Erosion-driven drawdown of atmospheric carbon dioxide: The organic pathway

Rapidly eroding, coastal mountain belts, where steep rivers and submarine channels connect upland sources to nearby marine sinks are hotspots of organic carbon transfer from life biomass, soil and exhumed bedrock into geological storage. Using observations from the Southern Alps of New Zealand, and Taiwan, we have mapped this organic pathway to geological carbon sequestration, and can evaluate the magnitude and efficiency of transfers between sources and sinks. We demonstrate that POC is harvested by landsliding, but importantly also by common and widespread surface runoff on steep hillslopes. Although terrestrially sourced POC is found in many sedimentary environments associated with mountain belts and frontier basins, it appears to be most abundantly trapped and preserved in marine turbidites. The loss of all forms of POC in onward transport through short, steep routing systems to this repository is limited. This is in marked contrast to larger routing systems, in which only the most resilient forms of POC survive into long-term deposition.     

Danske provinsbyers indre differentiering og differentieringen mellem danske provinsbyer

Pedersen, P. O. & Rasmussen, P., 1973: Danske provinsbyers indre differentiering og differentieringen mellem danske provinsbyer. Geografisk Tidsskrift, 72, 49–56. København, September 30., 1973.

This paper analyses the inner differentiation in the three largest provincial towns in Denmark by means of a factor analysis of 25 variables characterizing the population and the housing in 40 zones, 14 in Århus (187,000 inh.), 14 in Odense (133,000 inh.), and 12 in Ålborg (123,000 inh.). The paper especially focuses on the differences in inner differentiation between the three towns.     

Nye kandidater udgået fra Københavns Universitets Geografiske Institut

Danish Journal of Geography: 71–82, 1995.

This paper presents two mega events as tools in the strategic planning of the Copenhagen area. Due to growing inter-metropolitan competition, increasingly offensive and complex means are applied. This demands strong leadership, stable longterm planning and willingness to accept the costs in order to reach the objectives. Marketing versus strategic planning is discussed. The general position of Copenhagen in the European urban system gives perspective to a potential change on the South Scandinavian urban scene. New instruments of strategic planning in Greater Copenhagen are introduced. The competitive level of Copenhagen is analyzed in relation to Stockholm, Berlin and Hamburg. Two examples of mega events are discussed that represent typical elements in urban competition: cultural events and infrastructure improvements. 1) Copenhagen as ‘The cultural City of Europe’ in 1996 represents a temporary mega event. 2) The planned bridge between Copenhagen and the south Swedish city of Malmö, combined with Swedish entrance into EU, opens up for development of the first cross-national integrated large-city region outside the European centre. This is an example of a mega event which will alter the scene permanently. Both events are important issues used in developing a growth strategy for Greater Copenhagen. But neither the cultural city nor the bridge may by themselves guarantee any advantages. It depends upon the ability of local actors to develop and promote the quality of their city. The paper represents a continuation and elaboration on earlier papers, see Matthiessen (1990, 1992) and Andersen &; Jørgensen (1994).     

Meteorological Observations in 1999 at the Arctic Station,Qeqertarsuaq (Godhavn), Central West Greenland/Evidence of a warmer climate around AD 600, Mittivakkat Glacier,South East Greenland

In october 1990 an automatic weather station was established at the Arctic Station (65° 15', 53°31'W), Qeqertarsuaq (Godhavn), Central West Greenland. The Station register parameters each 20 minutes, and the paramters have been described in an earlier paper in this journal by Nielsen et al.(1995). The present paper summarizes meteorological parameters during 1999.

During a field campaign in 1999, woody remains from Salix glauca were found on a nunatak, 515 m. a.s.l. on the Mittivakkat Glacier, South East Greenland. Radio carbon dating determined the age of a wood sample to AD 640. Together with analyses of macroscopic botanical remains and insect rests in peaty material found nearby, these results indicate, that a warmer climate prevailed near the glacier around AD 600. These findings are in accordance with temperature records based on studies of ice cores from the Greenland Ice sheet.     

Observations of sea ice influence on the littoral sediment exchange,North Zealand,Denmark

Nielsen, Niels: Observations of sea ice influence on the littoral sediment exchange, North Zealand, Denmark. Geografisk Tidsskrift 88:61–67. Copenhagen. 1988.

In 1985 and 1986 monthly surveys of sediment volumes were carried out on a sandy beach and its nearshore platform at the north coast of Zealand. Both winters in the research period had temperatures below average, and consequently abundant sea ice formations. ‘Ice winters’ in open Danish waters occur statistically about 1/3 of the winters. The appearance of sea ice resulted in marked loss of sediment from the whole littoral zone, but by far the largest net erosion could be detected on the nearshore plane. An important factor is assumed to be the interaction of waves with the icefoot and ice pile-ups. For the beach itself, ice-glazing of the beach surface and interstitial frost in the foreshore sediments caused wave erosion within and just off the swash zone due to variations of the percolation parameter. This dynamic was observed during both the freeze-up and thaw-up periods. On the backshore, wind-derived forms characterized the winter beach, but here the net sediment budget was less affected.     

Sensitivity of DaisyGIS to LAI: Implications for land use based modelling of nitrate leaching

Geografisk Tidsskrift, Danish Journal of Geography 106(2): 75–85, 2006

Scaling is an important issue when measuring, modelling and understanding coupled socio-environmental terrestrial systems. Scaling may be enhanced through the incorporation of remotely sensed data. This paper assesses the sensitivity of DaisyGIS to changes in the Leaf Area Index (LAI) and discusses the implications for land use based modelling of nitrate leaching using remote sensing based LAI estimates. It is shown how DaisyGIS simulates nitrate leaching quite well over the period 2001 to 2004 except for one plot during a season with winter rape. It was found that the model is sensitive to changes in LAI with increases of up to 262% on nitrate leaching rates when reducing LAI by 15%. At the same time, the nitrate leaching rates at the field level vary considerably due to local changes in the water balance determined by soil profile characteristics. DaisyGIS is already an important tool for aiding decision makers and this study has shown how remote sensing based LAI estimates may be a valuable tool for model parameterisation and potentially for model validation.     

Commercial hunting activities in the Greenland Sea: The impact of the European blubber industry on East Greenland Inuit societies/Optically Stimulated Luminescence dating of Inuit settlement structures in coastal landscapes of Northeast Greenland

Geografisk Tidsskrift—Danish Journal of Geography 110(2):357–363, 2010

Geografisk Tidsskrift—Danish Journal of Geography 110(2):365–371, 2010     

Modeling shoreline sand waves on the coasts of Namibia and Angola

The southwestern (SW) coast of Africa (Namibia and Angola) features long sandy beaches and a wave climate dominated by energetic swells from the Southsouthwest (SSW), therefore approaching the coast with a very high obliquity. Satellite images reveal that along that coast there are many shoreline sand waves with wavelengths ranging from 2 to 8 km. A more detailed study, including a Fourier analysis of the shoreline position, yields the wavelengths (among this range) with the highest spectral density concentration. Also, it becomes apparent that at least some of the sand waves are dynamically active rather than being controlled by the geological setting. A morphodynamic model is used to test the hypothesis that these sand waves could emerge as free morphodynamic instabilities of the coastline due to the obliquity in wave incidence. It is found that the period of the incident water waves, T_p, is crucial to establish the tendency to stability or instability, instability increasing for decreasing period, whilst there is some discrepancy in the observed periods. Model results for T_p = 7–8 s clearly show the tendency for the coast to develop free sand waves at about 4 km wavelength within a few years, which migrate to the north at rates of 0.2–0.6 km yr^?1. For larger T_p or steeper profiles, the coast is stable but sand waves originated by other mechanisms can propagate downdrift with little decay.     

Endemic avifaunal biodiversity and tropical forest loss in Makira, a mountainous Pacific island

Anthropogenic habitat changes and the introduction of pigs, dogs, cats and rats have caused a catastrophic decline in the terrestrial biodiversity of Pacific archipelagos. At present, economic globalization and an increased demand for timber are promoting industrial logging and plantation expansion. Commercial logging can be sustainable but in practice it more often leads to land degradation, especially on small flat islands. On large and mountainous islands, however, more modest impacts can be expected as the narrowly endemic species tend to inhabit montane forests where logging is difficult. In this study we use ornithological data collected at different elevations to assess the extent to which the avifauna of Makira, a large mountainous island in Melanesia, will be affected by deforestation of the lowlands, most of which are under timber concessions. Our data suggest that a majority of the endemic bird species use lowland forest to some extent and that this may even apply to species hitherto associated with montane forest. If current commercial forestry programmes are continued, the forest habitat may be disturbed or lost over large parts of Makira, potentially undermining the natural resource base for the local subsistence economy, exacerbating climate change and threatening the integrity of one of the most important areas for biodiversity conservation on earth. Our study highlights the importance of understanding the habitat requirements of endemic species and the urgency of establishing and effectively managing community-based protected areas in suitable lowland forests of the Pacific.