Vegetation changes and plant wax biomarkers from an ombrotrophic bog define hydroclimate trends and human-environment interactions during the Holocene in northern Norway

Holocene climate records from northern Europe improve our understanding of important North Atlantic ocean and atmospheric circulation systems to long-term insolation-driven changes, as well as more rapid forcing and feedback mechanisms. Here we assess Holocene climate and environmental changes in northern Norway based on the analysis of pollen, non-pollen palynomorphs, plant macrofossils, and plant wax biomarkers from a high latitude ombrotrophic bog. We define the extent and thickness of Hollabåttjønnen Bog (0.16 km2), which is located 10 km north of Tromsø. Several cores were analyzed, including a 5.16-m core that spans the last 9.5 cal ka BP. Vegetation changes from several sites were reconstructed and the distribution and hydrogen isotopic composition (δD) of n-alkanes (C21–C33) were analyzed. Our data show several distinct climate intervals that primarily indicate changes in bog surface moisture. In the early Holocene (c. 9.5–7.7 cal ka BP), wetter conditions are defined by the presence of wetland sedges and grasses, higher concentrations of mid-chain length n-alkanes, and a similarity in δD values among homologs. A dry mid-Holocene (c. 7.7–3.8 cal ka BP) is inferred from the presence of a heath shrubland, low peat accumulations rates, and significant differences between δD values of mid- and long-chain length n-alkanes. The late Holocene (c. 3.8 cal ka BP-present) is marked by the onset of wetter conditions, lateral bog expansion, and an increase in sedges and grasses. The Hollabåttjønnen Bog record is also significant because its margins were an important location for human settlement. We correlate early Holocene environmental conditions with changes in Stone Age structures recently excavated, and we identify the occurrence of coprophilous fungi, such as Sporormiella and Sordaria, likely associated with reindeer grazing activity beginning c. 1 cal ka BP. This site therefore provides important regional paleoclimate information as well as context for evaluating local prehistoric human-environment interactions.

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The History of Pastoral Activities in S Italy Inferred from Palynology: A Long-Term Perspective to Support Biodiversity Awareness

Sustainability ◽

10.3390/su11020404 ◽

2019 ◽

Vol 11 (2) ◽

pp. 404 ◽

Cited By ~ 9

Author(s):

Assunta Florenzano

Keyword(s):

Environmental Sustainability ◽

Southern Italy ◽

Environmental Changes ◽

Coprophilous Fungi ◽

Human Environment ◽

The Holocene ◽

Mediterranean Habitats ◽

15Th Century ◽

The Impact

The present-day Mediterranean landscape is a result of the long-term human–environment–climate interactions that have driven the ecological dynamics throughout the Holocene. Pastoralism had (and still has) an important role in shaping this landscape, and contributes to maintaining the mosaic patterns of the Mediterranean habitats. Palaeoecological records provide significant multi-proxy data on environmental changes during the Holocene that are linked to human activities. In such research, the palynological approach is especially useful for detailing the complexity of anthropogenically-driven landscape transformations by discriminating past land uses and pastoral/breeding activities. This paper focuses on the palynological evidence for the impact of centuries of grazing on the vegetation of Basilicata, a region of southern Italy where animal breeding and pastoralism have a long tradition. A set of 121 pollen samples from eight archaeological sites (dated from the 6th century BC to the 15th century AD) and five modern surface soil samples were analyzed. The joint record of pollen pasture indicators and spores of coprophilous fungi suggests that continuous and intense pastoral activities have been practiced in the territory and have highly influenced its landscape. The palaeoecological results of this study provide us with better knowledge of the diachronical transformations of the habitats that were exposed to continuous grazing, with a shift toward more open vegetation and increase of sclerophyllous shrubs. The palynological approach gives insights into the vocation and environmental sustainability of this southern Italy region on a long-term basis.

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Sequence completed – palynological investigations on Lateglacial/Early Holocene environmental changes recorded in sequentially laminated lacustrine sediments of the Nahe palaeolake in Schleswig-Holstein, Germany.

10.31233/osf.io/bt9m8 ◽

2020 ◽

Cited By ~ 2

Author(s):

Sascha Krüger ◽

Morten Fischer Mortensen ◽

Walter Dörfler

Keyword(s):

Environmental Changes ◽

Vegetation History ◽

Lacustrine Sediments ◽

Early Holocene ◽

Laminated Sediments ◽

Spatial Proximity ◽

Environment Interaction ◽

Human Environment ◽

Complete Discussion ◽

Laacher See Tephra

The exploration of Lateglacial vegetation history in Schleswig-Holstein is elaborate and comprehensive. Despite being one of the most studied areas, regarding to the Lateglacial, no biostratigraphy covering the complete Lateglacial and Early Holocene periods without hiatus have so far been recovered. In this paper we present a biostratigraphy of the Nahe palaeolake, therewith intending to deal with this desideratum.The special strength of the presented sequence is expressed in the fact that these are the only palynologically investigated sequentially annual laminated limnic sediments of the Lateglacial in Schleswig-Holstein. These laminated sediments, as well as radiocarbon dating of botanical macrofossils and three geochemically confirmed cryptotephra layers (Laacher See Tephra, Vedde Ash and Saksunarvatn Ash), provide excellent chronological control and allow for a Europe-wide correlation. Particularly important is a complete discussion of the vegetation history and the spatial proximity to Late Palaeolithic sites, which renders it possible to evaluate potential human-environment-interaction long before classical palynological human indicators occur.

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Late Pleistocene and early Holocene climate and environmental changes in the Horton Plains, central Sri Lanka

Quaternary International ◽

10.1016/j.quaint.2012.08.1200 ◽

2012 ◽

Vol 279-280 ◽

pp. 385

Author(s):

Rathnasiri Premathilake

Keyword(s):

Sri Lanka ◽

Late Pleistocene ◽

Environmental Changes ◽

Early Holocene ◽

Holocene Climate

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Lateglacial and early-Holocene climate variability reconstructed from multi-proxy records on Andøya, northern Norway

Quaternary Science Reviews ◽

10.1016/j.quascirev.2014.01.018 ◽

2014 ◽

Vol 89 ◽

pp. 108-122 ◽

Cited By ~ 16

Author(s):

Hilary H. Birks ◽

Ingelinn Aarnes ◽

Anne E. Bjune ◽

Stephen J. Brooks ◽

Jostein Bakke ◽

...

Keyword(s):

Climate Variability ◽

Early Holocene ◽

Holocene Climate ◽

Northern Norway ◽

Proxy Records

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Varved sediment responses to early Holocene climate and environmental changes in Lake Meerfelder Maar (Germany) obtained from multivariate analyses of micro X-ray fluorescence core scanning data

Journal of Quaternary Science ◽

10.1002/jqs.2935 ◽

2017 ◽

Vol 32 (3) ◽

pp. 427-436 ◽

Cited By ~ 18

Author(s):

Celia Martin-Puertas ◽

Rik Tjallingii ◽

Menno Bloemsma ◽

Achim Brauer

Keyword(s):

Environmental Changes ◽

Multivariate Analyses ◽

Early Holocene ◽

Holocene Climate ◽

X Ray ◽

Varved Sediment

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Human used upper montane ecosystem in the Horton Plains, central Sri Lanka – a link to Lateglacial and early Holocene climate and environmental changes

Quaternary Science Reviews ◽

10.1016/j.quascirev.2012.07.002 ◽

2012 ◽

Vol 50 ◽

pp. 23-42 ◽

Cited By ~ 12

Author(s):

Rathnasiri Premathilake

Keyword(s):

Sri Lanka ◽

Environmental Changes ◽

Early Holocene ◽

Holocene Climate

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Leaf wax <i>n</i>-alkane distributions record ecological changes during the Younger Dryas at Trzechowskie paleolake (Northern Poland) without temporal delay

10.5194/cp-2018-6 ◽

2018 ◽

Author(s):

Bernhard Aichner ◽

Florian Ott ◽

Michał Słowiński ◽

Agnieszka M. Noryśkiewicz ◽

Achim Brauer ◽

...

Keyword(s):

Chain Length ◽

Younger Dryas ◽

Isotope Ratios ◽

Early Holocene ◽

Geochemical Data ◽

Vegetation Changes ◽

Quantitative Interpretation ◽

Plant Source ◽

Leaf Wax ◽

Northern Poland

Abstract. While of higher plant origin, a specific plant source assignment of sedimentary leaf wax n-alkanes remains difficult. Recent compilations of global plant data sets have demonstrated an overlapping and non-systematic production of different chain-length homologues among different classes of terrestrial vegetation. Further, n-alkane distributions can change within the same species due to environmental changes. In addition, it is unknown how fast a changing catchment vegetation would be reflected in sedimentary leaf wax archives. However, in particular for a quantitative interpretation of n-alkane C and H isotope ratios in terms of paleohydrological and paleoecological changes, a better understanding of transfer times and dominant sedimentary sources of leaf wax n-alkanes is required. In this study we aim to identify the major leaf wax contributors to a Central European lacustrine system. Therefore, we tested to what extent leaf wax n-alkane compositional changes (expressed through compound concentration ratios, such as nC27 vs. nC31, average chain length ACL, etc.) can be linked to known vegetation changes, specifically during the Younger Dryas cold period (YD), by comparison with high-resolution palynological data from the same archive. We analysed leaf wax n-alkane concentrations and distributions in decadal resolution from a sedimentary record from Trzechowskie paleolake – TRZ – (Northern Poland), covering the Late Glacial to early Holocene (13,360–9,940 yrs BP). As additional source indicator of targeted n-alkanes, compound specific carbon isotopic data have been generated in lower time resolution. The results showed rapid responses of n-alkane distribution patterns coinciding with major climatic and paleoecological transitions. We find a shift towards higher ACL values at the Allerød/YD transition between 12,680 and 12,600 yrs BP, coeval with a decreasing contribution of arboreal pollen (mainly Pinus and Betula) and a subsequently higher abundance of pollen derived from herbaceous plants (Poaceae, Cyperaceae, Artemisia), as well as shrubs and dwarf shrubs Juniperus and Salix. The termination of the YD was characterized by a successive increase of n-alkane concentrations coinciding with a sharp decrease of ACL values between 11,580–11,490 years BP, reflecting the expansion of woodland vegetation at the YD/Holocene transition. Centennial reversals to longer chain lengths during the Allerød could possibly be linked to Greenland Interstadial 1b (GI-1b). A similar pattern during the early Holocene has more likely been triggered by rapid ecological responses in course of warming, rather than to reflect a local impact of a Preboreal Oscillation or 11.4 yr event. Another gradual increase in ACL values after 11,200 yrs BP, together with decreasing n-alkane concentrations, most likely reflects the early Holocene vegetation succession with a decline of Betula. These results show, that n-alkane distributions reflect vegetation changes and that a fast (i.e. subdecadal) signal transfer occurred. However, our results also indicate that a standard interpretation of directional changes in biomarker ratios remains difficult. Instead, responses such as changes of ACL need to be discussed in context of other proxy data. In addition, we find that organic geochemical data integrate different ecological information compared to pollen, since some gymnosperm species, such as Pinus, produce only very low amount of n-alkanes and thus their contribution may be largely absent from biomarker records. Our results demonstrate that a combination of palynological and n-alkane data can be used to infer the major sedimentary leaf wax sources and constrain leaf wax transport times from the plant source to the sedimentary sink and thus pave the way towards quantitative interpretation of compound specific hydrogen isotope ratios for paleohydrological reconstructions.

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