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The Kangerlussuaq area of southwest Greenland encompasses diverse ecological, geomorphic, and climate gradients that function over a range of spatial and temporal scales. Ecosystems range from the microbial communities on the ice sheet and moisture-stressed terrestrial vegetation (and their associated herbivores) to freshwater and oligosaline lakes. These ecosystems are linked by a dynamic glacio-fluvial-aeolian geomorphic system that transports water, geological material, organic carbon and nutrients from the glacier surface to adjacent terrestrial and aquatic systems. This paraglacial system is now subject to substantial change because of rapid regional warming since 2000. Here, we describe changes in the eco- and geomorphic systems at a range of timescales and explore rapid future change in the links that integrate these systems. We highlight the importance of cross-system subsidies at the landscape scale and, importantly, how these might change in the near future as the Arctic is expected to continue to warm.

Suggests that becoming an expert teacher and judging teaching quality are complex and situational, exploring the use of a conceptual framework for analyzing eight teaching portfolios submitted by new university teachers as an assessment and qualification requirement. The study made a case for analyzing portfolios by asking whether teachers held student-centered conceptions of teaching and were reflective practitioners. (SM)

Analyzes the teaching portfolios of eight novice geography teachers focusing on how useful portfolios are for teacher development, what the portfolios reveal about their teaching philosophies, what can be learned about the experience of novice teachers, and the extent of discipline-specific material present in the portfolios. (CMK)

Mineral dust concentrations are coupled to climate over glacial-interglacial cycles with increased dust deposition occurring during major cold phases over the last ~100 ka. Holocene records suggest considerable spatial and temporal variability in the magnitude, frequency and timing of dust peaks that reflects regional or local drivers of dust emissions and transport. Here, we present stratigraphical, geochemical and isotopic evidence for dust deposition from two high-resolution peat sequences 200 km apart in northern Scotland spanning the last c. 8200 years. εNd isotope data suggest the dominant minerogenic dust source switches between a low latitude (likely Saharan) and a high latitude, Icelandic source. Marked peaks in increased minerogenic dust deposition at: c. 5.4–5.1, 4.0–3.9, 2.8–2.6, 1.0 and 0.3 ka BP occur against a backdrop of low dust deposition during the mid-Holocene (c. 5.0–4.0 ka BP) and increased background levels of dust during the neoglacial period (<4.0 ka BP). These dust peaks coincide with periods of glacial advance in Iceland and heightened storminess in the North Atlantic. Isotope data for additional dust peaks at c. 1.0 and 0.7 ka BP and the last ~50 years suggest these reflect increased dust from the Sahara associated with aridity and land-use change in North Africa during the Late-Holocene, and modern anthropogenic sources. This work highlights the complexity of Holocene records of dust deposition in the North Atlantic and emphasises the role of dynamic sub-Polar glaciers and their meltwater systems as a significant dust source. [ABSTRACT FROM AUTHOR]

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1745-5871.2007.00457.x Byline: JOANNA E. BULLARD (1), GRANT H. MCTAINSH (2), PAUL MARTIN (3) Keywords: stage-discharge relationships; ephemeral rivers; URBS; HEC-RAS; Australia Abstract: Abstract The method for deriving a stage-discharge relationship has a significant impact on the shape of the river's rating curve. We compare rating curves for a single gauging station on a mutiple-channelled river in Australia compiled using three different methods - the Urban Runoff and Basin Systems (URBS) rainfall-runoff model, an empirically-based velocity-area method, and the predictive Hydrologic Engineering Centre-River Analysis System (HEC-RAS) computer model. The rainfall-runoff model was found to predict lower discharges for stage heights over 3.5 m than both the empirically-based velocity-area method and the HEC-RAS model. The empirically-based velocity-area model predicts similar discharges to the rainfall-runoff model for stage heights less than 3 m but much higher discharges for larger flood events. The HEC-RAS model predicts higher discharges than both other rating curves at all stage heights probably due to under-estimation of the impact of surface roughness on flow velocity. The three models are discussed with particular reference to their use on multiple-channelled rivers. Author Affiliation: (1)Department of Geography, Loughborough University, Loughborough, Leicestershire, LE11 3TU, United Kingdom. (2)Australian Rivers Institute, Australian School of Environmental Studies, Griffith University, Brisbane, Queensland 4111, Australia. (3)Department of Natural Resources and Mines, Woolloongabba, Queensland 4054, Australia. Article History: Received 11 January 2006; Revised 28 August 2006; Accepted 15 September 2006 Article note: (*) Corresponding author. Email: j.e.bullard@lboro.ac.uk