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Stimulation des mikrobiellen Stickstoffkreislaufs in aquatischen Sedimenten durch bioturbierende Makroinvertebraten

Bioturbierende Makroinvertebraten können den mikrobiellen Stickstoffkreislauf in aquatischen Sedimenten vermutlich erheblich stimulieren. Vor dem Hintergrund der hohen Belastung limnischer und brackiger Ökosysteme mit Nitrat und Ammonium kommt diesem Phänomen eine überaus wichtige ökosystemare Funktion als Senke für anorganische Stickstoffverbindungen zu. Der eigentliche Ort der stimulierten mikrobiellen Stoffumsetzungen, das Ökosystemkompartiment 'Wohnröhre' (gemeinsames Habitat von Makroinvertebraten und Mikroorganismen) ist in bisherigen Studien fast immer ausgeklammert worden, so dass keine Details über das quantitative Ausmaß der dort stattfindenden Prozesse bekannt sind. Daher soll die mikrobielle Lebensgemeinschaft der Wohnröhren bioturbierender Makroinvertebraten erstmals mit moderner Methodik auf (1) struktureller Ebene (Fluoreszuenzin-situ-Hybridisierung und Mikroautoradiografie) und (2) funktioneller Ebene (Mikrosensorentechnik) in Labor- und Freilandexperimenten untersucht werden.

Towards understanding the determinants of stream macroinvertebrate responses to environmental change mediated by glacial recession

The world is currently experiencing a major biodiversity crisis due to human activities. A primary concern is the on-going and rapid biological consequences of global climate change. Climate change is impacting alpine landscapes at unprecedented rates, with severe impacts on landscape structure and catchment hydrodynamics, as well as temperature regimes of glacial-fed rivers. Most glaciers are expected to be dramatically reduced and many even gone by the year 2100, concomitantly with changes (timing and magnitude) in temperature and precipitation. These environmental changes are predicted to have strong impacts on the persistence and distribution of alpine organisms, their population structure and community assembly, and, ultimately, ecosystem functioning. However, how alpine biodiversity (aquatic macroinvertebrates in our case) will respond to these changes is poorly understood. Most previous studies predict the presence of species based on the distribution of putatively suitable habitats but ignore biotic traits, such as dispersal, and potential eco-evolutionary responses to such changes. Clearly, accurate predictions on species responses require integrative studies incorporating landscape dynamics with eco-evolutionary processes. The primary goal of the proposed research is to empirically test determinants of alpine macroinvertebrate responses to rapid environmental change mediated by glacial recession. Climate-induced glacial retreat is occurring rapidly and in a replicated fashion (i.e. over multiple catchments and continents), which provides a natural experiment for testing determinants of organismal and species diversity responses to climate change in alpine waters. The responses of alpine aquatic macroinvertebrates are highly important because of their known sensitivity (i.e. response rates) to environmental change and their fundamental role in ecosystem functioning. Using an integrative comparative and experimental approach, we will target the following main question: What are the roles of ecological and evolutionary processes in population level responses of macroinvertebrates to environmental change? The study will take advantage of rapid glacial recession (environmental change) to empirically examine spatio-temporal patterns in species distribution in nature, combined with experimental and population genetics approaches. The data generated will be used to explicitly address the role of eco-evolutionary processes (determinants) on population level responses for selected key species. Spatial and temporal variation in species distribution, phenotypic and genetic variation will be quantified for two stream macroinvertebrates (hemimetabolous mayfly Baetis alpinus, holometabolous caddisfly Allogamus uncatus), and measuring landscape features and physico-chemical parameters along longitudinal transects downstream of glaciers and selected side-slope tributaries (as potential stepping stones for dispersal and colonization).

Monitoring data from the federal state Saxony (Germany)

<p>The dataset consists of occurrence data of the aquatic organism groups fish, macroinvertebrates and macrophytes that were sampled in the German federal state Saxony between 2007 and 2011. The sampling was conducted according to the protocols of the national monitoring programme for implementation of the Water Framework Directive.</p> <p>For additional metadata see: http://data.freshwaterbiodiversity.eu/metadb/bf_mdb_view.php?entryID=BFE_93</p>

Monitoring data from the federal state Berlin (Germany)

<p>The dataset consists of occurrence data of the aquatic organism group macroinvertebrates that were sampled in the German federal state Berlin between 2006 and 2010. The sampling was conducted according to the protocols of the national monitoring programme for implementation of the Water Framework Directive.</p> <p>For additional metadata see: http://data.freshwaterbiodiversity.eu/metadb/bf_mdb_view.php?entryID=BFE_89</p>

Monitoring data from the federal state Mecklenburg-Western Pomerania (Germany)

<p>The dataset consists of occurrence data of the aquatic organism groups fish, macroinvertebrates and macrophytes that were sampled in the German federal state Mecklenburg-Western Pomerania between 2006 and 2010. The sampling was conducted according to the protocols of the national monitoring programme for implementation of the Water Framework Directive.</p> <p>For additional metadata see: http://data.freshwaterbiodiversity.eu/metadb/bf_mdb_view.php?entryID=BFE_90</p>

Monitoring data from the federal state Bavaria (Germany)

<p>The dataset consists of occurrence data of the aquatic organism groups macroinvertebrates and macrophytes that were sampled in the German federal state Bavaria between 2004 and 2009. The sampling was conducted according to the protocols of the national monitoring programme for implementation of the Water Framework Directive.</p> <p>For additional metadata see: http://data.freshwaterbiodiversity.eu/metadb/bf_mdb_view.php?entryID=BFE_88</p>

Monitoring data from the federal state Saxony-Anhalt (Germany)

<p>The dataset consists of occurrence data of the aquatic organism groups fish, macroinvertebrates and macrophytes that were sampled in the German federal state Saxony-Anhalt in 2008 and 2009. The sampling was conducted according to the protocols of the national monitoring programme for implementation of the Water Framework Directive.</p> <p>For additional metadata see: http://data.freshwaterbiodiversity.eu/metadb/bf_mdb_view.php?entryID=BFE_94</p>

Monitoring data from the federal state North Rhine-Westphalia (Germany)

<p>The dataset consists of occurrence data of the aquatic organism groups fish, macroinvertebrates and macrophytes that were sampled in the German federal state North Rhine-Westphalia between 2004 and 2009. The sampling was conducted according to the protocols of the national monitoring programme for implementation of the Water Framework Directive.</p> <p>For additional metadata see: http://data.freshwaterbiodiversity.eu/metadb/bf_mdb_view.php?entryID=BFE_91</p>

Monitoring data from the federal state Rhineland-Palatinate (Germany)

<p>The dataset consists of occurrence data of the aquatic organism groups fish, macroinvertebrates and macrophytes that were sampled in the German federal state Rhineland-Palatinate between 2006 and 2009. The sampling was conducted according to the protocols of the national monitoring programme for implementation of the Water Framework Directive.</p> <p>For additional metadata see: http://data.freshwaterbiodiversity.eu/metadb/bf_mdb_view.php?entryID=BFE_92</p>

Monitoring data from the federal state Hesse (Germany)

<p>The dataset consists of occurrence data of the aquatic organism groups fish, macroinvertebrates and macrophytes that were sampled in the German federal state Hesse between 2005 and 2008. The sampling was conducted according to the protocols of the national monitoring programme for implementation of the Water Framework Directive.</p> <p>For additional metadata see: http://data.freshwaterbiodiversity.eu/metadb/bf_mdb_view.php?entryID=BFE_87</p>

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