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    New Zealand isopollen and isochrone maps : an integrative approach to reconstructing the paleoenvironment since the last glacial maximum : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Geography at Massey University, Palmerston North, New Zealand
    (Massey University, 2002) Tinkler, Robert John
    series of isopollen and isochrone maps for New Zealand since the Last Glacial Maximum (LGM) is presented; these maps suggest likely paleovegetation patterns in New Zealand since the LGM. To the best of my knowledge, they are the first constructed for any region in the Southern Hemisphere. The procedure used to construct the maps was unique in a number of ways. Contouring was predominantly acheived using kriging techniques on a computer package rather than manual contouring, which has been the norm in other regions. An integrative approach was used; marine microfossil data was utilised to derive paleo-sea surface temperatures which, when combined with faunal freezing temperatures, yielded a priori theoretical altitudinal limits for selected taxa to augment the fossil pollen data. Terrestrial macrofossil data was used to evaluate the resultant maps. Paleo-shorelines, also derived from macrofossil studies, are shown. Paleo-shorelines are important in that coastal areas may have served as refugia during, and migration routes after, the LGM. The resultant maps show that an integrative approach was generally successful. The maps give a more holistic view of New Zealand's paleoenvironment than is possible from studying individual fossil pollen diagrams, and some interesting conclusions are reached. The southern limit of continual forest in the late glacial period may have been 2° south of commonly accepted limits. The existence of a Younger Dryas-synchronous cooling in New Zealand is shown to be unlikely from a palynological perspective.
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    The late Holocene vegetational and climate history of Western Hawkes Bay : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Quaternary Science at Massey University
    (Massey University, 1998) Hannan, Colleen Therese
    Sediments from (a) a flush, two peat mires and two ponds from a 94 km transect along the Mohaka Fault trace (a northern extension of the Wellington Fault) set in the eastern foothills of the Ruahine Range, in western Hawkes Bay, New Zealand, and (b) from a lake at Te Pohue in northwestern Hawkes Bay, are analysed for their pollen and charcoal records to reconstruct the late Holocene vegetational and climatic history of the region. Western Hawkes Bay lies westward of an obliquely converging plate boundary, the Hikurangi Trough. This oblique convergence has resulted in tectonic strain being partitioned into domains of extension, contraction and strike-slip across Hawkes Bay. Within the study area, strain has resulted dominantly in primary tectonic landforms such as fault scarps and fault lines, and secondary tectonic landforms such as tilted and folded surfaces. Features of movement along the Mohaka Fault in the geomorphology include right-laterally offset streams, ridges with distinctive linear troughs along the line of the fault and the formation of triangular spurs. The region generally has a warm, dry climate, and suffers from drought periodically, with the drought often being broken by heavy rains in the autumn. These rains may be of cyclonic proportion. Due to both seismic and co-seismic activity in the region, the landscape is both uplifted and broken, and continually subject to mass movement; localised topoclimates are also common. This study determines how the western Hawkes Bay vegetational cover and its composition have changed in response to late Holocene climate changes through analysis of sediment cores. Also addressed is the extent to which tectonism, volcanicity, fire, major storm events and human activity have left a local overprint on the regional vegetational pattern. Climatically the region may be divided into three sectors: a dry central sector, (Big Hill site); flanked by moister southern and northern sectors. The regional vegetation in the southern sector was dominated by a Nothofagus- mixed podocarp forest in the Kashmir region from c. 800 yrs BP. up to when the site was affected by fire in 1888. In the Hinerua region, 14 kms farther north, Nothofagus fusca with a minor Dacrydium cupressinum-dominated/ mixed podocarp forest, was established by c. 2790 yrs BP. The regional vegetation of the central sector from c. 3700 to 3000 yrs BP. was predominantly a Prumnopitys taxifolia/mixed podocarp forest. There was also a notable Nothofagus component. There is a c 1900 year hiatus in the vegetation record between c. 3000 and 1150 yrs BP when no sediment accumulated at the Big Hill site. The regional forest of the central sector at c. 1150 yrs BP. was still a predominantly Prumnopitys taxifolia-dominated/mixed podocarp forest. However, Nothofagus was less important in this latter forest. At Willowford, 18 kilometres north of Big Hill, the same Prumnopitys taxifolia -dominated/mixed podocarp forest was evident at about 500 yrs BP. At Hawkstone, 10 kms north of Willowford, a Nothofagus/ P. taxifolia-dominated mixed podocarp forest was established by 6500 yrs BP. About 3400 yrs BP Dacrydium cupressinum became the dominant podocarp, thus placing the Hawkstone region within the northern climatic sector from this date, up to the present. The regional vegetation of the northern sector from 1850 yrs BP. until European land clearance in the late 19th century at Te Pohue, was a Dacrydium cupressinum -dominated/mixed podocarp assemblage with a notable Prumnopitys taxifolia component. Several erosional events have been identified in the stratigraphy of the sites. By estimating the age of these events by sediment accumulation rates, some of these events have been tentatively linked to Grant's (1985) hypothesis of periodic climate-forced erosional events having partially destroyed the forest cover in the western Hawkes Bay region. Using radiocarbon dates from this study, often in conjunction with sediment accumulation rates, it has been possible to identify some erosional events as earthquake generated by linking these events to other known and radiocarbon dated movements along the Mohaka Fault trace in western Hawkes Bay. Volcanicity has been identified as a factor influencing forest cover in the northern pari of western Hawkes Bay. At Hawkstone, microscopic charcoal has been identifed at several levels throughout the 6500 year pollen record of the site. However, the sediment accumulation rate was too low to determine the exact nature of the disturbance, and the forest quickly recovered in each case. Although a 0.20 m layer of reworked lapilli from the Waimihia eruption (3280 ± 20 yrs BP.) was recorded at the site, no fire or disturbance to the vegetation was recorded. However, above the Taupo Tephra (1850 ± 10 yrs BP.) fire is continually recorded at the site. As a result the regional forest did not return. Primary ignimbrite from the Taupo eruption forms the base of the Te Pohue site. The regional forest was destroyed by fire in conjunction with this event. A similar forest to before the event, was re-established within c. 230 years. Polynesian deforestation is identified by the advent of high frequencies of Pteridium exculentum and microscopic charcoal in the pollen record in the Willowford region c. 480 ± 170 yrs BP., and in the Big Hill region c. 435 ° 140 yrs BP.; and are coincident with the decline of indigenous forests in each case. European settlement, commencing in the mid-nineteenth century at Te Pohue and about 1880 AD. at Hinerua, is identified by the decline of indigenous forests in these areas, coincident with the appearance of exotic pollen types such as Pinus. Taraxacum and pasture grasses.
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    Palaeoecology by palynology : a palaeoecological study of the vegetation of the Tongariro Volcanic Centre, New Zealand, immediately prior to the c. 232 AD Taupo eruption : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Plant Biology at Massey University
    (Massey University, 2001) Banks, Natalie Jane
    The usual source of pollen for analysis has been from within deposits of peat from lakes, bogs and mires. Soils have not generally been considered a potentially useful pollen source. Under some circumstances, however, (such as volcanic eruptions) a soil may be buried so rapidly that the pollen it contains will be more or less completely preserved in the resulting palaeosol. Studies of such volcanically buried palaeosol pollen have been made overseas. The last eruption from the Taupo Volcanic Centre occurred approximately 1800 years ago. The culminating phase of the eruption ejected ca 30 cubic kilometres of ignimbrite as a very hot and fluid pyroclastic flow which covered an area with a radius of 70-90 km centred on Lake Taupo. This deposit is known as the Taupo Tephra. The purpose of the present investigation was to examine peats and palaeosols directly beneath the Taupo Tephra from a variety of sites within the Tongariro area and to analyse any pollen preserved. Samples were taken from a total of 42 sites at various altitudes and distances from the eruptive source, and pollen extracted. Each sample taken, therefore, was from a buried soil or peat directly below the Taupo Tephra. The pollen contained within these samples and contains pollen deposited immediately prior to the eruption. An initial qualitative investigation indicated that the ignimbrite acts as an effective filter in preventing any contemporary pollen and spores from percolating through into underlying layers. The preservation of pollen was reasonably good at most sites allowing some conclusions to be drawn as to the structure and composition of the pre-eruption forests of the Tongariro area. Beech forest was widespread throughout, especially at higher altitudes, although mixed conifer associations were also evident, particularly in the west. At those sites where pollen preservation was poor, some alternative conclusions can be drawn about preservation environments within palaeosols. The pH value is particularly important, and pollen and spores are not well preserved when the soil pH value is in excess of 6.0. The possibility of differential preservation within the New Zealand flora is also examined.
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    A high resolution record of late quaternary climatic and environmental change in Taranaki, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Earth Science at Massey University, Palmerston North, New Zealand
    (Massey University, 2013) Tinkler, Robert John
    A high-resolution characterisation of climatic and environmental change in Taranaki, New Zealand over the last 80,000 years using biotic and abiotic proxies is presented. This research contributes to the small set of sediment cores that extend from the present back through the Last Glacial Maximum (LGM) in the southern North Island, and adds to the small number of near-continuous cores in New Zealand. Fossil pollen data presented here provides a record of vegetation changes in response to climate change (temperature, wind and rainfall). In addition, the project applies a recently developed pollen temperature transfer function (Wilmshurst et al. 2007) to quantify, for the first time, temperature change across the entire LGM in this region, and elucidates the timing of Late Quaternary New Zealand climatic events and phases. Climate change timing and magnitude is tested against the climate event stratigraphy (CES) developed by the NZ-INTIMATE (INTegration of Icecore, Marine and Terrestrial archives) group (Alloway et al. 2007), including: Last Glacial Coldest Period (LGCP); the mid-eLGM Interstadial; the Last Glacial-Interglacial Transition (LGIT); Termination I; the Antarctic Cold Reversal (ACR); the Late-Glacial Warm Period (LGWP), the Late-Glacial Reversal (LGR); and Early Holocene Warming (EHW). During the Moerangi Interstadial between 40,000 and 30,000 cal yrs BP, both the Eltham and coastal Taranaki pollen records show that cold-climate taxa such as Nothofagus menziesii, Nothofagus subg. Fuscospora, Hoheria, Plagianthus, Phyllocladus and Poaceae dominated the pollen assemblage. In addition to being cold, low numbers of fern and tree fern spores imply that conditions were drier than present. The LGCP at Eltham (29,000 – 18,000 cal yrs BP) began around 1,200 years earlier than similar records from elsewhere in New Zealand. Transfer functions suggest that mean annual temperatures at the LGCP/ LGM at Eltham were 5.7°C cooler than present. Within the LGCP, the mid-eLGM Interstadial described in similar records from New Zealand seems to be evident in the W-MAT-derived temperature curve at Eltham, where warming of around 0.8°C occurs between 27,000 and 24,500 cal yrs BP. The LGIT appears to have begun around 18,000 cal yrs BP and concluded around 14,600 cal yrs BP at Eltham, which agrees well with speleothem data from Northwest Nelson, but is more short-lived than at Otamangakau Bog where the LGIT is thought to have persisted for another 1,500 years. A period of sharp cooling inferred from the Eltham pollen record between 16,600 and 15,000 cal yrs BP, when mean annual temperature fell between 1°C and 4°C from the previous period, is matched in time, but not in intensity at some other western and central North Island, and some South island sites, and may be a sampling artefact. The LGWP duration at Eltham (14,600 – 13,500 cal yrs BP) broadly corresponds with NZ-INTIMATE and Northwest Nelson estimates of 14,800 – 13,500 cal yrs BP; mean annual temperatures at Eltham came within 0.6°C of modern-day mean annual temperatures at this time. The timing of the LGR at Eltham shows good agreement with NZ-INTIMATE estimates (Alloway et al. 2007; Lowe et al. 2008), that is, from around 13,500 to 12,500 cal yrs BP. The LGR onset at Eltham preceded onset at the Auckland maars by 600 years and concluded 1,500 years earlier than at Auckland; mean annual temperature at Eltham at this time was approximately 2°C cooler than the present day MAT of 11.2°C. The EHW event commenced at Eltham around 12,500 cal yrs BP, around 1,000 years earlier than at Kaipo Bog, Otamangakau Bog; and largely synchronous with the Auckland maars and Okarito. Pollen records from coastal Taranaki sites span d18O Stage 5a (Otamangakau Interstadial, c. 80,000 yrs BP) through to d18O Stage 2 (Last Glacial-Interglacial Transition, c. 18,500 cal yrs BP), and encompass the stadial complex between these two interstadials (d18O Stage 4, c. 70,000 – 60,000 yrs BP). These records contribute to the small number of pollen-based paleoenvironmental and paleoclimatic narratives for New Zealand extending from the LGIT to the Otamangakau Stadial (d18O stage 5a) time periods. A major contribution of the current A High Resolution Record of Late Quaternary Climatic and Environmental Change in Taranaki, New Zealand study is to reconstruct and characterise d18O stage 5a and d18O stage 4 temperatures based on two pollen transfer functions developed by Wilmshurst et al. (2007). During d18O Stage 5a around 80,000 cal yrs BP, conditions were warmer and wetter than the succeeding glacial. d18O Stage 4 and the early part of d18O Stage 3 were cool with relatively low precipitation and were likely to have been windy at coastal Taranaki sites. Although d18O Stage 4 was cool, it was not as cold as the LGM: pollen transfer functions showed decreases in estimated mean annual temperature from d18O stage 5a, with mean annual temperatures falling around 2°C to reach 7°C. Precipitation likely decreased during d18O stage 4, as indicated by low levels of drought-intolerant taxa Dacrydium cupressinum, Cyathea smithii, and monolete spores, whilst low shrub diversity implies that disturbance was likely to have been low. During early d18O stage 3, the climate warmed and became wetter in coastal Taranaki, as indicated by increasing conifer abundance; in particular Dacrydium cupressinum, high abundance of Cyathea smithii, and a decline in cold-tolerant Nothofagus, Halocarpus, Asteraceae, and Poaceae after 60,000 yrs BP. These conditions persisted for < 5,000 years before temperatures decreased again, then between 50,000 and 40,000 yrs BP the decline in Poaceae and cold-tolerant shrubs Phyllocladus, Halocarpus and Asteraceae, as well as the sharp rise in tall tree conifers, all point to climate amelioration. Conditions were still relatively cool; although pollen transfer functions imply that that mean annual temperatures increased slightly, with mean annual temperature estimates fluctuating between 7°C and 8°C, this was approximately 3 to 4°C cooler than present. For the first time in New Zealand, aerosolic quartz dust was extracted from organic sediments; this peat-derived data informs a paleowind narrative for Taranaki. The technique used in the current study to extract quartz from peats can be considered successful, insofar as relatively pure samples of quartz could be isolated in sufficient mass to be able to measure them, and relate the data to the age model and the coeval pollen influx. The paleowind reconstructions from Eltham can be summarised as follows: strong winds dominated between 36,200 and 35,100 cal yrs BP, 30,746 and 32,101 cal yrs BP, 28,364 to 17,477 cal yrs BP, and 16,118 to 15,806 cal yrs BP. Intermediate winds occurred between 30,746 and 28,364 cal yrs BP, 17,477 and 16,118 cal yrs BP, and 15,619 to 14,916 cal yrs BP; winds of light intensity dominated between 34,777 and 32,101 cal yrs BP and 14,916 and 9,900 cal yrs BP. Major dust peaks at 31,358 cal yrs BP; 21,300 cal yrs BP and 15,955 cal yrs BP all correlated well with the Vostok ice core as well as marine core P69 (Stewart & Neall 1984), and Onaero and Waitui in northern Taranaki. Similarly, dust minima after about 15,000 cal yrs BP at Eltham, Vostok, marine core P69, Onaero, and Waitui suggests that the quartz dust signature at Eltham is consistent with both global and regional estimates of dust influx as the atmospheric dust load responded to changes in wind direction and strength, in particular the intensity of westerly winds, and changes to sediment source area characteristics such as vegetation cover. Combining fossil pollen data and aerosolic quartz dust results is a new technique to investigate the relationship between wind intensity, temperature and plant assemblages. The Eltham fossil pollen and aerosolic quartz data was analysed to determine how the relative proportions of competitive, stress tolerant and ruderal taxa respond to winds of differing intensities over time, as well as quantifying the impact of wind of different intensities on plant diversity over the period 36,200 to 9,900 cal yrs BP. In essence, competitor, C-selected taxa increased in relative abundance, and stress-tolerant, S-selected and ruderal, r-selected taxa decreased over the last 15,000 years at Eltham, as both temperature and wind intensity ameliorated. Wind data was examined against pollen diversity data to test the Intermediate Disturbance Hypothesis (IDH) in the vegetation of the Taranaki region. A moderate relationship between floral diversity and dust flux was found, with periods of high and low dust flux corresponding to lower diversity, and periods of intermediate dust flux corresponding to higher diversity, as predicted by the IDH.