Terrestrial palynology from marine cores as an indicator of environmental change for the Waipaoa Sedimentary System and north-eastern New Zealand

Mildenhall, Dallas C.; Orpin, Alan R.

doi:10.1016/j.margeo.2009.11.005

Cited by 9 publications

(6 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both records oscillate similarly over time, with more dominant tree ferns spores during interglacial periods and more dominant Asteraceae during glacial periods. Similar trends are recorded in land-ocean comparisons of modern and last glacial age from the New Zealand region (Dunbar et al, 1997;Wilmshurst et al, 1999;Mildenhall, 2003;Wilmshurst and McGlone, 2005;Crouch et al, 2010;Mildenhall and Orpin, 2010). .…”

Section: Marine-terrestrial Core Comparison In Southwestern New Zealandsupporting

confidence: 72%

“…4.15 and 4.18). This preservation bias is recognised in other New Zealand sequences where marine sediments deposited over the last glacial cycle are matched to proximal terrestrial counterparts (Heusser and van de Geer, 1994;Wright et al, 1995;Wilmshurst et al, 1999;McGlone, 2001;Carter et al, 2002;Mildenhall, 2003;Mildenhall et al, 2004;Mildenhall and Orpin, 2010;Ryan et al, 2012). The selective yet important preservation of bisaccate gymnosperm pollen at MD06-2991 may result from their superior hydrodynamic performance, meaning that they stay afloat longer than other pollen morphologies and are thus increasingly dominant in samples further offshore (Chaloner and Muir, 1968;Mudie, 1982;Smirnov et al, 1996;Traverse, 2007;Crouch et al, 2010;Luo et al, 2014).…”

Section: Palynomorph Taphonomy Representivity and Paleovegetation Rec...mentioning

confidence: 90%

“…In addition, the morphology of these grains increases their hydrodynamic performance, enabling them to float for long distances as suspended sediment and therefore avoid mechanical abrasion (Chaloner and Muir, 1968;Mudie, 1982;Smirnov et al, 1996;Traverse, 2007;Luo et al, 2014). This is considered to make these taxa over-represented in marine sediments compared to their terrestrial counterparts of the same age (Mildenhall and Orpin, 2010). By contrast pollination from insects or animals produces fewer pollen grains due to the direct transport from the source to the receptor, with smaller numbers typically found in palynological records (Moar, 1970;Macphail and McQueen, 1983;Moar et al, 2011).…”

Section: Production and Dispersalmentioning

confidence: 99%

“…However, taphonomic processes affect palynomorphs during fluvial and marine transport. In marine sediments, taxa with more robust, non-anemophilous (i.e., not wind-pollinated) palynomorphs, such as Asteraceae and Cyathea spp., often appear in greater relative abundance than in terrestrial depositional settings (Crouch et al, 2010;Mildenhall and Orpin, 2010;Ryan et al, 2012). Conversely, central-south Westland terrestrial records contain a wider array of palynomorphs, including some taxa that deteriorate beyond recognition during offshore transport (e.g., Vandergoes et al, 2013a).…”

Section: Marine Environmentmentioning

confidence: 99%

See 3 more Smart Citations

Late Quaternary vegetation and climate history reconstructed from palynology of marine cores off southwestern New Zealand

Ryan¹

View full text Add to dashboard Cite

<p>Little is known about how mid-latitude Southern Hemisphere terrestrial vegetation responded during glacial terminations and the warmer phases of the Late Quaternary, especially beyond the last glacial cycle where records are commonly fragmentary and poorly-dated. The timing, magnitude and sequence of environmental changes are investigated here for terminations (T) I, II and V and their subsequent warm interglacials of MIS 1, 5e and 11 by direct correlation of terrestrial palynomorphs (pollen and spores) and marine climate indicators in marine piston cores MD06-2990/2991 recovered from the East Tasman Sea, west of South Island, New Zealand. The climate there is strongly influenced by the prevailing mid-latitude westerly wind belt that generates significant amounts of orographic rainfall and the proximity of the ocean which moderates temperature variability. Chronological constraint for the cores is provided by δ¹⁸O stratigraphy, radiocarbon chronology and the identification of two widespread silicic tephra horizons (25.6 ka Kawakawa/Oruanui Tephra (KOT); ~345 ka Rangitawa Tephra (RtT)) sourced from the central North Island. Similar vegetation changes over the last two glacial cycles at MD06-2991 and in the adjacent nearby on land record of vegetation-climate change from Okarito Bog permit transfer of the well resolved Marine Isotope Stage (MIS) chronology to Okarito for the pre radiocarbon dated interval (~139-28 ka). Placing both sequences on a common age scale nonetheless assumes there is minimal lag between pollen production and final deposition on the seafloor. However, the timing of Late Pleistocene palynomorph events and KOT between independently dated marine and terrestrial sedimentary sequences are found in this study to be indistinguishable, which supports the direct transfer of terrestrially derived ages to the marine realm and vice versa. Vegetation change in southwestern New Zealand is of similar structure during T-I and T-II, despite different amplitudes of forcing (i.e., insolation rise, CO₂ concentrations). In a climate amelioration scenario, shrubland-grassland gave rise to dominantly podocarp-broadleaf forest taxa, with accompanying rises in mean annual air temperature (MAAT) estimated from Okarito pollen typically synchronous with nearby ocean temperatures. The T-II amelioration commenced after ~139 ka in response to increasing boreal summer insolation intensity, with prominent ocean-atmosphere warming over the period from ~133-130 ka. In contrast, northern mid-high latitude paleoclimate records display cooling over Heinrich Stadial 11 (~135-130 ka), and are prominently warm from ~130-128 ka, while southwestern New Zealand and the adjacent ocean displays cooling. Such millennial-scale climate asynchrony between the hemispheres is most likely a result of a systematic, but non-linear re-organisation of the ocean-atmosphere circulation system in response to orbital forcing. The subsequent MIS 5e climatic optimum in Westland was between ~128-123 ka, with maximum temperatures reconstructed in the ocean and atmosphere of 2.5°C and 1.5°C higher than present. Similarities revealed between land and sea pollen records in southwestern New Zealand over the last ~160 ka offer confidence for assessing vegetation and climate for older intervals, including T-V/MIS 11, for which no adjacent terrestrial equivalents currently exist. Vegetation change over T-V is similar to T-II and T-I, with southern warming antiphased with northern mid-high latitude cooling. Tall trees and the thermophilous shrub Ascarina lucida define interglacial conditions in the study region between ~428-396 ka. East Tasman Sea surface temperatures rose in two phases; 435-426 ka (MIS 12a-MIS 11e) and 417-407 ka (MIS 11c climatic optimum), reaching at least ~1.5-2°C warmer than present over the latter. Similarly, Ascarina lucida dominance over MIS 11c is akin to that displayed during the early Holocene climatic optimum (11.5-9 ka) in west-central North Island, where MAAT average ~3°C higher today. This contrasts markedly with the dominance of the tall tree conifer Dacrydium cupressinum for the Holocene (MIS 1) and last interglacial (MIS 5e) in southwestern New Zealand. Biogeographic barriers are proposed to have inhibited the migration of species from more northerly latitudes better adapted to warmer climatic conditions over MIS 5e and MIS 11.</p>

show abstract

Section: Marine-terrestrial Core Comparison In Southwestern New Zealandsupporting

confidence: 72%

Section: Palynomorph Taphonomy Representivity and Paleovegetation Rec...mentioning

confidence: 90%

Section: Production and Dispersalmentioning

confidence: 99%

Section: Marine Environmentmentioning

confidence: 99%

See 2 more Smart Citations

Late Quaternary vegetation and climate history reconstructed from palynology of marine cores off southwestern New Zealand

Ryan¹

View full text Add to dashboard Cite

show abstract

“…). Mildenhall and Orpin () review the results of marine cores from north‐east New Zealand, noting that most seaward records show a stable, undisturbed landscape immediately prior to Polynesian arrival. There is evidence of podocarps but seral taxa such as Coriaria spp.…”

Section: Evidence For the Anthropocene In New Zealandmentioning

confidence: 99%

Māori settlement of New Zealand: The Anthropocene as a process

Holdaway

Emmitt

Furey³

et al. 2018

Archaeology in Oceania

View full text Add to dashboard Cite

The lateness and prominence of Polynesian colonisation of New Zealand make it an ideal place to investigate the Anthropocene. We review the Anthropocene as a process and the information needed to understand the consequences of ongoing human-environmental interaction. Elsewhere in the world, a lengthy history complicates the ability to differentiate between the impact of people on the environment and the consequences of engagement. In New Zealand, engagement is not only of short duration but the landmass has a long coastline, with numerous offshore islands. These characteristics provide the scope to study the impact of engagement where it is particularly discernible. We introduce one such island, Ahuahu (Great Mercury Island). Upon arrival, Polynesian colonists found a temperate, geologically complex land covered in forest, populated by a diverse endemic flora and fauna. They knew how to produce crops and exploit wild food sources but had to rapidly adapt to new conditions marginal to production and new technological possibilities. The New Zealand case study allows consideration of whether the processes involved in creating the phenomena described by the Anthropocene are global, directional and inevitable, or are due to local, small-scale changes related to particular forms of production by Māori, and their capacity to construct environmental change. RÉSUMÉ Le retard et la proéminence de la colonisation Polynésienne de la Nouvelle-Zélande en font un lieu idéal pourétudier l'Anthropocène. Nous examinons l'Anthropocène en tant que processus et les informations nécessaires pour comprendre les conséquences d'une interactioncontinue avec l'environnement humain. Ailleurs dans le monde, une longue histoire complique la capacitéà différencier l'impact des personnes sur l'environnement et les conséquences de l'engagement. En Nouvelle-Zélande, l'engagement est non seulement de courte durée, mais la masse terrestre a un long littoral avec de nombreusesîles au large des côtes. Ces caractéristiques permettent d'étudier l'impact de l'engagement là où il est particulièrement discernable. Nous présentons une de cesîles, Ahuahu (Great Mercury Island). À leur arrivée, les colons Polynésiens ont trouvé une terre tempérée et géologiquement complexe recouverte de forêts peuplées d'une faune et d'une flore endémiques diverses. Ils savaient produire des récoltes et exploiter des sources alimentaires sauvages, mais devaient s'adapter rapidementà de nouvelles conditions marginalesà la production età de nouvelles possibilités technologiques. L'étude de cas Néo-Zélandaise permet de déterminer si les processus impliqués dans la création des phénomènes décrits par l'Anthropocène sont mondiaux, directionnels et inévitables, ou sont dusà des changements locauxà petiteéchelle liésà des formes particulières de production des Maoris età leur capacitéà construire des changements environnementaux. Mots-clés l'Anthropocène, Nouvelle-Zélande, Maori, Ahuahu TUHINGA WHAKARĀPOPOTÓ Ki te aro atu ki te ao whānui, he nohonga hou a Aotearoa. Nā tēnā, he when...

show abstract

Using pollen in turbidites for vegetation reconstructions

McDonald,

Strachan,

Holt

et al. 2024

J Quaternary Science

View full text Add to dashboard Cite

Turbidites, deposited by sub‐aqueous gravity flows, are common in sedimentary archives worldwide and present a unique challenge and opportunity when reconstructing past vegetation through pollen analysis. When sampling pollen from a sediment core for palaeovegetation records, it is common practice to target background sediments (i.e. pelagic sediment) and avoid sampling turbidites, as they are presumed to portray a misleading picture of past vegetation. This assumption stems from our limited understanding of pollen abundance and distribution through turbidites, meaning that palynologists overlook deposits that could potentially be used to reconstruct past vegetation and climate. We present pollen assemblage and sedimentological data from four recent (<150 years) deep marine turbidite deposits from the Hikurangi Subduction Margin, Aotearoa‐New Zealand, with the aim of understanding the abundance and distribution of pollen in fine‐grained turbidites. We find that pollen is diluted in the bases of turbidites, but despite this dilution, the proportions of different pollen taxa remain consistent through each turbidite. These results confirm that pollen can be sampled from turbidites for palaeovegetation reconstructions and that sampling the fine‐grained upper parts of turbidites will provide the best pollen recovery.

show abstract

Terrestrial palynology from marine cores as an indicator of environmental change for the Waipaoa Sedimentary System and north-eastern New Zealand

Cited by 9 publications

References 39 publications

Late Quaternary vegetation and climate history reconstructed from palynology of marine cores off southwestern New Zealand

Late Quaternary vegetation and climate history reconstructed from palynology of marine cores off southwestern New Zealand

Māori settlement of New Zealand: The Anthropocene as a process

Using pollen in turbidites for vegetation reconstructions

Contact Info

Product

Resources

About