Projects/Activities

Periglacial conditions have characterized the geomorphological development of river systems and have activated eolian processes during the Quarternary ice ages in Europe. Frost and melt mechanisms have also caused deformations on micro and macro scale in soil and sediments. Specific periglacial phenomena are indicative for (paleo-) climatic conditions

In the wake of topical research issues such as global change and energy resources, one can recognize two priority targets for the study of fossil plant remains: - insight into the role of land plants and phytoplankton as monitors, recorders, motors and moderators of climatic and environmental change; -insight into the predictive value of organic remains with respect to genesis, composition, occurrence, quality and quantity of fossil fuel reserves. In harmony with these targets, current research at the Laboratory of Palaeobotany and Palynology (LPP) is aimed to provide for basic contributions to the palaeoecological study and interpretation of Palaeozoic, Mesozoic and Cenozoic plant life. Four interconnected areas of scientific emphasis are currently distinguished: - biotic change: documentation and causal analysis of changes of past plant biota in terrestrial and marine environments, both at short and long time-scales; - selective preservation: identification of the biological, physical and chemical factors that determine selective preservation of organic matter during transport, sedimentation and burial; - methodology: development and introduction of new analytical methodology relevant to the study and interpretation of fossil plant remains; - systematics: generation and compilation of systematic data aimed at the accurate identification and classification of fossil plant remains. Overview of results LPP strives after a balance between the study of land plant remains and organic-walled marine phytoplankton (mainly dinoflagellates). Research objectives are related to both short (latest Pleistocene-Holocene) and long time-scales (late Palaeozoic-Cenozoic). Short time-scales Modern land plant communities can be understood only in the light of their history since the onset of the last deglaciation (15,000 yr BP). In western and southern Europe this history is governed by the climatically induced spread of forest communities and their subsequent recession as man's influence expanded. Through fine-scale analysis (temporal and spatial, as well as systematic), of assemblages of microscopic and macroscopic plant remains, research concentrates on the accurate discrimination between autogenic, climatically induced, and anthropogenic vegetational change in contrasting physiographic entities: (1) crystalline mountains in France and the Iberian peninsula; (2) landscapes characterized by Pleistocene-Holocene eolian (sand, loess) deposition in the Netherlands and Germany; (3) fluvial plains in the Netherlands; (4) littoral landscapes in Portugal, and (5) Arctic landscapes of Spitsbergen, Jan Mayen and Greenland. Following earrlier research experiences with respect to the palaeoecological analysis of pollen assemblages from the Vosges (France), in the research period special attention was given to deciphering the complex, altitude related, late Pleistocene-Holocene pollen signals from other low mountain ranges. Results have demonstrated that the spatial distribution of vegetation patterns can be followed through time by recognizing: (1) common time-proportionate trends in pollen values, and (2) local pollen components characteristic for altitudinal vegetation zones and lake/mire development. Long time-scales For the recognition and evaluation of biotic change on long time-scales, LPP concentrates on the study of land plant and phytoplankton records from sedimentary successions that contrast with respect to: (1) time of formation (selected late Palaeozoic, Mesozoic and Cenozoic intervals); (2) paleotectonic and palaeogeographic history (intracratonic; passive and active plate margins); (3) depositional environment (terrestrial to deep-marine); and (4) biogeographic provinciality. Temporal and spatial distribution patterns of plant remains are explored for proxy variables indicative of terrestrial and marine environmental change. Investigated variables include land temperature, humidity, precipitation, runoff, sea-level, sea surface temperature, salinity, nutrient supply, productivity, organic burial rate and CO2 level. In the review period particular attention has been given to the development of palaeoecological models of dinoflagellate cyst distribution in marine sediments. It has been shown that: (1) the potential of dinoflagellates in Mesozoic and Cenozoic time-resolution may frequently exceed that of planktonic foraminifera and calcareous nannoplankton, and (2) dinoflagellates can be applied in novel ways to further the environmental understanding of depositional sequences and sedimentary cycles defined by physical (seismic, sedimentological) analysis. Although research related to global change programmes is generally restricted to the Late Tertiary-Quaternary, there is one notable exception. It is recognized that a better understanding of the patterns and processes of past mass extinctions can contribute to an understanding of present and future man-induced extinction processes. Work by LPP concentrates on the profound biotic crises at the Permian/Triassic (P/Tr) and Cretaceous/Tertiary (K/T) junctions. Study of the P/Tr land plant record has now revealed ecosystem collapse in the terrestrial biosphere. At the K/T junction, it has been demon-strated that dinoflagellates have remained immune to extinction. Independent of configurations predicted by meteorite-impact or massive volcanism, therefore, palynological studies enable high-resolution reconstruction of environmental change, both during pre-crisis times and the phases of K/T ecosystem decline and recovery.

Overall objective is to obtain net fluxes for carbon and freshwater water from an Arctic catchment under base-case and global change scenarios. Objective of the Vrije Universiteit Amsterdam is to study the temporal and patial variability in floodplain sediment balance over the last 2000 years. Research activities: Selected areas in the Usa basin will be studied in detail, both in the zones of continuous and discontiunous permafrost. Fieldwork was and will be conducted in the summers of 1998 and 1999. At selected field sites, the present day processes of river erosion and deposition will be evaluated and the natural evolution and variation of amount and rate of erosion and deposition will be determined for the last 2000 years.

- To support the further development of a geocryological database for the Usa Basin (East-European Russian Arctic), including key characteristics of permafrost such as distribution, coverage, temperature, active layer, etc. - To create GIS-based permafrost maps at the scale of 1:1,000,000 for the entire Usa Basin and at 1:100,000 for selected key sites. - To reconstruct the history of permafrost dynamics at key sites in the region over the last thousands of years using palaeoecological analysis and radiocarbon dating of peat deposits, and over the last few decades using remote sensing imagery and/or monitoring (base case scenario). - To predict permafrost dynamics at key sites in the region under future conditions of climate change (20-100 yrs), using a 1-dimensional permafrost model (future global change scenario). - To assess the effects of permafrost dynamics under base case and global change scenarios on urban, industrial and transportation infrastructure in the Usa Basin. Research activities Based on several representative sites, late Holocene permafrost dynamics will be characterized using palaeoecological techniques. Variability in permafrost conditions over the last few decades will be studied based on the available data from long-term monitoring station records and from a time series of remote sensing images (optional). Mathematical modelling of permafrost dynamics will be carried out for at least two sites and a forecast of permafrost degradation in the area under anticipated climate warming will be developed. The likely effects of permafrost degradation upon regional infrastructure (inhabited localities, heat and power engineering, coal and ore mines, oil and gas extracting complex, pipelines and railways) will be analyzed using a GIS approach. GIS data layers on permafrost dynamics and infrastructure will be compared in order to delimitate high risk areas based on existing infrastructure and anticipated permafrost degradation. Hereafter, the created GIS may serve as a basis for more detailed forecasting of permafrost dynamics under both natural and anthropogenic climate changes in lowland and alpine areas of the East-European Russian Arctic.

The global thermohaline circulation is driven by sinking of cold, dense surface waters in the Greenland and Norwegian Seas and its replacement by warmer surface water from lower latitudes. This global circulation system, the conveyor belt, is the main regulator of global climate. Even slight disturbances of this delicate system will cause significant climate changes, especially for NW Europe. While the current hydrographical situation and associated overflow pathways are well-documented, paleoceanographic studies of the Greenland and Faroe/Shetland (F/S) overflow pathways are still scarce. The F/S pathway is presently the subject of study of the MAST program (ENAM project). This project focusses on the late Quaternary overflow history of the important East Greenland pathway. High resolution multichannel sleevegun seismic data recently collected by the Geological Survey of Greenland and Denmark (GEUS) allowed identification of suitable box- and piston-coring sites. Results from the high-resolution cores, allowing direct correlation with regional atmospheric changes documented in the Greenland ice-cores will provide new information on causes and mechanisms of climate change. The continental slope and rise off SE-Greenland can be considered as a potential key area for paleoceanographic and paleoclimatic studies, since: 1) The area is located in the immediate vicinity of the Denmark Strait arctic gateway for water mass exchange between the Arctic and Atlantic ocean. Recent hydrographic measurements (Dickson 1994) demonstrate the important role of the area with regard to hydrographic processes contributing to the formation of NADW. 2) The seafloor morphology and information from multichannel seismic recording shows the presence of numerous large detached sediment drifts and other drift-related features, which will provide important paleoceanographic information as outlined before. 3) The distribution and architecture of the sediment drifts is also affected by down-slope processes transporting upperslope/shelf sediments of mainly glacial origin. Thus the area offers an unique opportunity to study the sediment drifts both with regard to the (paleo)oceanic flow regime and the climatically-inherited signal from the down-slope sediment input. Research activities: All research is directed towards documentation of high resolution natural climate variability during the late Quaternary. Separate topics include: 1. Seismic/sidescan sonar studies 2. High resolution quantitative micropaleontology (planktonic/benthic foraminifera, diatoms, calcareous nannoplankton, dinoflagellates) 3. High resolution stable oxygen/carbon isotope studies 4. DNA studies on planktonic foraminifera (with University of Edinburgh)

This project studies the climate development in polar areas during the last 400 years using the results of pollen analysis of soil samples collected in the Arctic regions, and written information collected in Dutch archives. Dutch sailors were sailing in Arctic waters already long before Willem Barentsz tried to find the northeast passage to China and India in the 1590s. They reported their observations to their principals and these reports are sometimes preserved. In this way written sources with much information about may aspects of the Atlantic Arctic are kept in reports in the Dutch archives. In these reports valuable information about the weather in the last 400 years is registered and also if serial these data can be interpreted as climate information. In combination with the information of the pollendiagrams of the collected soil samples, it will be possible to reconstruct the climate development in the Arctic in the last 400 years.

The project aims at studying the lateral and vertical (stratigraphic) variations in the composition of particulate organic debris (palynodebris sensu Boulter and Riddick, 1986) from a suite of Holocene sediment cores from off W, S, and SE Greenland, via the Reykjanes Ridge south of Iceland, to the Faeroe Islands. The main objective is to elucidate changes in paleoenvironmental and - hydrographic parameters such as temperature, trophic level, salinity, and energy in the water mass. In particular, the study aims at mapping the distribution of different species of organic walled dinoflagellate cysts in relation to these parameters.

Population monitoring of Gyrfalcon, Golden Eagle, Willow Grouse and Passerine birds

In 1990, the Directorate for Nature Management (DN) established an area for integrated monitoring within Børgefjell National Park, Røyrvik, N Trøndelag. Studies of vegetation-environment relationships in the area was performed by NINA. The area includes both subalpine birch forest and low alpine heath. The new established vegetation investigation included all together 80 different species. This material was processed numerically by using multivariate methods. Indirect gradient analyses were performed using Detrended Correspondence Analysis (DCA) and Local Nonmetric Multidimentional Scaling (LNMDS). Direct gradient analyses were performed by using rescaled hybrid Canonical Correspondence Analysis (CCA). Non-parametric correlation analyses, Kendall’s , were performed between environmental parameters and DCA axis values. The results of the numerical and statistical processing were used partly to provide a description of the vegetational structure in the material and partly to quantify how much each ecological parameters contributed to determination of vegetational structure. This work shows the species distribution along various complex gradients; moisture, nutrient conditions, light etc. The investigation is primarily designed to study vegetation dynamics along these gradients and whether changes in the number of species can be related to changes in physical, biotic and, not least, chemical parameters. Variance analysis was performed to assess to what extent the sample plots tends move in a determined direction from 1990 to 1995. The variation between the years were not significant along the primary complex gradients, but there were a significant displacement of species along the following gradients. The most important species were: Vaccinium vitis-idaea, Melampyrum sylvaticum and Hylocomium splendens), which showed an increase and some cryptogams like Brachythecium reflexum, B. salebrosum and Cladonia ecmocyna which declined.

In 1993, the Directorate for Nature Management (DN) established a new area for the monitoring of terrestrial ecosystems in Dividalen National Park in Troms County. This report presents the reanalysis of vegetation and soil from this terrestrial monitoring area. The area in Dividalen is located in the northern boreal birch forest, in a relatively continental section where the dominant type of vegetation is bilberry-mountain crowberry birch forest (A4c). The structure of the vegetation is analysed by multivariate methods (ordination). In Dividalen all together 131 species were found; 75 vascular plants, 18 mosses, 14 liverworts and 24 lichens. This is a decrease from the number of species recorded in 1993 when 141 species were found in the same mesoplots: 74 vascular plants, 24 mosses, 18 liverworts and 25 lichens. The decrease was not significant for the total number of species or for the total number of vascular plants. However the total number of cryptogames showed a slight significant decrease in number between 1993 and 1998. This may be due to increased cover of several ericoid species. In Dividalen we found no significant changes in vegetation composition for the periode 1993 – 1998 along the first four ordination axes. However, there were changes in mesoplots with high DCA1 values. The changes were in the direction towards lower species richness. Species like Myosotis decumbens, Poa alpina, Solidago virgaurea, Cerastium fontanum and Rumex acetosa ssp. lapponicus showed the largest decrease in these mesoplots. Species that showed the largest increase were Vaccinium vitis-idaea, Mnium spinosum and Polytrichum juniperinum. We have found no relations between these changes and acidification due to deposition of pollutans. Lack of disturbance factors in the area in the last years, which favours an increase in ericoid vegetation, is the probable explanation for the changes.

The study covers many areas of ecotoxicology research on polar bears. Monitoring of POP levels and studies of effects on endocrine disruption, immune system, reproduction, and demography are all parts of the study.

To monitor the inflow of salt and heat to through the Barents Sea to the Arctic Ocean.

This is an ongoing activity for monitoring variability in temperature and salinity in Barents Sea

To increase the understanding of temporal and spatial dynamics of cod and other commercial gadoid species, including the influence of environmental variability on population parameters, and make this knowledge available in assessable form for fisheries management.

Investigation of benthic faunal communities for: taxon distribution/ biodiversity mapping; examination of effects of glacial and physical disturbance on community structure; relation between faunal structure and sediment contaminants.

Multi-institutional, international cooperative project to determine the possible responses of Arctic marine communities to future global climate change by comparing retrospective patterns in benthic composition and distributions to past climatic events in the Barents and Bering Seas.

The aim of the project is to obtain more insight in the response of the Greenland ice sheet to climatic change. For this purpose we will link our surface energy-balance model to an atmospheric model, so that the model can be forced by variables characterizing the atmosphere outside the thermal influence of the ice sheet itself. The modelling is supported by the mass-balance and meteorological data that we collect along a transect in West Greenland (the Kangerlussuaq-transect or K-transect). The albedo of the ice sheet is studied by means of satellite data and measurements obtained from a helicopter. Research activities - develop numerical models of the surface energy balance and the boundary layer above the ice sheet - perform annual measurements of the mass balance and ice velocity along the K-transect - maintain two automatic weather stations along the K-transect - study the surface albedo by means of remote-sensing images - improve methods to retrieve the surface albedo from satellite data by means of measurements obtained from a helicopter

Land ice forms an important component of the climate system. Sea level variations are closely related to the total ice volume. However, the relation between glacier mass balance and meteorological conditions is inderstood only broadly. In particular, the strong variation of mass balance patterns on the 10-300 km scale has hardly been investigated. Reduction of the uncertainty in estimating changes in glacier mass balance for climate change scenario's requires a better knowledge of the processes that lead to the spatial variability of glacier mass balance. The goal of the project is to indentify and model the most important factors leading to mesoscale variability of the mass balance field on ice caps.