Egill Erlendsson

1000 years of environmental change and human impact at Stóra-Mörk, southern Iceland: A multiproxy study of a dynamic and vulnerable landscape

Multiproxy pollen, sediment, plant macrofossil and subfossil insect analyses are used to explore environmental change at Stóra-Mörk in southern Iceland between ad 500 and 1500. Previous palaeoecological studies in Iceland have indicated that vegetation and landscape change rapidly succeeded the initial settlement of the island around ad 871, with strong environmental consequences. However, recent high-resolution studies in western and northern Iceland suggest that the timing and amplitude of these changes may be less uniform than previously assumed. The palaeoecological evidence from Stóra-Mörk shows an initially muted anthropogenic signal. Before the early tenth century, the area was characterized by damp birch and willow woodland. Large-scale human impact did not begin until after ad 920 when a change in land use to grazing and crop production is observed in the pollen, insect and plant macrofossil records. Shifts in vegetation and insect taxa and in aeolian deposition indicate that this activity resulted in woodland reduction, increased soil instability, eutrophication and land surface drying. The relatively late appearance of large-scale human impact at Stóra-Mörk is consistent with the tenth-century farm establishment suggested by the historical record, and the delay in settlement at the location may relate to an initial avoidance of labour-intensive woodland clearance and/or management of woodland resources. This paper adds to the emerging body of evidence that suggests that the scale and timing of the initial effect of the human presence on Icelandic environments was influenced by complex and varied climatic, landscape, vegetational and cultural factors.

The palaeoecology of a high status Icelandic farm

Abstract Written sources indicate that the farm of Reykholt in Borgarfjörður, Iceland was built on the land of the original settlement farm, and that it had acquired the primary status in the valley by the early 12th century. Archaeological evidence suggests that the farm together with a church may have been established as early as ca. 1000 AD, which is when Christianity was adopted in Iceland. The site became one of the countrys major ecclesiastical centres, growing in wealth and stature, not least during the occupancy of the writer and chieftain Snorri Sturluson in the first half of the 13th century. Long-term excavations included a palaeoenvironmental sampling programme aimed at the investigation of the economy and environment of the farm. This paper focuses upon the results of the palaeoecological analysis and places them into the historical context of the farm.

Feasting in Viking Age Iceland: sustaining a chiefly political economy in a marginal environment

The authors show that the principal correlates of feasting in Viking Age Iceland were beef and barley, while feasting itself is here the primary instrument of social action. Documentary references, ethnographic analogies, archaeological excavation and biological analyses are woven together to present an exemplary procedure for the recognition of feasting more widely.

The onset of the palaeoanthropocene in Iceland: Changes in complex natural systems:

Pre-industrial human impacts on the past environment are apparent in different proxy records at different times in different places. Recognizing environmentally transformative human impacts in palaeoenvironmental archives, as opposed to natural variability, is a key challenge in understanding the nature of the transition to the Earth’s current ‘Anthropocene’ condition. Here, we consider the palaeoenvironmental record for Iceland over the past 2.5 ka, both before and after the late ninth century human settlement (landnám). The Scandinavian colonization of the island was essentially abrupt, involving thousands of people over a short period. The colonization triggered extensive changes in Icelandic ecosystems and landscapes. A volcanic ash known as the Landnám tephra was deposited over most of Iceland immediately before the settlement began. The Landnám tephra layer thus provides a uniquely precise litho-chrono-stratigraphic marker of colonization. We utilize this marker horizon as an independent definition of the effective onset of the local palaeoanthropocene (which is conceptually related to, but distinct from, the global Anthropocene). This allows us to evaluate proxy records for human impact on the Icelandic environment and to assess how and when they show transformative impact. Based on this analysis, we consider the implications for understanding and defining the Anthropocene in those areas of the Earth where such a clear independent marker of the onset of significant human impacts is lacking.

The timing and causes of the final pre-settlement expansion of Betula pubescens in Iceland

Palynological data from southern and western Iceland show rising values for the pollen of Betula pubescens for the period AD 600—800. The increased values for B. pubescens probably stem from both improved flowering conditions and increased coverage and density of woodlands associated with short-lived climatic amelioration within a phase of longer-term harsh climate. The swift response to climate change in the palynological record and good correlation with comparative data from other proxies indicates that Icelandic palynology offers an important, yet largely underexploited, tool for the reconstruction of Icelandic Holocene environments.

Landscapes of Contrast in Viking Age Iceland and the Faroe Islands

Abstract The arrival of the Vikings in the Faroe Islands and Iceland in the ninth century AD from Scandinavian and British Isles homelands essentially represented the colonisation of virgin landscapes. Environmental investigations show that their imported agricultural package was supplemented in coastal areas by bird and marine resources which, for the Faroes at least, continued to be of significance. The Faroese also developed appropriate land management practices such as outfield grazing and soil augmentation to counteract any detrimental affects arising from, for instance, reductions in the bird population, soil and slope erosion and the lack of naturally fertile soils. It seems that there had always been sufficient resources available for an enterprising human population and that the Faroes did not exceed their carrying capacity during the Norse period. The Icelanders faced different challenges: a more extreme climate, the rapid and substantial erosion of volcanic soils following settlement and the disappearance of what had probably been a substantial woodland resource. Actions were taken to conserve woodlands before they were completely destroyed and regulatory mechanisms assisted the maintenance of grazing, but did not stem soil erosion.

Life on the periphery is tough: Vegetation in Northwest Iceland and its responses to early-Holocene warmth and later climate fluctuations

Long- and short-term climate variations in the North Atlantic have been of sufficient magnitude to leave a discernible mark on the history of vegetation and landscape stability in Iceland during the Holocene. A reconstruction of early- and mid-Holocene vegetation around Lake Kagaðarhóll, Northwest Iceland, examines how climate fluctuations have affected the terrestrial ecosystem. A thorough reconstruction has been made using pollen and plant macrofossil analyses combined with proxies for organic and inorganic matter. The record shows the development from a period of pioneer vegetation towards a woodland ecosystem. The deposition of the Saksunarvatn tephra at c. 10,300 cal. yr BP caused a 100-year period of instability, followed by a gradual trend of stabilization over several centuries while material left behind by retreating glaciers and tephra was being contained by expanding and developing vegetation. Early-Holocene warmth is indicated by high pollen production of Juniperus communis around the lake by c. 10,100 cal. yr BP and birch woodland being established around the lake by c. 9200 cal. yr BP, much earlier than previously believed for this locale. Cooling climate between c. 8700 and 8200 cal. yr BP halted woodland development, with reduced plant reproduction likely caused by cold spring and summer temperatures. Woodlands became re-established from c. 7900 cal. yr BP before entering a decline from c. 6000 cal. yr BP, with harsher environmental conditions apparent after c. 4200 cal. yr BP. The Kagaðarhóll record compares favourably with other palaeoclimatic data from the North Atlantic, demonstrating the potential of pollen and macrofossil data for reconstructions of environmental change in Iceland and as an indicator of climate variability in the North Atlantic during the Holocene.

Cereal cultivation as a correlate of high social status in medieval Iceland

Utilising a multi-profile palynological approach and a rapid scanning technique, this paper examines whether or not cereal cultivation is representative of a medieval Icelandic farmstead’s social status; first as a correlate by confirming that cereals were grown in association with the archaeological features characteristic of high status and second, as an indicator in its own right through comparison with other datasets from inferred lower status farms in the same valley. The results suggest that medieval cereal cultivation in Mosfellsdalur was confined to the landholding of the Mosfell Estate. This is probably a direct consequence of the locale being settled early during Iceland’s colonisation and thereby allowing settlers there to secure the prime location in the valley for agriculture. The later abandonment of cereal cultivation on the Estate also appears to be linked to social circumstances in Mosfellsdalur c. ad 1200. An evaluation of other pollen studies and historical sources intimates a transition in cereal cultivation from inland toward coastal (and perhaps geothermal) sites in the mid-13th century, probably as a consequence of the onset of the Little Ice Age. These sites may also be linked with high status institutions. Despite this effort to adapt to altered climate conditions, cereal cultivation in Iceland is believed to have been completely abandoned by ad 1500. Overall, the temporal and spatial dynamics of cereal cultivation are shown to be complex, subject to both societal and environmental changes.

Holocene environmental change and development of the nutrient budget of histosols in North Iceland

Backround and aimsLittle is known about vegetation changes in Icelandic peatlands in the context of soil chemical properties. By connecting soil chemical and physical characteristics with palaeobotanical data we examined interactions between climate, histosols, vegetation and land use during the Holocene.MethodsExchangeable base cations, cation exchange capacity (CEC), base saturation (BS), decomposition rates, using carbon:nitrogen ratio (C:N) and von Post humification, and soil physical properties were determined. Vegetation development was reconstructed based on pollen analysis. The impact of geographic location was examined by comparing results from three sloping fens (coastal, inland and highland fringe).ResultsMinerogenic content was highest in the proximity of the active volcanic zone, reflected in higher C:N and nutrient content in the histosol profiles of the fens inland and at the highland fringe. The coastal site revealed exceptionally high BS. C:N was either stable throughout the profile or increased with depth. Plant species richness, and evenness based on pollen data, and pollen concentrations were greatest at the site with lowest nutrient levels.ConclusionsMinerogenic content facilitates the ability of histosols to bind nutrients. Plant growth is optimised at the sites with lower fertility levels. C:N alone is not a reliable indicator of decomposition rates, but depends on the quality of the organic parent material. Environmental conditions driven by climate changes caused alterations in vegetation and soil properties before the human settlement of Iceland (c. AD 870), but overall the histosols showed resilience towards severe degradation. After the settlement, the histosols struggled to buffer the impact caused by destruction of vegetation and increased erosion. This study increases our understanding of environmental and anthropogenic determinants of soil- and vegetation development.

A Bayesian approach to linking archaeological, paleoenvironmental and documentary datasets relating to the settlement of Iceland (Landnám):

Icelandic settlement (Landnám) period farmsteads offer opportunities to explore the nature and timing of anthropogenic activities and environmental impacts of the first Holocene farming communities. We employ Bayesian statistical modelling of archaeological, paleoenvironmental and documentary datasets to present a framework for improving chronological robustness of archaeological events. Specifically, we discuss events relevant to the farm Hrísbrú, an initial and complex settlement site in southwest Iceland. We demonstrate that tephra layers are key in constraining reliable chronologies, especially when combined with related datasets and treated in a Bayesian framework. The work presented here confirms earlier interpretations of the chronology of the site while providing increased confidence in the robustness of the chronology. Most importantly, integrated modelling of AMS radiocarbon dates on Hordeum vulgare grains, palynological data, documented evidence from textual records and typologically diagnostic artefacts yield increased dating reliability. The analysis has also shown that AMS radiocarbon dates on bone collagen need further scrutiny. Specifically for the Hrísbrú farm, first anthropogenic footprint palynomorph taxa are estimated to around AD 830–881 (at 95.4% confidence level), most likely before the tephra fall out of AD 877 ± 1 (the Landnám tephra layer), demonstrating the use of arable fields before the first known structures were built at Hrísbrú (AD 874–951) and prior to the conventionally accepted date of the settlement of Iceland. Finally, we highlight the importance of considering multidisciplinary factors for other archaeological and paleoecological studies of early farming communities of previously uninhabited island areas.