scholarly journals Ancient plant DNA, macro- and microfossil studies of the lake sediments from the High Arctic lake Tenndammen, Svalbard

Author(s):  
Anastasia Poliakova ◽  
Lena M. Håkansson ◽  
Anders Schomacker ◽  
Sandra Garces Pastor ◽  
Inger Greve Alsos

<p>Ancient DNA metabarcoding applied together with the investigations of the plant macro-remains, pollen, spores and non-pollen palynomorphs (NPP), open new perspectives and give better taxonomical resolution, allowing to obtain more precise and specific data on the local environment conditions and their changes. So far, only three multiproxy studies that involve both molecular and palaeobotanical/palynological methods are available for the high Arctic archipelago Svalbard. We intend to contribute filling this gap. Therefore, a field trip to Svalbard was undertaken in September, 2019, and three sediment cores were retrieved from the Tenndammen lake (N 78°06.118; E 15°02.024, 7 m asl) which is a small and shallow water body (ca 2.5 m depth). The lake is located in the valley of Colesdalen, a well-known Svalbard’s biodiversity hot spots and a home for about seven to ten thermophilic plant species.</p><p>To investigate the Holocene to modern vegetation history of this place, the 85cm core Te2019 was chosen, it was described for lithology, X-rayed, µXRF-scanned, line-scan photographed with high resolution and sampled for sedaDNA, pollen, spores and NPP studies as well as for studies on plant macrofossils. Ten 14C AMS dates were taken in order to establish an age-depth model. The DNA record contains around 100 taxa, most findings of those are supported by pollen studies (Asteraceae, <em>Betula</em>, Brassicaceae, <em>Salix, Saxifraga, Vaccinium</em>/Ericaceae) and by spores (<em>Equisetum</em> and Bryophyta). In addition, various fungi spores were identified. Investigations of plant macro-remains well support findings of the aquatic (i.e. Warnstorfia fluitans) and terrestrial mosses (e.g. <em>Aulacomnium</em> conf. <em>turgidum, Bryum</em> spp., <em>Distichium capillaceum, Calliergon richardsonii, Scorpidium cossonii, Sphagnum</em> spp., <em>Rhizomnium</em> spp.). Besides, fragments of <em>Salix</em> and <em>Betula</em> leaves and fruit parts, various leaf, stem tissues and flower fragments of <em>Saxifraga</em> species were found within the samples from the same depths with the correspondence to DNA records. Three DNA zones (SvDNA 1 – SvDNA3) and  one subzone within the earliest zone (SvDNA-1a – SvDNA-1b) were established. Relations between DNA, pollen and macrofossil zones were studied. This study is performed within the “Future ArcTic Ecosystems” (FATE) research program: Initiative for investigation on drivers of diversity and future scenarios from ethnoecology, contemporary ecology and ancient DNA.</p>

2021 ◽  
Author(s):  
Barbara von Hippel ◽  
Kathleen R. Stoof-Leichsenring ◽  
Luise Schulte ◽  
Peter Seeber ◽  
Laura S. Epp ◽  
...  

<p>Climate change has a great impact on boreal ecosystems including Siberian larch forests. As a consequence of warming, larch grow is possible in areas where climate used to be too cold, leading to a shift of the tree line into more arctic regions. Most plants co-exist in symbiosis with heterotrophic organisms surrounding their root system. In arctic ecosystems, mycorrhizal fungi are a prerequisite for plant establishment and survival because they support nutrient uptake from nutrient-poor soils and maintain the water supply. Until now, however, knowledge about the co-variation of vegetation and fungi is poor. Certainly, the understanding of dynamic changes in biotic interactions is important to understand adaptation mechanisms of ecosystems to climate change.</p><p>We investigated sedimentary ancient DNA from Lake Levinson Lessing, Taymyr Peninsula (Arctic Siberia, tundra), Lake Lama, Lake Kyutyunda (both northern Siberia, tundra-taiga transition zone) and Lake Bolshoe Toko (southern Siberia, forest area) covering the last about 45.000 years using ITS primers for fungi along with the chloroplast P6 loop marker for vegetation metabarcoding. We found changes in the fungal communities that are in broad agreement with vegetation turnover. To our knowledge, this is the first broad ecological study on lake sediment cores to analyze fungal biodiversity in relation to vegetation change on millennial time scales.</p>


1973 ◽  
Vol 51 (11) ◽  
pp. 2085-2103 ◽  
Author(s):  
Rolf W. Mathewes

The postglacial vegetation history of the University of British Columbia Research Forest was investigated using percentage and absolute pollen analysis, macrofossil analysis, and radiocarbon dating. A marine silty clay deposit records the oldest (12 690 ± 190 years before present (B.P.)) assemblage of terrestrial plant remains so far recovered from the postglacial of south-coastal British Columbia. Lodge-pole pine (Pinus contorta) dominated this early vegetation, although some Abies, Picea, Alnus, and herbs were also present. Sediment cores from two lakes were also studied. The older is Marion Lake, where five pollen assemblage zones are recognized, beginning with a previously undescribed assemblage of Pinus contorta, Salix, and Shepherdia in clay older than 12 350 ± 190 B.P. The pollen diagram from Surprise Lake (11 230 ± 230 B.P.) is divided into three pollen zones which show the same major trends of vegetation change as the Marion Lake diagram.The first report of the postglacial vegetation history of cedar (Thuja and perhaps Chamaecyparis) in southwestern British Columbia is presented from pollen and macrofossil analyses.At about 10 500 B.P. in both lakes, pollen of Douglas fir (Pseudotsuga menziesii) began a rapid increase, probably in response to climatic amelioration. The palynological evidence, supported by well-preserved bryophyte subfossils, suggests that humid coastal conditions have prevailed in the study area since about 10 500 B.P., with virtually no evidence for a classical Hypsithermal interval between 8500 B.P. and 3000 B.P.


1985 ◽  
Vol 23 (3) ◽  
pp. 301-312 ◽  
Author(s):  
Marjorie Green Winkler

Pollen and charcoal analysis of radiocarbon-dated sediment cores from Duck Pond in the Cape Cod National Seashore provide a continuous 12,000-yr vegetation and climate history of outer Cape Cod. A Picea-Hudsonia parkland and then a Picea-Pinus banksiana-Alnus crispa boreal forest association grew near the site between 12,000 and 10,000 yr B.P. This vegetation was replaced by a northern conifer forest of Pinus strobus-P. banksiana, and, subsequently, by a more mesophytic forest (Pinus strobus, Tsuga, Quercus, Fagus, Acer, Ulmus, Fraxinus, Ostrya) as the climate became warmer and wetter by 9500 yr B.P. By 9000 yr B.P. a Pinus rigida-Quercus association dominated the landscape. High charcoal frequencies from this and subsequent levels suggest that the pine barrens association developed during a warmer and drier climate that lasted from 9000 to about 5000 yr B.P. Increased percentages of Pinus strobus pollen indicate a return to moister and cooler conditions by about 3500 yr B.P. A doubled sedimentation rate, increased charcoal, and increased herb pollen suggest land disturbance near the pond before European settlement. These results suggest a rapid warming in the northeast in the early Holocene and support a hypothesis of a rapid sea level rise at that time. Comparison of the pollen results from Duck Pond with those from Rogers Lake, Connecticut, illustrates the importance of edaphic factors in determining the disturbance frequency and vegetation history of an area.


Author(s):  
Cathy Whitlock

The Paleoecologic recod provides unique insights into the response of communities to environmental perturbations of different duration and intensity. Climate is a primary agent of environmental change and its long-term effect on the vegetation of the Yellowstone/Grand Teton region is revealed in a network of pollen records (Whitlock, 1993). Fire frequency is controlled by climate, and as climate changes so too does the importance of fire in shaping spatial patterns of vegetation. The prehistoric record of Yellowstone's Northern Range, for example, shows the response of vegetation to the absence of major fires in the last 150 years (Whitlock et al., 1991; Engstrom et al., 1991). In longer records spanning the last 14,000 years, periods of frequent fire are suggested by sediments containing high percentages of fire-adapted trees, including lodgepole pine and Douglas-fir, and high amounts of charcoal (Bamosky et al., 1987; Millspaugh and Whitlock, 1993; Whitlock, 1993). The primary research objective has been to study the vegetational history of Yellowstone and its sensitivity to hanges in climate and fire frequency. This information is necessary to understand better the relative effects of climate, natural disturbance, and human perturbation on the Yellowstone landscape. Fossil pollen and plant macrofossils from dated-lake sediment cores provide information on past vegetation and climate. The frequency of charcoal particles and other fire indicators in dated lake-sediment cores offer evidence of past fires.


Author(s):  
Cathy Barnosky

During the late Quaternary, the Jackson Hole area has reen repeatedly glaciated-the most recent and least extensive ice advance occurred during the Pinedale Glaciation (ca. 25,000-9,000 yr B.P.; Love and Reed, 1971). The objective of this research is to study the vegetation history of Jackson Hole since Pinedale time, as a means of interpreting the development and stability of modern plant communities. The research is based on an examination of pollen and plant-macrofossiil records contained in lake-sediment cores collected near the former ice margin. The environmental history of this region is poorly known and the paleoecological information provided by this study should help fill a gap in our understanding of the vegetation, climate, and glacial history of the Northern Rocky Mountains.


1986 ◽  
Vol 64 (9) ◽  
pp. 1977-1986 ◽  
Author(s):  
R. Scott Anderson ◽  
Ronald B. Davis ◽  
Norton G. Miller ◽  
Robert Stuckenrath

The changing character of vegetation and the effects of disturbance on vegetation are inferred from pollen, plant macrofossils, charcoal, and microlepidopteran larvel head capsules in sediment cores from Upper South Branch Pond, Maine. Following deglaciation 12 500 – 12 000 years ago, a herb–shrub tundra developed which included moss species characteristic of calcareous, mineral soils. Fire and infestation by microlepidopterans were unimportant initially but became important upon arrival of spruce, paper birch, balsam fir, white pine, and tamarack trees (ca. 10 200 – 9500 years BP). Fires were infrequent in the watershed between 7500 and 5000 years BP. The relatively stable forests of this period, dominated by hemlock and yellow birch, grew in what may have been the moistest part of the Holocene. The maximum postglacial abundance of microlepidopteran larvae is centered around the hemlock decline (ca. 4800 years BP). Subsequently, the forest was composed largely of deciduous trees and white pine. Fire incidence was greater, and fewer fossils of microlepidoptera were deposited. Lack of major disturbances between ca. 3300 and 2600 years BP coincided with increases in hemlock, tamarack, yellow birch, and arbor vitae. Increases in boreal conifers began by about 1700 years ago, suggesting cooler, and perhaps wetter, climate. An increase in microlepidoptera accompanied the recent expansion of boreal conifers.


2003 ◽  
Vol 33 (6) ◽  
pp. 1144-1166 ◽  
Author(s):  
Robyn Flakne

A vegetation history for Isle Royale National Park, Michigan, U.S.A., is reconstructed using pollen and spores extracted from two lake sediment cores. Lily Lake is on the southwestern end of the main island of Isle Royale surrounded by northern hardwoods forest. Lake Ojibway is on the northeastern end of the main island surrounded by boreal forest. Pollen and spore records were analyzed using pollen percentage diagrams, nonmetric multidimensional scaling ordination, and modern analog analysis. Squared chord distances for temporally paired subsamples from each site were calculated to determine palynological dissimilarities between the sites through time. These analyses revealed an overall vegetation history that is consistent with other regional reconstructions. High percentages of spruce pollen, indicating a cool climate, are present in the early Holocene, whereas high percentages of pine pollen, indicating a dry climate, occur in the mid-Holocene. The pollen records from the two sites diverge with increased precipitation during the late Holocene. At this time, birch-dominated forest is established near Lily Lake on till-derived soils. At Lake Ojibway, a mixed birch, pine, spruce, and fir forest is established on bedrock-derived soils. The divergence in forest composition is most pronounced within the last 500 years, and this divergence is tentatively attributed to the response of taxa on different substrates to increasing precipitation. Other possible explanations for the recent divergence include changing microclimates or disturbance regimes.


2012 ◽  
Vol 8 (2) ◽  
pp. 1409-1441 ◽  
Author(s):  
A. A. Andreev ◽  
E. Morozova ◽  
G. Fedorov ◽  
L. Schirrmeister ◽  
A. A. Bobrov ◽  
...  

Abstract. Frozen sediments from three cores bored in permafrost surrounding of the El'gygytgyn Impact Crater Lake have been studied for pollen, non-pollen palynomorphs, plant macrofossils, and rhizopods. The palynological study of the cores contributes to a higher resolution of time intervals presented in a poor temporal resolution in the lacustrine sediments; namely the Allerød and succeeding periods. Moreover, permafrost records better reflect local environmental changes, thus, allowing more reliable reconstruction of the local paleoenvironments. The new data confirm that shrub tundra with dwarf birch, shrub alder and willow dominated in the lake surroundings during the Allerød warming. Younger Dryas pollen assemblages reflect abrupt changes to grass-sedge-herb dominated environments reflecting significant climate deterioration. Low shrub tundra with dwarf birch and willow dominate the lake vicinity at the onset of the Holocene. The founds of larch seeds indicate its local presence around 11 000 cal. yr BP and, thus a northward shift of treeline by about 100 km during the early Holocene thermal optimum. Forest tundra with larch and shrub alder stands grew in the area during the early Holocene. After ca. 3500 cal. yr BP similar-to-modern plant communities became common in the lake vicinity.


Insects ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 427 ◽  
Author(s):  
Jean-Christophe Simon ◽  
Frédérique Mahéo ◽  
Lucie Mieuzet ◽  
Christelle Buchard ◽  
Jean-Pierre Gauthier ◽  
...  

Arctic ecosystems are subjected to strong environmental constraints that prevent both the colonization and development of many organisms. In Svalbard, few aphid species have established permanent populations. These high arctic aphid species have developed peculiar life-history traits such as shortened life cycles and reduced dispersal capacities. Here, we present data on the distribution and population genetics of Acyrthosiphon svalbardicum in Spitsbergen, the main island of the Svalbard archipelago, and compared its genetic structure with that of its close relative Acyrthosiphon brevicorne, sampled in the top of Scandinavian mainland. We found that A. svalbardicum is common but heterogeneously distributed along the west coast of Spitsbergen. We recorded this species up to 79°12’, which constitutes the northernmost location for any aphid. Genetic structure examined using microsatellite markers showed more pronounced spatial differentiation in A. svalbardicum than in A. brevicorne populations, presumably due to reduced dispersal capacities in the former species. Although populations of A. brevicorne and A. svalbardicum were well-delineated at nuclear loci, they shared similar cytoplasmic DNA haplotypes as revealed by sequence analysis of two DNA barcodes. These results raise questions about whether these two taxa are different species, and the colonization sources and history of the Svalbard archipelago by A. svalbardicum.


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