pureora Forest Park, 1983–87

Populations of ship rats (Rattus rattus) and Norway rats (R. norvegicus) were sampled over the five years 1983–87 at Pureora Forest Park, by Fenn and rat kill‐traps every three months. Fenn and rat traps recorded similar capture rates in comparable habitats, although Fenns caught more heavy and fewer young rats. Ship rats (n = 1793 collected) were more abundant, heavier and larger in native forest, regardless of logging history, than in exotic forest of any age. Young ship rats (age classes 1–3) were most abundant in unlogged interior native forest, and in autumn and winter after summer and autumn breeding. Capture rates declined after peaking in 1985, probably due to reduced recruitment of young rats following lower pregnancy rates in adult females. The irregular annual seasonal cycle of reproduction and abundance observed at Pureora is the same as that described for non‐commensal ship rat populations elsewhere in New Zealand and the world. Thirty five of 43 Norway rats collected came from a single trap by the Waipapa Stream, apparently set near a permanent colony. Pregnant female Norway rats were trapped in every season, suggesting year‐round breeding. This implies that both species can recover rapidly after control operations conducted at any time of year, but especially in spring and summer. Future research should include manipulative exploration of factors limiting ship rat abundance and Norway rat distribution.

Sustainability of Beilschmiedia tawa-Dominated Forest in New Zealand: Population Predictions Based on Transition Matrix Model Analysis

Beilschmiedia tawa (Lauraceae) is a common canopy tree which is often dominant in lowland forests in the North Island and northern South Island of New Zealand. The sustainability of B. tawa-dominated forests was investigated at Pureora Forest Park, west of Lake Taupo, central North Island, where a range of sites with different extents of disturbance by logging was studied. Demographic studies-estimates of seedfall, recruitment, growth, and mortality rates-yielded data for life history tables. Based on these, Leslie matrix models were used to determine the rate of increase of five populations. Of these, three logged populations were apparently declining, whereas unlogged forest showed moderate population increase. These population studies suggested that B. tawa is a K-selected species capable of regeneration only within forest. The smaller size-classes are shade tolerant and stems accumulate in the stripling size-class. High light conditions are needed for growth from this class to the sapling class.

A 426-year floating tree-ring chronology fromPhyllocladus trichomanoidesburied by the Taupo eruption at Pureora, central North Island, New Zealand

Abstract This paper presents a 426-year chronology, developed from Phyllocladus tnchomanoides D.Don cross-sections preserved in a forest buried by the Taupo eruption (c. A.D. 186) at a site in Pureora Forest Park, Central North Island, New Zealand. The chronology statistics are compared with those from four contemporary sites representing a wide range of latitudes and altitudes. The modern site most closely resembling the buried forest in these parameters was one nearby at Waihora lagoon. The large amount of common variance in the chronologies, and significant correlations between trees from both the buried forest and Waihora lagoon sites, indicate good potential for palaeoclimatic reconstruction. The stage of formation of the incomplete outer ring observed in wood from the buried forest chronology indicates that the Taupo volcano erupted in late summer or early autumn.