Showing papers on "Driftwood published in 2016"

Design of Sediment Traps with Open Check Dams. II: Woody Debris

Abstract: Sediment traps with open check dams are widely used structures in flood hazard mitigation. This paper and its companion review the literature on their design. The companion paper examines hydraulic and deposition processes associated with sediment transport. However, field feedback has shown that open check dam behaviors during floods are dramatically influenced by the presence or absence of driftwood. To better assess large woody debris hazards and influences, this paper first reports the methods available to estimate driftwood production in terms of volume and dimensions. Information is given on their recruitment and transfer in the catchment. The presence of driftwood and the relevance of trapping them strongly influence the choice of the suitable shape and type of the open check dam. The performance of the different open check dam shapes in terms of driftwood management is detailed. Design criteria to estimate clogging probabilities, trapping efficiencies, volume capacities to trap driftwood, ...

Fungi Sailing the Arctic Ocean: Speciose Communities in North Atlantic Driftwood as Revealed by High-Throughput Amplicon Sequencing

Abstract: High amounts of driftwood sail across the oceans and provide habitat for organisms tolerating the rough and saline environment. Fungi have adapted to the extremely cold and saline conditions which driftwood faces in the high north. For the first time, we applied high-throughput sequencing to fungi residing in driftwood to reveal their taxonomic richness, community composition, and ecology in the North Atlantic. Using pyrosequencing of ITS2 amplicons obtained from 49 marine logs, we found 807 fungal operational taxonomic units (OTUs) based on clustering at 97 % sequence similarity cut-off level. The phylum Ascomycota comprised 74 % of the OTUs and 20 % belonged to Basidiomycota. The richness of basidiomycetes decreased with prolonged submersion in the sea, supporting the general view of ascomycetes being more extremotolerant. However, more than one fourth of the fungal OTUs remained unassigned to any fungal class, emphasising the need for better DNA reference data from the marine habitat. Different fungal communities were detected in coniferous and deciduous logs. Our results highlight that driftwood hosts a considerably higher fungal diversity than currently known. The driftwood fungal community is not a terrestrial relic but a speciose assemblage of fungi adapted to the stressful marine environment and different kinds of wooden substrates found in it.

The role of sea ice for vascular plant dispersal in the Arctic

Abstract: Sea ice has been suggested to be an important factor for dispersal of vascular plants in the Arctic. To assess its role for postglacial colonization in the North Atlantic region, we compiled data on the first Late Glacial to Holocene occurrence of vascular plant species in East Greenland, Iceland, the Faroe Islands and Svalbard. For each record, we reconstructed likely past dispersal events using data on species distributions and genetics. We compared these data to sea-ice reconstructions to evaluate the potential role of sea ice in these past colonization events and finally evaluated these results using a compilation of driftwood records as an independent source of evidence that sea ice can disperse biological material. Our results show that sea ice was, in general, more prevalent along the most likely dispersal routes at times of assumed first colonization than along other possible routes. Also, driftwood is frequently dispersed in regions that have sea ice today. Thus, sea ice may act as an important dispersal agent. Melting sea ice may hamper future dispersal of Arctic plants and thereby cause more genetic differentiation. It may also limit the northwards expansion of competing boreal species, and hence favour the persistence of Arctic species.

An 11 000‐year record of driftwood delivery to the western Queen Elizabeth Islands, Arctic Canada

Abstract: Fifty-six new radiocarbon dates from driftwood (mainly Larix, Picea and Populus spp.) collected from the modern and raised shorelines of Melville and Eglinton islands (western Canadian High Arctic) are presented and compared to other driftwood collections from the Canadian Arctic Archipelago (CAA) and Greenland. By documenting the species (provenance) and spatio-temporal distribution of driftwood at various sites across the Arctic, regional characterizations of former sea-ice conditions and changes in Arctic Ocean circulation patterns may be deduced. The earliest postglacial invasion of the Canadian Arctic Archipelago by driftwood is recorded on central Melville Island at c. 11 cal. ka BP, suggesting that the modern circulation pattern of Arctic Ocean surface water southeast through the archipelago was established >1000 years earlier than previously proposed. Throughout most of the Holocene until c. 1.0 cal. ka BP, the rate of driftwood delivery to the western Arctic islands was low (~1 recorded stranding event per 200 years) and intermittent, with the longest break in the record occurring between c. 3.0 and 5.0 cal. ka BP. This 2000-year hiatus is attributed to a period of colder temperatures causing severe sea-ice conditions and effectively making the coasts of the western Arctic islands inaccessible. After c. 1.0 cal. ka BP, driftwood incursion increased to maximum Holocene levels (~1 recorded stranding event every 20 years). Driftwood identified to the genus level as Larix that was delivered at this time suggests that the Trans Polar Drift current was regularly in its most southwestern position, related to a dominantly positive Arctic Oscillation mode. The Little Ice Age appears to have had little impact on driftwood entry to the western Canadian Arctic Archipelago, indeed the general abundance in the latest Holocene may record infrequent landfast sea ice.

Examining Possible Driftwood Use in Viking Age Icelandic Boats

Abstract: While boat and ship graves are known from across northern Europe, and are particularly associated with the Viking Age, only seven examples of such monuments have been excavated in Iceland. Furthermore, no shipwrecks are known dating from this period in Iceland, and examples of boat timbers preserved by waterlogging are very rare. As such, the mineralized wood remains from these burials comprise the vast majority of direct archaeological evidence currently available for the boats used in daily life in early Iceland. This paper uses taxonomic identification of mineralized wood remains from the Icelandic boat graves, along with comparative data from Europe and Scandinavia, to discuss boat construction and repair in early Iceland, including the possibilities of driftwood utilization and the importation of boats from Norway. The economic and social significance of the practice of boat burial in Iceland is also explored, with regard to the importance of boats as transport and the limited availability of wood su...

Effects of Boreal Timber Rafting on the Composition of Arctic Driftwood

Abstract: Wood from the boreal forest represents an important resource for paper production and sawmill processing Due to poor infrastructure and high transportation costs on land, timbers are often transported over long distances along large river systems Industrial river rafting activities started at the end of the 19th century and were intensified in western Russia and central Siberia from the 1920s to the 1980s After initial single stem rafting, timber is today mostly floated in ship-guided rafts Lost wood can be transported further to the Arctic Ocean, where it may drift within sea ice over several years and thousands of kilometers before being deposited along (sub-)Arctic coastlines Here, we introduce dendro-dated tree-ring width series of 383 driftwood samples from logged timber that were collected along different driftwood-recipient coastlines in Greenland, Iceland and Svalbard The majority of driftwood is Pinus sylvestris from the southern Yenisei region in central Siberia, whereas Larix sp and Picea sp from western Russia and eastern Siberia are rare Although our results are based on a small sample collection, they clearly show the importance of timber rafting on species, age and origin of Arctic driftwood and indicate the immense loss of material during wood industrial river floating

A new secondary ecotope for talitrids: driftwood in the Bay of Fundy

Abstract: Platorchestia platensis (Amphipoda, Talitridae) was previously known ecologically as a wrack generalist, but here we describe a secondary driftwood ecotope for this species. The trophic dependence of driftwood-acclimated P. platensis on rotting wood was confirmed by successfully culturing it within driftwood, without further addition of food. The stranded driftwood in which P. platensis was found contained gribble burrows (round and of 0.6 to 5 mm diameter). We hypothesize that P. platensis used the empty gribble burrows for interspecific squatting (to gain initial entry to driftwood and for shelter). We found eleven driftwood depositories in a 230 km length of shoreline in Passamaquoddy Bay. The commonest driftwood was of spruce and eastern white cedar. The small marsh at Hartley Cove contained a driftwood depository, where the new driftwood ecotope was discovered. This site was studied temporally to understand how wind and tidal forces might affect import and export of driftwood.

Chemical Differentiation between Immersed and Dry Wood Samples in Nunavik (Northern Quebec, Canada): Preliminary Results

Abstract: The primary aim of this study was to differentiate immersed wood samples from dry wood samples based on chemical analysis. The method has been developed to be applied to wood found in archaeological sites to distinguish between driftwood and wood that was cut in the forest tundra and then transported to the sites. The results of our research show that Na concentrations in the immersed samples were much higher than in the dry samples for coniferous and deciduous wood samples. Principal components analysis (PCA) based on the element concentrations normalized to the total cation concentrations show that the data from the immersed wood samples and the dry wood samples clustered into two separate groups.

Driftwood Biomass in Italy: Estimation and Characterization

Abstract: In Italy, the accumulation of driftwood along the shore is a significant issue, especially for the coastal municipalities of the Central and Northern regions. The purpose of this study was to evaluate the distribution and availability of the coastal driftwood in Italy and its impacts, as well as analyzing its chemical–physical properties to evaluate possible employment in combustion applications. On the basis of a data gathering campaign for the period 2010–2014, about 60,000 tons of driftwood are reported to accumulate along the Italian shores every year. The two regions hardest-hit were Liguria and Veneto, with about 15,000 tons and 12,000 tons, respectively. Three sites were selected for driftwood sampling. The main issue deriving from chemical characterization was the high chlorine content (up to 2% on dry basis) and metal oxides in the ashes. Driftwood samples were then subjected to a natural washing cycle for 1 month; results revealed a significant drop in chlorine and metal oxides contents (up to 80%) and a low decrease of the lower heating value (about 20%). Furthermore, the percolated water was analyzed in terms of chemical oxygen demand (COD), showing values (up to 1100 mg O2/L) above the Italian limits for discharges into surface waters.

Driftwood: Redefining Sound Sculpture Controllers

Abstract: The Driftwood is a maneuverable sculpture that is both an instrument and a controller. Tactilely, it is a micro-terrain one can explore with the hands as with the ears. Closed circuit sensors, moving wooden parts and Piezo microphones are discussed in the design phase alongside background and musical implementation concepts. Electronics and nature converge in this instrument harmoniously referencing our technological growth, changing world and environment. When engaging with the sonic sculpture, silent objects become audible and rest-wood is venerated. It is revealed to the musician interacting with Driftwood that our actions intervene directly with issues relating to sustainability and the amount of value we place on the world in which we live.