Roundup: Breeding Grounds, Ecosystems, Macroinvertebrates

Posted by on Nov 28, 2016

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Roundup: Chronosequences, Drift and Catchments

 

Glacier Retreat Exposes New Breeding Grounds:

From Molecular Ecology: “The rate of global glacial retreat has increased due to climate change and is projected to lead to the disappearance of alpine glaciers by 2050 if warming continues at its current rate (Fitzharris 1995). One consequence of glacial retreat is exposure of subglacial till [sediment carried and deposited by a glacier], which subsequently develops into mineral soil that supports grassland ecosystems (Anderson 1988). This process can be observed in the glacier foreland, with increasing distance from the glacier terminus used as a proxy for time since retreat: a chronosequence (Hämmerli et al. 2007)… If the sites follow the same ecological trajectory, chronosequences can provide useful insights into successional processes (Walker et al. 2010).”

Learn more about the consequences of glacier retreat here:

Kluane National Park, Yukon, Canada (Source: Creative Commons, Oltgolpis)

Kluane National Park, Yukon, Canada (Source: Oltgolpis/Creative Commons).

 

Drift Patterns in High Mountain Streams:

From Acta Biologica:”This study highlighted the strong seasonality of the diurnal [occurs every 24 hours] drift pattern of the different taxa. This could be explained by the seasonality that characterizes high mountain stream ecosystems in their main physico-chemical features (e.g. discharge, water temperature, suspended solid transport, etc.) (Brittain et alii, 2000)… A second reason could be the low abundance of individuals found, especially in June and August at stations g and ac and in all periods at station ng, that hindered the analysis of the daily activity pattern of most taxa.”

Interested in learning more about these studies? Find them here:

Trentino, Italy (Source: Creative Commons, Marcello Colajanni)

Trentino, Italy (Source: Marcello Colajanni/Creative Commons).

 

Macroinvertebrate Communities in Catchments:

From Hydrobiologia: “Groundwater-fed streams are typically hotspots of aquatic biodiversity within glacierized catchments [natural drainage areas from runoff]. Surface water physicochemistry and macroinvertebrate communities within five groundwater-fed streams were characterized across catchments in Denali National Park, interior Alaska. The main aim of this study was to assess whether hydrological controls on macroinvertebrate communities (e.g. flow permanence) identified within previous catchment-specific studies are present at wider spatial scales, across multiple groundwater-fed streams located on alluvial terraces [a river terrace made of deposits of clay, silt, sand and gravel] within glacierized catchments… The high diversity and structural heterogeneity of macroinvertebrate communities observed across alluvial terrace streams indicated the importance of these systems as biodiversity hotspots in regions under threat from climate change.”

For more on this study:

Denali National Park (Source: Creative Commons, Bill Shupp)

Denali National Park (Source: Bill Shupp/Creative Commons).

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