IMPACTS OF DRYING ON THE ABUNDANCE OF GAMMARUS FOSSARUM POPULATIONS IN SMALL STREAMS IN CENTRAL EUROPE
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| Year of publication | 2017 |
| Type | Conference abstract |
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| Description | Climate change strongly affects the flow regime of small streams and causes, among other, more frequent and longer drying up. Changes in the population dynamic of aquatic invertebrates and the rate of their recovery after this disturbance indicate the duration of the dry-phase impact on populations of model organisms. The main aim of our study was to compare the fluctuation in abundance of Gammarus fossarum populations in relation to dry-phase using spring and autumn samples from 9 pairs of near-pristine streams (intermittent/permanent in each region) sampled in 2012- 2015 during BIODROUGHT project (www.biodrought.eu). We assessed the impact of drought duration (measured in days), the accessibility of refugia and other factors on the abundance of the model species in intermittent streams within year (before and after drying) and between years. Moreover, we investigated the rate of recolonization. Former research proved that intermittent streams are recolonized after dry period initially by bigger males, probably by upstream or downstream migration from permanent reaches. According to the abundance of autumn population and the time lag between the channel rewatering after the dry phase and the sampling date, and with knowledge of spring abundance, we estimated the rate of recolonization in relation to drought duration and extent in four subsequent seasons. The data comparison of intermittent and permanent streams from the same geographical regions can help quantify direct impact of drought that will probably strongly affect stream communities in Central Europe with increasing frequency. |
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