Arctic water source dynamics, stream habitat and biodiversity in a changing climate: a field-based investigation in Swedish Lappland

• Main Author: Mellor, Christopher Joseph
• Other Authors: Hannah, David M., Milner, Alexander (Sandy), na
• Format: Thesis
• Language: English
• Published: 2012
• Subjects: G Geography (General); QE Geology; QK Botany; Arctic; Kårsavagge; Lappland; Climate change; Global warming; Northern Sweden
• Online Access: http://etheses.bham.ac.uk//id/eprint/3689/8.hassmallThumbnailVersion/Mellor12PhD.pdf; http://etheses.bham.ac.uk//id/eprint/3689/; http://etheses.bham.ac.uk//id/eprint/3689/8/Mellor12PhD.pdf

The dynamic interaction between different water sources plays a key role in the structure and functioning of Arctic stream systems. Ice melt, snowmelt, groundwater and rainfall mix to produce a diverse range of physicochemical conditions. The heterogeneous habitat matrix created is home to a variety of cold stenothermic species. Recent trends in earth surface temperatures associated with global warming have co-in sided with a reduction in global glacier mass balance and a hastening in the onset of spring thaw. This field based study investigated the physicochemical habitat diversity within a glacierized Arctic catchment, Kårsavagge in Northern Sweden. Hydrological, meteorological and physicochemical data spanning 2007 to 2010 were collected with intensive collection during the summer melt seasons of 2008 and 2009. In conjunction with these data, macroinvertebrate and fish sampling was carried out during both of the intensive summer monitoring periods. The key focus of the sampling regime was to compare lateral and longitudinal habitat variability, investigate the extent to which this was linked to dynamic water source interactions by modeling contributions from identified sources and assess the impact of this physicochemical habitat template on the macroinvertebrate and fish communities in the light of predicted climate change. The key findings discussed within are (1) Lateral habitat and biological diversity was equivalent to that observed longitudinally. (2) The ARISE framework used for modeling different water source contributions is applicable to an Arctic scenario, however its utility decreases with increasing catchment size. (3) The key habitat variables structuring macroinvertebrate and fish distribution were concerned with mediating/ mitigating the extent of the glacial signal. A conceptual model is presented that illustrates the potential impact of loss of this glacial signal on local biodiversity