Climate changes, lead pollution and soil erosion in south Greenland over the past 700 years

A peat core from southern Greenland provided a rare opportunity to investigate human-environment interactions, climate change and atmospheric pollution over the last ~ 700 years. X-ray fluorescence, gas chromatography-combustion, isotope ratio mass spectrometry, peat humification and fourier-transform infrared spectroscopy were applied and combined with palynological and archaeological evidence. Variations in peat mineral content seem to be related to soil erosion linked with human activity during the late Norse period (13th–14thcenturies AD) and the modern era (20thcentury). Cooler conditions during the Little Ice Age (LIA) are reflected by both slow rates of peat growth and carbon accumulation, and by low bromine (Br) concentrations. Spörer and Maunder minima in solar activity may be indicated by further declines in Br and enrichment in easily degradable compounds such as polysaccharides. Peat organic matter composition was also influenced by vegetation changes at the end of the LIA when the expansion of oceanic heath was associated with polysaccharide enrichment. Atmospheric lead pollution was recorded in the peat after ~ AD 1845, and peak values occurred in the 1970s. There is indirect support for a predominantly North American lead source, but further Pb isotopic analysis would be needed to confirm this hypothesis.

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Recent Lateral Expansion of Sphagnum Bogs Over Central Fen Areas of Boreal Aapa Mire Complexes

Ecosystems ◽

10.1007/s10021-021-00726-5 ◽

2021 ◽

Author(s):

Lars Granlund ◽

Ville Vesakoski ◽

Antti Sallinen ◽

Tiina H. M. Kolari ◽

Franziska Wolff ◽

...

Keyword(s):

Remote Sensing ◽

Carbon Accumulation ◽

Aerial Images ◽

Ice Age ◽

Spatial Patterning ◽

Lateral Expansion ◽

Peat Core ◽

Sphagnum Bogs ◽

Ams Dating ◽

Pollen Density

AbstractWe investigated recent changes in spatial patterning of fen and bog zones in five boreal aapa mire complexes (mixed peatlands with patterned fen and bog parts) in a multiproxy study. Comparison of old (1940–1970s) and new aerial images revealed decrease of flarks (wet hollows) in patterned fens by 33–63% in middle boreal and 16–42% in northern boreal sites, as lawns of bog Sphagnum mosses expanded over fens. Peat core transects across transformed areas were used to verify the remote sensing inference with stratigraphic analyses of macrofossils, hyperspectral imaging, and age-depth profiles derived from 14C AMS dating and pine pollen density. The transect data revealed that the changes observed by remote sensing during past decades originated already from the end of the Little Ice Age (LIA) between 1700–1850 CE in bog zones and later in the flarks of fen zones. The average lateral expansion rate of bogs over fen zones was 0.77 m y−1 (range 0.19–1.66) as estimated by remote sensing, and 0.71 m y−1 (range 0.13–1.76) based on peat transects. The contemporary plant communities conformed to the macrofossil communities, and distinct vegetation zones were recognized as representing recently changed areas. The fen-bog transition increased the apparent carbon accumulation, but it can potentially threaten fen species and habitats. These observations indicate that rapid lateral bog expansion over aapa mires may be in progress, but more research is needed to reveal if ongoing fen-bog transitions are a commonplace phenomenon in northern mires.

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Human–environment interactions at a short-lived Arctic mine and the long-term response of the local tundra vegetation

Polar Record ◽

10.1017/s0032247420000418 ◽

2021 ◽

Vol 57 ◽

Author(s):

Frigga Kruse ◽

Gary R. Nobles ◽

Martha de Jong ◽

Rosanne M. K. van Bodegom ◽

G. J. M. (Gert) van Oortmerssen ◽

...

Keyword(s):

Isotope Analysis ◽

Isotopic Analysis ◽

The Arctic ◽

Human Environment ◽

Habitat Creation ◽

Waste Dumps ◽

Threatened Plant Species ◽

Visual Impact ◽

Local Ecosystem

Abstract Arctic mining has a bad reputation because the extractive industry is often responsible for a suite of environmental problems. Yet, few studies explore the gap between untouched tundra and messy megaproject from a historical perspective. Our paper focuses on Advent City as a case study of the emergence of coal mining in Svalbard (Norway) coupled with the onset of mining-related environmental change. After short but intensive human activity (1904–1908), the ecosystem had a century to respond, and we observe a lasting impact on the flora in particular. With interdisciplinary contributions from historical archaeology, archaeozoology, archaeobotany and botany, supplemented by stable isotope analysis, we examine 1) which human activities initially asserted pressure on the Arctic environment, 2) whether the miners at Advent City were “eco-conscious,” for example whether they showed concern for the environment and 3) how the local ecosystem reacted after mine closure and site abandonment. Among the remains of typical mining infrastructure, we prioritised localities that revealed the subtleties of long-term anthropogenic impact. Significant pressure resulted from landscape modifications, the import of non-native animals and plants, hunting and fowling, and the indiscriminate disposal of waste material. Where it was possible to identify individual inhabitants, these shared an economic attitude of waste not, want not, but they did not hold the environment in high regard. Ground clearances, animal dung and waste dumps continue to have an effect after a hundred years. The anthropogenic interference with the fell field led to habitat creation, especially for vascular plants. The vegetation cover and biodiversity were high, but we recorded no exotic or threatened plant species. Impacted localities generally showed a reduction of the natural patchiness of plant communities, and highly eutrophic conditions were unsuitable for liverworts and lichens. Supplementary isotopic analysis of animal bones added data to the marine reservoir offset in Svalbard underlining the far-reaching potential of our multi-proxy approach. We conclude that although damaging human–environment interactions formerly took place at Advent City, these were limited and primarily left the visual impact of the ruins. The fell field is such a dynamic area that the subtle anthropogenic effects on the local tundra may soon be lost. The fauna and flora may not recover to what they were before the miners arrived, but they will continue to respond to new post-industrial circumstances.

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Quantifying soil carbon accumulation in Alaskan terrestrial ecosystems during the last 15 000 years

Biogeosciences ◽

10.5194/bg-13-6305-2016 ◽

2016 ◽

Vol 13 (22) ◽

pp. 6305-6319 ◽

Cited By ~ 2

Author(s):

Sirui Wang ◽

Qianlai Zhuang ◽

Zicheng Yu

Keyword(s):

20Th Century ◽

Average Rate ◽

Terrestrial Ecosystems ◽

Carbon Accumulation ◽

The Holocene ◽

Holocene Thermal Maximum ◽

Peat Core ◽

Thermal Maximum ◽

Soil Carbon Accumulation ◽

Climate Cooling

Abstract. Northern high latitudes contain large amounts of soil organic carbon (SOC), of which Alaskan terrestrial ecosystems account for a substantial proportion. In this study, the SOC accumulation in Alaskan terrestrial ecosystems over the last 15 000 years was simulated using a process-based biogeochemistry model for both peatland and non-peatland ecosystems. Comparable with the previous estimates of 25–70 Pg C in peatland and 13–22 Pg C in non-peatland soils within 1 m depth in Alaska using peat-core data, our model estimated a total SOC of 36–63 Pg C at present, including 27–48 Pg C in peatland soils and 9–15 Pg C in non-peatland soils. Current vegetation stored 2.5–3.7 Pg C in Alaska, with 0.3–0.6 Pg C in peatlands and 2.2–3.1 Pg C in non-peatlands. The simulated average rate of peat C accumulation was 2.3 Tg C yr−1, with a peak value of 5.1 Tg C yr−1 during the Holocene Thermal Maximum (HTM) in the early Holocene, 4-fold higher than the average rate of 1.4 Tg C yr−1 over the rest of the Holocene. The SOC accumulation slowed down, or even ceased, during the neoglacial climate cooling after the mid-Holocene, but increased again in the 20th century. The model-estimated peat depths ranged from 1.1 to 2.7 m, similar to the field-based estimate of 2.29 m for the region. We found that the changes in vegetation and their distributions were the main factors in determining the spatial variations of SOC accumulation during different time periods. Warmer summer temperature and stronger radiation seasonality, along with higher precipitation in the HTM and the 20th century, might have resulted in the extensive peatland expansion and carbon accumulation.

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Fully automated, high-precision instrumentation for the isotopic analysis of tropospheric N2 O using continuous flow isotope ratio mass spectrometry

Rapid Communications in Mass Spectrometry ◽

10.1002/rcm.6623 ◽

2013 ◽

Vol 27 (15) ◽

pp. 1723-1738 ◽

Cited By ~ 11

Author(s):

Katherine E. Potter ◽

Shuhei Ono ◽

Ronald G. Prinn

Keyword(s):

Mass Spectrometry ◽

High Precision ◽

Continuous Flow ◽

Isotope Ratio ◽

Isotope Ratio Mass Spectrometry ◽

Isotopic Analysis

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Improved methodologies for continuous-flow analysis of stable water isotopes in ice cores

Atmospheric Measurement Techniques ◽

10.5194/amt-10-617-2017 ◽

2017 ◽

Vol 10 (2) ◽

pp. 617-632 ◽

Cited By ~ 14

Author(s):

Tyler R. Jones ◽

James W. C. White ◽

Eric J. Steig ◽

Bruce H. Vaughn ◽

Valerie Morris ◽

...

Keyword(s):

Continuous Flow ◽

Ice Core ◽

Flow Analysis ◽

Ice Cores ◽

Isotope Ratio Mass Spectrometry ◽

Absorption Spectrometry ◽

Isotopic Analysis ◽

Water Isotopes ◽

Stable Water Isotopes ◽

Continuous Flow Analysis

Abstract. Water isotopes in ice cores are used as a climate proxy for local temperature and regional atmospheric circulation as well as evaporative conditions in moisture source regions. Traditional measurements of water isotopes have been achieved using magnetic sector isotope ratio mass spectrometry (IRMS). However, a number of recent studies have shown that laser absorption spectrometry (LAS) performs as well or better than IRMS. The new LAS technology has been combined with continuous-flow analysis (CFA) to improve data density and sample throughput in numerous prior ice coring projects. Here, we present a comparable semi-automated LAS-CFA system for measuring high-resolution water isotopes of ice cores. We outline new methods for partitioning both system precision and mixing length into liquid and vapor components – useful measures for defining and improving the overall performance of the system. Critically, these methods take into account the uncertainty of depth registration that is not present in IRMS nor fully accounted for in other CFA studies. These analyses are achieved using samples from a South Pole firn core, a Greenland ice core, and the West Antarctic Ice Sheet (WAIS) Divide ice core. The measurement system utilizes a 16-position carousel contained in a freezer to consecutively deliver ∼  1 m  ×  1.3 cm2 ice sticks to a temperature-controlled melt head, where the ice is converted to a continuous liquid stream and eventually vaporized using a concentric nebulizer for isotopic analysis. An integrated delivery system for water isotope standards is used for calibration to the Vienna Standard Mean Ocean Water (VSMOW) scale, and depth registration is achieved using a precise overhead laser distance device with an uncertainty of ±0.2  mm. As an added check on the system, we perform inter-lab LAS comparisons using WAIS Divide ice samples, a corroboratory step not taken in prior CFA studies. The overall results are important for substantiating data obtained from LAS-CFA systems, including optimizing liquid and vapor mixing lengths, determining melt rates for ice cores with different accumulation and thinning histories, and removing system-wide mixing effects that are convolved with the natural diffusional signal that results primarily from water molecule diffusion in the firn column.

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Late-Holocene seasonal moisture variability: Range Creek Canyon, Utah, USA

The Holocene ◽

10.1177/0959683620972769 ◽

2020 ◽

pp. 095968362097276

Author(s):

Mariangelica Groves ◽

Andrea R Brunelle ◽

Mitchell J Power ◽

Kenneth L Petersen ◽

Zachary J Lundeen

Keyword(s):

Zea Mays ◽

Colorado Plateau ◽

Summer Precipitation ◽

Isotopic Analysis ◽

Pinus Edulis ◽

Ice Age ◽

Dry Period ◽

Climatic Zones ◽

Elemental Ratios ◽

Moisture Conditions

A 3300 year-long reconstruction of paleoenvironmental moisture conditions was constructed from a sediment core from North Gate Bog (NGB) in the northern section of Range Creek Canyon within the Colorado Plateau. The methods used to analyze the record include loss on ignition (LOI), magnetic susceptibility (MS), elemental analysis with X-ray fluorescence (XRF), charcoal influx, isotopic analysis, elemental ratios and pollen percentages, influx, and ratios. This study adds two new insights to the paleoenvironmental record of the northern section of the Colorado Plateau. First, four climatic zones were established. Zone 1 (3300–2750 cal yr BP) had 100-year wet to dry variations with droughts recorded from 3300–3200, 3000–2900, and 2800–2700 cal yr BP. Zone 2 (2750–1600 cal yr BP) had an overall dry period with an 800-year transition to increased warmth and winter moisture. Zone 3 (1600–850 cal yr BP) had an overall warm, wet, summer precipitation climate conducive to the establishment of Zea Mays and Pinus edulis, two staple foods of the Fremont culture. The Medieval Climate Anomaly (MCA) registered warm and wet in this part of the Colorado Plateau. Zone 4 (850–0 cal yr BP) had a sharp transition to a drier climate from 850 to 400 cal yr BP. During the Little Ice Age (LIA), wetter climate taxon increases such as Artemisia, Cyperaceae, and Pinus edulis. The second overall finding in this study was that NGB was a place of human activity including Fremont farming. The identification of a Zea mays pollen grain confirms the archeological presumptions that this higher elevation site was used to farm corn along with other sites in Range Creek Canyon (RCC). The post Fremont occupation period was marked by a sharp increase in organic material and a return of pinyon-juniper woodlands.

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