Boris K. Biskaborn

Siberian larch forests and the ion content of thaw lakes form a geochemically functional entity

Siberian larch forests growing on shallow permafrost soils have not, until now, been considered to be controlling the abiotic and biotic characteristics of the vast number of thaw-lake ecosystems. Here we show, using four independent data sets (a modern data set from 201 lakes from the tundra to taiga, and three lake-core records), that lake-water geochemistry in Yakutia is highly correlated with vegetation. Alkalinity increases with catchment forest density. We postulate that in this arid area, higher evapotranspiration in larch forests compared with that in the tundra vegetation leads to local salt accumulation in soils. Solutes are transported to nearby thaw lakes during rain events and snow melt, but are not fully transported into rivers, because there is no continuous groundwater flow within permafrost soils. This implies that potentially large shifts in the chemical characteristics of aquatic ecosystems to known warming are absent because of the slow response of catchment forests to climate change.

Late Holocene thermokarst variability inferred from diatoms in a lake sediment record from the Lena Delta, Siberian Arctic

Thermokarst lakes in the Siberian Arctic contain sediment archives that can be used for paleoenvironmental inference. Until now, however, there has been no study from the inner Lena River Delta with a focus on diatoms. The objective of this study was to investigate how the diatom community in a thermokarst lake responded to past limnogeological changes and what specific factors drove variations in the diatom assemblage. We analysed fossil diatom species, organic content, grain-size distribution and elemental composition in a sediment core retrieved in 2009 from a shallow thermokarst lake in the Arga Complex, western Lena River Delta. The core contains a 3,000-year record of sediment accumulation. Shifts in the predominantly benthic and epiphytic diatom species composition parallel changes in sediment characteristics. Paleoenvironmental and limnogeological development, inferred from multiple biological and sedimentological variables, are discussed in the context of four diatom zones, and indicate a strong relation between changes in the diatom assemblage and thermokarst processes. We conclude that limnogeological and thermokarst processes such as lake drainage, rather than direct climate forcing, were the main factors that altered the aquatic ecosystem by influencing, for example, habitat availability, hydrochemistry, and water level.

Knowledge Transfer by the Global Terrestrial Network for Permafrost (GTN-P)

Permafrost is a direct indicator of climate change and permafrost temperature and active-layer thickness have been identified as Essential Climate Variables (ECV) by the global observing community. The existing data, however, were far from being homogeneous and were not yet optimized for databases, without framework for data reporting or archival and the data documentation was incomplete. Within the EU FP7 project PAGE 21, Arctic Portal has developed a central Data Management System (DMS) for permafrost monitoring parameters of the Global Terrestrial Network for Permafrost (GTN-P) and others. Each component of the DMS, including parameters, data levels and metadata formats were developed in cooperation with the GTN-P, the International Permafrost Association (IPA) and Arctic Portal. The researcher can now edit, visualize and download standardized datasets, metadata, charts and statistics of all relevant parameters for a specific site in all partner countries. The GTN-P DMS is based on an object oriented model (OOM) following the framework Model/View/Controller (MVC) of Cakephp. It is implemented with open source technologies with the PostGIS database and Geoserver. To ensure interoperability and enable potential inter-database search, the system follows the evolution of the Semantic Web (Linking Geospatial Data); the database structure and content are mapped towards xml, xslt, rdf, and owl. Moreover, metadata comply with the ISO 19115/2 and ISO TC/211 standards for geospatial information. Datasets are then normalized based on a control vocabulary registry. Tools are further developed to provide data processing, analysis capability and quality control. The end of the distribution chain deliver highly structured datasets towards modelers in NetCDF files, format developed by UNIDATA. The elaboration of this project highlights the absence of standardized data model for scientific relational databases as well as a lack of ontology definition and mapping within and between scientific communities.Permafrost ecosystems occupy a quarter of the land surface in the Northern Hemisphere. Ongoing rapid temperature change in these areas causes permafrost warming in the Arctic and thawing in the Subarctic regions (Romanovsky et al. Permafr Periglac Process 21:106–116 2010).

Paleolimnological studies in Russian northern Eurasia: A review

This article presents a review of the current data on the level of paleolimnological knowledge about lakes in the Russian part of the northern Eurasia. The results of investigation of the northwestern European part of Russia as the best paleolimnologically studied sector of the Russian north is presented in detail. The conditions of lacustrine sedimentation at the boundary between the Late Pleistocene and Holocene and the role of different external factors in formation of their chemical composition, including active volcanic activity and possible large meteorite impacts, are also discussed. The results of major paleoclimatic and paleoecological reconstructions in northern Siberia are presented. Particular attention is given to the databases of abiotic and biotic parameters of lake ecosystems as an important basis for quantitative reconstructions of climatic and ecological changes in the Late Pleistocene and Holocene. Keywords: paleolimnology, lakes, bottom sediments, northern

Modern modes of provenance and dispersal of terrigenous sediments in the North Pacific and Bering Sea: implications and perspectives for palaeoenvironmental reconstructions

During expedition 202 aboard the RV Sonne in 2009, 39 seafloor surface sediment sites were sampled over a wide sector of the North Pacific and adjoining Bering Sea. The data served to infer land–ocean linkages of terrigenous sediment supply in terms of major sources and modes of sediment transport within an over-regional context. This is based on an integrated approach dealing with grain-size analysis, bulk mineralogy and clay mineralogy in combination with statistical data evaluation (end-member modelling of grain-size data, fuzzy cluster analysis of mineralogical data). The findings on clay mineralogy served to update those of earlier work extracted from the literature. Today, two processes of terrigenous sediment supply prevail in the study area: far-distance aeolian sediment supply to the pelagic North Pacific, and hemipelagic sediment dispersal from nearby land sources via ocean currents along the continental margins and island arcs. Aeolian particles show the finest grain sizes (clay and fine silt), whereas hemipelagic sediments have high abundances of coarse silt. Exposed sites on seamounts and the continental slope are partly swept by strong currents, leading to residual enrichment of fine sand. Four sediment sources can be distinguished on the basis of distinct index minerals revealed by statistical data analysis: dust plumes from central Asia (quartz, illite), altered materials from the volcanic regions of Kamchatka and the Aleutian Arc (smectite), detritus from the Alaskan Cordillera (chlorite, hornblende), and fluvial detritus from far-eastern Siberia and the Alaska mainland (quartz, feldspar, illite). These findings confirm those of former studies but considerably expand the geographic range of this suite of proxies as far south as 39°N in the open North Pacific. The present integrated methodological approach proved useful in identifying the major modern processes of terrigenous sediment supply to the study region. This aspect deserves attention in the selection of sediment core sites for future palaeoenvironmental reconstructions related to aeolian and glacial dynamics, as well as the recognition of palaeo-ocean circulation patterns in general.

Open research data, data portals and data publication – an introduction to the data curation landscape

During the past decade, the relevance of research data stewardship has been rising significantly and data publication has become more familiar. Preservation of research data for long-term use, including its storage in adequate repositories has been identified as a key issue by the scientific community as well as by research agencies and the public. In practice, however, the current state of data sharing and re-use requires considerable improvement. This paper reviews recent developments in this area, and aims to provide some guidance to the increasing diversity of newly developed digital solutions, such as data journals, online data repositories, and citable digital object identifier (DOI) for datasets. We examine the differences and similarities between different examples of Arctic-related data management, including the newly created database of the Global Terrestrial Network for Permafrost GTN-P, a Canadian example of a (meta)data portal (Polar Data Catalogue), and examples of data repositories (e.g., PANGAEA, Nordicana D) and data journals (e.g., Earth System Science Data). We also describe the newly established Registry of Research Data Depositories (re3data.org) as a convenient resource for individual researchers to get an overview on and identify an appropriate repository for their scientific datasets as well for funding agencies during the evaluation process of the data management plan of research proposals. Zusammenfassung: In den letzten zehn Jahren ist die Bedeutung des Zugangs und der Nachnutzung von Forschungsdaten gestiegen. Neue Publikationsstrategien für Forschungsdaten stellen sicher, dass wissenschaftliche Daten dauerhaft in geeigneten Daten-Repositorien gespeichert und zugänglich gemacht werden können. Auch wenn die Umsetzung dieser Publikationsstrategien von der wissenschaftlichen Community und von Forschungsförderorganisationen als zentrale Herausforderung für das Wissenschaftssystem benannt wird, ergeben sich in der Praxis noch viele Herausforderungen. Dieser Artikel gibt einen Überblick über aktuelle Entwicklungen im Bereich des Forschungsdatenmanagements. Exemplarisch werden einige Beispiele für den offenen Zugang vorgestellt und Publikationsstrategien für Forschungsdaten beschrieben. U.a. werden Aufgabe und Dienstleistung von Daten-Repositorien, Daten-Journalen sowie Daten-Portalen im Bereich der Arktisforschung erläutert. Exemplarisch werden folgende digitale Forschungsdateninfrastrukturen vorgestellt: Das kanadische (Meta)daten-Portal Polar Data Catalogue, die neue Datenbank des Global Terrestrial Network for Permafrost GTN-P (Metadaten und Daten), die Daten-Repositorien PANGAEA und Nordicana D sowie das Daten-Journal Earth System Science Data (ESDD). Darüber hinaus wird der Service des Registry of Research Data Repositories (re3data. org) vorgestellt. Dieses internationale Verzeichnis unterstützt Forschende und Forschungsförderer bei der Identifikation von geeigneten Daten-Repositorien zur Speicherung und Zugänglichmachung ihrer Forschungsdaten.