Tararua Range Research Articles

Eight new species of the genus Nesamblyops Jeannel (Anillini: Carabidae: Coleoptera) from New Zealand with notes about dispersal of the genus to the North Island

Species of flightless litter ground beetles of the tribe Anillini, genus Nesamblyops, from the North Island and from the north-eastern part of the South Island are revised. Eight new species are described and one previously known species, Nesamblyops oreobius (Broun), is re-described. Nesamblyops oreobius, the only hitherto recorded species from the North Island, is most similar to the group of two new species from the South Island, N. confusus n. sp. (type locality: New Zealand, Marlborough Sounds, Mount Stokes) and N. lescheni n. sp. (type locality: New Zealand, Marlborough Sounds, D'Urville Island), based on the structure of the male genitalia. The second species of the genus known from the North Island, N. tararua n. sp. (type locality: New Zealand, Wellington, Tararua Range) represents another lineage, based on the structure of the male genitalia, and is closely related to a group of three new species from the South Island, N. brouni n. sp. (type locality: New Zealand, Canterbury, Southern Alps, Lewis Pass), N. distinctus n. sp. (type locality: New Zealand, Marlborough, Richmond Range, Fabians Valley), and N. townsendi n. sp. (type locality: New Zealand, Marlborough Sounds, Tennyson Inlet). Nesamblyops carltoni n. sp. (type locality: New Zealand, Nelson, Richmond Range, Dun Mountain) and N. parvulus n. sp. (type locality: New Zealand, Marlborough Sounds, Mount Stokes), both from the South Island occupy an isolated position among the examined species. All species are illustrated with digital images of habitus, body parts, and drawings of genitalia. Distribution maps for all species are also provided. Geographical evidence of Nesamblyops dispersal to the North Island is discussed, based on distributional data.

Phylogeography reveals a North Island range extension for New Zealand's only sexually wing-dimorphic stonefly (Stenoperla helsoni)

ABSTRACTStenoperla helsoni is an endemic New Zealand stonefly characterised by distinctive sexually dimorphic wing loss. Previous distribution records indicated that this species was restricted to the South Island's Southern Alps, although our recent collections of wing-reduced specimens from a site in the Tararua Ranges suggest that this species may extend into the lower North Island. We amplified the mitochondrial COI gene to confirm the identity of North Island specimens, and to assess phylogeographic structuring within the species and genus. North Island specimens were confirmed as S. helsoni, indicating that this species has a much wider geographic range than previously thought. This broad distribution, combined with low levels of intraspecific divergence, suggests that female S. helsoni may be strong fliers, despite males being flightless. Distinct North Island and South Island populations were identified, with a 1.5% divergence between the two populations.

Reconstruction and paleoclimatic significance of late Quaternary glaciers in the Tararua Range, North Island, New Zealand

Reconstructed mountain glaciers are routinely used as a proxy for climate in the search for evidence of interhemispheric climate fluctuations during the Quaternary. In New Zealand, valley glaciers at the Last Glacial Maximum (LGM) extended from an ice sheet centred on New Zealand's Southern Alps to below present-day sea level. In contrast, evidence of LGM glacial activity on the North Island is rare. Here, a glacioclimatic reconstruction is presented of two former glaciers in the Tararua Range (41°S) in the southern North Island. At Mt. Aston, an isolated cirque basin contains landform evidence of a marginal niche glacier. At Park Valley, the lateral moraine of a larger cirque glacier has yielded published cosmogenic isotope ages. The paleoglacier reconstruction shows that paleoequilibrium line altitudes increased northwards across New Zealand during the local LGM. Hence, at this latitude only topography >1200 m above present day sea-level was of sufficient elevation to allow small glaciers to form. The Mt Aston glacier covered only 0.18 km2 with an equilibrium line altitude (ELA) of c. 1287 m above present sea level. A mean ELA glacier thickness of c. 25 m gives a basal shear stress at the ELA of c. 100 kPa−1, with a mean summer (December, January, February, DJF) temperature at the ELA of no lower than 5.5 °C below present, below which precipitation would have been insufficient to support the reconstructed glacier. Implied LGM paleo-temperatures from both the ELA reconstruction and the glaciological reconstruction broadly accord with other paleo-temperature proxies from the North Island. Park Valley glacier covered c. 0.45 km2 with an ELA of c. 1270 m and a mean ELA basal shear stress of 65 kPa. Its balance discharge was 9 × greater than at Mt Aston. It appears to have been glaciologically viable across a wide range of paleotemperatures: thus, the more marginal glacier is a more useful paleoclimatic indicator because it places a maximum limit on LGM temperature depression, which the larger glacier does not. ELAs of both glaciers closely approximate the regional LGM ELA trend surface. The paleo-glacier reconstructions imply that together with temperature driving LGM paleo-ELA depression, changes in south-westerly airflow over New Zealand, bringing moisture-laden but cool air, maximized snowfall and minimised winter melt. The corollary is that patterns of Quaternary glacier fluctuations may be interpreted as responses, at least in-part, to precipitation-driven changes, and secondly, North Island glaciation was probably more extensive than previously assumed.

DNA sequence analysis confirms the identity of the intergeneric hybrid Argyrotegium mackayi × Leucogenes leontopodium (Asteraceae: Gnaphalieae)

DNA sequencing of the nuclear internal transcribed spacer (ITS) and plastid trnK intron confirms that wild intergeneric hybrids between Argyrotegium mackayi and Leucogenes leontopodium occur in the Tararua Range of the North Island of New Zealand. Both parent species belong to the tribe Gnaphalieae (Asteraceae), already known in New Zealand for numerous intergeneric hybrid combinations. However, an Argyrotegium × Leucogenes hybrid is an especially wide cross within this group. In keeping with the presumed breeding biology of the two parent species, plastid DNA sequences indicate A. mackayi as the maternal parent of the sequenced sample.

The Wairarapa region

Wai'ra'rapa - The place Maori called "Land of Glistening Waters". Wairarapa is a region of big skies, wide valleys rolling hill country and rugged coastline. It has a total land area of 8423 square kilometres. The region is named after Lake Wairarapa, which situated at the bottom of the Wairarapa Plain, North of Palliser Bay. Wairarapa is located on the South Eastern Corner of the North Island bounded by the Pacific Ocean in the East, Tararua district in the North and the Tararua Ranges in the west.

SAHKE geophysical transect reveals crustal and subduction zone structure at the southern Hikurangi margin, New Zealand

The Seismic Array Hikurangi Experiment (SAHKE) investigated the structure of the forearc and subduction plate boundary beneath the southern North Island along a 350 km transect. Tomographic inversion of first‐arrival travel times was used to derive a well‐resolved 15–20 km deep P wave image of the crust. The refracted phases and migrated reflection events image subducting slab geometry and crustal structure. In the west, Australian Plate Moho depth decreases westward across the Taranaki Fault system from 35 to ∼28–30 km. In the east, subducted Pacific Plate oceanic crust is recognized to have a positive velocity gradient, but becomes less distinct beneath the Tararua Ranges, where the interface increases in dip at about 15 km depth from <5° to >15°. This bend in the subducted plate is associated with vertical clusters in seismicity, splay fault branching, and low‐velocity high‐attenuation material that we interpret to be an underplated subduction sedimentary channel. We infer that a step down in the decollément transfers slip on the plate interface at the top of a subduction channel to the oceanic crust and drives local uplift of the Tararua Ranges. Reflections from the Wairarapa Fault show that it is listric and soles into the top of underplated sediments, which in turn abut the Moho of the overriding plate at ∼32 km depth, near the downdip end of the strongly locked zone. The change in dip of the Hikurangi subduction interface is spatially correlated with the transition from geodetically determined locked to unlocked areas of the plate interface.

A Relict Pronival (Protalus) Rampart in the Tararua Range, North Island, New Zealand

ABSTRACTDebris ridges in New Zealand are routinely assumed to be ‘moraines’ and used as key Southern Hemisphere paleoclimatic sites without detailed evaluation of ridge origin. Here we assess the origin of a debris ridge adjacent to Dundas Ridge in the Tararua Range, North Island, New Zealand, through measurements of ridge morphology and sedimentary properties. The ridge has a steep c. 35° distal slope (height 18 m), compared with the c. 19° proximal slope (height 6 m), and on all transects the distal slopes contain the coarsest material (median b‐axis clast widths of 0.18‐0.25 m), compared to distal samples (0.34‐0.37 m). Clast shape (C40 range 40‐60%) and angularity (RA>65%) indicate typically angular and ‘slabby’ clasts, and along with the lack of fines, and the ca. 40‐m‐distance between the ridge crest and the foot of the backwall, lead us to reject a glacial (moraine) origin for the ridge. The single ridge morphology precludes a protalus rock glacier origin, while the lack of a broad hillslope scar and debris apron beyond the ridge excludes a landslide origin. Instead, we interpret the ridge as a pronival (protalus) rampart formed by supranival debris supply–from the ca. 200 m‐high southeastern slopes of Dundas Ridge–across a snowbed. Re‐distribution of snow by prevailing westerlies from Mt Dundas Ridge into the basin would have nourished the snowbed, which is likely to have formed during the interval 24‐18 ka BP, when a minor alpine‐style glaciation affected sectors of the Tararua Range. This is the first pronival rampart detailed in New Zealand, raising the possibility that debris ridges of pronival origin may also be present elsewhere in New Zealand's mountains. Copyright © 2012 John Wiley & Sons, Ltd.

G. Leslie Adkin (1888–1964) and glaciation of the Tararua Range, North Island, New Zealand

Research initiated in 1909 by G. Leslie Adkin (1888–1964) suggested that the central Tararua Range on the North Island, New Zealand, was subjected to only limited alpine-style glaciation during the Late Pleistocene. This was based on the ‘U-shaped’ cross-profiles in the uppermost parts of several valleys, and cirque basins. Findings were published in Transactions of the New Zealand Institute, but were not met with universal acceptance by luminaries such as Charles Cotton. Adkin’s work remained the only published glacial research undertaken on the North Island’s axial ranges until the latter part of the 20th century. Adkin holds a special position in New Zealand science, because although he worked full-time as a farmer he published nearly 40 articles in scientific journals on topics as varied as Māori archaeology and geoscience.

Lateral moraine age in Park Valley, Tararua Range, New Zealand

Recent geomorphologie and sedimentologic investigations in Park Valley, in the central Tararua Range, have identified several landforms of glacial erosion and deposition, including cirque basins, a U‐shaped glacial valley, and a lateral moraine ridge. The presence of Kawakawa tephra (Aokautere Ash) within loess c. 50 cm beneath the surface of the moraine has indicated that the moraine was formed prior to 27 ka, suggesting late MIS 3 glaciation in this sector of New Zealand. However, recently published 10Be cos‐mogenic dates from glacially‐scoured bedrock and an erratic block on the surface of the moraine indicate that glaciation was much later, the corollary being that the Kawakawa tephra has been re‐distributed post‐eruption, perhaps from the ridgelines surrounding the moraine. Here, two optically‐stimulated luminescence ages on the loess are reported that suggests most of the moraine was formed during late MIS 3 or early MIS 2, and that a readvance at c. 17.7–18.7 ka extended as far as the moraine.

First cosmogenic 10Be constraints on LGM glaciation on New Zealand's North Island: Park Valley, Tararua Range

AbstractWe report the first direct ages for late Quaternary glaciation on the North Island of New Zealand. Mt Ruapehu, the volcanic massif in the North Island's centre, is currently glaciated and probably sustained glaciers throughout the late Quaternary, yet no numeric ages have been reported for glacial advances anywhere on the North Island. Here, we describe cosmogenic 10Be ages of the surface layers of a glacially transported boulder and glacially polished bedrock from the Tararua Range, part of the axial ranges of the North Island. Results indicate that a limited valley glaciation occurred, culminating in recession at the end of the last glacial coldest period (LGCP, ca. 18 ka). This provides an initial age for deglaciation on the North Island during the last glacial–interglacial transition (LGIT). It appears that glaciation occurred in response to an equilibrium‐line altitude (ELA) lowering of ∼1400 m below the present‐day mean summer freezing level. Ages for glaciation in the Tararua Range correspond closely to exposure ages for the last glacial maximum (LGM) from the lateral moraines of Cascade Valley in the South Island, and in Cobb Valley, in northern South Island. The corollary is that glaciation in the Tararua Range coincided with the phase of maximum cooling during MIS 2, prior to the Antarctic Cold Reversal (ACR), during the LGCP. Copyright © 2008 John Wiley & Sons, Ltd.

A debris ridge in Park Valley, Tararua Range, New Zealand, as evidence for pleistocene glaciation

Geomorphologic and sedimentologic investigations in Park Valley, Tararua Range, have identified the presence of a lateral moraine toward the head of the valley. This section of Park Valley is U‐shaped, southwest facing with the elongate ridge situated on the true right (northwestern) side of the valley. A variety of approaches is used to test the possible process origins of the ridge, including topographic and spatial positioning, sedimentology, and paleoclimatic extrapolations. Results indicate the ridge consists of glacial diamict deposited as a lateral moraine, supporting recent hypotheses about late Pleistocene glaciation and erosional development of valleys and cirques of this sector of the range.

George Leslie Adkin (1888-1964): glaciation and earth movements in the Tararua Range, North Island, New Zealand

Abstract In the northern hemisphere the broad extent of glaciation had been mostly accepted by the start of the twentieth century, but in New Zealand at that time even the general picture of glaciation was uncertain. Julius von Haast had established that in the South Island the glaciers had extended out considerably from the Southern Alps, but the extent of glaciation in the North Island was unknown. Two rival viewpoints were put forward in 1909. James Park thought that there was a widespread ice sheet, which covered the South Island, Cook Strait and much of the North Island; Patrick Marshall thought that the extent of ice was much less, and argued that much of Park's evidence was spurious. The argument was ‘somewhat resolved’ by a young amateur geologist, Leslie Adkin, who showed that glaciation in the North Island was at most modest, and largely confined to the uppermost part of the main axial ranges. Adkin was a farmer and had no university education, but he published nearly 40 articles in scientific journals on topics as varied as Maori archaeology, and glacial and tectonic geomorphology. This article examines the evidence he adduced for the occurrence of a limited Pleistocene glaciation in the Tararua Range in the south of the North Island, and considers the role of the amateur in New Zealand geology.

The geomorphic work of George Leslie Adkin (1888–1964) and glaciation in the Tararua Range, North Island, New Zealand

Abstract: Research initiated in 1909 by G. Leslie Adkin (1888–1964) suggested Park Valley in the Tararua Range was glaciated during the Late Quaternary, based on the ‘U‐shaped’ cross‐profiles in the uppermost parts of several valleys. Findings were published, but were not met with universal acceptance. Adkin's work remained the only glacial research undertaken on the North Island's axial ranges until the latter part of the 20th century. Adkin holds a special position in New Zealand, because although he worked full‐time as a farmer he published nearly 40 articles in scientific journals on topics as varied as Māori archaeology and geomorphology.

Valley cross‐profile morphology and glaciation in Park Valley, Tararua Range, New Zealand

Previous anecdotal research by G. L. Adkin over 90 years ago suggested that Park Valley in the Tararua Range was glaciated during the Late Quaternary, on the basis of the “U‐shaped” cross‐profile character of the uppermost parts of the valley. We quantitatively describe the cross‐profile morphology of the upper parts of Park Valley in the Tararua Range, using the power‐law model (y = axb ) and the form ratio model (FR = D/2W). Comparison of these results with morphological data published in global studies of glaciated landscapes suggests the upper parts of Park Valley have indeed been glaciated. Palaeoglacier reconstruction of this area gives a surface area of c. 1.41 km2, a maximum thickness of 130 m and a maximum basal shear stress value of 99 kPa. The equilibrium‐line altitude of the former glacier has been calculated as c. 1210 m, and with the absence of any dated moraines, the glacier is assumed to have formed during the Otira Glaciation.

Valley morphology and glaciation in the Tararua Range, southern North Island, New Zealand

An empirical evaluation of valley cross‐profile morphology using 1:50 000 scale topographic maps is performed on four valleys in the Tararua Range (southern North Island) to determine possible glacial influences on valley development. Power‐law (y = axb ) and quadratic equations (y = a + bx + cx2 ) are fitted to cross‐profiles by statistical regression. Comparison of b exponents and c coefficients from the power‐law and quadratic equations, respectively, with results from areas glaciated during the late Quaternary, indicates a glacial signature on the upper parts of some of the valleys. This supports the hypothesis that the uppermost parts of valleys in the Tararua Range have been fashioned by glacial erosion.

Myrsine aquilonia and M. umbricola (Myrsinaceae), two new species from New Zealand

Myrsine aquilonia and M. umbricola are described as new species from New Zealand. M. aquilonia occurs on the Poor Knights Islands and at several places on the adjacent Northland Peninsula. It is distinguished from the other New Zealand species of Myrsine by an upright growth habit and being up to 12 m tall, spreading branches and branchlets, large‐diameter trunk, often producing suckers from exposed roots near the trunk, and large obovate green leaves with a prominent apical notch. M. aquilonia is considered to have a conservation status of “At Risk (Sparse)” using the New Zealand Threat Classification System, for while abundant on the Poor Knights Islands it is known from only a few plants at the other Northland locations of Tutukaka, Te Arai, and Unahi. Myrsine umbricola is known only from silver beech forest in the Tararua Range, lower North Island, where it is sympatric withM. divaricata. This species forms a small, bushy shrub up to 4 m tall with slender trunks, and has spreading branches and branchlets and shiny, obovate, dark green leaves. M. umbricola is assessed as having a conservation status of “Acutely Threatened (Nationally Endangered)” as it is known from few subpopulations, is restricted to a small geographic area, and appears to have recruitment failure. Myrsine divaricata A.Cunn. and M. ×montana Hook.f. are lectotypified and this hybrid is attributed to M. divaricata × M. salicina.

Flora of New Zealand ‐ Gramineae supplement I: Danthonioideae

The newly erected grass subfamily Danthonioideae encompasses four New Zealand genera viz Chionochloa, Cortaderia, Pyrrhanthera, and Rytidosperma, 43 endemic species comprise it. In Rytidosperma new chromosome counts confirm earlier reports of diploid and hexaploid species and report tetraploids (2n = 48) as an additional level of ploidy. In Pyrrhanthera 2n =, c. 156, which is the highest chromosome number in the subfamily and second highest recorded in the Gramineae. New Zealand species of Cortaderia should not be included in the same clade as South American species according to cladistic analyses of rpoC2 and ITS sequences. Morphologically this separation fails. Monophyletic Chionochloa is generically secure. Earlier data on the triterpene methyl ethers (TMEs) isolated from the epicuticular leaf wax of species of Chionochloa and Cortaderia are interpreted along modern pathways of the biosynthesis of the precursor sterols and triterpenols, and their subsequent methylation. In Chionochloa where 18 taxa in 33 synthesise TMEs mostly as single compounds, dedicated synthases for each of several triterpenoids is indicated. Non‐randomness of TME synthesis is characteristic, but there is no total accord between taxonomic treatment and TME synthesis. Zones of TME‐richness lie in the Tararua and Rimutaka Ranges, southern North Island (6 TMEs), and Canterbury, South Island (5 TMEs).

An Example of the Use of Forensic Palynology in Assessing an Alibi

A man was found shot in the back on Mount Holdsworth in the Tararua Ranges north of Wellington, the capital city of New Zealand. Police investigations pinpointed one individual who had been seen in the area, knew, and had the means and motive to kill the victim. His alibi was that an eyewitness was mistaken as he never had been in the area and the jacket he was reported to have been wearing had been purchased in The Netherlands and brought to Wellington, where it never had left the city. Furthermore the distinctive board shorts that he was reported to have been wearing had been purchased in a small coastal New Zealand town after the victim had been murdered. Pollen of Nothofagus menziesii, a mountain plant, on the clothing suggested that the alibi was untrue and that the clothing had been in mountains in the vicinity of Mount Holdsworth or a similar mountain scene where Nothofagus menziesii was growing.

Use of ISSR profiles and ITS-sequences to study the biogeography of alpine cushion plants in the genus Raoulia (Asteraceae)

Nuclear ITS sequences and ISSR profiles provide evidence that Raoulia rubra is endemic to the Tararua Range in the southern part of the North Island of New Zealand. Populations in the South Island previously ascribed to R. rubra are better ascribed to R. eximia. Our findings suggest that glaciation of the central mountains of the South Island during the last ice age have had a major impact on the evolution of the South Island cushion Raoulia species in New Zealand. However, simple hypotheses accounting for the effect of Pleistocene climate change are insufficient to explain patterns of endemism in the group.

The Manawatu aquifers, North Island, New Zealand: Clarification of hydrogeology using a multidisciplinary environmental tracer approach

AbstractA recently developed approach to carbon isotope methodology (process recognition via isotope diagrams) is applied in a multidisciplinary study of precipitation‐recharged aquifers of the lowlands–plains area of the Manawatu (south‐west North Island). Urban and rural areas rely on groundwater from the upper levels of a deep basin sequence comprising marine and terrestrial sediments of Pleistocene age. Hydrochemical and isotopic (18O, 3H, 13C and 14C) data are merged with known details of geology and hydrogeology to reveal two separate confined aquifers within the depth range to 200 m. The shallower of these, below unconfined, locally recharged groundwater, is recharged on the foothills of the Ruahine Range to the north‐east of the study area; flow direction is NE–SW. The deeper confined aquifer is recharged on the Tararua Range to the immediate east; flow direction essentially is transverse (SE–NW) to that in the shallower aquifer. Two processes are identified as dominant contributors to concentration and isotopic composition of dissolved inorganic carbon (DIC), namely addition of CO2 from decay of organic materials and carbonate dissolution. Limitations of carbon isotope methods in determining residence times are illustrated by the data. Although the confined groundwater is essentially tritium‐free, only a few samples showed conclusive evidence of significant ageing on the time‐scale of 14C. Copyright © 2001 John Wiley & Sons, Ltd.