Agriculture is the dominant land use form in Lower Austria, covering more than 46 % of the total area. Agriculture delivers significant amounts of dissolved organic matter (DOM) to streams, thereby changing basic processes at the water-sediment interface and affecting the ecological state of the stream ecosystem. In January 2017 WasserCluster Lunz started the project “organic carbon cycling in streams” with project leader Gabriele Weigelhofer. The aim of the project is, thus, to investigate the influence of agricultural land use on the quantity and quality of DOM inputs to streams and to clarify the effects of this DOM on the aquatic carbon cycling in stream ecosystems.
Veronika Kasper wrote her master thesis under supervision of Thomas Hein about Microphytobenthos (MPB), small algae attached to a substrate. It plays a major role in lotic ecosystems and is often affected by multiple stressors. Thermopeaking (TP) combines stress of sudden flow velocity increase (Hydropeaking) and abrupt water temperature alteration. Although this effect is prevalent in alpine regions, studies concerning its influence on MPB are a critical knowledge gap. Therefore the aim of this project was to provide knowledge about the impact of TP on MPB, considering as well successional and habitat aspects.
The effect of temperature change on aquatic food webs is gaining increasing scientific attention. The recent IPCC report anticipated a rise in lake water temperature of up to 4°C, accompanied by a series of weather events that may cause frequent temperature fluctuations. In this study, masterstudent Paula Take investigated under supervision of Martin Kainz how increasing temperature affects the biodiversity and biochemical composition of plankton communities by conducting long-term, multi-seasonal mesocosm experiments.
On Tuesday, November 8th, took place the kick-off meeting for the project InterBird in the directorate of national park Sarród Kócsagvár. Working group leader Robert Ptacnik and WCL-researcher Zsófia Horváth talked about their activities in the course of this interregional project. In the focus of their work is the food web of soda pans from primary produciton to birds. The basic aim of the project is the cross-border coordination of activities and research of nature protection for the perpetuation of biodiverstiy.
In September started the new FWF-project „GROW“, a cooperation between working group leader Martin Kainz and Ariana Chiapella (USA), who will work at WasserCluster for one year. In this project we will investigate dietary trajectories from various food sources to fish in established mesocosm settings.
The delineation of trophic pathways in aquatic food webs is necessary for evaluating the structure and flow of energy among organisms. Understanding the importance of each energy pathway is also necessary for studying food webs in the context of anthropogenic stressors.
In the context of global change and loss of biotic diversity, understanding relationships between diversity and ecosystem functioning has become mandatory. Therefore, it is necessary to investigate underlying mechanisms that generate and maintain diversity patterns across spatial scales. Theresa Lumpi wrote her master’s thesis about this topic and finished successfully in September.
In this study we examined the effects of ecological connectivity along with important environmental parameters on freshwater microbial communities. Experimental communities were established in 40 mesocosms (300 L) inoculated with water from three lakes in Lower Austria.
More than 220 guests visited WasserCluster at the open days on 2nd and 3rd September.
On the programme there were talks about Lake Lunz trough the ages, guided tours and hands-on experiments for kids and adults as well as a mini-excursion to our outdoor constructions. It was a pleasure for us, to host so many guests!
Within the project „PowerStreams“ two master students finished their theses in the end of August under supervision of Thomas Hein and co-supervision of Gabi Weigelhofer. Felix Bauer investigated the production of greenhouse gases in context with the pollution of streams. In the focus of Katharina Leitners thesis was the context between background ammonium concentration, season and ammonium uptake/ retention ability of streams. For both theses nine streams in Lower Austria were sampled in spring and summer 2015.