NERC Arctic Research Station (Harland House): projects/activities

Please contacty dr Jemma Wadham or Andy Wright, University of Bristol UK

Diversity of cyanobacteria and eukaryotic microalgae in subglacial soil (Ny-Ålesund, Svalbard) Study of the reinvasion and establishment of plant and animal life after ice retreat is one on the most important ecological problems. In the past, many Arctic and Antarctic research projects have dealt with primary succession processes and the effects of climate warming. Cyanobacteria and algae are widespread in polar wetlands and soils and produce visible biomass, which represents a considerable global pool of fixed carbon. Together with associated microorganisms, they are involved in energy flow, mineral cycling, weathering processes and the biological development of the polar landscape. The processes primary succession by cyanobacteria and algae are influenced by many ecological factors. However, two of them (1) aerobiological and water inputs of viable cells and spores into deglacaited areas and, (2) ability to endure freeze-dry desiccation for long periods of time (perennial character) play a detrimental role in the processes of primary succession. The diversity and abundance of cyanobacteria and eukaryotic microalgae will be studied in the vicinity of Ny-Ålesund, Southern part of Kongsfjorden, Spitsbergen, 79°N in the following habitats:  subglacial soil (samples will be collected from below glacier ice)  freshly deglaciated soil (close to glacial margins - up to 50m)  glacial ice surface (cryoconite, streams flowing on ice surface, etc.)  soils of habitats deglaciated many years ago (more than 50 years ago) The collection of these samples will be focussed on soils that have not been in contact with environment above the ice.

Prof. I.D. Hodkinson Dr. S.J. Coulson School of Biological & Earth Sciences, Liverpool John Moores University, Byrom St., Liverpool L3 3AF, UK (Contact details: Tel. 0151 2312030 Fax. 0151 207 3224 email i.d.hodkinson@livjm.ac.uk; s.j.coulson@livjm.ac.uk) Prof. N.R. Webb NERC Centre for Ecology & Hydrology, Winfrith Technology Centre, Dorchester, Dorset, DT2 8ZD, (Contact details: email nrw@ceh.ac.uk) Objectives and Hypotheses Our main objectives are to:  describe, measure and model patterns and rates of invertebrate community development and succession following glacial retreat in the high Arctic using known chronosequences.  cross-relate rates of community change to known climatic shifts.  relate invertebrate community development to rates of key ecological processes such as decomposition of organic matter.  evaluate the potential for more southerly species successfully to invade existing Arctic invertebrate communities.  develop descriptive and predictive models of community development under conditions of climatic amelioration. We are testing the following hypotheses:  that dispersal of particular functional groups of invertebrates in response to climate warming is a rate-limiting factor for invertebrate succession and community development in the high Arctic.  that invertebrate community development in response to climatic warming is deterministic and directional, and therefore predictable.  that the magnitude and stability of key ecosystem processes, such as decomposition, in the high Arctic are linked to biotic complexity, which can be suitably characterised by the invertebrate community composition.  that natural succession provides a useful model for predicting rates of invasion by colonising species following climatic amelioration. Study sites Studies on two contrasting but complementary chronosequences on west Spitsbergen commenced in June 2000, an oligotrophic succession on t he glacial foreland of Midtre Lovénbre and a relatively eutrophic succession on Lovénøyene, a series of islands in Kongsfjord. A 1.5 km transect was established, extending from the foot of the Midtre Lovénbre to the terminal moraines and across the sandur. Seven equally spaced sampling sites (approx 20 x 40 m) were established at right angles to the main transect line). Each site was chosen to represent the most mature vegetation type present at each point. By contrast, each Lovénøy was viewed as a separate sample site. The chronology of glacial 'retreat' was established from vertical and oblique aerial and ground based photographs held by the Norsk Polarinstitutt Archive, Tromsø, from historical records and ground photographs and, for the oldest site, by radiocarbon dating of the soil. Results Ages of sites: The ages of the sites from the Midtre Lovénbre sequence vary between 2 years (site one) to 1900 (site seven), while the islands vary between 100 (Leirholmen) to 1800 (Storholmen). Plant community description and soil formation A detailed description has been made in the changes in the plant community (18 taxa) from site 1-7 on the Lovénbre - from unconsolidated parent to almost 100% ground cover. The presence, abundance and dynamics of each species have been described. Species have been characterised as early, mid or late successional. Parallel trends occur in soil characteristics including increasing depth, increasing organic matter and water content, decreasing clast size and a lowering of pH. Animal community description The soil fauna comprise primarily Collembola, mites, Enchytraeidae and chironomid larvae. Herbivores (one aphid and sawfly larvae) are few but hymenopteran parasitoids and predators (spiders and gamasid mites) are abundant. The distribution patterns of species and their abundances have been quantified for both the Lovénbre and Lovénøyene chronosequnces. The very first colonisers of bare moraines are Linyphiid spider species (predators). Other early soil colonisers are generally the surface active species such as the collembolan Isotoma anglicana. The poorest colonisers are the deep soil dwelling species. Experiments are thus underway examining wind blown dispersal and survival on seawater. A cellular automaton model, using absolute density and pitfall trap is being used to simulate diffusion dispersal of soil animals. A set of unusual weather conditions in late July produced a mass immigration of a small moth Plutella xylostella into Svalbard. This chance event has allowed us to track in detail the movement of associated weather systems and to reconstruct the direction and source of immigrants. Such events are rare but may become increasingly frequent as climate changes, opening a closed gateway for animals from further south to move into the Arctic. Continuing work Current visit (late July/early August) is aimed at collecting supporting information on the plant cover and microhabitat characteristics for manuscripts in preparation.

Based upon research previously undertaken at Sheffield University, nutrients released from High Arctic glaciers during the summer ablation season are shown to rarely be in balance with bulk inputs deposited on the glacier surface as winter accumulation. Nutrient budgets suggest glaciers to release an excess of nitrate relative to annual bulk deposition, whilst up to 40% of the Ammonium deposited on the glacier surface appears to be sequestered from the inorganic budget (Hodson., in prep). Contrary to popular understanding, such an imbalance would suggest glaciers to be agents of nutrient storage, release and utilisation. In conjunction with a range of recent research (Sharp et.al, 1999., Skidmore et.al, 2000) this may potentially demonstrate high Arctic glaciers to be dynamic biological systems supporting a plethora of microbial life, rather than biologically inert cryospheric entities as so widely perceived in much of the research literature. Ammonium and Nitrate are nutrients of key importance not only to the maintenance of microbial life in such hostile environments, but also to the primary productivity of ice-marginal freshwater and marine ecosystems. However, as yet, their dynamics have proved difficult to explain. Field research undertaken during summer 2002 used natural isotopes to fingerprint sources and sinks of nutrients within the glacial system, thereby enabling a better understanding of biogeochemical cycling within the glacial environment. Whilst analysis of isotopic samples from this field season is still ongoing, new areas of research have been highlighted. The significance of organic nutrients in biogeochemical cycling has largely been regarded as insignificant, especially with regard to glacier geochemistry (reference). However, large fluxes of organic carbon have been observed emanating from the subglacial drainage of glacier Midre-Lovenbreen (Wynn, unpublished Data) and Dissolved Organic Nitrogen (DON) is now known to represent upto 40-50% of annual nitrogen inputs in glacier snowpacks (Hodson, in prep). Furthermore, bacteria, cysts and algae present within small supraglacial melt pools known as ‘cryoconite holes’, hold the potential to utilise inorganic nutrients and retain them in the organic phase. Consequently, omitting the role of organic nutrients from glacial biogeochemical studies allows only a limited understanding of the chemical and biological interactions occurring within Arctic glaciers. A field study addressing the significance of dissolved organic nutrients within glacial systems is to be undertaken during summer 2003. A new method is currently being investigated which will allow the concentration and subsequent isotopic analysis of dissolved organic nutrients retained on ion exchange resins. Use of environmental isotopes in conjunction with major ion chemistry will help determine the provenance, fate and bioavailability of organic nutrients within the glacial system. Lysimeters inserted into the snowpack will enable the release of organic nutrients into the glacier to be continuously monitored, allowing subsequent changes in meltwater isotopic signatures to be studied relative to this. Particular emphasis shall be given to Nutrient cycling within cryoconite holes and fluxes of organic matter emanating from the subglacial drainage as these represent two possible sites of organic/inorganic interaction. Fieldwork is to be undertaken on Midre-Lovenbreen, Svalbard, a polythermal glacier well known and studied by the author. Initial sample processing shall be accomplished in the laboratory facilities provided in Ny-Alesund, whilst subsequent isotopic analysis is to be undertaken at the British Geological Survey in Nottingham.

Please contact Dr Jelte Rozema.

Mosses and lichens are important components of arctic ecosystems as well as being an internationally important component of the biodiversity of the British Isles and Scandinavia. They are typically associated with nutrient poor ecosystems and are often eliminated with increased supplies of nitrogen. This study is part of a programme examining the impact of elevated nitrogen in nutrient poor ecosystems on mosses and lichens. This particular study will examine the contribution of airborne nitrogen in the form of ammonia to the growth of mosses in the arctic tundra in Kongsfjord. Breeding colonies of seabirds deposit large quantities of guano, which can be major sources of nitrogen as well as heavy metals (Headley 19xx) and other contaminants in the marine ecosystems. The nitrogen in fish and other organisms high up in the marine food chains have higher concentrations of the heavier stable isotope of nitrogen called 15N. The ratio of this isotope to the usual isotope of nitrogen (14N) can be used as a marker as to the relative contributions of different forms of nitrogen that are being utilised by an organism. By taking samples of moss at different distances from seabird colonies and analysing these and the soil and guano for the concentrations of the two stable isotopes of nitrogen (15N:14N ratio) the relative contributions of nitrogen from the soil and atmosphere can be determined. This can then be utilised along with details of the relative abundance of the mosses along transects away from seabird colonies to ascertain how important atmospheric ammonia is in altering the species composition of moss communities.

Please contact Dr Clare Robinson

Please contact Dr Cornelius Lutz

In 2001 we were granted an LSF award for work on dissolved organic nitrogen in arctic ecosystems. In collaboration with Bjorn Solheim and Christina Wegener of the University of Tromso, we studied (a) the DON and DIN content of a range of soils around Ny Alesund and (b) the relative uses of nitrogen fixation and DON in a defined range of communities. We established a long term experiment at Stuphallet on dry tundra, where we made additions of nitrogen to fixed quadrats. The nitrogen additions were of nitrate, ammonium, glycine and glutamate at 10 kg ha-1. This is the first long-term experiment where organic N additions have been made to tundra. Our hypothesis is that DON is a preferred N source for tundra angiosperms. Within 10 days of application of the N in 2001, there were no significant changes in plant chlorophyll content or N content, not surprisingly as the plants were fruiting and end-of-season N retranslocation and leaf loss were in progress. This application is to make measurements on these plots to test the hypothesis after one year, and to make further applications.

The high Arctic contains delicate, relatively pristine ecosystems that are increasingly subject to exported aerial pollution (e.g. nitrogen) and higher than average climatic temperature change. Together these factors may potentially change important biogeochemical processes (e.g. the cycling of carbon and nitrogen) and ecosystem dynamics. This project involving the University of Nottingham, The British Geological Survey and IACR Rothamsted is now entering its second field season. The project concentrates on the release and the subsequent fate of N, entering the tundra ecosystem, as a pulse during the spring thaw. The questions we propose addressing are (i) how important is this event in transferring enhanced N deposition to tundra ecosystems, and how much is lost as run-off to lacustrine and inshore marine environments, (ii) how does enhanced N affect the carbon cycle (i.e. plant growth, decomposition processes) and (iii) what is the impact on soil N mineralizationimmobilization dynamics. Two plot experiments have been set up at contrasting vegetation sites around Kongsfjorden (Brandalspyntyn and Ny-London). We have simulated the release of N from the snowpack by applying 15N label as the snow has melted. An accurate audit regarding the fate of this snowpack N can then be made (i.e. does it remain in the soil, enter the tundra flora and soil microbiology or is it lost from the system). In addition, using techniques for combined 18O+15N analysis of nitrate, we can distinguish between atmospheric- and soil-derived nitrate. This will allow us to assess and source losses of N from the tundra during the brief summer growing season. These complementary approaches will provide a quantitative understanding of the fate of deposited N in the pristine Arctic environment. The overall aim will be to parameterize an N-flux model for this important ecosystem.

The high Arctic contains delicate, relatively pristine ecosystems that are increasingly subject to exported aerial pollution (e.g. nitrogen) and higher than average climatic temperature change. Together these factors may potentially change important biogeochemical processes (e.g. the cycling of carbon and nitrogen) and ecosystem dynamics. This project involving the University of Nottingham, The British Geological Survey and IACR Rothamsted is now entering its second field season. The project concentrates on the release and the subsequent fate of N, entering the tundra ecosystem, as a pulse during the spring thaw. The questions we propose addressing are (i) how important is this event in transferring enhanced N deposition to tundra ecosystems, and how much is lost as run-off to lacustrine and inshore marine environments, (ii) how does enhanced N affect the carbon cycle (i.e. plant growth, decomposition processes) and (iii) what is the impact on soil N mineralizationimmobilization dynamics. Two plot experiments have been set up at contrasting vegetation sites around Kongsfjorden (Brandalspyntyn and Ny-London). We have simulated the release of N from the snowpack by applying 15N label as the snow has melted. An accurate audit regarding the fate of this snowpack N can then be made (i.e. does it remain in the soil, enter the tundra flora and soil microbiology or is it lost from the system). In addition, using techniques for combined 18O+15N analysis of nitrate, we can distinguish between atmospheric- and soil-derived nitrate. This will allow us to assess and source losses of N from the tundra during the brief summer growing season. These complementary approaches will provide a quantitative understanding of the fate of deposited N in the pristine Arctic environment. The overall aim will be to parameterize an N-flux model for this important ecosystem.

To determine where different types of impurities (primarily specific inorganic chemical species and microbes) are located on a microspopic scale within the ice and what controls their distribution.