Research ArticlePredicted sea-ice loss will terminate Iceland's driftwood supply by 2060 CE
Introduction
Arctic driftwood was pivotal for the medieval Norse expansion across the European/North Atlantic sector (Alix, 2005, Alix, 2012, Alix, 2016; Mooney, 2016a; Pinta, 2018). Representing the only major wood resource in the treeless environment of the high-northern latitudes, driftwood was crucial for fire fuel, construction timber, boat building and a wide range of other routine items (Arnold, 1994; Gulløv, 1997; Hreinsson, 1997; Kristjánsdóttir et al., 2001; Le Mouël and LeMouël, 2002; Ljungqvist, 2005; Alix, 2009a, Alix, 2009b; Mooney, 2016a, Mooney, 2016b; Pinta, 2018; Omurova et al., 2020; Vanlandeghem et al., 2020). The dendrochronological and biochemical study of driftwood can provide unique insights into past human settlement patterns and environmental changes across the high-northern latitudes (Blanchette et al., 2016; Shumilov et al., 2020). Due to its high social and economic value, the amount of driftwood was carefully recorded by farmers and fishers along the Arctic coastlines (Fig. 1; Krisjansson, 1980; Johansen, 1999; Steelandt et al., 2013). To date, driftwood still plays an essential role for all human settlements beyond the northern treeline (Johansen, 1999; Shaw, 2012; Steelandt et al., 2013), where it is frequently used as firewood and building material (Claire and Brewster, 2004; Rekaviður, 2022, https://rekavidur.com/).
Due to natural riverbank erosion and industrial wood logging, huge amounts of driftwood enter the Arctic Ocean every year through the large boreal river systems (Eggertsson, 1993, Eggertsson, 1994; Johansen, 1998; Hellmann et al., 2017; Ahmed et al., 2020; Hole et al., 2021). After entering the Arctic Ocean, driftwood is usually ice-rafted for several years before being released from melting multiyear sea-ice, and deposited along the shallow coastlines of Greenland, Iceland, Svalbard, or the Canadian Archipelago (Häggblom, 1982; Steelandt et al., 2015; Hellmann et al., 2017; Dalaiden et al., 2018; Krumpen et al., 2019). The spatiotemporal supply of driftwood depends on the interplay of factors and processes in both, the boreal source and Arctic sink regions, as well as the complex transport pathways in-between (Fig. 2). These may include river discharge rates, logging and transport activities, permafrost thawing, floods, wildfires, ice and other dams, sea surface temperatures, surface winds, sea-ice extent and drift, water salinity, species-specific floating capacities of wood, as well as ocean currents, such as the Transpolar Drift and the Beaufort Gyre (Hole and Macias-Fauria, 2017; Sander et al., 2021; Tsubouchi et al., 2021). Furthermore, it has been argued that long-term climate and environmental changes have affected the dispersal of Arctic driftwood at different rates and intensities throughout the Holocene (Funder et al., 2011; Nixon et al., 2016). While driftwood was abundant on Ellesmere Island from around 10–6 k years BP, driftwood was particularly sparse in northern Greenland during the Holocene Thermal Maximum around 8–6 k years BP, because of reduced multiyear sea-ice and more open water (Funder et al., 2011). Conversely, a sudden increase in driftwood abundance along the shallow coastlines of Greenland and a decrease of such material on Ellesmere Island began after around 6 k years BP, whereas the past around 2.5 k years were characterized by centennial-scale fluctuations in the amount and origin of driftwood (Funder et al., 2011). As a rule of thumb, less driftwood supply is indicative of coastal blocking by persistent land-fast ice. The physical causes and societal consequences of long-term variation in the transportation and accumulation of Arctic driftwood are still unclear.
To gain deeper insights into the climate dependency of Icelandic driftwood supply, we analyse 289 tree-ring width series from conifers that were collected in 1989 and 2019 along remote shorelines in north-eastern Iceland (Fig. 2; Supplementary Table S1). We then combine our annually resolved and absolutely dated driftwood evidence with the output of state-of-the-art climate model simulations to assess the role of sea-ice extent for past and future changes in driftwood abundance across the North Atlantic/European sector.
Section snippets
Sampling
A total of 289 Arctic driftwood samples were collected during two sampling campaigns along the northern coastline of the almost uninhabited Langanes peninsula in north-eastern Iceland (66.38°N, 14.87°W). During the first sampling campaign in 1989, disc samples of 181 driftwood remains were collected, and another 108 samples were collected 30 years later in 2019. In both cases, the sampling focussed on large and old driftwood remains due to their higher probability for successful cross-dating.
Icelandic driftwood composition
Logged trees dominate our driftwood collection with 83%, whereas naturally fallen trees characterized by the presence of a root collar account for only 17% of all material (Fig. 4). The combination of precise wood anatomical species identification and dendrochronological cross-dating is necessary for tracing the origin of driftwood (Hellmann et al., 2017), which has often been neglected in the past (Funder et al., 2011; Hole et al., 2021). Composed of P. sylvestris (67%), Larix spp. (23%), and
Author contributions
T.K., M.R., O.E., P.C., T.Z. and U.B. collected driftwood. A.K., O.E. and U.B. provided the boreal reference chronologies. T.K., M.R., O.E. and H.V. processed the driftwood samples. T.C. performed the proxy-model comparison. T.K. and U.B. wrote and revised the paper with input from all others.
Data availability
The data are available on request from the corresponding author.
Declaration of Competing Interest
The authors declare no competing interests.
Acknowledgements
The work was supported by the Establishing bilateral cooperation with Icelandic forest service (EHP-BF10-OVNKM-1-023-01-2018, EEA and NORWAY GRANTS 2014–2021), the SustES project–Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797), the ERC project Monostar (grant number AdG 882727), and Geografický výzkum dynamiky přírodních a společenských prostorových procesů (GEODYN)” (MUNI/A/1570/2020). Part of
References (87)
Deciphering the impact of change on the driftwood cycle: contribution to the study of human use of wood in the Arctic
Glob. Planet. Chang.
(2005)- et al.
Arctic driftwood reveals unexpectedly rich fungal diversity
Fungal Ecol.
(2016) - et al.
A model to interpret driftwood transport in the Arctic
Quat. Sci. Rev.
(2018) - et al.
Holocene driftwood incursion to Southwestern Victoria Island, Canadian Arctic Archipelago, and its significance to paleoceanography and archaeology
Quat. Res.
(2000) - et al.
Dendro-provenancing of Arctic driftwood
Quat. Sci. Rev.
(2017) Origin of driftwood in North Norway and its relevance for transport routes of drift ice and pollution to the Barents Sea
Sci. Total Environ.
(1999)- et al.
Notes towards an optimal sampling strategy
Dendrochronologia
(2018) - et al.
Climate change influences on species interrelationships and distributions in high-Arctic Greenland
- et al.
An Icelandic medieval stave church made of drift timber: the implications of the wood identification
J. Cult. Herit.
(2001) A ‘North Atlantic island signature’ of timber exploitation: evidence from wooden artefact assemblages from Viking Age and medieval Iceland
J. Archaeol. Sci. Rep.
(2016)
Construction history and timber use of the medieval settlement Nadymskiy Gorodok in the northwestern Siberian forest-tundra
J. Archaeol. Sci.
Tree-ring dating of Russian Pomor settlements in Svalbard
Dendrochronologia
Ancient arctic pyro-technologies: experimental fires to document the impact of animal origin fuels on wood combustion
J. Archaeol. Sci. Rep.
Recent trends in freshwater influx to the Arctic Ocean from four major Arctic-draining Rivers
Water
Driftwood, Timber and Shrubs! Wood Used by Ruin Islander Thule at Skraeling Island, Eastern Ellesmere Island, Canada
Persistance and change in Thule wood use
Using wood on King Island, Alaska
Études/Inuit/Studies
A Critical Resource: Wood Use and Technology in the North American Arctic. The Oxford Handbook of the Prehistoric Arctic
Frequent long-distance plant colonization in the changing Arctic
Science
The Importance of Wood in the early Thule Culture of the Western Arctic
The Seasonal and Regional transition to an Ice-Free Arctic
Geophys. Res. Lett.
A simple cross-dating program for tree-ring research
Tree-Ring Bull.
The Picea-Larix problem. IAWA
Bulletin
Partitioning uncertainty in projections of Arctic Sea ice
Environ. Res. Lett.
Key indicators of Arctic climate change: 1971–2017
Environ. Res. Lett.
Global evidence that deforestation amplifies flood risk and severity in the developing world
Glob. Chang. Biol.
Arctic Sea-ice variability during the instrumental era
Geophys. Res. Lett.
Cruising an archive: on the palaeoclimatic value of the Lena Delta
The Holocene
Not all Driftwood is Created Equal. Wood Use and Value along the Yukon and Kuskokwim Rivers, Alaska. Alaska Jo
Anthropol.
Arctic open-water periods are projected to lengthen dramatically by 2100
Commun. Earth Environ.
Arctic amplification is caused by sea-ice loss under increasing CO2
Nat. Comm.
Abrupt Holocene climate change as an important factor for human migration in West Greenland
PNAS
2017. Influence of high-latitude atmospheric circulation changes on summertime Arctic Sea ice
Nat. Clim. Chang.
Relationships between Arctic Sea ice drift and strength modelled by NEMO-LIM3.6
Cryosphere
Beitrag zur Rationalisierung eines dendrochronologischen Verfahrens und zur Analyse seiner Aussagesicherheit
Forstwiss. Centralblatt.
Origin of the driftwood on the coasts areas of Iceland, a dendrochronological study
Jökull
Driftwood as an indicator of relative changes in the influx of Arctic and Atlantic water into the coastal areas of Svalbard
Polar Res.
Global Sea-Ice Concentration Climate Data Record 1979–2019 (v2.0, 2017), OSI-450 and OSI-430-b, doi: 10.15770/EUM_SAF_OSI_0008
Evaluation of Climate Models
A 10,000-year record of Arctic Ocean sea-ice variability—view from the beach
Science
Evaluating crossdating accuracy: a manual and tutorial for the computer program COFECHA
Tree-Ring Res.
From Middle Ages to Colonial Times. Archaeological and Ethnohistorical Studies of the Thule Culture in South West Greenland 1300–1800 AD
Driftwood in Svalbard as an indicator of sea ice conditions
Geografiska Annal. Ser. A Phys. Geogr.
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