| 1. |
- Bindler, Richard, 1963-, et al.
(author)
-
Reshaping the landscape: mining, metallurgy and a millennium of environmental changes in south-central Sweden
-
Other publication (other academic/artistic)abstract
- Before the recognition of emerging environmental issues during the 20th century such as acid rain, mercury pollution, climate change and biodiversity loss, human activities had already significantly altered landscapes around the globe. As elsewhere in Europe, the introduction of agriculture into Sweden during the Bronze and Iron Ages led to changes in forest cover, especially in southern areas, but also more limited impacts in central and northern Sweden along river valleys and coastal areas. In central Sweden the rise and rapid spread of ore mining and metallurgy from the 12th and especially 13th century initiated a widespread reshaping of the landscape named after its mining heritage –Bergslagen (mining laws). This mineral rich 89,000 km2 region encompasses ~5000 metallurgical sites (furnaces, smelters, foundries, forges) and ~10000 mines registered in the Swedish National Antiquities Board’s database.Analyses of >30 lake-sediment records using a combination of geochemical, diatom and pollen analyses, in combination with archaeological and historical records and toponyms, add important details to the early, poorly documented history of mining/metallurgy as well as provide insights into some of the environmental impacts across this large landscape. These impacts included damming of lakes and regulation of watercourses for waterpower, increase in erosion, emission of metals to surface waters and the atmosphere (and leaching from slag piles), decrease in forest cover and changes in water quality. The discontinuous appearance of pollen from cultivated plants (cereals) indicates some limited settlement before the 12th century, but the regular occurrence thereafter of cereal pollen together with a sharp increase in charcoal particles and geochemical evidence of mining/metallurgical activities, indicates mining/metallurgy was a driving force for settlement. Decline in forest cover was gradual from the 13th century, but was more significant from the late 16th century when iron and copper production increased exponentially. The increased demand for charcoal and increased agriculture, including an expansion of summer forest farms, contributed to a reduction in inferred forest cover to 40–80% – as compared to pre-anthropogenic (≤2000 BP) values of 84–95%. From the 16th century charcoal became the limiting resource within Bergslagen and metallurgy expanded to regions adjoining Bergslagen, contributing to a more widespread decline in forest cover also beyond the Bergslagen landscape.In association with the increase in land-use activities and resulting changes in vegetation cover, there was a decline (20–50%) in spectrally inferred lake-water total organic carbon, which we hypothesize resulted from a decreased pool of labile soil carbon. In some lakes closely connected with blast furnaces, where the peasant-miners also lived and farmed, there was an increase in diatom-inferred lake-water pH – as observed previously in SW Sweden in association with Iron Age land use. Only in a suite of lakes in close proximity to the smelting of copper sulfide ores in the surroundings of Falun was there evidence for pre-20th century acidification.While current rates of environmental change may be unprecedented, they build on an already modified landscape. Because pre-industrial conditions, i.e., pre-19th century, are often used as a reference level the scale of current changes may underestimate the full extent of ecosystem and environmental impacts.
|
|
| 2. |
- Jones, Samantha E., et al.
(author)
-
Lake and crannog : A 2500-year palaeoenvironmental record of continuity and change in NE Scotland
- 2022
-
In: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 285
-
Journal article (peer-reviewed)abstract
- Wetland environments have been important resources for human habitation since prehistoric times and in parts of northern Europe these have witnessed the construction of artificial islet settlements, known as ‘crannogs’ in Scotland and Ireland. This paper presents a high-resolution multi-proxy palaeoenvironmental study from the Loch of Leys, Aberdeenshire, Scotland, the site of a recently excavated crannog that provides a chronological context for its inhabitation. The combined datasets demonstrate that the first occupation from AD 20–210 coincided not only with a transitional phase from lake to wetland (mire) but also with the timing of the first major Roman campaigns in northeast Scotland. Techniques including microfossil analysis, geochemistry, IR-spectroscopy and physical properties integrated with archaeological and historical records have helped to better define both natural changes that took place in the wetland environment and human activity (agriculture, fires, metal working) spanning the Roman Iron Age through to the present. This has allowed a better understanding of the responses of existing Iron Age communities to Roman military activity (e.g. through continuity or change in land use) as well as the resources exploited in frontier zones during the Roman and post Roman eras. This has wider significance not just for Scotland but also for other parts of Europe that had similar frontiers and conflict zones during the Roman period.
|
|
| 3. |
- Lopez-Costas, Olalla, et al.
(author)
-
Human bones tell the story of atmospheric mercury and lead exposure at the edge of Roman World
- 2020
-
In: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 710
-
Journal article (peer-reviewed)abstract
- Atmospheric metal pollution is a major health concern whose roots pre-date industrialization. This study pertains the analyses of ancient human skeletons and compares them with natural archives to trace historical environmental exposure at the edge of the Roman Empire in NW Iberia The novelty of our approach relies on the combination of mercury, lead and lead isotopes. We found over a 700-year period that rural Romans incorporated two times more mercury and lead into their bones than post-Romans inhabiting the same site, independent of sex or age. Atmospheric pollution sources contributed on average 57% (peaking at 85%) of the total lead incorporated into the bones in Roman times, which decreased to 24% after the decline of Rome. These values and accompanying changes in lead isotopic composition mirror changes in atmospheric Pb deposition recorded in local peatlands. Thus, skeletons are a time-transgressive archive reflecting contaminant exposure.
|
|
| 4. |
- López-Merino, Lourdes, et al.
(author)
-
Reconstructing the impact of human activities in a NW Iberian Roman mining landscape for the last 2500 years
- 2014
-
In: Journal of Archaeological Science. - : Elsevier. - 0305-4403 .- 1095-9238. ; 50, s. 208-218
-
Journal article (peer-reviewed)abstract
- Little is known about the impact of human activities during Roman times on NW Iberian mining landscapes beyond the geomorphological transformations brought about by the use of hydraulic power for gold extraction. We present the high-resolution pollen record of La Molina mire, located in an area intensely used for gold mining (Asturias, NW Spain), combined with other proxy data from the same peat core to identify different human activities, evaluate the strategies followed for the management of the resources and describe the landscape response to human disturbances. We reconstructed the timing and synchronicity of landscape changes of varying intensity and form occurred before, during and after Roman times. An open landscape was prevalent during the local Late Iron Age, a period of relatively environmental stability. During the Early Roman Empire more significant vegetation shifts took place, reflected by changes in both forest (Corylus and Quercus) and heathland cover, as mining/metallurgy peaked and grazing and cultivation increased. In the Late Roman Empire, the influence of mining/metallurgy on landscape change started to disappear. This decoupling was further consolidated in the Germanic period (i.e., Visigothic and Sueve domination of the region), with a sharp decrease in mining/metallurgy but continued grazing. Although human impact was intense in some periods, mostly during the Early Roman Empire, forest regeneration occurred afterwards: clearances were local and short-lived. However, the Roman mining landscape turned into an agrarian one at the onset of the Middle Ages, characterized by a profound deforestation at a regional level due to a myriad of human activities that resulted in an irreversible openness of the landscape.
|
|
| 5. |
- Martínez Cortizas, Antonio, et al.
(author)
-
Early atmospheric metal pollution provides evidence for Chalcolithic/Bronze Age mining and metallurgy in Southwestern Europe
- 2016
-
In: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 545-546, s. 398-406
-
Journal article (peer-reviewed)abstract
- Although archaeological research suggests that mining/metallurgy already started in the Chalcolithic (3rd millennium BC), the earliest atmospheric metal pollution in SW Europe has thus far been dated to similar to 3500-3200 cal. yr. BP in paleo-environmental archives. A low intensity, non-extensive mining/metallurgy and the lack of appropriately located archives may be responsible for this mismatch. We have analysed the older section (>2100 cal. yr. BP) of a peat record from La Molina (Asturias, Spain), a mire located in the proximity (35-100 km) of mines which were exploited in the Chalcolithic/Bronze Age, with the aim of assessing evidence of this early mining/metallurgy. Analyses included the determination of C as a proxy for organic matter content, lithogenic elements (Si, Al, Ti) as markers of mineral matter, and trace metals (Cr, Cu, Zn, Pb) and stable Pb isotopes as tracers of atmospheric metal pollution. From similar to 8000 to similar to 4980 cal. yr. BP the Pb composition is similar to that of the underlying sediments (Pb 15 +/- 4 mu g g(-1); Pb-206/Pb-207 1.204 +/- 0.002). A sustained period of low Pb-206/Pb-207 ratios occurred from similar to 4980 to similar to 2470 cal. yr. BP, which can be divided into four phases: Chalcolithic (similar to 4980-3700 cal. yr. BP), Pb-206/Pb-207 ratios decline to 1.175 and Pb/Al ratios increase; Early Bronze Age (similar to 3700-3500 cal. yr. BP), Pb-206/Pb-207 increase to 1.192 and metal/Al ratios remain stable; Late Bronze Age (similar to 3500-2800 cal. yr. BP), Pb-206/Pb-207 decline to their lowest values (1.167) while Pb/Al and Zn/Al increase; and Early Iron Age (similar to 2800-2470 cal. yr. BP), Pb-206/Pb-207 increase to 1.186, most metal/Al ratios decrease but Zn/Al shows a peak. At the beginning of the Late Iron Age, Pb-206/Pb-207 ratios and metal enrichments show a rapid return to pre-anthropogenic values. These results provide evidence of regional/local atmospheric metal pollution triggered by the earliest phases of mining/metallurgy in the area, and reconcile paleo-environmental and archaeological records.
|
|
| 6. |
- Martínez Cortizas, Antonio, et al.
(author)
-
Holocene atmospheric dust deposition in NW Spain
- 2020
-
In: The Holocene. - : SAGE Publications. - 0959-6836 .- 1477-0911. ; 30:4, s. 507-518
-
Journal article (peer-reviewed)abstract
- Atmospheric dust plays an important role in terrestrial and marine ecosystems, particularly those that are nutrient limited. Despite that most dust originates from arid and semi-arid regions, recent research has shown that past dust events may have been involved in boosting productivity in nutrient-poor peatlands. We investigated dust deposition in a mid-latitude, raised bog, which is surrounded by a complex geology (paragneiss/schist, granite, quartzite and granodiorite). As proxies for dust fluxes, we used accumulation rates of trace (Ti, Zr, Rb, Sr and Y) as well as major (K and Ca) lithogenic elements. The oldest, largest dust deposition event occurred between similar to 8.6 and similar to 7.4 ka BP, peaking at similar to 8.1 ka BP (most probably the 8.2 ka BP event). The event had a large impact on the evolution of the mire, which subsequently transitioned from a fen into a raised bog in similar to 1500 years. From similar to 6.7 to similar to 4.0 ka BP, fluxes were very low, coeval with mid-Holocene forest stability and maximum extent. In the late Holocene, after similar to 4.0 ka BP, dust events became more prevalent with relatively major deposition at similar to 3.2-2.5, similar to 1.4 ka BP and similar to 0.35-0.05 ka BP, and minor peaks at similar to 4.0-3.7, similar to 1.7, similar to 1.10-0.95 ka BP and similar to 0.74-0.58 ka BP. Strontium fluxes display a similar pattern between similar to 11 and similar to 6.7 ka BP but then became decoupled from the other elements from the mid Holocene onwards. This seems to be a specific signal of the granodiorite batholith, which has an Sr anomaly. The reconstructed variations in dust fluxes bear a strong climatic imprint, probably related to storminess controlled by North Atlantic Oscillation conditions. Complex interactions also arise because of increased pressure from human activities.
|
|
| 7. |
- Mighall, Tim M., et al.
(author)
-
Climate Change, Fire and Human Activity Drive Vegetation Change during the Last Eight Millennia in the Xistral Mountains of NW Iberia
- 2023
-
In: Quaternary. - : MDPI AG. - 2571-550X. ; 6:1
-
Journal article (peer-reviewed)abstract
- An 8500-year record of high-resolution pollen, non-pollen palynomorph, microscopic charcoal and selected geochemical data (Ti, Zr and Pb) is presented from an ombrotrophic mire from the Xistral Mountains, Galicia, North-West Iberia. The results suggest that vegetation changes over the last eight millennia are primarily the result of human disturbance, fire and climate change. Climate and fire were the main factors influencing vegetation development during the early to mid-Holocene, including a short-lived decline in forest cover c. 8.2 cal. ka BP. Changes associated with the 4.2 and 2.8 cal. Ka BP events are less well defined. Human impact on vegetation became more pronounced by the late Holocene with major periods of forest disturbance from c. 3.1 cal. ka BP onwards: during the end of Metal Ages, Roman period and culminating in the permanent decline of deciduous forests in the post-Roman period, as agriculture and metallurgy intensified, leading to the creation of a cultural landscape. Climate change appears to become less influential as human activity dominates during the Late Holocene.
|
|
| 8. |
- Myrstener, Erik, et al.
(author)
-
Long-term development and trajectories of inferred lake-water organic carbon and pH in naturally acidic boreal lakes
- 2021
-
In: Limnology and Oceanography. - : John Wiley & Sons. - 0024-3590 .- 1939-5590. ; 66:6, s. 2408-2422
-
Journal article (peer-reviewed)abstract
- Monitoring of surface waters in the boreal region over the last decades shows that waters are becoming browner. This timeframe may not, however, be sufficient to capture underlying trajectories and driving mechanisms of lake-water quality, important for prediction of future trajectories. Here we synthesize data from seven lakes in the Swedish boreal landscape, with contemporary lake-water total organic carbon (TOC) concentrations of 1.4–14.4 mg L−1, to conceptualize how natural and particularly human-driven processes at the landscape scale have regulated lake-water TOC levels over the Holocene. Sediment-inferred trends in TOC are supported by several proxies, including diatom-inferred pH. Before ~ 700 ce, all lakes were naturally acidic (pH 4.7–5.4) and the concentrations of inferred lake-water TOC were high (10–23 mg L−1). The introduction of traditional human land use from ~ 700 ce led to a decrease in lake-water TOC in all lakes (to 5–14 mg L−1), and in four poorly buffered lakes, also to an increase in pH by > 1 unit. During the 20th century, industrial acid deposition was superimposed on centuries of land use, which resulted in unprecedentedly low lake-water TOC in all lakes (3–11 mg L−1) and severely reduced pH in the four poorly buffered lakes. The other lakes resisted pH changes, likely due to close connections to peatlands. Our results indicate that an important part of the recent browning of boreal lakes is a recovery from human impacts. Furthermore, on a conceptual level we stress that contemporary environmental changes occur within the context of past, long-term disturbances.
|
|
| 9. |
- Myrstener, Erik, et al.
(author)
-
Long-term development of clear- and brown-water acidic lakes in the Swedish boreal landscape : implications for contemporary lake-water quality
-
Other publication (other academic/artistic)abstract
- The recent browning of surface waters and its effects on water quality across northern latitudes continue to raise questions about the driving mechanisms and future trajectories. However, even when based on multi-decadal environmental monitoring data, assessments of contemporary trends and drivers often overlook potential underlying long-term changes in lake-water quality. Here we synthesize data from seven clear- and brown-water acidic lakes in the Swedish boreal landscape to conceptualize how natural and human-driven processes have regulated lake-water quality, measured as spectrally inferred lake-water total organic carbon (TOC) and diatom-inferred pH. From 10,000 BCE to ~500 CE, all studied lakes were browner (lake-water TOC 10–24 mg L-1) and underwent natural acidification, decreasing from pH ~7 to 4.7–5.4. From ~500 to 1850 CE, historical human land use caused lake-water TOC to decline by ~50% in all lakes and in the poorly buffered, clear-water lakes, pH to increase by >1 unit. During the 20th century, the interaction between centuries of land use and more recent industrial acid deposition resulted in unprecedentedly low lake-water TOC (3–8 mg L-1) in all lakes and severely re-duced pH in the poorly buffered lakes, whereas those surrounded by peatlands resisted these pH changes. These extreme values coincided with the onset of environmental monitoring, meaning that contempo-rary increases in lake-water TOC and pH occur within the context of past, long-term disturbances, which are therefore crucial to consider for the purposes of lake management and prediction of lake responses to future environmental disturbances, especially climate change.
|
|
| 10. |
- Ninnes, Sofia, et al.
(author)
-
Investigating molecular changes in organic matter composition in two Holocene lake-sediment records from central Sweden using pyrolysis-GC/MS
- 2017
-
In: Journal of Geophysical Research - Biogeosciences. - : American Geophysical Union (AGU). - 2169-8953 .- 2169-8961. ; 122:6, s. 1423-1438
-
Journal article (peer-reviewed)abstract
- Organic matter (OM) is a key component of lake sediments, affecting carbon, nutrient, and trace metal cycling at local and global scales. Yet little is known about long-term (millennial) changes in OM composition due to the inherent chemical complexity arising from multiple OM sources and from secondary transformations. In this study we explore how the molecular composition of OM changes throughout the Holocene in two adjacent boreal lakes in central Sweden and compare molecular-level information with conventional OM variables, including total carbon, total nitrogen, C:N ratios, delta C-13, and delta N-15. To characterize the molecular OM composition, we employed a new method based on pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), which yields semiquantitative data on > 100 organic compounds of different origin and degradation status. We identify large changes in OM composition after deglaciation (circa 8500 +/- 500 B.C.), associated with early landscape development, and during the most recent 4050 years, driven by degradation processes. With molecular(-)level information we can also distinguish between natural landscape development and human catchment disturbance during the last 1700 years. Our study demonstrates that characterization of the molecular OM composition by the high-throughput PyGC/MS method is an efficient complement to conventional OM variables for identification and understanding of past OM dynamics in lake-sediment records. Holocene changes observed for pyrolytic compounds and compound classes known for having different reactivity indicate the need for further paleo-reconstruction of the molecular OM composition to better understand both past and future OM dynamics and associated environmental changes.
|
|
